Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

DRAFT ENVIRONMENTAL IMPACT STATEMENT

DETROIT DAM DOWNSTREAM FISH PASSAGE AND TEMPERATURE CONTROL WILLAMETTE RIVER BASIN NORTH SANTIAM RIVER, OREGON

U.S. Army Corps of Engineers, Portland District 333 SW 1ST AVE, PORTLAND, OR 97208 Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

Draft Environmental Impact Statement Detroit Dam Downstream Fish Passage and Temperature Control

Lead Agency Department of the Army U.S. Army Corps of Engineers Portland District Post Office Box 2946 / 333 SW First Ave. Portland, OR 97208-2946

Project Location: Marion County, Oregon Linn County, Oregon For further information contact: Kelly Janes, Environmental Resource Specialist U.S. Army Corps of Engineers Portland District Post Office Box 2946 Portland, OR 97208-2946 (503) 808-4704 [email protected] Date by Which Comments Must be July 23, 2019 Received:

Abstract: The U.S. Army Corps of Engineers (Corps) operates 13 dams and reservoirs in Oregon’s Willamette River basin, which are a part of the Willamette Valley System. The Corps is investigating constructing and operating a temperature control and a downstream fish passage facility to enhance fish passage through the Detroit Dam. The listing of several species under the Endangered Species Act required the Corps to assess of the effects of operations in the Willamette Valley System. Based on that assessment, the National Marine Fisheries Service issued the Endangered Species Act Section 7(a)(2) Consultation, Biological Opinion and Magnuson-Stevens Fishery Conservation & Management Act Essential Fish Habitat Consultation on the Willamette River Basin Flood Control Project issued July 11, 2008. The Reasonable and Prudent Alternative detailed in the Biological Opinion requires the Corps, among other things, to implement downstream passage and temperature control at Detroit and Big Cliff Dams on the North Santiam River in Marion and Linn Counties, Oregon. This EIS compares the potential alternatives for and environmental of constructing downstream fish passage and temperature control necessary to prevent Willamette Valley System operations from jeopardizing the continued existence of endangered species or threatened species.

2 Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

Environmental Impact Statement Detroit Dam Downstream Fish Passage and Temperature Control Project Willamette River Basin North Santiam River, Oregon Prepared by: U.S. Army Corps of Engineers, Portland District May 2019

Executive Summary

RESPONSIBLE PARTY The responsible lead Federal agency for this Environmental Impact Statement (EIS) is the U.S. Army Corps of Engineers, Portland District (Corps). The National Marine Fisheries (NMFS), U.S. Fish and Wildlife Service (USFWS), and the Oregon Department of Fish and Wildlife (ODFW) are cooperating agencies. PROJECT LOCATION AND AUTHORIZATION The project area is located in the North Santiam River Watershed in Linn and Marion Counties, Oregon. Detroit Dam is one of 13 Corps dams in Oregon’s Willamette River basin, which are a part of the Willamette Valley System (WVS). Congress authorized the WVS principally by three separate Flood Control Acts: 1938, 1950, and 1960. House Document 531, as incorporated by the Flood Control Act of May 17, 1950 (81st Congress, 2nd Session), remains the overall guiding document pertaining to the operation and maintenance of the WVS. Congress authorized the WVS with full recognition that it would cut off extensive areas of upstream habitat. To compensate for the loss of spawning habitat, Congress authorized the construction of several fish hatcheries. PROJECT PURPOSE AND NEED The purpose of the Detroit Downstream Fish Passage Project (Project)—consistent with authorized project purposes—is:

1. To enhance fish passage of Upper Willamette River (UWR) Chinook salmon and steelhead on the North Santiam River to reaches downstream of the Detroit and Big Cliff dams; and

2. To modify temperatures on the North Santiam and mainstem Santiam Rivers below Detroit Dam with the objective of meeting operational temperature targets optimized for adult and juvenile salmonids. To enhance fish passage at Detroit Dam would necessitate making improvements to—and continuing the operations and maintenance of—associated fish facilities.

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

The need for the Project arose in 2008 when NMFS issued the NMFS Endangered Species Act Section 7(a)(2) Consultation, Biological Opinion and Magnuson-Stevens Fishery Conservation & Management Act Essential Fish Habitat Consultation on the Willamette River Basin Flood Control Project (2008 BiOp). The 2008 BiOp determined that the Corps’ continued operation of the WVS would jeopardize the existence of two species: UWR spring Chinook salmon (Oncorhynchus tshawytscha) and winter steelhead (O. mykiss). The Detroit Dam and Reservoir are located within an area NMFS has designated as critical habitat of high conservation value for UWR spring Chinook salmon and winter steelhead. Based on an assessment of its abundance, productivity, spatial structure, and diversity, NMFS considers (with considerable certainty) the North Santiam population of UWR Chinook salmon to be at a high risk of extinction (McElhany et al. 2000, NMFS 2016). Chronically unfavorable conditions within a reduced geographic distribution create much of the risk; however, the potential for catastrophic events such as landslides, hatchery-related disease outbreaks, or volcanic events is also a contributor (NMFS 2008). McElhany et al. (2007) classified the winter-run steelhead population in the North Santiam subbasin as facing a low extinction risk based on its abundance and productivity, though they expressed a high degree of uncertainty (NMFS 2016). However, winter steelhead data presented in Falcy (2017) appears to show a downward trend in winter steelhead abundance since 1985. The proposed action in the EIS would implement the NMFS Reasonable and Prudent Alternative (RPA), which includes measures for fish passage, water quality, flows, water contracts, habitat improvements, and hatcheries. Specifically, the proposed action will implement RPA measure 4.12.3, “Detroit Dam Downstream Passage”, which states that the Action Agencies “would investigate the feasibility of improving downstream fish passage at Detroit Dam and if found feasible they would construct and operate downstream passage facilities.” RPA 4.12.3 also states, “Temperature control would also be considered in designing the passage facility.” Additionally, RPA measure 4.1 requires the continued capture of UWR spring Chinook salmon below several Corps dams, including Detroit, and transporting them into habitat upstream of the dams. Finally, RPA measure 5.2 states that the Action Agencies “would make structural modifications or major operational changes for improved water quality to at least one of the Project dams” and identified Detroit Dam as “the highest priority dam for construction of a temperature control structure or operational changes to achieve temperature control.” The USFWS similarly issued a BiOp in 2008 for the effects of the WVS on Oregon chub (Oregonichthys crameri - now delisted), bull trout (Salvelinus confluentus), and bull trout critical habitat. USFWS recently issued a 2018 BiOp on the re-initiation of consultation on the Willamette River Basin Flood Control Project effects to Revised Bull Trout Critical Habitat. The USFWS BiOp reached a no jeopardy determination ‘as long as the Action Agencies implement the NMFS RPA while considering its effects on Oregon chub and bull trout’.

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

DECISION MAKING PROCESS SUMMARY Improving downstream fish passage and temperature control at high-head dams is extremely complex and challenging and is only generally described in the RPA. A major reason it is so technically complex and difficult is that high head dams operated for flood risk management have large seasonal fluctuations in reservoir elevation. Detroit has the added complexity of being operated for multiple other purposes (including water supply, hydropower, water quality fish and wildlife, and recreation). Balancing these missions while also moving fish around a 400 foot barrier in a reservoir that moves up and down more than a hundred feet over the course of every year is very challenging from a technical and biological standpoint. Therefore, the Corps spent many years developing, assessing, and screening numerous alternatives for both downstream passage and temperature control. In Appendix A, the Detroit Downstream Passage Project Interim Alternatives Report, describes this process and the resulting decisions on what alternative to pursue for detailed design analysis. Due to the complexities and challenges of the project, the Corps screened out many alternatives because they were not technically feasible. Others were screened out because they posed risks to dam safety that could not be mitigated, would impede the Corps ability to manage floods, or would eliminate one or more purposes of Detroit Dam over the long term. The remaining received one or more rounds of further design and assessment and the Corps screened out many more because they would not meet the project objectives and therefore would not meet the project purpose and need. The Corps analysis showed that there is one technically feasible option that provides both temperature control and downstream passage while meeting the project objectives and without violating the project constraints. be further refined, if necessary, to address dam safety concerns. Alternatives for how these features are constructed have a range of potential effects depending on the construction methods that are used. The range of alternatives in this EIS is differentiated by the manner in which each alternative is constructed, while the features of each alternative are the same. PROPOSED ACTION Under the proposed action plan, the Corps would construct the following to meet both the temperature control and downstream passage elements of purpose and need: Temperature control element: A selective withdrawal structure (SWS; also referred to as a temperature control tower) to control water temperature passing through Detroit Dam. The construction of the SWS would be highly complex and challenging, requiring the construction of a 300-ft tall (approximate) tower attached to the face of dam. The SWS foundation would require blasting adjacent to the dam and, therefore, its construction would pose some risk to dam safety. For this reason, the design and constructability will undergo extensive risk assessments to ensure all construction complies with Corps dam safety regulation (Chapters 21 and 22 of ER 1110-2-1156

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

(Safety of Dams, Policy and Procedures) and NWD Regulation NWDR 1110-1-3 (Modifications at Existing Corps-Owned Civil Works Projects)).The SWS would have sliding high intake weirs (HIW) and low intake gates (LIG) that would allow the Corps to move warm surface water and cool water at depth, respectively, through Detroit Dam. The resulting outflow would mix the warm surface water and cool deep reservoir water in Big Cliff Reservoir so that dam releases would meet temperature targets downstream. Designs would be further refined, if necessary, to address dam safety concerns. Downstream passage element: A floating screen structure (FSS) attached to the SWS to collect downstream migrating fish. The FSS would be a 300 x 100-ft (approximate) barge designed to screen downstream migrating fish from reservoir outflows and hold them for transport downstream. The FSS connects to the SWS HIW and outflows would go through the FSS and into the SWS wet well for release downstream. The FSS would float up and down the SWS and over the full range of reservoir operational elevations as prescribed by the Water Control Diagram. Fish collected in the FSS would be transported downstream using the trap-and-haul method, with the option to integrate volitional passage in the future if it is determined to be feasible and meets project objectives. The Project would also include continued operation of the existing Minto Adult Fish Collection Facility (Minto Fish Facility) to provide upstream fish passage. To construct the SWS and FSS, the Corps would not change the Detroit Reservoir elevations outside of the normal Water Control Diagram. This means that construction of the SWS would be entirely in the wet (under water with divers or from floating barges, as appropriate). The Corps would stage major construction activities on the Detroit Dam Road and at the Oregon State Parks Maintenance Yard. The Corps’ proposed action works within Detroit Dam’s authorized purposes, is a gravity fed system, and meets project objectives. The proposed action would meet the Corps’ purpose and need to provide a temperature control solution that is combinable with a downstream fish passage solution. The proposed temperature control facility would meet temperature targets developed optimized for adult and juvenile salmonids. The proposed downstream fish passage alternative would provide for a volitional swim- up facility, the ability to hold fish, and the capability for water-to-water transfer of fish from the FSS to a point of release in the river downstream of the dam. Once complete, the proposed action would improve the survival rate of juvenile UWR Chinook salmon and steelhead in their downstream migration to reach adulthood, as well as improve the survival of returning adult fish migrating up the North Santiam River and spawning upstream of Detroit Dam. While the Project would result in a net benefit to fish in the long-term, there are short-term effects from construction that range from negligible to moderate. 6

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

Once complete, the proposed action would improve the survival rate of juvenile UWR Chinook salmon and steelhead in their downstream migration to reach adulthood, as well as improve the survival of returning adult fish migrating up the North Santiam River and spawning upstream of Detroit Dam. While the Project would result in a net benefit to fish in the long-term, there are short-term effects from construction that range from negligible to moderate. It may also improve passage survival for non-listed aquatic species in addition to salmon and steelhead. SCOPING AND PUBLIC INVOLVEMENT Prior to the release of the Draft EIS for public review, the Corps provided a variety of opportunities for the public to gain awareness of its efforts to improve survival of Endangered Species Act (ESA)-listed fish species. Prior to the initiation of public scoping, the Corps conducted a series of public informational meetings in the basin to explain the newly released 2008 BiOp and how it could affect Corps projects and what alternatives were being developed for temperature control and downstream passage at Detroit Dam. Following scoping, the Corps attended over 20 meetings with interested stakeholder groups, to include hosting three public meetings midway through the EIS process to share the Corps’ alternatives formulation and screening process. Public scoping for the Project began on November 24, 2017 when the Federal Register published the Notice of Intent to prepare an EIS. The Notice of Intent included notice that the Corps would be holding two public scoping meetings and the public scoping included a 45-day comment period. Following the public open house style scoping meeting, the Corps was asked to extend the scoping period. The Corps extended the scoping comment period for an additional fifteen days and held an additional public scoping meeting. The public scoping meetings were well all attended and during the 60- day comment period, a total of 198 comments were received from individuals and groups, including federal and state agencies, city and county governments, and non- governmental organizations. Topics present in the submissions included, but were not limited to, opinions on potential alternatives for meeting the project purpose and concerns over the projects impacts on water supply, the local economy, recreation, agricultural, reservoir fisheries, and environmental justice. AREAS OF CONTROVERSY / ISSUES RAISED BY AGENCIES AND THE PUBLIC Major issues brought forward by local, state and federal agencies and the public during scoping include the potential impact of project construction on water supply, recreation, regional/local socioeconomics, and fish and wildlife habitat. EIS ANALYSIS DISCIPLINES Corps employees from the following disciplines contributed to the EIS analysis: • Environmental Resource Specialist • Structural Engineer 7

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

• Cost Engineer • Geotechnical Engineer • Hydraulic Engineer (Water Quality Specialist) • Hydraulic Engineer • Fish Biologists • Wildlife Biologist • Environmental Engineer • Civil Engineer • Archeologist • Economist • Social Scientist ALTERNATIVES ANALYSIS In order for an alternative to meet project purpose and need, it must meet the objectives for both project elements: temperature control and downstream passage. The objectives of the Detroit Downstream Passage Project include: • Provide for implementation of downstream passage and continued operation of existing associated upstream passage facilities so that any above-dam fish- reintroduction effort can be self-sustaining (on average) over time. • Improve water quality below Detroit Dam in the North Santiam and mainstem Santiam Rivers such that water temperatures meet targets optimized for adult and juvenile salmonids and the number and severity of total dissolved gas exceedances are minimized. The Corps started the analysis by formulating alternatives separately for each of the two major project elements, with an intent to combine the preferred alternative for each element to form the proposed action. The Corps did not carry forward any alternative that precluded the ability of the Project to meet the objective for both elements. Additionally, in order for the Corps to consider an alternative, it could not violate the Project constraints. Project constraints represent restrictions that limit the range of alternatives the Corps can propose. The Corps identified the following project constraints: • Actions will not result in a reduction of the Corps’ ability to operate the dam for the flood risk management authorized purpose. • Actions will meet Corps dam safety requirements. • Actions will maintain the Willamette Project’s other authorized purposes (hydropower, recreation, etc.) over the long-term.

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

ALTERNATIVE PLANS CONSIDERED After several rounds of quantitative and qualitative alternatives screening, the Corps found the SWS paired with an FSS to be the only feasible solution for meeting both purpose and need. However, there are four reasonable construction alternatives (CA) and three reasonable construction staging area alternatives (SA). The Corps would potentially use the staging area to construct sections of the SWS before floating them into place to be installed at the dam. Additionally the entire FSS would be assembled at the staging area and, once complete, be floated (like a barge) to be connected to the SWS. The Corps has assessed these alternatives in the EIS along with the No Action Alternative. The Corps’ proposed action combines the preferred CA with the preferred SA. Additionally, there are construction activities and long-term operations that the Corps would implement under any action alternatives. Table ES- 1 summarizes these alternatives and associated project features. Descriptions for each alterative are provided below, the main feature of the CAs is whether—and to what degree and duration—each proposes to drawdown the Detroit Reservoir.

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

Table ES- 1. Alternatives assessed in the EIS and associated project features (Preferred alternatives are in bold) Alternative Preferred Construction Activities Operations CA1. No Action No None Current Operations CA2. SWS and FSS • Access And Road • SWS Operations to meet constructed with a two No Improvements downstream temperature year deep drawdown • Construction Of A Boat targets Ramp And Access Road • FSS Operations to collect CA3. SWS and FSS • Construction Traffic downstream migrating fish constructed with a one No • Staging And Concrete Batch • Trap and haul to transport year deep drawdown Plant Areas fish collected at the FSS to Minto North the fish release site at the CA4. SWS and FSS o Detroit Dam Minto Facility and release constructed with a one No o Operation Yard them into the North year variable drawdown o Detroit Dam Santiam River CA5. SWS and FSS Visitors Parking • Maintenance of the SWS, constructed with no YES Lot and Detroit FSS, and fish release site drawdown Dam Road • Monitoring and evaluation o Cumley Creek SA 1. Mongold State Park No Confluence • Marine equipment use • Temporary environmental SA 2. Oregon State Parks YES controls Maintenance Yard • Potential upgrades at the Minto Fish Facility for fish SA 3. Detroit Lake State No release Recreation Area • Monitoring and evaluation

CA1. No Action: As required by NEPA, the Corps has carried the No Action Alternatives forward for analysis to provide a comparison of the environmental effects between the no action and action alternatives. The No Action Alternative would not meet the purpose and need, as the Corps would not take any action to enhance downstream fish passage. Under the No Action Alternative, current Corps activities at Detroit Dam would continue with no changes to the function and operation of the dam and existing fish facilities. Because UWR Chinook salmon and steelhead above Detroit Dam would be unable to reach a level of production and survival to achieve population replacement, the release of hatchery-origin adult Chinook salmon would continue to supplement the natural-origin UWR Chinook salmon segregated-group annually released to the approximately 4 mile reach above Minto. Under the No Action Alternative, there would be no need for a construction staging area, no use of borrow or disposal sites, no construction of access roads, and no improvements to the Minto Adult Fish Facility. The existing facility and roadways would remain intact.

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

CA2. SWS and FSS Constructed with a Two-year Deep Drawdown: This alternative involves the construction of the SWS tower on dry land by drawing Detroit Reservoir down to 1,300 ft mean sea level elevation—150 ft lower than the lowest elevation Detroit typically goes for normal operation under the Water Control Diagram. The Corps would hold the reservoir at this drawdown elevation for a 28-month period starting just after Labor Day. Following completion of the SWS, the Corps would assemble the FSS at the preferred construction SA and float it to the SWS where it would connect to the SWS between the SWS and the dam. Under a 1,300-ft elevation drawdown, Detroit Dam would only pass inflow during the summer months. Inflow can get as low as 400 cfs and the low flow would have a significant impact on downstream water supply for municipal and industrial, aesthetic, and agricultural purposes as well as on fish and wildlife habitat, including habitat for ESA-listed species. Additionally, a drawdown to this level would expose reservoir sediments that have not been exposed since the Corps completed the dam in 1953. The sediments are very fine, highly erodible, and stay suspended in the water column for a long time once disturbed. As a result, during the initial drawdown, the flow would cut into the newly exposed sediments and dramatically increase sediment transport and turbidity in the reservoir and downstream. This would result in significant turbidity and sedimentation impacts to the water supply and habitat downstream. Finally, under the CA2 proposed drawdown, Detroit Reservoir would not be accessible to water-based recreation. Detroit Reservoir is a major recreational draw in the North Santiam River basin and a driving socioeconomic factor the communities in the basin depend on. Therefore, CA2 would also have significant recreation and socioeconomic impacts. CA3. SWS and FSS Constructed with a One-year Deep Drawdown: This alternative would be the same as CA2 except that the Corps would only draw Detroit Reservoir down to the 1,300-ft elevation for a 16-month period. After 16 months, the Corps would allow the reservoir to fill to the typical elevation under the normal rule curve and would complete the SWS underwater using divers or from the reservoir surface on floating barges, as appropriate. The impacts under CA3 would be the same as under CA2 but limited to 1 year. CA4. SWS and FSS Constructed with a One-year Variable Drawdown: Under CA4, the Corps would start construction of the SWS under water. However, the Corps would initially drawdown Detroit Reservoir to elevation 1,400 to facilitate construction by reducing the water depth in which the initial SWS construction would occur. In the spring, following the initial drawdown, the Corps would allow the reservoir to raise to elevation 1,450. By having a 1,450-ft reservoir elevation (rather than the 1,300-ft elevation proposed under CA2 and CA3) at the start of the conservation season, the Corps would be able to meet BiOp minimum flow targets by maintaining 1,000 cubic feet per second (cfs) outflows throughout the dry summer months. During the summer,

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

the reservoir pool elevation would go below initial drawdown level as the Corps maintains 1,000 cfs outflows. As the reservoir level recedes over the summer months, the Corps would be building up the SWS tower and the tower height would eventually go above the reservoir elevation. The remainder of the SWS would be constructed from floating barges. Following completion of the SWS, the Corps would assemble the FSS at the preferred SA and float it to the upstream face of the SWS for attachment. Under CA4, outflows at Detroit Dam would remain similar to current conditions, therefore, there would be no low flow impacts to water supply and habitat downstream. However, sediment transport and turbidity impacts to water supply and habitat would be similar or worse because maintaining 1,000 cfs outflows would result in increased reservoir sediment transport throughout the summer months as the reservoir elevation goes below typical levels. CA4 would also have the same impact to recreation as those under CA3, limiting reservoir recreation over 1 year. CA5. SWS and FSS Constructed with No Drawdown: CA5 is the preferred CA alternative. It meets the purpose and need while avoiding and minimizing the environmental effects of its implementation. Under CA5, the Corps would not drawdown Detroit Reservoir and would continue to operate the dam based on the normal rule curve. The Corps would complete construction with divers or from floating barges, as appropriate. There would be negligible to moderate impacts associated with this alternative. SA1. Mongold State Park: This alternative involves using the Mongold Day-Use Area for staging the construction of SWS components and the assembly of the FSS before floating them out to the SWS site for installation. The staging area would be prepared in the near shore area of the reservoir and coffer dammed off to maintain a dry work area. The Mongold Day-Use Area is a state park located on Corps property but administered by the Oregon Parks and Recreation Department. It is located on the North Santiam Highway (OR-22) about 3.5 miles west of the town of Detroit and about 4 miles east of Detroit Dam. Facilities include a boat ramp, swimming area, fishing area and picnic area. The Mongold boat launch is one the highest traffic areas on the reservoir since it is one of the only public boat launching locations on the reservoir and has the lowest boat ramp access. Staging construction at SA1 would limit public access due to safety considerations and, therefore, would significantly impact recreation. SA2. Oregon State Parks Maintenance Yard: SA2 is the Corps’ preferred staging alternative. The Oregon State Parks Maintenance Yard (Maintenance Yard) is located ¾ of a mile north of Mongold on the OR-22. The Corps would most likely use the southern half of the Maintenance Yard but extend down to the water. SA2 is inaccessible to the public and provides enough area for the Oregon State Parks Department to continue typical operation activities. There would be minimal to moderate impacts under SA2.

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

SA3. Detroit Lake State Recreation Area: The Detroit Lake State Recreation Area is located 1.8 miles north of Mongold, on the OR-22 across the highway from the U.S. Forest Service (USFS) Detroit Ranger Station. The site is a campground run by the USFS on Corps property that offers 300 camping sites, horseshoe pits, a basketball court, a volleyball area, and a playground. There are two courtesy boat ramps, two removable boat moorages, and a fishing dock. Under SA3, staging space would be upland in the area of existing campsites, camp loops A and B, which would require demolition during construction resulting in moderate impacts to recreation. COMPARISON OF ALTERNATIVES’ ENVIRONMENTAL CONSEQUENCES Section 3 of the EIS describes the impacts of the No Action/No Project Alternative for comparison to those of the action alternatives. The Corps has assessed the environmental effects of the proposed construction and staging activities of each SA and CA separately. Table ES-2 presents a summary of the effects that helped drive the Corps decision on the preferred alternative. Table ES- 3 and Table ES- 4 summarizes all the effects and their intensity and duration.

Table ES- 2. Environmental impact decision drivers

Water Water Supply: Supply: Recreation: Agriculture: Agriculture: Recreation: Recreation: people at estimated indirect direct indirect direct Jobs lost risk of cost to Construction impact Construction impact1 to impact1 to impact due to losing construct Fish and Alt Cost visitor complexity cropland agricultural visitor’s visitor municipal alternative Wildlife Comparison spending irrigators industry willingness spending and water foregone (rounded) (rounded) to pay2 forgone industrial supply (rounded) water facilities availability (millions)3 CA1 No Cost NA $0 $0 $0 None 0 0 $0 None Moderately Significant High – impacts to construction listed 49,000 – CA2 Lowest Cost of large $54,000,000 $85,000,000 $6,300,000 $23,000,000 140 $28 - $100 species 180,000 structure and attached to aquatic dam. habitat High – Significant construction impacts to of large listed 49,000 – CA3 CA2 + $11M structure $20,000,000 $31,00,000 $3,150,000 $11,000,000 140 $28 - $100 species 180,000 attached to and dam partially aquatic in the wet habitat High – Significant construction impacts to of large listed 49,000 – CA4 CA2 + $96M structure $3,500,000 $6,000,000 $3,150,000 $11,000,000 140 $28 - $100 species 180,000 attached to and dam partially aquatic in the wet habitat

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

Water Water Supply: Supply: Recreation: Agriculture: Agriculture: Recreation: Recreation: people at estimated indirect direct indirect direct Jobs lost risk of cost to Construction impact Construction impact1 to impact1 to impact due to losing construct Fish and Alt Cost visitor complexity cropland agricultural visitor’s visitor municipal alternative Wildlife Comparison spending irrigators industry willingness spending and water foregone (rounded) (rounded) to pay2 forgone industrial supply (rounded) water facilities availability (millions)3 Negligible Extremely impacts to High - listed construction species of large and CA5 CA2 +$100M $0 $0 $3,150,000 $0 0 0 $0 structure aquatic attached to habitat in dam entirely Detroit in the wet Reservoir only 1Direct impact to agriculture are those effects to individual farmers who may experience reductions in irrigation. Indirect impacts are secondary economic impact because of the impact to the local agricultural economy (impacts to labor, services that support farmers, suppliers, food processing, etc.). Totals are computed in Appendix I. Other social effects from direct and impacts to agriculture are described in Appendix K. 2Willingness to pay is the value of recreation to recreation visitors based on a unit day value for fiscal year 2019 (see Corps Economic Guidance Memorandum 19-03). Totals are computed in Appendix H. Other social effects from direct and impacts to recreation are described in Appendix K. 3High risk the City of Salem could not implement design, permitting, financing, and construction of alternative water supply facilities in the timeline of the Project.

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

Table ES- 3. Assembly staging area alternatives summary matrix IMPACT SA1. Mongold State Park t SA2. Oregon State Parks SA3. Detroit Lake State Recreation Maintenance Yard - PREFERRED Area ALTERNATIVE Air Quality MINOR - Small, localized reduction in air MINOR - Small, localized reduction MINOR - Small, localized reduction quality. in air quality. in air quality. Noise MODERATE - Moderate, localized MODERATE - Moderate, localized MODERATE - Moderate, localized increases in noise. increases in noise. increases in noise. Geology/ Soils/ Seismology No impacts to seismology No impacts to seismology No impacts to seismology MINOR - Localized, short-term impacts. MINOR - Localized, short-term MINOR - Localized, short-term impacts. impacts. Hydrology/ Hydraulics MINOR - Localized, short-term impacts. MINOR - Localized, short-term MINOR - Localized, short-term impacts. impacts. Sediment Transport/ Turbidity MINOR - Localized, short-term impacts. MINOR - Localized, short-term MINOR - Localized, short-term impacts. impacts. Water Quality MINOR - Localized, short-term impacts. MINOR - Localized, short-term MINOR - Localized, short-term impacts. impacts. Vegetation MINOR - Localized, short-term impacts. MODERATE - Localized, short-term MODERATE - Localized, short-term impacts to vegetation, including tree impacts to vegetation, including removal. tree removal. Fisheries/ Hatcheries NONE NONE NONE

Fish and Wildlife (including MODERATE - Localized, short-term MINOR - Localized, short-term MODERATE - Localized, short-term Threatened and Endangered impacts. impacts. impacts. Species) Water Supply NONE NONE NONE Hydropower NONE NONE NONE Agriculture NONE NONE NONE Recreation SIGNIFICANT - Reduction or cessation of NONE MODERATE - Reduction of visitor visitor access at highly visited recreational access to campground for site for approximately 8 years approximately 8 years. Aesthetics MODERATE - Localized, short-term MODERATE- Localized, short-term MODERATE impacts. impacts. Localized, short-term impacts.

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

IMPACT SA1. Mongold State Park t SA2. Oregon State Parks SA3. Detroit Lake State Recreation Maintenance Yard Area PREFERRED ALTERNATIVE Transportation/ Circulation MODERATE - Localized, short-term MODERATE- Localized, short-term MODERATE- Localized, short-term impacts. impacts. impacts. Cultural, Archeological, and The Corps would be required to perform a cultural resource inventory at site prior to project implementation. The Corps Historical Resources will consult with State Historic Preservation Office and affected tribes to ensure all construction/staging zones are inventoried. The Corps intends on entering into a programmatic agreement that will include a phased approach to identification, evaluation, and resolution of adverse effects (36 C.F.R 800.4 and 800.6). Any newly documented resources would be evaluated for listing in the National Register. Other Social Effects SIGNIFICANT - eduction or cessation of NONE MODERATE - Reduction of visitor visitor access at highly visited recreational access to campground for site for approximately 8 years. approximately 8 years. Public Health and Safety NONE Climate Change NONE

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

Table ES- 4. Construction alternatives summary matrix IMPACT CA2. 2 year drawdown to CA3. 1 year drawdown to CA4. 1 year variable drawdown CA5. Normal Rule Curve elevation 1,300 feet elevation 1,300 feet Operation PREFERRED ALTERNATIVE

Air Quality MINOR MINOR MINOR MINOR Small, localized reduction in Small, localized reduction in Small, localized reduction in Small, localized reduction in air quality. air quality. air quality. air quality. Noise MINOR MINOR MINOR MINOR Small, localized increases in Small, localized increases in Small, localized increases in Small, localized increases in noise. noise. noise. noise. Geology/ Soils/ No impacts to seismology No impacts to seismology No impacts to seismology No impacts to seismology Seismology MINOR MINOR MINOR MINOR localized, short-term impacts localized, short-term impacts localized, short-term impacts localized, short-term impacts to geology and soils to geology and soils to geology and soils to geology and soils Hydrology/ Hydraulics SIGNIFICANT SIGNIFICANT MODERATE NONE Greatly reduced spring and Greatly reduced spring and Variable reductions in summer flows in the North summer flows in the North reservoir pool during Santiam during the 28-month Santiam during the 16-month drawdown. proposed drawdown. proposed drawdown. Greatly reduced reservoir Greatly reduced reservoir pool. pool. Sediment Transport/ SIGNIFICANT SIGNIFICANT SIGNIFICANT MINOR Turbidity Substantially raised and Substantially raised and Substantially raised and Short term increases in persistent sediment load and persistent sediment load and persistent sediment load and reservoir turbidity due to associated suspended associated suspended associated suspended blasting and excavated sediment concentrations and sediment concentrations and sediment concentration and material placement. turbidity in the winter during turbidity in the winter during turbidity during the winter initial drawdown. initial drawdown. during intial drawdown and throught the summer during the drawdown period.

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

IMPACT CA2. 2 year drawdown to CA3. 1 year drawdown to CA4. 1 year variable drawdown CA5. Normal Rule Curve elevation 1,300 feet elevation 1,300 feet Operation PREFERRED ALTERNATIVE

Water Quality MODERATE MODERATE MODERATE NEGLIGIBLE Increases in downstream Increases in downstream Increases in downstream temperatures. temperatures. temperatures. Greater diurnal variation of Greater diurnal variation of Greater diurnal variation of dissolved oxygen and pH in dissolved oxygen and pH in dissolved oxygen and pH in the reservoir and the reservoir and the reservoir and downstream. downstream. downstream. Increase risk of toxic algae Increase risk of toxic algae - Increase risk of toxic algae blooms. blooms. blooms. Downstream water quality Downstream water quality degradation from point degradation from point source discharges in the form source discharges in the form of temperature, nutrient, and of temperature, nutrient, and biochemical oxygen demand biochemical oxygen demand pollution. pollution. Fish and Wildlife MODERATE to SIGNIFICANT MODERATE to SIGNIFICANT MODERATE MODERATE (including Threatened During summers of 28-Month During summer of 16-Month Dewatering of redds Localized, short-term impacts. and Endangered drawdown: drawdown: Reduced spawning habitat Long-term beneficial impacts Species) Significantly reduced Significantly reduced Water quality (turbidity) and to ESA-listed salmonids from mainstem aquatic habitat. mainstem aquatic habitat. habitat degradation enhanced downstream Reduction in upstream Reduction in upstream (sedimentation) passage and temperature passage. passage. Increased stress levels and control. Dewatered floodplain habitat Dewatered floodplain habitat mortality in Chinook and (important for chub). (important for chub). reservoir fish populations with Dewatering of redds. Dewatering of redds. limited cold water refuge area Decreased spawning habitat. Decreased spawning habitat. (less than Alts 2&3) Delayed upstream migration Delayed upstream migration Increased stress levels due to of adult Chinook salmon, shift of adult Chinook salmon, shift crowding of fish into smaller in fry emergence, and in fry emergence, and areas increased stress / mortality of increased stress / mortality of Noise and pressure waves salmonids in warm water salmonids in warm water from blasting may displace, years. years. injury, or kill fish

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

IMPACT CA2. 2 year drawdown to CA3. 1 year drawdown to CA4. 1 year variable drawdown CA5. Normal Rule Curve elevation 1,300 feet elevation 1,300 feet Operation PREFERRED ALTERNATIVE

Water quality and habitat Water quality and habitat Long-term beneficial impacts degradation (sedimentation) degradation (sedimentation) to ESA-listed salmonids from for aquatic environment, for aquatic environment, enhanced downstream including ESA listed species including ESA listed species passage and temperature habitat and recently delisted habitat and recently delisted control. chub habitat. chub habitat. Increased stress levels and Increased stress levels and mortality in Chinook and mortality in Chinook and reservoir fish populations with reservoir fish populations with limited cold water refuge limited cold water refuge area. area. Increased stress levels due to Increased stress levels due to crowding of fish into smaller crowding of fish into smaller areas. areas. Noise and pressure waves Noise and pressure waves from blasting may displace or from blasting may displace or injury fish. injury fish. Potential for amphibian Potential for amphibian stranding, a temporal loss of stranding, a temporal loss of wetlands, a decrease in wetlands, a decrease in available waterfowl foraging available waterfowl foraging habitat acreage within Detroit habitat acreage within Detroit Reservoir during drawdown. Reservoir during drawdown. Long-term beneficial impacts Long-term beneficial impacts to ESA-listed salmonids from to ESA-listed salmonids from enhanced downstream enhanced downstream passage and temperature passage and temperature control. control. Fisheries/ Hatcheries MODERATE MODERATE NONE NONE Increased turbidity will result Increased turbidity will result in stress to fish at the Minto in stress to fish at the Minto Fish Facility Fish Facility

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

IMPACT CA2. 2 year drawdown to CA3. 1 year drawdown to CA4. 1 year variable drawdown CA5. Normal Rule Curve elevation 1,300 feet elevation 1,300 feet Operation PREFERRED ALTERNATIVE

Vegetation MINOR MINOR MINOR NONE Short-term increase in in- Short-term increase in in- Short-term increase in in- reservoir wetland species. reservoir wetland species. reservoir wetland species. Short-term sedimentation of Short-term sedimentation of Short-term sedimentation of wetland species downstream wetland species downstream wetland species downstream Short-term desiccation of Short-term desiccation of downstream wetlands. downstream wetlands. Water Supply SIGNIFICANT SIGNIFICANT SIGNIFICANT NONE Reductions in ability of Reductions in ability of Reductions in ability of municipal and industrial and municipal and industrial and municipal and industrial water irrigation water supply irrigation water supply supply providers to serve their providers to serve their providers to serve their customers due to turbidity customers due to low flows customers due to low flows impacts on intake structures. and turbidity impacts on and turbidity impacts on intake structures. intake structures. Hydropower MODERATE MODERATE MODERATE MODERATE Cessation of power Cessation of power Cessation of power Cessation of power production during SWS production during SWS production during SWS production during SWS construction resulting in a construction resulting in a construction resulting in a construction resulting in a value of the energy and value of the energy and value of the energy and value of the energy and capacity loss of $19.09 million capacity loss of $19.09 million capacity loss of $19.09 million capacity loss of $19.09 million annually. annually. annually. annually. Agriculture SIGNIFICANT SIGNIFICANT NONE NONE Reductions in ability of Reductions in ability of irrigation water supply irrigation water supply providers to serve providers to serve 17,000acres of agricultural 17,000acres of agricultural lands due to low flows lands due to low flows Recreation SIGNIFICANT SIGNIFICANT SIGNIFICANT NONE Drawdown levels will make Drawdown levels will make Drawdown levels will make boat ramps inaccessible boat ramps inaccessible boat ramps inaccessible resulting in the loss of water resulting in the loss of water resulting in the loss of water based recreation based recreation based recreation opportunities. opportunities. opportunities. 8

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

IMPACT CA2. 2 year drawdown to CA3. 1 year drawdown to CA4. 1 year variable drawdown CA5. Normal Rule Curve elevation 1,300 feet elevation 1,300 feet Operation PREFERRED ALTERNATIVE

Aesthetics MODERATE MODERATE MODERATE MINOR Low levels will result in Low levels will result in Low levels will result in Short-term impacts due to dewatered reservoir would dewatered reservoir would dewatered reservoir would construction activities. result in the short-term result in the short-term result in the short-term degradation of views at degradation of views at degradation of views at Detroit Reservoir. Detroit Reservoir. Detroit Reservoir. Short-term impacts due to Short-term impacts due to Short-term impacts due to construction activities. construction activities. construction activities. Transportation/ MODERATE MODERATE MODERATE MODERATE Circulation Short-term increases in traffic Short-term increases in traffic Short-term increases in traffic Short-term increases in traffic due to construction activities due to construction activities due to construction activities due to construction activities Detroit Dam Road would be Detroit Dam Road would be Detroit Dam Road would be Detroit Dam Road would be closed over the duration of closed over the duration of closed over the duration of closed over the duration of construction. construction. construction. construction. Cultural, MODERATE TO SIGNIFICANT MODERATE TO SIGNIFICANT MODERATE TO SIGNIFICANT MODERATE TO SIGNIFICANT Archeological, and Attachment of SWS to Detroit Attachment of SWS to Detroit Attachment of SWS to Detroit Attachment of SWS to Detroit Historical Resources Dam results in impacts to Dam results in impacts to Dam results in impacts to Dam results in impacts to structure eligible for listing in structure eligible for listing in structure eligible for listing in structure eligible for listing in the National Register. the National Register. the National Register. the National Register. Exposure during the Exposure during the Exposure during the drawdown of cultural drawdown of cultural drawdown of cultural resources typically inundated resources typically inundated resources typically inundated (risk of degradation and (risk of degradation and (risk of degradation and looting). looting). looting). Other Social Effects SIGNIFICANT SIGNIFICANT SIGNIFICANT NEGLIGABLE Impacts to residents, Impacts to residents, Impacts to business and businesses and communities businesses and communities communities from Salem to from Salem to Idanha, from Salem to Idanha, Idanha that depend on including impacts to including impacts to summer recreation tourism agricultural, food processing agricultural, food processing operations, water supply and operations, water supply and water quality, recreation, water quality, recreation, tourism, businesses, schools, tourism, businesses, schools, and social services. and social services. 9

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

IMPACT CA2. 2 year drawdown to CA3. 1 year drawdown to CA4. 1 year variable drawdown CA5. Normal Rule Curve elevation 1,300 feet elevation 1,300 feet Operation PREFERRED ALTERNATIVE

Public Health and MODERATE MODERATE NONE NONE Safety Low flows during drawdown Low flows during drawdown would negatively impacts the would negatively impacts the ability to provide water for ability to provide water for fire protection to the Cascade fire protection to the Cascade School District. School District. Climate Change MINOR MINOR MINOR MINOR Increased greenhouse gasses Increased greenhouse gasses Increased greenhouse gasses Increased greenhouse gasses during construction due to during construction due to during construction due to during construction due to forgone hydropower forgone hydropower forgone hydropower forgone hydropower production resulting in a production resulting in a social production resulting in a social production resulting in a social social cost of carbon of cost of carbon of cost of carbon of cost of carbon of approximately $11,000. approximately $11,000. approximately $11,000. approximately $11,000.

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

READER’S GUIDE TO THE DRAFT EIS The goal in preparing this draft EIS is to produce an EIS that is clear and understandable for not only agency decision makers, but also the public. The vastness of the river system, the wealth of data used to analyze environmental impacts to river resources, and the complexity of the relationships among river uses made this a challenge. Eighteen appendices accompany this document and form the basis of the EIS. These appendices provide extensive detail on existing conditions and effects of the alternatives. To repeat this information in the main EIS would make the document too detailed and voluminous for practicality. The EIS format is designed to provide summary-level information that is supported by the more comprehensive appendices.

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

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Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

Contents FIGURES 17 TABLES 20 ACRONYMS ...... 22 SECTION 1 - INTRODUCTION ...... 1-26 1.1 DOCUMENT STRUCTURE ...... 1-26 1.2 BACKGROUND ...... 1-27 1.3 PURPOSE AND NEED ...... 1-28 PURPOSE ...... 1-28 NEED ...... 1-29 PURPOSE AND NEED BACKGROUND ...... 1-29 1.4 LEAD AGENCY ...... 1-32 1.5 COOPERATING AGENCIES ...... 1-32 1.6 PROJECT LOCATION ...... 1-32 DETROIT PROJECT DESCRIPTION ...... 1-36 SECTION 2 - ALTERNATIVES ...... 2-43 2.1 ALTERNATIVE FORMULATION AND SCREENING HISTORY ...... 2-43 2.2 ALTERNATIVES CONSIDERED BUT ELIMINATED ...... 2-46 2.3 CA1. NO ACTION ...... 2-49 2.4 OVERVIEW OF ALTERNATIVES ...... 2-50 PROJECT DESIGN EVOLUTION ...... 2-51 2.5 CONSTRUCTION ALTERNATIVES ...... 2-55 CA1. NO ACTION ...... 2-55 CA2. SWS AND FSS CONSTRUCTED WITH A TWO-YEAR DRAWDOWN TO ELEVATION 1,300 FT 2-55 CA3. SWS AND FSS CONSTRUCTED WITH A ONE-YEAR DRAWDOWN TO ELEVATION 1,300 FT 2-57 CA4. SWS AND FSS CONSTRUCTED WITH A ONE-YEAR VARIABLE DRAWDOWN ...... 2-57 CA5. SWS AND FSS CONSTRUCTED WITH NO DRAWDOWN ...... 2-61 2.6 STAGING AREAS ALTERNATIVES ...... 2-61 SA1. MONGOLD STATE PARK ...... 2-63 SA2. OREGON STATE PARKS MAINTENANCE YARD ...... 2-64 SA3. DETROIT LAKE STATE RECREATION AREA ...... 2-66 2.7 PROJECT FEATURES COMMON TO ALL ACTION ALTERNATIVES ...... 2-67 PROJECT COMPONENTS AND OPERATION ...... 2-67 CONSTRUCTION ...... 2-76 FLEXIBILITY TO ACCOMMODATE VOLITIONAL PIPE BYPASS ...... 2-88 ANCILLARY LONG-TERM PROJECT OPERATIONS ...... 2-89 2.8 SUMMARY COMPARISON OF ALTERNATIVES ...... 2-91 ENVIRONMENTALLY PREFERABLE ALTERNATIVE ...... 2-103 RELATIONSHIP OF SHORT-TERM USES AND LONG-TERM PRODUCTIVITY ...... 2-103 IRREVERSIBLE AND IRRETRIEVABLE COMMITMENT OF RESOURCES ...... 2-103 SECTION 3 - AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES ...... 3-104 3.1 AIR QUALITY ...... 3-105 ENVIRONMENTAL CONSEQUENCES ...... 3-106 3.2 NOISE ...... 3-107 ENVIRONMENTAL CONSEQUENCES ...... 3-107 3.3 GEOLOGY, SEISMOLOGY, AND SOILS ...... 3-108

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

GEOLOGIC SETTING ...... 3-108 SITE SEISMICITY ...... 3-109 RESERVOIR LANDSLIDES ...... 3-110 ENVIRONMENTAL CONSEQUENCES ...... 3-112 3.4 HYDROLOGY AND HYDRAULICS ...... 3-113 BASIN HYDROLOGY...... 3-113 ENVIRONMENTAL CONSEQUENCES ...... 3-118 3.5 SEDIMENT TRANSPORT AND TURBIDITY ...... 3-127 SEDIMENT TRANSPORT ...... 3-127 TURBIDITY ...... 3-128 DETROIT RESERVOIR SEDIMENTS ...... 3-128 ENVIRONMENTAL CONSEQUENCES ...... 3-129 3.6 WATER QUALITY ...... 3-135 BASIN WATER QUALITY ...... 3-135 ENVIRONMENTAL CONSEQUENCES ...... 3-142 METHODOLOGY AND SCALE OF ANALYSIS ...... 3-142 3.7 WILDLIFE ...... 3-146 NORTHERN SPOTTED OWL ...... 3-149 RED TREE VOLE ...... 3-150 BALD EAGLE AND MIGRATORY BIRDS ...... 3-151 ENVIRONMENTAL CONSEQUENCES ...... 3-151 3.8 FISH AND AQUATIC SPECIES ...... 3-160 ANADROMOUS FISH ...... 3-162 RESIDENT FISH...... 3-172 OTHER AQUATIC SPECIES ...... 3-177 ENVIRONMENTAL CONSEQUENCES ...... 3-177 3.9 THREATENED AND ENDANGERED SPECIES...... 3-206 SPECIES UNDER NMFS JURISDICTION ...... 3-207 SPECIES UNDER USFWS JURISDICTION ...... 3-208 ENVIRONMENTAL CONSEQUENCES ...... 3-211 3.10 ADULT FISH FACILITIES, HATCHERIES, AND FISHERIES ...... 3-211 ENVIRONMENTAL CONSEQUENCES ...... 3-212 3.11 VEGETATION ...... 3-219 UPLANDS ...... 3-219 WETLANDS ...... 3-220 OPEN WATER ...... 3-221 SPECIAL STATUS PLANT SPECIES ...... 3-221 INVASIVE SPECIES ...... 3-223 ENVIRONMENTAL CONSEQUENCES ...... 3-223 3.12 WATER SUPPLY ...... 3-229 MUNICIPAL ...... 3-232 IRRIGATION / AGRICULTURE ...... 3-236 COMMERCIAL/INDUSTRIAL ...... 3-237 FISH AND WILDLIFE ...... 3-237 FLOWS ...... 3-238 ENVIRONMENTAL CONSEQUENCES ...... 3-238 3.13 HYDROPOWER ...... 3-242 ENVIRONMENTAL CONSEQUENCES ...... 3-245 3.14 TRANSPORTATION/CIRCULATION ...... 3-249 14

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

ENVIRONMENTAL CONSEQUENCES ...... 3-250 3.15 AESTHETIC RESOURCES ...... 3-252 ENVIRONMENTAL CONSEQUENCES ...... 3-254 3.16 CULTURAL, ARCHEOLOGICAL AND HISTORICAL RESOURCES ...... 3-256 CULTURAL SETTING ...... 3-256 CULTURAL RESOURCES IN THE PROJECT AREA OF POTENTIAL EFFECT (APE) ...... 3-256 ENVIRONMENTAL CONSEQUENCES ...... 3-258 3.17 RECREATION ...... 3-267 ENVIRONMENTAL CONSEQUENCES ...... 3-271 3.18 SOCIOECONOMICS ...... 3-273 REGIONAL SOCIOECONOMICS ...... 3-273 AGRICULTURE ...... 3-278 RECREATION ...... 3-288 M&I WATER SUPPLY ...... 3-288 ENVIRONMENTAL CONSEQUENCES ...... 3-293 3.19 OTHER SOCIAL EFFECTS (OSE) ...... 3-297 ENVIRONMENTAL CONSEQUENCES ...... 3-298 ENVIRONMENTAL JUSTICE ...... 3-303 3.20 PUBLIC HEALTH AND SAFETY ...... 3-309 ENVIRONMENTAL CONSEQUENCES ...... 3-309 3.21 CLIMATE CHANGE ...... 3-312 ENVIRONMENTAL CONSEQUENCES ...... 3-313 SECTION 4 - CUMULATIVE IMPACTS ...... 4-317 4.1 DEFINE THE GEOGRAPHIC BOUNDARIES AND TIMEFRAME FOR ANALYSIS ...... 4-317 4.2 RESOURCE-SPECIFIC CUMULATIVE IMPACTS ...... 4-319 RESOURCE AREAS DISMISSED FROM CUMULATIVE IMPACT ANALYSIS ...... 4-319 FISH, AND AQUATIC SPECIE INCLUDING THREATENED AND ENDANGERED SPECIES ...... 4-320 WATER QUALITY ...... 4-321 SECTION 5 - PREFERRED ALTERNATIVE ...... 5-323 5.1 INFORMATION USED TO INFORM THE DECISION ...... 5-323 5.2 DESCRIPTION OF THE PREFERRED ALTERNATIVE ...... 5-323 5.3 SUMMARY OF THE PREFERRED ALTERNATIVES EFFECTS, INCLUDING CUMULATIVE ASSESSMENT . 5-324 SECTION 6 - REVIEW AND CONSULTATION REQUIREMENTS ...... 6-326 6.1 TRIBAL CONSULTATION...... 6-326 6.2 CONSULTATION WITH FEDERAL, STATE, AND LOCAL AGENCIES ...... 6-326 NATIONAL MARINE FISHERIES SERVICE AND U.S. FISH AND WILDLIFE SERVICE ...... 6-326 BONNEVILLE POWER ADMINISTRATION...... 6-326 U.S. FOREST SERVICE ...... 6-327 OREGON DEPARTMENT OF FISH AND WILDLIFE ...... 6-327 OREGON WATER RESOURCES DEPARTMENT ...... 6-327 OREGON STATE HISTORIC PRESERVATION OFFICE ...... 6-327 OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY ...... 6-328 OREGON PARKS AND RECREATION DEPARTMENT ...... 6-328 SANTIAM WATER CONTROL DISTRICT AND SYDNEY IRRIGATION COOPERATIVE ...... 6-328 COUNTIES ...... 6-328 CITIES ...... 6-328 6.3 PUBLIC ENGAGEMENT ...... 6-329 DRAFT EIS COMMENTS ...... 6-333 RESPONSE TO COMMENTS ...... 6-333 15

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

LIST OF COMMENTERS ...... 6-333 SECTION 7 - COMPLIANCE WITH APPLICABLE FEDERAL ENVIRONMENTAL LAWS AND REGULATIONS ...... 7-334 SECTION 8 - LIST OF PRINCIPLE PREPARERS ...... 8-340 SECTION 9 - REFERENCES CITED ...... 9-341 APPENDICES ...... download seperately

16 Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

FIGURES

Figure 1. North Santiam River Basin and the Willamette River from its confluence with the Santiam River to the City of Salem...... 1-33 Figure 2. Map of the North Santiam watershed ownership (ODEQ 200) ...... 1-35 Figure 3. Interior view of Detroit Dam ...... 1-39 Figure 4. Detroit Dam - pertinent elevations ...... 1-39 Figure 5. Minto Fish Collection Facility location ...... 1-41 Figure 6. Isometric view of the freestanding SWS, including an access bridge and conduits attached to the dam ROs and penstocks ...... 2-52 Figure 7. Initial FSS/SWS Configuration ...... 2-52 Figure 8. Isometric view of the attached SWS ...... 2-53 Figure 9. Isometric rendering looking southeast of the proposed penstock ...... 2-54 Figure 10. Redesigned FSS/SWS Configuration ...... 2-54 Figure 11. Detroit Reservoir drawdown to elevation 1,300 ft under CA2 and CA3 ...... 2-56 Figure 12. Detroit Reservoir drawdown to elevations under CA4 ...... 2-59 Figure 13. Conceptual graph of reservoir and tower construction elevations under CA4 ...... 2-60 Figure 14. Example footprint shown for the Oregon State Parks Maintenance Yard Assembly Staging Area Alternative ...... 2-63 Figure 15. Mongold State Park - proposed staging area outlined in red ...... 2-64 Figure 16. Detroit Lake State Park's Maintenance Yard Staging Area Alternative - proposed staging area outlined in red ...... 2-65 Figure 17. Detroit Lake State Recreation Area Alternative - proposed staging area outlined in red ...... 2-67 Figure 18. a. Conceptual FSS Design in plan/birds-eye view (numbers denote ft), b. Conceptual FSS Design in profile/cross section ...... 2-74 Figure 19. Proposed excavation and in-reservoir material placement areas adjacent to the SWS site .. 2-77 Figure 20. Southshore Road Improvements ...... 2-81 Figure 21. Proposed Boat Ramp and Construction Access Road...... 2-83 Figure 22. Minto North Staging Area ...... 2-84 Figure 23. Detroit Dam Operations Yard Staging Area...... 2-85 Figure 24. Northwest Visitor Parking Lot and Detroit Dam Road Staging Area ...... 2-85 Figure 25. Cumley Creek Confluence Staging Area ...... 2-86 Figure 26. Proposed Debris Boom Locations ...... 2-90 Figure 27. Construction photo of right (north abutment) of Detroit Dam ...... 3-109 Figure 28. Landslide deposits around Detroit Reservoir (Modified from OR Department of Geology, 2018) ...... 3-110 Figure 29. OR-22 Sunken Grade Landslide (plan view) (GeoStabilization International, Inc. 2014) .... 3-111 Figure 30. Highway 22 Sunken Grade landslide cross-section (GeoStabilization International, Inc. 2014). Shows repair design ...... 3-111 Figure 31. Map of Santiam Basin, including hydropower projects, population centers, and control points ...... 3-116 Figure 32. Detroit Reservoir Daily Average Inflow and Regulated Outflow ...... 3-117 Figure 33. Detroit Reservoir Pool Daily Elevation Statistics ...... 3-117

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

Figure 34. Simulated WVS reservoir elevations (median daily) for all alternatives. For multi-year alternatives (CA 2, 3, and 4), values represent the average elevation for one year of operations (January through December) occurring during. Figure shows that, under all alternatives, the operation at Detroit would result in very small changes to the reservoir levels at the other dams in the WVS. Therefore, the lines for all the other dams largely overlap except at Detroit where the project alternative ops are shown. Each alternative’s impacts section describe the small deviations between each alternative and the No Action Alternative...... 3-120 Figure 35. Simulated pool elevation at Detroit Reservoir during one year of the 1,300 ft drawdown period (Jan-Dec). These conditions persist for one additional year during the drawdown operations occurring in CA2. The colored lines represent results from each alternative, while the shaded area represents the results from the No Action Alternative...... 3-122 Figure 36. Simulated North Santiam flow at Mehama during one year of the 1,300 ft drawdown period (Jan-Dec). These conditions persist for one additional year during the drawdown operations occurring in CA2. The colored lines represent results from each alternative, while the shaded area represents the results from the No Action Alternative...... 3-122 Figure 37. Simulated pool elevation at Detroit Reservoir for CA4 ...... 3-125 Figure 38. Simulated outflows at Detroit for CA4 ...... 3-125 Figure 39. Simulated flow on the North Santiam at Mehama for CA4 ...... 3-126 Figure 40. Computational mesh domain for Detroit Reservoir (at Detroit Dam), Big Cliff Pool and Dam, and a short segment of the North Santiam River below Big Cliff Dam ...... 3-130 Figure 41. Long-term 7-day mean of daily max temperature immediately below Detroit Dam, Oregon 3-137 Figure 42. Comparison of the estimated no dam temperature range upstream (“UpstreamMix1977- 2017”: light blue shaded region) and historic temperatures downstream of Detroit Dam (USGS 14181500; “Niagara2008-2017”: pink shaded region). Purple and Green dots are the maximum temperature targets used in this study and operationally 2017-2019, respectively...... 3-138 Figure 43. 7-day average DO immediately downstream of Big Cliff Dam at Niagara (USGS 14181500) on the North Santiam River...... 3-139 Figure 44. Periodicity Table for UWR spring Chinook salmon in the North Santiam River below Big Cliff Dam taken from the WFOP (2018) ...... 3-163 Figure 45. Spawner abundance estimates based on redd count expansion and pHOS estimates based on carcass recoveries through 2016 (Sharpe et al. 2017) ...... 3-166 Figure 46. Periodicity Table for UWR winter steelhead in the North Santiam River below Big Cliff Dam taken from the WFOP (2018)...... 3-168 Figure 47. All known Oregon Chub population in the Willamette River basin in 2017. Green circles indicate locations where Oregon Chub were detected during sampling. Red circles indicate locations where Oregon Chub were not detected during sampling but were observed previously. Overlapping symbols represent multiple locations occurring at or near the same survey location. Figure is from ODFW 2017 Oregon Chub Investigations (2018)...... 3-175 Figure 48. Simulated outflows at Detroit Reservoir during 1 year of the 1,300 ft drawdown period (Jan-Dec). These conditions persist for 1 additional year during the drawdown operations occurring in CA2. Black dashed lines represent flows at 1,000, 1,250 and 1,500 cfs. The blue dashed lines break up the year into key periods of the year representing Chinook salmon and steelhead life history stages ...... 3-183

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

Figure 49. Inflow percentiles at Detroit Dam for water years in the period of record: 1935 to 2008. Inflows at Detroit would essentially be outflows at Big Cliff and the flow in the North Santiam passing Minto Fish Facility. Some minor inputs via creeks and streams would slightly augment the flow passing Minto Fish Facility, but these sources would be minimized when they would be needed most: the mid to late-summer months. The yellow line is the 50th percentile or median, the green is the 25th percentile, the purple is the 5th percentile. The dotted black line is 895 cfs...... 3-214 Figure 50. Detroit Reservoir project boundary (white) and National Wetland Inventory identified wetlands within the footprint of Detroit Reservoir (blue) ...... 3-220 Figure 51. Water supply infrastructure at Geren Island ...... 3-232 Figure 52. Geren Island Water Treatment Facility on the North Santiam River Source: City of Salem website at https://www.cityofsalem.net/Pages/salem-water-source.aspx ...... 3-234 Figure 53. North Santiam USGS Gauge Stations ...... 3-238 Figure 54. Map of Detroit Reservoir with Location of Recreational Facilities ...... 3-270 Figure 55. Employment by Sectors within the Economy (Non-Service, Service, and Government) For the Two County Region (data source: U.S. Department of Commerce 2018 Bureau of Economic Analysis) ...... 3-276 Figure 56. Ratio of Farm Related Jobs to Total Employment (Data Source: United States Department of Agriculture National Agricultural Statistics Service, 2017 Census of Agriculture ) ..... 3-279 Figure 57. Farm Earnings as a Percent of Total Earnings (2016 dollars) (Data Source: United States Department of Agriculture National Agricultural Statistics Service, 2017 Census of Agriculture) ...... 3-279 Figure 58. Map of Marion County with Santiam Water Control District Outlined in Black ...... 3-283 Figure 59. Map of SWCD Channels and Ditches (data source: SWCD) ...... 3-284 Figure 60. Overview of Crops Found Within SWCD ...... 3-285 Figure 61. Overview of Crops Found Within SIC ...... 3-286 Figure 62. City of Salem Service Area and Wholesale Water Customers (GIS, 2014) ...... 3-290 Figure 63. Annual average water consumption per day (GSI, 2019) ...... 3-291 Figure 64. Monthly metered consumption by customer category, July 2012–June 2017 (GSI, 2019) .. 3-291 Figure 65. Area of Interest to Compare with State and National Data from EPA Environmental Justice Screening and Mapping Tool ...... 3-307 Figure 66. Environmental and demographic indicators for the area of interest displayed in Figure 65 (Region) compared to State and National values from EPA Environmental Justice Screening and Mapping Tool ...... 3-308 Figure 67. Project Timeline ...... 6-332

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

TABLES

Table 1. Pertinent Data - Detroit and Big Cliff Dams and Reservoirs ...... 1-38 Table 2. Flow rates and ramp rate requirements for Big Cliff Dam (USACE 2018) ...... 1-40 Table 3. Alternatives* assessed in the EIS ...... 2-46 Table 4. Alternatives eliminated from further consideration ...... 2-46 Table 5. Alternatives and project features ...... 2-51 Table 6. Minto Fish Facility adult transport period and hauling frequency ...... 2-76 Table 7. Environmental Decision Drivers ...... 2-92 Table 8. Assembly staging area alternative summary matrix ...... 2-94 Table 9. Construction alternatives summary matrix ...... 2-96 Table 10. North Santiam 2008 BiOp Flow Requirements ...... 3-115 Table 11. CA2 sediment transport model outputs ...... 3-131 Table 12. CA4 sediment transport model outputs...... 3-134 Table 13. Detroit / Big Cliff Dams Downstream Water Temperature 2017 Interim and Original Resource Agency Targets (Daily Average)* and ODEQ’s 2006 TMDL Targets (Seven- Day Average) ...... 3-137 Table 14. Point Source Surface water permits in the North Santiam and Middle Willamette basin potentially affecting water quality under extreme low flows in the North Santiam River 3-141 Table 15. ODEQ defined 7Q10 Streamflow values in which the dilution from point source discharge permits for the North Santiam, Santiam, and Willamette Rivers ...... 3-142 Table 16. Wildlife Sensitive Species List for North Santiam Subbasin from Detroit Reservoir to the confluence with the South Santiam River. (Data source: Species information compiled using geospatial data provided by Oregon Biodiversity Information Center (2016). This list does not include fish species considered sensitive which are covered under the aquatic species section)...... 3-148 Table 17. Fish species found in the North Santiam Watershed (Snyder et al. 2006 and ODFW, personal communication) ...... 3-161 Table 18. Estimated numbers of wild and hatchery-origin adult UWR Chinook passing upstream at Bennett Dam, North Santiam River, 2001-2005, as determined by analyses of otoliths in non-fin-clipped fish and coded wire tags in fin-clipped fish (McLaughlin et al. 2008). 3-164 Table 19. Fish counts at Lower and Upper Bennet Dams are included*...... 3-164 Table 20. Oregon Chub population abundance estimates from 2013‐2017, listed by Recovery Area*...... 3- 174 Table 21. Upper optimal temperature criteria developed for salmon and steelhead life history stages (Richter and Kolmes, 2005). These thresholds where used to compare alternatives to determine impacts to salmonids ...... 3-178 Table 22. Percent of maximum habitat area at specified flows (cfs) for spring Chinook salmon and steelhead life stages between Big Cliff and the city of Gates (Reach 1) on the North Santiam River, Oregon. Table from Gagner et al. 2014...... 3-186 Table 23. Comparison of modeled temperatures (see Section 3.15) at Niagara under CA1, CA2, and CA3...... 3-188 Table 24. Degree-days (summarized from Section 3.6) for periods when UWR Chinook salmon are spawning and eggs are incubating for CA1 – CA4 ...... 3-189 Table 25. Degree-days (summarized from Section 3.6) for periods when UWR winter steelhead are spawning and eggs are incubating for CA1 – CA4 ...... 3-189 Table 26. Comparison of modeled temperatures (see Section 3.15) at Mehama under CA1, CA2, and CA3*...... 3-190

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

Table 27. Comparison of modeled temperatures (see Section 3.15) at Niagara under CA1 and CA4*...... 3- 201 Table 28. Comparison of modeled temperatures (see Section 3.15) at Mehama under CA1 and CA4*. ... 3- 202 Table 29. Species listed, proposed to be listed, or are candidate species under the Endangered Species Act for Linn and Marion Counties. Information was obtained through USFWS Environmental Conservation Online System (ECOS), https://ecos.fws.gov/ecp/...... 3-210 Table 30. Wetland types and acreage at Detroit Reservoir ...... 3-221 Table 31. Plant Sensitive Species List that may occur near the North Santiam River from Detroit Reservoir to the confluence with the South Santiam River. Species described are listed as 1 or 2 on the Oregon species list are included within this table; species ranked 3 or 4 are not included within this table ...... 3-222 Table 32. Large M&I water users average monthly water use (AWU)...... 3-230 Table 33. Estimated Generation Values for the Base Case ...... 3-244 Table 34. Estimated Generation Values for the CA2 ...... 3-247 Table 35. CA2 – Hydropower Value (losses) ...... 3-248 Table 36. Cultural Resources Located within or overlapping with Project APE ...... 3-257 Table 37. Overview of Socioeconomic Metrics (Population, Employment and Personal Income) for both Marion and Linn Counties (the Region) ...... 3-275 Table 38. Employment by Industry, Marion County ...... 3-277 Table 39. Employment by Industry, Linn County ...... 3-277 Table 40. Farm Employment for Marion and Linn Counties Relative to the U.S...... 3-278 Table 41. Gross Expense Ratio for All Farms ...... 3-280 Table 42. Percent of Land Area in Farms ...... 3-281 Table 43. Comparison of Farm Products across Two Counties and the Nation. The Census of Agriculture data on farms by type are only reported by the number of farms. They are not reported by employment, income, or acreage ...... 3-282 Table 44. Summary of Alternatives’ Economic Impacts ...... 3-297 Table 45. Ethnicities within Marion and Linn Counties, 2016 data from U.S. Census Bureau ...... 3-304 Table 46. Median Household Income for Linn and Marion Counties Compared to the Nation...... 3-305 Table 47. Summary of emissions and social cost of carbon (eGRID2016)...... 3-316 Table 48. Summary of resources included and excluded from cumulative effects analysis ...... 4-320 Table 49. Other Applicable Laws ...... 7-334

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

ACRONYMS

7Q10 lowest 7-consecutive-day average flow event expected to occur once every 10 years, on average ADC average day consumption AdH Adaptive Hydraulics Model aMW average megawatts APE area of potential effect AQI Air Quality Index ASR Aquifer Storage and Recovery ATU accumulated thermal units AWU average monthly water use BiOp Biological Opinion BGEPA Bald and Golden Eagle Protection Act BLM Bureau of Land Management BOR Bureau of Reclamation BPA Bonneville Power Administration CA Construction Alternative CAA Clean Air Act CDL Cropland Data Layer CEQ Council on Environmental Quality CFD Computational Fluid Dynamics cfs cubic feet per second COP Configuration/Operation Plan CRCLA Comprehensive Environmental Response, Compensation, and Liability Act CRR Cohort Replacement Rate CWA Clean Water Act CY cubic yards dbh diameter at breast height DO Dissolved Oxygen DPS Distinct Population Segment EA Environmental Assessment ECOS Environmental Conservation Online System EDR Engineering Documentation Report EFH Essential Fish Habitat EIS Environmental Impact Statement EM Engineering Manual ER Engineering Regulation ESA Endangered Species Act ESCP Erosion and Sediment Control Plan ESU Evolutionary Significant Unit f/s feet per second FBW Fish Benefits Workbook FERC Federal Energy Regulation Commission

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

FNU Formazin Nephelometric Unit FSS Floating Screen Structure ft feet FY fiscal year HEC-ResSim Hydrologic Engineering Center Reservoir Systems HGMP Hatchery Genetic Management Plan HIW High Intake Weirs IHNV Infectious Haematopoietic Necrosis IPaC Information, Planning, and Conservation System KPO Kokanee Power of Oregon LIG Low Intake Gates MAII may adversely impact individuals MBTA Migratory Bird Treaty Act M&I municipal and industrial MPSF minimum perennial streamflows MSL mean sea level MW megawatt MWh megawatt hour NAAQS National Ambient Air Quality Standards NASS USDA National Agriculture Statistical Service Ne effective population size NEPA National Environmental Policy Act NF National Forest Road NGVD National Geodetic Vertical Datum of 1929 NHPA National Historic Preservation Act NMFS National Marine Fisheries Service NPDES National Pollution Discharge Elimination Systems OARRA Oregon Archaeological Records Remote Access ODF Oregon Department of Forestry ODFW Oregon Department of Fish and Wildlife ODOT Oregon Department of Transportation ODWR Oregon Water Resource Department ODEQ Oregon Department of Environmental Quality OHA Oregon Health Authority O&M operations and maintenance OPRD Oregon Parks and Recreation Department ORBIC Oregon Biodiversity Information Center ORV outstandingly remarkable values OSE Other Social Effects PM particulate matter ppm parts per million psi pounds per square inch Q flow RECONS Civil Works Regional Economic System

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

RM river mile RM&E Research, Monitoring, and Evaluation RO Regulating Outlet RPA Reasonable and Prudent Alternative RQD Rock Quality Designation SA Staging Alternative SEF Sediment Evaluation Framework SHPO State Historic Preservation Office SIC Sidney Irrigation Cooperative SL Screening Levels SLAM Species Lifecycle Analysis Module SOC Species of Concern SSC suspended sediment concentration SWCD Santiam Water Control District SWS Selective Withdrawal Structure TDG total dissolved gas TMDL Total Maximum Daily Load VSP Viable Salmonid Population USDA U.S. Department of Agriculture USFS U.S. Forest Service USFWS U.S. Fish and Wildlife Service USGS U.S. Geological Society UWR Upper Willamette River WATER Willamette Action Team for Ecosystem Restoration WFFDWG Willamette Fish Design Working Group WNF Willamette National Forest WTP Willingness to Pay WVS Willamette Valley System

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Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

SECTION 1 - INTRODUCTION The U.S. Army Corps of Engineers (Corps) prepared this Environmental Impact Statement (EIS) in compliance with the National Environmental Policy Act (NEPA) and other relevant Federal and State laws and regulations. This EIS has been prepared in accordance with NEPA, as amended, the Council on Environmental Quality’s (CEQ) NEPA regulations (40 C.F.R. parts 1500-1508), and the Corps’ NEPA regulations (33 C.F.R. part 230). This EIS discloses the direct, indirect, and cumulative environmental impacts that would result from the alternatives including CA5, the proposed action.

1.1 DOCUMENT STRUCTURE The Corps has organized this EIS into eight parts: 1. Introduction: This section includes information on the history of the Project, the purpose of and need for the Project, the lead agency and cooperating agencies of the Project, and the areas potentially affected directly or indirectly by the Project. 2. Alternatives: This section provides a detailed description of the alternatives for meeting the Project purpose and need, including those alternatives that the Corps eliminated from further consideration and the criteria utilized to screen the alternatives. Finally, this section describes the features of the action alternatives. The No Action Alternative is included in the array of alternatives considered. 3. Affected Environment and Environmental Effects: This section describes the existing conditions of the environment that project implementation may affect. This section also describes the probable direct and indirect environmental effects of implementing the alternatives not eliminated for further consideration. Within each section, the effects of the No Action Alternative provides a baseline for evaluation and comparison to the action alternatives. 4. Cumulative Impacts: This section analyzes the potential cumulative impacts that may occur following implementation of the proposed action when considered with other past, present, and reasonably foreseeable actions. 5. Review and Consultation: This section provides a list of tribes and agencies consulted during the development of the EIS as well as summarizes the Corps’ public involvement activities for the Project. 6. Compliance with Laws and Regulations: This section discusses the Project’s compliance with laws including the Endangered Species Act (ESA), the Clean Water Act (CWA), the National Historic Preservation Act (NHPA), as well as Executive Orders such as environmental justice.

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Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

7. List of Preparers: This section provides a list of individuals that contributed to the development of the EIS. 8. References: This section provides a list of references cited within in the EIS. 9. Appendices: This section provides a list of appendices suppporting the EIS.

1.2 BACKGROUND The Corps is investigating constructing and operating a temperature control and a downstream fish passage facility to enhance fish passage through the Detroit Dam. This project implements the National Marine Fisheries Service (NMFS) Reasonable and Prudent Alternative1 (RPA) as detailed in the Endangered Species Act Section 7(a)(2) Consultation, Biological Opinion and Magnuson-Stevens Fishery Conservation & Management Act Essential Fish Habitat Consultation on the Willamette River Basin Flood Control Project (BiOp) issued July 11, 2008 (NMFS 2008). The Corps operates 13 dams and reservoirs in Oregon’s Willamette River basin, which are a part of the Willamette Valley System (WVS). Congress authorized the WVS principally by three separate Flood Control Acts: 1938, 1950, and 1960. House Document 531, as incorporated by the Flood Control Act of May 17, 1950 (81st Congress, 2nd Session), remains the overall guiding document pertaining to the operation and maintenance of the WVS. Congress authorized the WVS with the full recognition that it would cut off extensive areas of upstream habitat. To compensate for this loss of the spawning habitat, Congress authorized the construction of several fish hatcheries. The listing of several species under the ESA required an assessment of the effects of operations in the WVS by the Corps’ Portland District. Based on that assessment, the Action Agencies requested consultation with NMFS, and subsequently NMFS issued the July 2008 BiOp evaluating the effect of continued operations and maintenance to species listed under the ESA that are under their jurisdictional purview. NMFS concluded that the Corps’ proposed action was not sufficient to avoid jeopardy or adverse modification of designated critical habitat for two fish species: Upper Willamette River (UWR) spring Chinook salmon and winter steelhead. Detroit Dam and Reservoir are located within areas deemed critical habitat of high conservation value for UWR Chinook salmon and steelhead (NMFS 2008). Large dams in the four historically most productive tributaries, including in the North Santiam River basin by Detroit Dam, restrict access to historical spawning and rearing areas. Although the Minto Adult Fish

1 A reasonable and prudent alternative in a biological opinion is an alternative method of project implementation, offered in a biological opinion reaching a jeopardy or adverse modification conclusion that would avoid the likelihood of jeopardy to the species or adverse modification of critical habitat. In the case of the 2008 BiOp the project implementation refers to the continued operations and maintenance of the WVS. 1-27

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

Collection Facility (Minto Fish Facility) provides access to migrating adults to historically high quality habitat above Detroit Dam, poor downstream fish passage for the North Santiam River populations continue to limit access. Detroit Dam operations have compounded this by changing the temperature of the North Santiam River at critical times in these species’ life cycles, impairing migration, spawning, and rearing success of these populations. This is in spite of interim temperature control operations that benefit downstream spawning and rearing success for a limited duration of the year. The NMFS BiOp included an RPA to the Corps’ proposed continued operation and maintenance of the WVS that, if implemented, would avoid the likelihood of jeopardy to listed species or adverse modifications to their critical habitats. The RPA includes measures for fish passage, water quality, flows, water contracts, habitat improvements, and hatcheries. Specifically, RPA 4.12.3, “Detroit Dam Downstream Passage”, states that the Action Agencies “would investigate the feasibility of improving downstream fish passage at Detroit Dam and if found feasible they would construct and operate downstream passage facilities.” RPA 4.12.3 also states, “Temperature control would also be considered in designing the passage facility.” Additionally, RPA 4.1 requires the continued capture of UWR spring Chinook salmon below several Corps dams, including Detroit, and transporting them into habitat upstream of these dams. Finally, RPA 5.2 states that the Action Agencies “would make structural modifications or major operational changes for improved water quality to at least one of the Project dams” and identifies Detroit Dam “as the highest priority dam for construction of a temperature control structure or operational changes to achieve temperature control.” The USFWS similarly issued a BiOp in 2008 for the effects of the WVS on Oregon chub (now delisted), bull trout, and bull trout critical habitat. The USFWS BiOp reached a no jeopardy determination as long as the Action Agencies implement the NMFS RPA and the Action Agencies consider the effects on Oregon chub and bull trout when implementing measures proscribed in the RPA. This EIS evaluates the potential environmental effects of constructing, operating, and maintaining temperature control and downstream fish passage at Detroit Dam while meeting NMFS fish passage design guidelines (NMFS 2011) as well as the Corps’ requirements for operator safety.

1.3 PURPOSE AND NEED

Purpose Consistent with the authorized project purposes, the purpose of the proposed Detroit Dam Downstream Fish Passage Project (the Project) is: 1. to enhance fish passage of UWR Chinook salmon and steelhead on the North Santiam to reaches downstream of the Detroit and Big Cliff Dams; and

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Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

2. to modify temperatures on the North Santiam and mainstem Santiam Rivers below Detroit Dam with the objective of meeting operational temperature targets optimized for adult and juvenile salmonids. To enhance fish passage at Detroit Dam would necessitate making improvements to—and continuing the operations and maintenance of—associated fish facilities.

Need The need for this project is to meet the requirements of the RPA from the NMFS BiOp, which identified measures to avoid jeopardizing the existence of ESA-listed fish for the continued operation and maintenance of the Willamette Valley Project (NMFS 2008). Specifically, Measures 4.12.3, 4.1, 4.2 and 5.2 of the RPA stipulate the need for this project. Measure 4.12.3 requires implementation of downstream fish passage at Detroit Dam if found feasible. The Corps determined downstream passage at Detroit Dam to be feasible during the Configuration/Operation Plan (COP) process following the issuance of the BiOp. The COP applied a science-based decision framework to organize and assess biological, technical and economic data for the wide range of alternatives under consideration. This analysis is detailed by the 2015 COP Phase II Report in Appendix D – “COP Phase II Alternatives” (USACE 2015) and is incorporated here by reference. Measures 4.1 and 4.2 require the continued capture of UWR Chinook salmon and UWR steelhead, respectively, below Corps dams, including Detroit and Big Cliff, and transporting them into habitat above the dams. Measure 5.2 states that the Corps “would make structural modifications or major operational changes for improved water quality to at least one of the Project dams” and identifies Detroit Dam “as the highest priority dam for construction of a temperature control structure or operational changes to achieve temperature control.”

Purpose and Need Background The abundance of UWR Chinook salmon and steelhead is currently much-reduced compared to historic levels and NMFS has listed both as threatened under the ESA. The ESA defines a threatened species as one that is likely to become an endangered species in the foreseeable future throughout all—or a significant portion—of its range. UWR Chinook salmon are currently at “very high” risk of extinction. Given current climatic conditions and the prospect of long-term climatic change, the inability of many populations to access historical headwater spawning and rearing areas may put this Evolutionary Significant Unit (ESU) at greater risk in the near future. The NMFS 2016 5- year Review (NMFS 2016) identifies restricted access to historical spawning and rearing areas due to Big Cliff and Detroit dams in the North Santiam River (one of the four historically most productive tributaries for UWR spring-run Chinook salmon) as an

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Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement ongoing concern. In the absence of an effective passage program, Detroit Dam would continue to confine access to more lowland reaches where land development, water temperatures, and water quality may be limiting. Pre-spawning mortality levels are generally high in the lower tributary reaches where water temperatures and fish densities are generally the highest (NMFS 2016). The population of UWR steelhead is currently at “moderate” risk of extinction. A population viability analysis conducted by Falcy 2017 predicted the 64.4% probability of the quasi-extinction of the North Santiam population of winter steel head over a 100 year period (with sea lion predation mortality estimated during 2017 will continue indefinitely). For the UWR steelhead Distinct Population Segment (DPS), the declines in abundance noted during the previous review (Ford et al. 2011) continued through the period 2010-2015, and accessibility to historical spawning habitat remains limited, especially in the North Santiam River. Although the recent magnitude of these declines is relatively moderate, the Northwest Fisheries Science Center updated status review (Ford et al. 2011) notes that continued declines would be a cause for concern. Key emergent or ongoing habitat concerns identified for UWR steelhead in the NMFS 2016 5-Year Review for UWR Chinook salmon and steelhead (NMFS 2016) include: • lack of accessibility to historical spawning habitat (especially in the North Santiam River, • degraded accessible habitat under continued development pressure in the lower reaches of North and South Santiam rivers, and • lack of high quality habitat below Detroit Dam on the North Santiam River. The dam and reservoir are located within areas NMFS has designated as critical habitat of high conservation value for UWR spring Chinook salmon and winter steelhead. Before the dams were constructed, adult UWR Chinook salmon and steelhead spawned in the upper reaches of the North Santiam River and in headwater tributaries such as Marion Creek, the Breitenbush River, and Blowout Creek, as well as in the mainstem below the dam sites and in Little North Santiam River. The offspring of these fish would migrate downstream as juveniles to the Pacific Ocean. The salmonids’ access to habitat blocked by the dams in the North Santiam subbasin remains of critical importance because the remaining spawning habitat below the dams would continue to degrade under current conditions, reducing abundance and productivity (NMFS 2016). Construction of Detroit and Big Cliff reservoirs in the 1950's reduced access to existing habitat for anadromous fish. Lack of access to historical spawning and rearing habitat above these dams restricts spatial distribution for the North Santiam populations of UWR Chinook salmon and steelhead to habitat below Big Cliff Dam. Additionally, dam operations and historic land use have structurally, hydrologically, and thermally altered their downstream habitat. These altered habitats often contain hatchery

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Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

produced salmonids, or their direct offspring, that may compete or interbreed with the wild fish. Ocean conditions are influential on survival rates of both steelhead and salmon and are beyond the Action Agencies control. This project to improve temperature control and downstream passage in the North Santiam responds to the 2008 NMFS BiOp and will aid in avoiding jeopardy by improving the freshwater environment, and may be critical during unproductive ocean cycles. Downstream Passage Need Background At the time of dam construction, mitigation was required for salmon and steelhead spawning and rearing habitat on the North Santiam River lost upstream of Detroit and Big Cliff dams. These requirements resulted in the North Santiam Spring Chinook Program (Program) which includes the Marion Forks Hatchery, the primary rearing facility for the Program, and the Minto Fish Facility, the primary collection facility for adults for the Program. The Program requires collection of broodstock for the hatchery program and collection of other fish for transport above Big Cliff and Detroit dams to spawn naturally. The Minto Fish Facility also handles adult winter steelhead and summer steelhead. Operators at Minto Fish Facility release winter steelhead into stream habitat above Minto Dam and release juvenile summer steelhead downstream to create increase harvest opportunities. The goals of the Program include the maintenance of a suitable conservation broodstock for ongoing and future population recovery efforts throughout the subbasin, including reintroduction efforts above the Big Cliff/Detroit Dam and Reservoir complex.

The Program addresses the upstream component of habitat access, however, downstream passage facilities are lacking. Safe downstream fish passage past Detroit and Big Cliff is essential to ensure that the Program can successfully reestablish population productivity. Current downstream passage of listed fish does not meet NMFS 2008 BiOp requirements due to excessive fish injuries and mortality. Without intervention, resource managers expect losses to continue to be moderate for upstream passage and high for downstream passage through the reservoirs and dams. For juvenile salmonids emigrating through Detroit Reservoir, there is little known of the effects of Detroit Reservoir. Biological data (see section 3.8.1.1) has been collected in recent years that provides information to support that a properly designed surface collector at Detroit Dam would be a viable alternative to improve downstream passage at the dam. Additionally, Detroit Dam operations tend to produce very slow water movement that possibly diminish migration cues, potentially causing juvenile salmonids to residualize (i.e., behave like resident fish) rather than migrate downstream (Giorgi et al. 1997). Romer and Monzyk, 2014 documented residualization and adfluvial life history for Chinook salomn in Green Peter. Resource managers expect that a proportion of juvenile offspring of adults outplanted above Detroit Reservoir would not successfully 1-31

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement emigrate from the reservoir because of predation and residualism. In addition, downstream routes available to fish at both Detroit and Big Cliff dams are only over the spillways, through the turbines, or via other outlets that have the potential to kill and injure juvenile fish as they migrate downstream. Per RPA measure 4.12.3 in the 2008 Willamette BiOp, providing downstream passage in North Santiam and mainstream Santiam rivers is required to reduce extinction risk in the short term as well as contributing to long-term viability. Temperature Control Need Background Construction and subsequent operation of the Detroit and Big Cliff dams also altered the temperature regime of the North Santiam and mainstem Santiam rivers below the dams. During early spring, water temperatures released from Detroit Dam are typically cooler than the downstream temperature targets, during the fall/early winter water temperatures are typically warmer than downstream targets. These effects on the seasonal thermal regime could persist as far downstream as Jefferson, Oregon. The altered temperature regime impairs the water quality needed for adult migration, spawning and incubation, and juvenile and kelt downstream survival. As a result, the altered temperature regime negatively affects the productivity of listed salmon and winter steelhead in the lower North Santiam River. NMFS has identified this as one of the most critical limiting factors for species recovery (NMFS 2011). Per RPA measure 5.2 in the 2008 Willamette BiOp, controlling stream temperatures in the North Santiam and mainstream Santiam rivers is required to meet downstream water temperature criteria for ESA-listed species and reduce extinction risk in the short term as well as contributing to long-term viability.

1.4 LEAD AGENCY For this proposed action, the Corps is the lead federal agency for compliance with NEPA. As the lead agency, the Corps ensures overall compliance with environmental laws and regulations regarding the proposed federal action.

1.5 COOPERATING AGENCIES According to the CEQ’s regulations for implementing NEPA (40 C.F.R. § 1501.6), and based on their jurisdiction by law and/or special expertise, NMFS, USFWS, and ODFW have agreed to participate in the Project as cooperating agencies for the purposes of satisfying the requirements for the proposed NEPA process.

1.6 PROJECT LOCATION The Project is located in the North Santiam Watershed and includes work at the Detroit Dam and Reservoir as well as some access roads, staging sites. The area affected by the alternatives varies and is described in detail for each alternative in SECTION 3, but may include areas within the North Santiam River from Detroit 1-32

Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

Reservoir to the confluence with the Santiam River as well as the surrounding urban and agricultural areas from Idanha to Salem (Figure 1). The proposed action may affect water quality in the Santiam River between its confluence with the North Santiam River and the Willamette River, therefore, this stretch of river is included in the action area (Figure 1). Additionally, due to the potential direct and indirect impacts of some of the alternatives on recreation and water supply, the area of effect includes the City of Salem, Marion and Linn County south of the North Santiam River, Marion County north of the North Santiam River, and Linn County south of the North Santiam River.

Figure 1. North Santiam River Basin and the Willamette River from its confluence with the Santiam River to the City of Salem.

Six subbasins, described below, divide the watershed (Figure 2):

• The Detroit Reservoir / Blowout Divide Creek Watershed is 112 square miles (71,679 acres) area of the west slope of the Cascade Range and includes the city of Detroit and Detroit Reservoir. Six major tributaries flow into the reservoir: Breitenbush River, North Santiam River, Box Canyon Creek, Blowout Creek, Kinney Creek and French Creek. Forestry is the dominant land use in this area. Over 50% of the watershed is in public ownership administered primarily by the U.S. Forest Service (USFS) Willamette National Forest (WNF) (Figure 2).

• The North Fork Breitenbush River Watershed is 108 square miles (69,119 acres) and Breitenbush River flows into Detroit Reservoir. This area drains the headwaters of the Cascade Range and has several popular hot springs including Breitenbush hot springs. The watershed is located in eastern Marion County. Mostly public-owned

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Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement forestlands managed by the USFS dominate the sub-watershed (Figure 2). Breitenbush River flows into Detroit Reservoir.

• The Upper North Santiam River Watershed is 229 square miles (146,559 acres) flowing from the upper Cascade Mountains. The North Santiam River flows into Detroit Reservoir and both Linn and Marion counties have jurisdiction in this watershed. USFS dominates the sub watershed’s ownership, however, it is 8% private-owned (Figure 2).

• The Middle North Santiam River Watershed drains an 86 square mile (55,039 acres) area of the Cascade Range downstream of Detroit Dam. Mill City, Gates, Stayton, Sublimity, Marion, Mehama and a portion of the City of Lyons are located within the watershed boundary. Forestry dominates the land use area. Private ownership dominates the watershed; however, the Bureau of Land Management (BLM) owns 11% of the watershed (Figure 2).

• The Lower North Santiam River watershed drains a 113 square mile (72,319 acres) area of the west slope of the Cascade Range downstream of Detroit Dam and includes the City of Jefferson and a large portion of the City of Lyons. The City of Lyons is located in Linn County, and Jefferson is located in Marion County. This is the most heavily populated watershed in the subbasin. Geren Island is located in this watershed and is the drinking water facility for the City of Salem, which withdraws water from the North Santiam River. Ownership is mostly private (Figure 2). Agricultural land use accounts for 67% of the watershed.

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Detroit Downstream Fish Passage Project DRAFT Environmental Impact Statement

Figure 2. Map of the North Santiam watershed ownership (ODEQ 200)

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Detroit Downstream Passage Project DRAFT Environmental Impact Statement

Detroit Project Description The Detroit Project consists of Detroit Dam and Reservoir and Big Cliff Dam and Reservoir. Located along the border of Marion and Linn Counties, in the rugged mountain forests below Mt. Jefferson, the two dams store the waters of the North Santiam River. Congress authorized the WVS with the full recognition that it would cut off extensive areas of upstream habitat. The Corps constructed both the Detroit and Big Cliff dams without adult fish ladders. To compensate, Congress authorized fish hatcheries and other measures. The Corps constructed Marion Forks Hatchery in 1951 to compensate for the lost salmon habitat caused by the construction of Detroit Dam and Big Cliff Reregulating Dam. Minto Fish Facility is a satellite facility for the Marion Forks Hatchery located on a tributary to the North Santiam above Detroit Reservoir. The Corps constructed Minto to collect adult Chinook salmon as broodstock to supply eggs for Marion Forks. The Corps funds the majority of the operating costs at Marion Forks and Minto as part of the Willamette Basin Fish Mitigation Program, with ODFW operating both the Marion Forks Hatchery and the Minto facility.

Detroit and Big Cliff Dams The Corps constructed Detroit Dam, located at river mile (RM) 60.9 on the North Santiam River, approximately 50 miles southeast of Salem, Oregon, in 1953 primarily to manage flooding (Figure 1). In addition to flood risk management, Detroit Dam’s authorized purposes include power generation, water supply for irrigation and municipal and industrial use, navigation, fish and wildlife, water quality, and recreation. Big Cliff is a re-regulating dam located at RM 58.1, about 3 miles downstream of Detroit Dam. Big Cliff is a small reservoir used to even out peak discharges of water utilized for power generation at Detroit Dam, and thereby controls downstream river level fluctuations. The Corps is responsible for the construction and operation of the Project for its authorized purposes and has exclusive control over all project lands adjacent to and beneath the water surfaces, to include withdrawn U.S. Forest Service (USFS) lands, for carrying out those purposes. The use or utilization of withdrawn USFS lands for purposes extraneous to project operation remains under the jurisdiction of the USFS. The responsibility for administering all other project lands within the boundary for recreation, fire protection, and land management is vested with the USFS, in accordance with a Memorandum of Understanding between the Secretary of Agriculture and the Secretary of the Army, effective November 10, 1954. In the state of Oregon, water law distinguishes between diverting water for storage, and releasing water from storage for use; each requires a different water

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Detroit Downstream Passage Project DRAFT Environmental Impact Statement

right. In Oregon, the right to store water conveys ownership of the stored water. Because national policy prohibits the Corps from holding state water rights, the U.S. Bureau of Reclamation (BOR) has held two Oregon water storage rights on behalf of the federal government for all WVS conservation storage since construction of the WVS was completed. Importantly, BOR’s state water rights that allow the federal government to store water in WVS reservoirs, including Detroit Reservoir, were designated exclusively for irrigation. BOR has 29 irrigation water contracts for stored water in the Detroit Reservoir. Table 1 provides pertinent data about Detroit and Big Cliff reservoirs. Detroit Dam is a 450-ft-high, 1,457-ft-long concrete gravity structure (Figure 3). The spillway is a concrete ogee-type with six Tainter gates located in the middle of the dam. There are four Regulating Outlets (ROs), two at elevation2 1,340 and two at elevation 1,265 located directly below the spillway. There is a fifth regulating outlet located in the south end of the spillway, at elevation 1,340, that was originally intended for hydraulic model testing, but was never - or rarely ever - used. Two steel-pipe penstocks on the north side of the spillway, with entrances at elevation 1,403, go through the dam and exit on the downstream side and provide water to the two 50- megawatt (MW) Francis turbines in the powerhouse. Figure 4 shows these outlets and their elevations in relationship to the maximum conservation pool (1,563.5 ft), the minimum conservation pool (1,450 ft), and the power pool (1,425 ft). In general, the Corps operates the Detroit Project per the Water Control Diagram (also referred to as the rule curve) in the Water Control Manual (USACE 1964b) (Figure 4). At full pool elevation (1,569 ft), Detroit Reservoir covers an area of 3,580 acres with 340,000 acre-ft of usable storage at the confluence of the North Santiam and Breitenbush Rivers. Table 2 provides the flow rates and ramp rate requirements for Big Cliff Dam (USACE 2018)

2 All elevations are in National Geodetic Vertical Datum of 1929 (NGVD 29)

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Detroit Downstream Passage Project DRAFT Environmental Impact Statement

Table 1. Pertinent Data - Detroit and Big Cliff Dams and Reservoirs Detroit Dam and Reservoir Big Cliff Dam and Reservoir River Mile 60.9 (from Santiam mouth) 58.1 (from Santiam mouth) Drainage Area (square miles) 438 452 Dam Height (ft) 450 172 Dam Crest (mean sea level 1,579.0 1,212.0 (MSL)) Maximum Pool 1,574.0 ft (472,600 acre-ft) 1,210.0 ft (5,300 acre-ft) Full Pool 1,569.0 ft (455,100 acre-ft) 1,206.0 ft (4,700 acre-ft) Maximum Conservation Pool 1,563.5 ft (436,000 acre-ft) 1,182.0 ft (2,300 acre-ft) Spillway Crest 1,541.0 ft (363,200 acre-ft) Minimum Conservation Pool 1,450.0 ft (154,400 acre-ft) Minimum Power Pool 1,425.0 ft (115,000 acre-ft) Turbines Two 50-MW Francis turbines at penstock One 18-MW Kaplan (2,800- elevation 1,403.0 ft (4,300-5,300 cubic ft per 3,200 cfs hydraulic second (cfs) combined hydraulic capacity) capacity) Spillway Gates Six radial Tainter gates (176,000 cfs combined Three radial Tainter gates hydraulic capacity) (179,000 cfs combined hydraulic capacity) Upper Regulating Outlets Two at elevation 1,340 ft (13,050 cfs combined capacity) Test Flume Conduit One at elevation 1,340 ft (same dimensions as Upper Regulating Outlets, not currently used) Lower Regulating Outlets Two at elevation 1,265 ft that are not used

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Detroit Downstream Passage Project DRAFT Environmental Impact Statement

Figure 3. Interior view of Detroit Dam

Figure 4. Detroit Dam - pertinent elevations

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Detroit Downstream Passage Project DRAFT Environmental Impact Statement

Table 2. Flow rates and ramp rate requirements for Big Cliff Dam (USACE 2018) Time Period or Criterion Target High Flow (> 2,000 cfs) High Flow (> 2,000 cfs) Minimum Flow (BiOp targets) 1,000 cfs Normal Maximum Flow* (for evacuation of stored 17,000 cfs flood water) Normal Rate of Increase per hour 100-1,000 cfs 500 cfs 1,000-3,000 cfs 1,000 cfs 3,000-17,000 cfs 1,500 cfs Maximum Rate of Increase per hour 2,000 cfs Maximum Rate of Decrease per hour 20% of flow Low Flow (< 2,000 cfs) Low Flow (< 2,000 cfs) February 1 – March 15 1,000 cfs March 16 – May 31 (winter steelhead spawning) 1,500 cfs June 1 – July 15 (winter steelhead incubation) 1,200 cfs July 16 – Sept 4 (rearing) 1,000 cfs Sep 5 – Oct 30 (Chinook spawning) 1,500 cfs Nov 1 – Jan 31 (Chinook incubation) 1,200 cfs Rate of Change (increase) based on a tailwater change of 0.3 feet/hour (ft/hr) Normal and 0.5 ft/day use when there is an emergency – power Special requirements, boating accident; based on a tailwater change of 0.3 ft/hr and 0.5 ft/day Rate of Change (decrease)

Maximum Rate - 0.1 ft/hr nighttime hrs, -0.2 ft/hr daytime hrs

Maximum Daily -1.0 ft/day

Detroit Fish Facilities Adult spring Chinook salmon and steelhead needed for ongoing fish management activities in the North Santiam subbasin are collected at the Minto Fish Facility located on the North Santiam River about 4 miles downstream of Big Cliff Dam and seven miles downstream of Detroit Dam (Figure 5). The Corps rebuilt the Minto Fish Facility in 2013 per the 2008 BiOp to incorporate current anadromous salmonid passage facility design criteria (NMFS 2008). At the Minto site, there is a barrier dam across the North Santiam that helps direct fish migrating upstream to the fish ladder entrance to the Minto Fish Facility. The facility consists of a fish ladder, presort pool and crowder, sorting flume, eight post-sort holding ponds fed by pumps, and many other features that accommodate both holding adult salmon and steelhead as well as acclimation of juveniles. The Minto facility’s intake and pump

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Detroit Downstream Passage Project DRAFT Environmental Impact Statement structure includes a Pumped Facility Water Supply System, Gravity Auxiliary Water Supply System, and screens. Ancillary buildings include a maintenance building, emergency generator building, site host, two shade structures, and stairwell access structures.

Figure 5. Minto Fish Collection Facility location The Minto Fish Facility, operated by ODFW under contract with the Corps, collects adult fish and sorts them for various dispositions. Minto operators pass natural-origin spring Chinook and winter steelhead above the barrier dam at Minto, into a 4-mile reach that terminates at Big Cliff Dam. Minto operators only pass natural-origin fish into this reach as it temporarily serves as an area protected from hatchery-origin fish influence. Minto collects resident fish including rainbow trout, coastal cutthroat trout, mountain whitefish and lamprey, which operators enumerate and pass above the barrier dam3. Hatchery summer steelhead adults are collected if needed for brood, are transferred to the Foster Fish Facility. Otherwise, disposition occurs according to the summer steelhead HGMP protocols. Minto collects hatchery UWR Chinook salmon adults and operators hold them for either outplanting above Detroit Dam or broodstock purposes. Collection of UWR Chinook salmon generally begins in May and continues through September. Minto operators transport collected adults destined for outplanting above Detroit Dam in June, July, August and September and holds adults sequestered for broodstock until September when

3 Lamprey (either Brook lamprey or Pacific lamprey) may be returned to the tailrace, pending fish management agency guidance for the year. A greater benefit to these species may be realized by leaving lamprey in areas where they are more likely to encounter other individuals, rather than passed above the barrier dam into relative isolation.

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Detroit Downstream Passage Project DRAFT Environmental Impact Statement spawning commences. Spawning occurs at Minto throughout the month of September in three to four distinct events.

After spawning concludes, Minto operators transfer the fertilized spring Chinook eggs via truck to the Marion Forks Hatchery. The Marion Forks Hatchery is located upstream of Detroit Dam, about 17 miles east of the town of Detroit, Oregon. The hatchery rears the juvenile fish for approximately 15 months then transfers them back to the Minto Fish Facility for final acclimation and release. Minto operators do not release juveniles from Marion Forks because it is located above two dams and their respective reservoirs and the mortality incurred from passage through these hydro projects would be too high. Juvenile spring Chinook are acclimated at Minto for 3 to 4 months and released in February or early March. Following the spring Chinook release, Minto operators transfer juvenile summer steelhead into the facility for acclimation. Minto operators allow these fish to remain on station for about a month and release them by the end of April.

Currently, there is no safe downstream passage for fish through Detroit Dam. Therefore, natural-origin spring Chinook and winter steelhead adults collected at Minto are not currently transported and released upstream of Detroit Dam. Natural- origin spring Chinook and winter steelhead are passed above the barrier dam at Minto, into a 4-mile reach that terminates at Big Cliff Dam. Only natural-origin fish are placed into this reach as it temporarily serves as an area protected from hatchery-origin fish influence. Operators transport and release (outplant) the hatchery-origin spring Chinook adults they collected at the Minto Fish Facility to sites above Detroit Dam to help inform reintroduction strategies.

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Detroit Downstream Passage Project DRAFT Environmental Impact Statement

SECTION 2 - ALTERNATIVES The Corps considered various alternatives for meeting the purpose and need of the Project. Improving downstream fish passage and temperature control at high- head dams is extremely complex and challenging and the RPA only generally describes it. A major reason it is so technically complex and difficult is that high head dams operated for flood risk management have large seasonal fluctuations in reservoir elevation. Detroit has the added complexity of being operated for multiple other purposes (water supply, hydropower, water quality fish and wildlife, and recreation). Balancing these missions while also moving fish around a 400 foot barrier in a reservoir that moves up and down more than a hundred feet over the course of every year is very challenging from a technical and biological standpoint.. Therefore, the Corps spent many years developing, assessing, and screening numerous alternatives for both downstream passage and temperature control. Due to the complexities and challenges of the project, the Corps quickly screened out many alternatives because they were not technically feasible, posed risks to dam safety that could not be mitigated, would impede the Corps ability to manage floods, or would eliminate one or more purposes of Detroit Dam over the long term. The remaining received one or more rounds of further design and assessment and the Corps screened out many more because they would not meet the project objectives and therefore would not meet the project purpose and need. The Corps analysis showed that there is one technically feasible option that provides both temperature control and downstream passage while meeting the project objectives and without violating the project constraints. Alternatives for how these features are constructed has a range of potential effects and the Corps used the construction method to define our range of alternatives. Below is a more detailed discussion of this screening process. This section describes the alternatives screening process, alternatives considered but eliminated from detailed analysis in the EIS, the No Action Alternative, and the action alternatives including the proposed action.

2.1 ALTERNATIVE FORMULATION AND SCREENING HISTORY In 2009, the Corps initiated an Environmental Assessment (EA) for the Project and began formulating alternative solutions for meeting the RPA as a part of the Configuration/Operation Plan (COP) process following the issuance of the BiOp. The COP applied a science-based decision framework to organize and assess biological, technical and economic data for the wide range of alternatives under consideration. This analysis is detailed in the 2015 COP Phase II Report in Appendix D – “COP Phase II Alternatives” (USACE 2015) and is incorporated here by reference. The criteria agreed on between NMFS and the Corps determined whether the alternatives were: (1) biologically beneficial, (2) technically feasible, and (3) cost

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Detroit Downstream Passage Project DRAFT Environmental Impact Statement effective. The COP primarily utilized cost effectiveness criteria to prioritize actions across the WVS. The COP primarily screened alternatives for downstream passage and temperature control at Detroit Dam based on the biological and technical criteria. The COP investigations for Detroit Dam culminated in a Detroit Downstream Passage Engineering Documentation Report (EDR) completed in 2017 (USACE 2017), incorporated here by reference. Additionally, the public requested several new alternatives for analysis during the NEPA scoping process. The Corps assessed these alternatives using the established screening criteria (see Appendix A for details). In all, the Corps assessed 21 alternatives for temperature control, eight alternatives for fish collection, three alternatives for fish transport, seven alternatives for construction, and eight alternatives for staging areas for the Project at Detroit Dam. The Interim Alternatives Report provided in Appendix A describes all alternatives considered and the screening analysis process and outcomes. To begin, the Project team developed an initial array of alternatives for providing downstream passage and temperature control. The COP prioritized and screened these alternatives for further engineering analysis using a qualitative evaluation of each alternative under biological, technical, and economic/other considerations. The Corps utilized the Project’s objectives and constraints to develop screening criteria (described in Appendix A). The objectives of the Detroit Downstream Passage Project include: • Provide for implementation of downstream passage and continued operation of existing associated upstream passage facilities so that any above-dam fish-reintroduction effort is able to sustain itself on average over time. • Improve water quality below Detroit Dam in the North Santiam and mainstem Santiam Rivers such that water temperatures meet targets optimized for adult and juvenile salmonids and the number and severity of total dissolved gas (TDG) exceedances are minimized. Project constraints represent restrictions that limit the range of alternatives the Corps can propose. The Corps identified the following project constraints: • Actions will not result in a reduction of the Corps’ ability to operate the dam for the flood risk management authorized purposes. • Actions will meet Corps dam safety requirements. • Actions will maintain the Willamette Project’s other authorized purposes (hydropower, recreation, etc.) over the long term. The Corps also used qualitative analysis of economic/other considerations in this initial phase of screening to eliminate alternatives that are impractical. For example, the one temperature control alternative considered early on is to pump warm surface

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Detroit Downstream Passage Project DRAFT Environmental Impact Statement

water from the reservoir over the dam to meet temperature targets. However, the Corps quickly screened out this alternative as the pool fluctuation and the resulting need to raise millions of gallons of water several hundred feet in elevation, an impractically large pump capacity and energy cost would be required.

Following this initial screening process, the Corps further developed the designs for each of the remaining alternatives and evaluated these based on a quantitative engineering analysis using a variety of evaluation tools. Based on this quantitative analysis, the Corps further screened the alternatives down to those considered reasonable. This analysis included determining whether an alternative met the Project objectives or violated a project constraint. If an alternative did not meet at least one of the Project objectives or violated a project constraint, the Corps screened it out. Additionally, in order for an alternative to meet the purpose and need, it could not preclude either downstream temperature control or downstream fish passage. Therefore, the Corps screened out all temperature control and downstream passage alternatives that were not combinable and, therefore, unable to meet both objectives. The Corps considered the remaining alternatives to be reasonable alternatives. Appendix A provides a detailed explanation of the screening process.

The Corps ultimately determined that the only technically feasible, reasonable alternative for meeting the purpose and need is a selective withdrawal structure (SWS) to control water temperature passing through Detroit Dam and a Floating Screen Structure (FSS) attached to the SWS to collect downstream migrating fish. Fish collected in the FSS would be transported downstream using a truck (e.g. trap- and-haul) with the option to integrate volitional passage in the future if it is determined to be feasible and will meet the project objectives. Sections 2.4 and 2.7.1 fully describe this solution.

Although there is only one reasonable alternative that is technically feasible, meets the purpose and need, and does not violate the project constraints, the Corps identified four reasonable alternatives for constructing this solution. The Corps also identified the alternative construction staging areas. As all staging areas are combinable with each of the construction alternatives, the Corps has assessed these separately and the Corps will combine the preferred staging areas with the preferred construction alternative in the proposed action. Table 3 summarizes the alternatives moved forward for assessment in this EIS. Table 4 summarizes the screening justification for each of the alternatives considered.

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Detroit Downstream Passage Project DRAFT Environmental Impact Statement

Table 3. Alternatives* assessed in the EIS Construction Alternatives (CA) – all CAs would Temperature Control Downstream Passage include the construction of a SWS and FSS Estimated Cost to Construct Estimated Cost to Construct (millions of US dollars) (millions of US dollars) CA1 – No Action $0 $ CA2 – 2 Year Drawdown to 1300 feet (ft), build $100 - $200 $250 completely in the dry CA3 – 1 Year Drawdown to 1300 ft, build $100 - $200 $250 partially in the dry/partially in the wet CA4 – 1 Year Variable Drawdown, build in the $200 - $250 $250 wet CA5 – No Drawdown, build in the wet under $200 - $250 $250 normal Water Control Manual operations (Preferred Alternative) Staging Areas Alternatives (SA) – All SAs are included in CA cost above included in CA cost above combinable with SA1 – Mongold State Park Day Use Area SA2 – Oregon Parks and Recreation Maintenance Yard (Preferred Alternative) SA3 – Detroit Lake Recreation Area *All alternatives would have the same long-term operation and maintenance requirements and, therefore, the same long-term operational costs (Life-Cycle costs). Due to the identical requirements and costs per alternative evaluated, the Life-Cycle costs were not a significant factor of consideration in the EIS analysis.

2.2 ALTERNATIVES CONSIDERED BUT ELIMINATED During the screening process, the Corps considered 21 alternatives for temperature control, eight alternatives for fish collection, and three alternatives for fish transport. Table 4 summarizes the alternatives considered but eliminated and the screening rationale. Appendix A provides details on each of these alternatives and the rationale for their screening. To form a complete Project alternative, the Corps had to combine an alternative from each major Project element in Table 4 (i.e., temperature control, fish passage, and fish transport); thereby a full project alternative would include one of each. Table 4. Alternatives eliminated from further consideration Project Element Alternative Screening Rationale TC 2 - Use Existing Inability to meet downstream temperature targets year round Temperature Equipment – Optimum for all year types. Operations Temperature TC 3 - Restrict Pool TC3 A. Run of river Violates constraints: long-term negative impacts to Temperature during conservation hydropower, water supply, and recreation authorized season purposes. Would also not be able to meet BiOp flow targets.

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Detroit Downstream Passage Project DRAFT Environmental Impact Statement

Project Element Alternative Screening Rationale TC3 B. Delayed Violates constraints: negatively impacts flood risk management Temperature drawdown of the authorized purpose. Negatively impacts downstream spawning reservoir and incubation of ESA listed spring Chinook salmon. TC3 C. Operate Detroit Violates constraints: long-term negative impacts to Reservoir at minimum hydropower, water supply, and recreation authorized Temperature conservation pool purposes. (elevation 1450 ft) year- Inability to improve downstream water temperatures. round TC 4 - Floating (Surface) Violates constraints: Dam safety - would not be structurally Temperature Withdrawal Structure stable in an earthquake. TC 5 - Modify Existing Equipment for Lower Would not meet temperature control and TDG requirements as Temperature Flows (Spillway and a stand-alone design. Regulating Outlet (RO) Gates) TC 6 - Pumps and/or Temperature Aerators in Nearfield Technical feasibility and various water quality issues. Forebay Inability to meet downstream temperature targets year round TC 7 - New Outlets in Temperature for all year types. Does not allow for continuous withdrawal of Dam surface water throughout the range of reservoir fluctuations. TC 8 - Heating/Cooling The size of heating/cooling exchangers required would not be Temperature System for Water practical to implement. Release TC 9 - Pump Water over The amount of pumping required would not be practical to Temperature Dam implement. Violates constraints: flood routing concerns and limitations for TC 10 - Temperature Temperature incorporating fish passage. Control Curtain Effectiveness concerns (see Appendix A for details).

TC 11 - SWS - Single This is a variation of the SWS. The single sliding outlet limits Temperature Sliding Outlet ability to incorporate fish passage.

TC 12 - SWS - Floating This is a variation of the SWS. The outlet configuration prohibits Temperature Outlet with Sliding the ability to incorporate fish passage (see Appendix A for Outlet details). TC 13 - Supplement Would not meet temperature objectives for the project (see Temperature Existing Equipment with Appendix A for details). Simple SWS TC 14 - Modify Existing Not technically feasible to meet the required downstream Temperature Equipment for Higher temperature targets year round for all year types. Head Range TC 15 - Floating Surface Violates constraints: Dam safety - structurally unstable Temperature Outlet Would not meet performance standards for the project Violates constraints - Dam safety risk. TC 16 – Slope Would provide the same or worse performance as TC 1 with Temperature Supported SWS additional risk and cost and without decreasing construction impacts.

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Detroit Downstream Passage Project DRAFT Environmental Impact Statement

Project Element Alternative Screening Rationale TC 17 - SWS located on This is a variation of TC1. The location on the south side of the Temperature the south side of the dam also makes it so any combined downstream passage dam would not meet the downstream passage objective. Would not change temperatures downstream. All the water downstream of Detroit Dam comes from the stratified Detroit TC 18 - Temperature reservoir either through the spillway or the existing outlets in Control Tower on the Temperature Detroit Dam and, therefore, a tower downstream of Detroit downstream side of Dam would not be able to access different levels of water in the Detroit Dam stratified Detroit Reservoir not already available under the existing configuration. Not technically feasible to function with existing dam outlets TC 19 – Modified “Flip” Temperature and to meet the required downstream temperature targets Marine Research Vessel year round for all year types. FC 1 - Head-of- Would not meet fish passage objective (see Appendix A for Fish Collection Reservoir (HOR) details). Collection FC 2 – Annual Deep Would not meet fish passage objective (see Appendix A for Fish Collection Reservoir Drawdown details). FC 3 - Prioritization of ROs under Typical Would not meet fish passage objective (see Appendix A for Fish Collection Winter Reservoir details). Elevations Not significantly different from the FSS carried forward as a FC 4 - Floating Surface Fish Collection reasonable alternative. Main difference is the need for pumps Collector (FSC) require additional cost. FC 5 – Selective Lowered performance and fish passage route may result in Withdrawal Structure Fish Collection substandard survival without modifications if used as a as Fish Passage standalone alternative for downstream passage. Structure FC 6 – Selective Would not meet the required biological performance criteria Fish Collection Withdrawal Structure with substantially greater cost. with Weir Box FC 8 - Floating net capture device that attracts fish by pumped water out of the The amount of pumping required would not be practical to Fish Collection reservoir through a implement. large hose or pipe through the dam spillway

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Detroit Downstream Passage Project DRAFT Environmental Impact Statement

Project Element Alternative Screening Rationale Data are currently insufficient to determine whether volitional high head bypass at Detroit Dam is biologically safe or technically feasible. A high head bypass study is underway to determine if volitional fish passage via bypass is feasible at Detroit Dam. The Corps would evaluate the volitional passage alternatives in a supplemental EA prepared to assess possible environmental impacts of implementation under the following Fish Transport FT 1 - Volitional Passage circumstances: • Volitional passage via bypass is determined to be feasible at Detroit Dam as a result of high head bypass study and • Trap and haul is determined not to provide adequate survival by monitoring performed during the first few years of operations. Infeasible due to flood risk management operation (high Fish Transport FT 3 - Fish Ladder or reservoir elevation variability annually) (see Appendix A for Bypass Channel details). CA 3 – Variable Low High construction cost and increased impacts resulting from Construction Drawdown with longer drawdown required to build coffer dams Temporary Cofferdam CA 6 – Dam within a High construction cost and increased impacts resulting from Construction Dam longer drawdown required to build temporary dams CA 7 – Flood Control Infeasible due to flood risk management operations. The Corps Construction Season (i.e. Winter) must hold water back during floods, which would continually Drawdown flood out the construction area (see Appendix A for details). CA 8 - Pneumatic Construction Infeasible due to water depth (see Appendix A for details). Caisson Construction The reservoir is too shallow in this area to feasible float SA 8 – Dutch Flat Staging Areas prefabricated materials to dam for installation.

2.3 CA1. NO ACTION The Corps is carrying forward this alternative for analysis as required by NEPA to provide a comparison of environmental effects between the no action and the action alternatives. The No Action Alternative would not meet the purpose and need, as the Corps would not take any action to address downstream fish passage. The No Action Alternative is also inconsistent with the 2008 NMFS BiOp RPA, which requires the Action Agencies to, if found feasible, improve downstream fish passage and provide temperature control at Detroit Dam. Implementing the RPA helps to ensure the Corps’ operation and maintenance of the WVS avoids jeopardizing ESA- listed fish species in the Willamette River basin. Under the No Action Alternative, current Corps activities at Detroit Dam would continue with no changes to the function and operation of the existing Detroit Dam and fish facilities described in detail below. A portion of the hatchery component of the DPS of UWR Chinook salmon that are currently transported upstream of the

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Detroit Downstream Passage Project DRAFT Environmental Impact Statement dam to spawn would remain in the tributaries and reservoir as juveniles. These juveniles would experience excessive risk of injury and mortality when passing through existing dam outlets during movement downstream. Because UWR Chinook salmon and steelhead above Detroit Dam would be unable to reach a level of production and survival to achieve population replacement, release of hatchery- origin adult Chinook salmon would continue to supplement the natural-origin UWR Chinook salmon segregated-group annually released to the approximately 4-mile reach above Minto. These releases also serve other purposes as well, including nutrient enrichment and other historic ecological roles. Under the No Action Alternative, there would be no need for a construction staging area, no use of borrow or disposal sites, no construction of access roads, and no improvements at the Minto Adult Fish Facility. The existing facility and roadways would remain intact.

2.4 OVERVIEW OF ALTERNATIVES Although there is only one feasible solution for meeting the purpose and need, there are four reasonable action alternatives for constructing this solution and three reasonable alternatives for the associated construction staging area. Each of these alternatives has a range of potential effects, supporting the using this basis to define the range of alternatives. The Corps has assessed these alternatives in the EIS along with the No Action Alternative. The Corps has identified the proposed construction alternative (CA) and staging alternative (SA) in the EIS. The Corps’ proposed action combines the proposed construction alternative with the proposed staging alternative. Additionally, there are construction activities and long-term operations that the Corps would implement under any action alternatives. The following sections describe each of the construction and staging alternatives as well as the project features common to all. Table 5 summarizes the alternatives and associated Project features. For the Detroit Downstream Fish Passage Project, the Corps’ proposed action is to construct the SWS and FSS without changing normal dam operation under the Water Control Diagram (CA5). The Corps’ proposed action includes the use of the Oregon State Parks Maintenance Yard (SA2) as the major construction staging area.

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Detroit Downstream Passage Project DRAFT Environmental Impact Statement

Table 5. Alternatives and project features Alternative Preferred Construction Activities Operations CA1. No Action No None Current Operations CA2. SWS and FSS • Access And Road • SWS Operations to meet constructed with a two No Improvements downstream temperature year deep drawdown • Construction Of A Boat targets Ramp And Access Road • FSS Operations to collect CA3. SWS and FSS • Construction Traffic downstream migrating fish constructed with a one No • Staging And Concrete • Trap and haul to transport year deep drawdown Batch Plant Areas fish collected at the FSS by CA4. SWS and FSS o Minto North tuck to the fish release site constructed with a one No o Detroit Dam at the Minto Facility and year variable drawdown Operation Yard release them into the CA5. SWS and FSS o Detroit Dam North Santiam River constructed with no Visitors Parking • Maintenance of the SWS, YES drawdown – PREFERRED Lot and Detroit FSS, and fish release site ALTERNATIVE Dam Road • Monitoring and evaluation o Cumley Creek Confluence SA 1. Mongold State Park No • Marine equipment use • Temporary environmental SA 2. Oregon State Parks controls Maintenance Yard– YES • Potential upgrades at the PREFERRED ALTERNATIVE Minto Fish Facility for fish release SA 3. Detroit Lake State • Monitoring and evaluation No Recreation Area

Project design evolution The major difference between each of the construction alternatives is whether and to what degree the Corps would drawdown Detroit Reservoir to facilitate construction of the SWS. Construction alternatives with a shortened or partial drawdown and the alternative with no drawdown would require under water construction. The development of these alternatives resulted in major changes to the design of the SWS structure and the configuration of the FSS and SWS. The Corps originally began the design of the SWS as a detached, stand-alone concrete tower approximately 150 ft upstream of the dam face (Figure 6). The outside dimensions of the tower would be 80 ft by 80 ft and it would be 259 ft tall from the top deck to the bottom of the tower wet well. The inside of the tower would be a generally open wet well for mixing water for temperature control downstream of the dam. The flow out of the tower would be routed through conduits connected to the existing penstocks and regulating outlets at the face of the dam. The conduits

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Detroit Downstream Passage Project DRAFT Environmental Impact Statement would be rectangular, steel framed pressure vessels supported by concrete piers and drilled shafts (Figure 6). A new bridge would provide the primary access and egress to and from the tower. Personnel would access the bridge from the south dam parking lot. The bridge would attach to the top of SWS (Figure 6). Concrete piers and drilled shafts would support each span of the bridge (not shown in Figure 6).

Figure 6. Isometric view of the freestanding SWS, including an access bridge and conduits attached to the dam ROs and penstocks

Under this initial SWS design, the Corps would moor the FSS between the SWS and Detroit Dam (Figure 7).

Figure 7. Initial FSS/SWS Configuration However, the Corps determined that construction of a freestanding tower and the associated conduits and bridge would be high risk and not cost effective for

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Detroit Downstream Passage Project DRAFT Environmental Impact Statement

alternatives requiring underwater construction. Therefore, the Corps redesigned the SWS as a hollow, rectangular concrete structure attached to the upstream face of the dam within the extents of the penstock monoliths, blocks 22 and 23 (Figure 8). The total overall dimensions of the SWS would be 108 ft wide, 40 ft deep, and approximately 370 ft tall. The SWS would have two mirrored halves at the expansion joint between blocks 22 and 23; each half would be 54 ft wide, which is equal to the width of one block. The Corps would anchor the SWS to the upstream face of the dam for its entire height. The top deck of the SWS would be accessible from the dam deck at elevation 1,579. No conduits or bridge would be required under this design, dramatically reducing construction costs.

Figure 8. Isometric view of the attached SWS

The SWS would route the flow out of the tower directly into the existing penstocks. In order to maintain the ability to pass flows out of the tower when the hydropower units are not running, the existing penstocks would need to be bifurcated and new outlet pipes constructed on the downstream face of the dam under this SWS configuration. Figure 9 illustrates the new pipe bifurcations.

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Detroit Downstream Passage Project DRAFT Environmental Impact Statement

Figure 9. Isometric rendering looking southeast of the proposed penstock

Under this refined SWS design, the Corps would moor the FSS on the upstream face of the attached SWS (Figure 10). The Corps would likely design the hull of the FSS so that it is close to Detroit Dam to enable operators to lift the fish pods with a hoist attached to the dam (Figure 10).

Figure 10. Redesigned FSS/SWS Configuration

The redesigned attached SWS with FSS on the upstream face was carried forward for all construction alternatives as the most cost effective design that also reduced implementation risks for alternatives requiring underwater construction (Figure 10). Construction of the 370 ft tall SWS attached to the dam’s face and existing penstock outlets would be complex and challenging. The design will undergo rigorous risk analysis to ensure construction will meet the Corps’ dam safety regulations. The following sections describe the construction activities and associated drawdowns under each construction alternative.

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Detroit Downstream Passage Project DRAFT Environmental Impact Statement

2.5 CONSTRUCTION ALTERNATIVES

CA1. No Action Under CA1, the Corps would not construct an SWS or FSS and would continue current operations.

CA2. SWS and FSS Constructed with a Two-year Drawdown to Elevation 1,300 ft Under CA2, the Corps would construct the SWS completely on dry land. To enable this, the Corps would use the lower ROs to draft the reservoir below the minimum conservation pool to elevation 1,300 ft, exposing an area where the Corps would build the SWS foundation. The drawdown would start in September and the Corps would hold Detroit Reservoir at elevation 1,300 ft (Figure 11) as much as possible for a 28-month period. The lower ROs do not have the capacity to maintain the reservoir at this low level during a moderate to major winter flood(s). There is some risk that the construction site could be flooded. This is unavoidable and may result in construction delay(s) requiring means to accelerate construction to make up for lost time. Once a flood is past, the Corps would draw down the reservoir as quickly as practicable. By lowering the pool for two years, the Corps could build the majority of the structure in the dry. Fish removal activities within Detroit Reservoir may be required during the reservoir drawdown for construction. Therefore, during the reservoir drawdown the Corps would monitor the dewatered areas for fish stranding. At the time of this EIS, the fish monitoring and salvage plan is under development. However, this plan would be similar to the 2016 Fish Salvage Plan for the Debris Removal and Intake Tower Trash Rack Repairs at Cougar Dam on the South Fork McKenzie River (Appendix L). Once the SWS tower is in place, the Corps would allow the reservoir to fill and Detroit Dam to return to normal operations while the Corps performs the remaining work to include installing the mechanical and electrical features. There would be no powerhouse availability for the duration of the SWS construction up until the SWS is operational. Additionally, a hydropower outage would be required during the months of July and August when the Corps connects the FSS to the SWS and commissions it.

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Detroit Downstream Passage Project DRAFT Environmental Impact Statement

Figure 11. Detroit Reservoir drawdown to elevation 1,300 ft under CA2 and CA3

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CA3. SWS and FSS Constructed with a One-year Drawdown to Elevation 1,300 ft Under CA3, the Corps would construct the SWS partially on dry land. As for CA2, the Corps would draft the reservoir below the minimum conservation pool to elevation 1,300 ft. However, the Corps would hold Detroit Reservoir at elevation 1,300 ft (Figure 9) as much as possible for only a sixteen-month period. During the drawdown, the Corps would construct the SWS on dry land, making as much progress on the tower construction as possible in a single year. Excavation and material placement would be the same as describe under CA2. The ability to manage a moderate to major winter flood is limited and the same constraints apply as for CA2. Following the sixteen-month period, the Corps would allow the reservoir to fill and return to normal operations. At this time, the Corps would build the remainder of the SWS either in the dry from floating docks or under water using divers when the pool is at maximum conservation. Construction would continue for year and four months after the drawdown ends. Hydropower outages would be the same as for CA2. Following the 16-month period, the Corps would allow the reservoir to fill and return to normal operations. At this time, the Corps would build the remainder of the SWS either in the dry from floating docks or under water using divers when the pool is at maximum conservation. Construction would continue for 1 year and 4 months after the drawdown ends. Similar to CA2, the concrete structure would be in place while the Corps completes the remaining work to include installing the mechanical and electrical features. There would be no powerhouse availability for the duration of the SWS construction until the SWS is operational. Additionally, a hydropower outage would be required during the months of July and August when the Corps connects the FSS to the SWS and commissions it.

CA4. SWS and FSS Constructed with a One-year Variable Drawdown Under CA4, construction would occur primarily under water. Under CA4, the Corps would start construction of the SWS under water. However, the Corps would drawdown Detroit Reservoir initially to elevation 1,400 to facilitate construction by reducing the water depth in which the initial SWS construction would occur. To enable this, the Corps would use the lower ROs to draft the reservoir. The drawdown would start in September and the Corps would hold Detroit Reservoir at or below elevation 1,400 as much as possible (Figure 12) until spring of the following year. The drawdown would start on September 6 followed by a partial spring refill (starting February 1 of the next calendar year) to a target elevation of 1,455 ft by May 1. In the spring, following the initial drawdown, the Corps would allow the

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Detroit Downstream Passage Project DRAFT Environmental Impact Statement reservoir to raise to elevation 1,450. By having a 1,450 ft reservoir elevation (rather than the 1,300 ft elevation proposed under CA2 and CA3) at the start of the conservation season, the Corps would be able to meet BiOp minimum flow targets by maintaining 1,000 cfs flows out of Detroit Dam in the dry summer months. The reservoir pool elevation would go below initial drawdown level as the Corps releases flows to maintain identified minimum flow targets in the dry summer months. As the reservoir level recedes over the summer months, the Corps would be building up the SWS tower and the tower height would eventually go above the reservoir elevation. When the SWS tower height is above the reservoir elevation, the Corps would be able to build the remainder of the SWS tower in the dry. Figure 13 provides a conceptual graph of the drawdown operations proposed under CA4 and the predicted tower height over time. After 16 months, the Corps would allow the reservoir to refill to typical levels and would resume normal operations. Hydropower outages would be the same as for CA2.

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Figure 12. Detroit Reservoir drawdown to elevations under CA4

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Figure 13. Conceptual graph of reservoir and tower construction elevations under CA4

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Detroit Downstream Passage Project DRAFT Environmental Impact Statement

CA5. SWS and FSS Constructed with no Drawdown CA5 is the Corps’ proposed construction alternative. Under this alternative, Detroit Reservoir would not be drawdown beyond normal operations. The Corps would continue to operate Detroit Dam based on the normal rule curve. The Corps would complete construction under water using divers or from floating barges, as appropriate. CA5 is the preferred alternative because it meets the purpose and need while minimizing the environmental effects of its implementation. Under CA5, there would be no drawdown and construction would be complete while the Corps operates Detroit Dam following the established rule curve. Under normal operations, the reservoir would submerge about half of the proposed structure during low pool. The reservoir would submerge the majority of the proposed structure for about half of the year. Therefore, CA5 would require the Corps to build the majority of the structure underwater using divers. Excavation and fill activities as well as underwater construction activities to build the tower would be the same as under CA4 but would be performed at a greater depth. If the Corps were able to build the tower height above the reservoir elevation, in–the-dry construction would occur from the deck of Detroit Dam and from barges or modular flexi-floats adjacent to the dam and SWS. Once the SWS tower is in place, the Corps would perform the remaining work to include installing the mechanical and electrical features. Hydropower outages would be the same as for CA2.

2.6 STAGING AREAS ALTERNATIVES Under all CAs, the Corps would assemble the project in two phases. The Corps would construct the SWS and ancillary sites in the first phase and the FSS in the second. A construction staging area would be utilized for the assembly of the FSS. The Corps may also use this staging area to precast concrete blocks and assemble segments of the SWS to be floated into place for alternatives requiring under water construction (CA3, CA4, and CA5). The Corps is considering several alternative locations for this staging area. Under each of these alternative locations, the staging area would be on the reservoir shoreline below the ordinary high water mark. In the first phase, once assembled, the Corps would be able to launch the completed segments of the SWS into the reservoir, move these to the SWS operation location using towboats, and install them, building up each component until the facility is complete. In the second phase, the Corps would use prefabricated modules to construct the FSS and the FSS mooring dolphins. The Corps would have these modules transported over public roads to the staging area where the Corps would assemble the entire FSS. Once complete, the Corps would launch the FSS like a barge and move it to the SWS using tugboats where the Corps would moor the FSS to the mooring dolphins and

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connect the FSS to the SWS. Once installed, the Corps would remove the staging pad and restore the area to pre-construction condition. Construction activities at the staging area can be broken into two subareas: (1) above Detroit normal high pool and (2) below normal high (within the reservoir). Construction activities above pool would be minimal and mostly temporary in nature. Above pool activities may include temporary construction access improvement to/from OR-22 to the staging site to improve traffic safety due to trucks entering and leaving the highway. In addition, the Corps would park temporary construction trailers at various locations around the site. Upon completion of FSS assembly, the Corps would remove temporary facilities. The greatest construction disturbance would be within the area typically flooded at normal high pool. The largest component to be constructed is a large basin approximately 200 ft by 300 ft in size. The Corps would excavate this basin down to an approximate elevation of 1,530 ft to allow the Corps to float the FSS out during the summer months. Based on geologic mapping, the Corps assumes the excavated materials to be silt to gravel sizes of glacial or fluvial origin. The Corps would design the excavated slopes to be stable, preventing possible slides and unplanned disturbances from construction assembly. In addition, the Corps would employ best management practices (BMPs) on all exposed soils to control erosion. The Corps would use materials from the excavation of the basin to construct an enclosed cofferdam, with a maximum height of about 40 ft and on the order 1,750 ft in length. Once the cofferdam is built the Corps will dewater the area inside perform fish salvage. The purpose of the cofferdam is to protect the construction site from flooding. The Corps may riprap the outward face of the cofferdam with large imported rock to prevent wave erosion and to reduce turbidity. Once the FSS assembly is complete, the Corps would remove the cofferdam and allow the basin to fill so that the Corps could float the FSS and tow it to the SWS for installation. At completion, the Corps would remove the cofferdam and return the shoreline back to its original contours.

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Figure 14. Example footprint shown for the Oregon State Parks Maintenance Yard Assembly Staging Area Alternative

Construction activity taking place within the basin may include general welding, forklift and earth moving traffic, track crane operation and foot-traffic. The Corps would employ BMPs to avoid spills, leaks and other debris from entering the reservoir. Environmental protection plans would include prevention as well as clean up measures in case of a spill or other unforeseen occurrence. The Corps evaluated the environmental effects of locating the staging area at three alternative sites, as described below. Appendix B provides the initial site evaluation and trade off analysis for these areas, including an additional site, the Dutch Flats Day Use Area (referred to as the Detroit Flats Day Use Area in Appendix B). The Corps screened out the Dutch Flats Day Use Area early in the process because the reservoir is too shallow in this area to enable the launch of the FSS. The Corps would identify the preferred staging area and combine it with the preferred construction alternative to complete the proposed action.

SA1. Mongold State Park Mongold Day-Use Area is a state park located on Corps property but administered by the Oregon Parks and Recreation Department (OPRD) (Figure 15). It is located on the OR-22 about 3.5 miles west of the town of Detroit and about 4 miles east of Detroit Dam. Facilities include a boat ramp, swimming area, fishing area and picnic area. In addition to the parking area, at low water there is significant space available with a gentle slope toward the water.

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Under SA1, the Corps would place the proposed cofferdam just off shore of the public swimming area (Figure 15). The access point to the site provides good construction access except for the stopping site distance approaching the entrance. The site distance is an important safety factor for trucks carrying heavy loads on the highway. Construction vehicles would utilize much of the available parking. The Corps would store equipment and materials on the grassy area upstream of the Mongold parking lot. SA1 currently has a minimal amount of trees and vegetation that the Corps would need to clear to make room for a staging site. The site is not located within a classified wetland according to the National Wetland Inventory. A developed day use area, the site would require minimal restoration to achieve its original aesthetic following construction. SA1 is the steepest of each of the alternative staging sites, which increases the risk of long-term erosion and would require larger amounts of excavation and grading work. Due to safety concerns during construction, the Corps would likely need to limit or preclude public access at the site, including at the boat ramp. The Mongold boat launch is one the most high traffic areas on the lake since it is one of the only public boat launching locations on the lake. Use of SA1 would also effect State Park Rangers who use the boat launch for their own vessels.

Figure 15. Mongold State Park - proposed staging area outlined in red

SA2. Oregon State Parks Maintenance Yard SA2 is the preferred staging alternative (Figure 16). The Oregon State Parks Maintenance Yard (Maintenance Yard) is located ¾ of a mile north of Mongold, on the OR-22. The Corps would most likely use the southern half of the Maintenance Yard but extend down to the water. There are two main gates to the Maintenance Yard separating it into two sides. The Corps is considering constructing the cofferdam in an offshore area off the west side of the Maintenance Yard where there are some picnic tables, an old shed, a brush pile, and trailer parking used by the park employees. The area is mostly flat with easy access to the highway.

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Detroit Downstream Passage Project DRAFT Environmental Impact Statement

The Maintenance Yard would require clearing of a large amount of vegetation and some old growth trees that are not possible to replace within a short time frame. The site is not located within a classified wetland according to the National Wetland Inventory, however, creating a staging site here would form some scarring to the land. The currently forested south side of the Maintenance Yard would be much barer following construction, even after the Corps plants new trees following construction. The current grade within the site would not be a big risk for future erosion but, with a large amount of vegetation being removed, temporary erosion control measures would be required. The Maintenance Yard is not within close range of any sensitive recreational or residential zones compared to the other sites. There is always a chance that some utilities could exist close to the site, but there are no obvious concerns within the Maintenance Yard. The Maintenance Yard is very close to the State Park maintenance facilities, which could easily cause some disruption to operations; however, it is feasible to allow the facility to be operational during the project. The main access point to the Maintenance Yard has a safe approach - the only concern is heading northbound around a bend before reaching the access point on the OR- 22. The Maintenance Yard has less overall space and more site preparation work than the other sites. However, geographically, this site provides a feasible construction area that presents the smallest disruption to the local community and visitors. The site is very close to the state park’s maintenance facilities, therefore, either the Corps would share the space with OPRD or OPRD would temporarily relocate the facilities. It appears feasible to provide an access road, staging, and lay down areas without completely relocating the maintenance facility.

Figure 16. Detroit Lake State Park's Maintenance Yard Staging Area Alternative - proposed staging area outlined in red

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SA3. Detroit Lake State Recreation Area The Detroit Lake State Recreation Area (Figure 17) is located 1.8 miles north of Mongold, on the OR-22 across the highway from the USFS Detroit Ranger Station. The site is a campground run by the USFS on Corps property that offers 300 camping sites, horseshoe pits, a basketball court, a volleyball area, and a playground. There are two courtesy boat ramps, two removable boat moorages, and a fishing dock. Under SA3, staging space would be upland in the area of some existing campsites, camp loops A and B, which would require demolition during construction. The proposed cofferdam location is just off shore of camp loops A and B. The Corps would access the site through the campground, which has two entrances. The highway is straight and flat in the area of the proposed access road, so the Corps does not have any sight distance safety concerns. This site would require clearing of the campground. The Corps would need to remove some trees and vegetation from the campground to use some upland areas of this site for access and staging. Following construction, restoration would restore the vegetation, campsites, and trees. However, the Corps would likely be required to remove some old, large trees, which cannot be replaced. This site is not part of a protected wetland area according to the National Wetland Inventory. Existing grades at the site are mostly flat, which limits the risk of erosion due to removed vegetation. The Corps would construct the cofferdam off the campground beach and the upland access and staging would be immediately adjacent to part of the campground. This has a negative effect on the recreational experience of campers, and the overall serenity of a popular outdoor recreation spot. It is also possible that the Corps would have to demolish some campground utilities and restore them once construction is completed. Slopes at this site are slightly less than at SA1 and SA2, so the cofferdam height may be slightly less, depending on the exact location. In addition, the Corps would have to construct an additional launch road/slipway to transport the FSS down to launch level at elevation 1,540 ft.

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Figure 17. Detroit Lake State Recreation Area Alternative - proposed staging area outlined in red

2.7 PROJECT FEATURES COMMON TO ALL ACTION ALTERNATIVES

Project Components and Operation The major project components include: • the SWS (the size, configuration, and ancillary structures would depend on the alternative construction methods described in section 2.4.1); • the FSS (described below); • improvements to the Minto Fish Facility to accommodate a fish acclimation and release site; • continued operations of the Minto Fish Facility to collect, transport, and release upstream adult migrants; • road improvements; • boat ramp for construction and operations access; • debris management; • fish conveyance via truck transport; and • flexibility to accommodate volitional pipe bypass.

SWS Features and Operation The Corps would operate the SWS for temperature control in all alternatives by directing inflow into the SWS wet well through two types of intakes: high intake weirs (HIW) that allow for surface inflow and low intake gates (LIG) that allow for inflow from deep in the reservoir. The water would pass from the wet well through the penstocks or ROs and into the tailrace, mix in the Big Cliff Reservoir, and be released through Big Cliff Dam, either through the turbine units or over the spillway and into the North Santiam River. By mixing warmer surface water and cooler at- depth water, the SWS would increase the operational capability for the Corps. In this way, the Corps will better meet the dam’s fish and wildlife authorized purpose by

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providing beneficial flows and increased water quality in the form of downstream temperature management to meet temperature targets while continuing to meet the Corps’ other authorized missions. The Detroit powerhouse includes two turbine units each rated at 50 MW. The Corps operates the powerhouse to provide power during peak demand, with one unit operating at 50 MW or both units operating with a total generation of 100 MW. During off-peak hours, when demand is low, the Detroit powerhouse is generally not operating. The SWS would generally operate for powerhouse flows. The water would mix in the wet well from the HIWs or LIGs or a combination of intakes, depending on temperature targets, and be released from the SWS into the powerhouse penstocks. When the powerhouse is not operating, the SWS operation would depend on the SWS configuration associated with the construction alternatives discussed in Section 2.4.1.

SWS Effectiveness Monitoring and Evaluation Currently, the Corps funds the U.S. Geological Society (USGS) to monitor/measure continuous TDG, temperature, and flow data downstream of Detroit Dam4. The Corps also continuously measures temperature at various depths in the reservoir. All data is telemetered to a real-time network and available instantly on the web5. This monitoring would continue before, during, and following project construction The goal of the project is to meet temperature targets downstream of Big Cliff Dam while providing downstream fish passage and minimizing impacts to the Detroit Project’s authorized purposes. The Willamette Fish Operations Plan (WFOP) and Section 3.6 of this EIS identify the monthly temperature targets for the North Santiam River below Big Cliff Dam. Temperature targets are based on species and life stage. These targets were originally developed and implemented on the South Fork McKenzie River at Cougar Dam for spring Chinook salmon. Since no winter steelhead are present in the McKenzie subbasin, a review of these targets in comparison to literature-based thermal preferences for winter steelhead indicate that these temperature targets are appropriate for the North Santiam River and meet the needs of both winter steelhead and spring Chinook salmon in the North Santiam

4 https://waterdata.usgs.gov/nwis http://www.nwd-wc.usace.army.mil/dd/common/dataquery/www/

5 http://www.nwd-wc.usace.army.mil/nwp/wm/wq_reports.html https://or.water.usgs.gov/cgi-bin/grapher/graph_setup.pl

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Detroit Downstream Passage Project DRAFT Environmental Impact Statement basin. Design of the SWS would provide flexibility in operation to meet modified temperature targets, if desired. Temperature targets may be refined through regional collaboration in the future as new information is gained to optimize adult migration conditions in the North Santiam River, juvenile rearing downstream of Big Cliff, downstream spawning, egg incubation and emergence timing. The Corps can complete monitoring of downstream water temperature using USGS gages at Niagara or other temperature meters in the North Santiam River where appropriate. Temperature monitoring near the SWS and FSS intakes would be necessary for operations to achieve downstream temperature targets.

FSS Features and Operation The Corps is using data on fish behavior collected at Detroit Dam and Reservoir, as well as other fish passage structures throughout the region, to design the FSS features. For instance, the Corps would connect the FSS to the SWS close to the dam based on data showing the high probability of fish in the reservoir reaching the dam. Data collected at Detroit Dam indicated fish depth varied by species, reservoir elevation, stratification, temperature, and diel period. However, Chinook and steelhead with active tags were shown to be at shallow depths throughout the study periods, which suggest they would be available for passage if a surface route were available. These studies were conducted with hatchery chinook and hatchery summer steelhead intended as wild fish surrogates. These may or may not behave like wild fish in Detroit reservoir, however, the FSS design utilizes data collected in Detroit Reservoir as well as data collected around the region that support FSS design features to maximize fish collection efficiency and survival.The FSS would be designed with surface entrances perpendicular to the dam (utilizing the dam as a guidance featur). The Corps would design the SWS to combine typically warmer surface-flow withdrawals with typically colder, deep low-level withdrawals to meet downstream temperature requirements. The FSS would operate in conjunction with the SWS, whereby all surface withdrawals through the SWS would first pass through the FSS. These operations would require most or all flow from the surface during the spring months from March to May. At other times of the year, smaller percentages of the total flow would pass through the FSS. In the fall, from September through December there may be significant flow through the SWS low-level withdrawals for temperature management. The Corps continues to evaluate the balance of maximizing attraction flow to the FSS at the surface with temperature management downstream for adult migration, spawning, incubation and emergence, as well as juvenile rearing conditions. The FSS would collect fish from the surface water flow that enters the SWS. For these operations, the Corps would connect the FSS to the two SWS HIWs. The FSS would move vertically with the annual forebay fluctuation cycle. Downstream

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Detroit Downstream Passage Project DRAFT Environmental Impact Statement migrating fish are attracted to flow because it indicates a potential downstream passage point; therefore, the Corps expects flow through the FSS into the SWS to attract migrating fish. Using screening passages within the FSS, it would safely screen the collected fish and prevent them from going through the FSS/SWS connection, into the SWS, and through the two Francis turbine units. These screening passages would direct the captured fish into fish transport pods (large holding tanks) within the FSS. Before the FSS passages direct captured fish into the pods, sorting bars would separate the large fish from the smaller fish to reduce predation while on the facility. Once the fish are in pods, the Corps would lift the pods via monorail and onto a fish transport truck which would then drive the captured fish to the Minto Fish Facility where they would be released them into the North Santiam River. Trash racks and raking operations at the screen entrances would limit debris (e.g. pine needs, sticks, trash, etc.) from entering the FSS. The FSS would be designed in accordance with the NMFS Fish Passage Design Criteria (NMFS 2011), the Corps’ Fisheries handbook of Engineering Requirements and Biological Criteria (Bell 1990), and The Surface Bypass Program Comprehensive Review Report (Sweeney et al. 2017). The Corps would operate this system so that the FSS collects fish within the entire range of normal reservoir elevations. Figure 18 provides a preliminary schematic of the FSS. The FSS would include the following major features: • The Corps would construct the FSS of steel with an (approximate) overall length of 300 ft, width of 100 ft, and depth (height) of 50 ft. The operating draft would be about 35 ft. • The FSS would sort fish by size and have sampling capabilities within the FSS. • The Corps would seal the FSS to the SWS, but would independently moor it from the SWS via mooring dolphins. • The FSS would be capable of handling flow ranges from 1,000 cfs to 5,600 cfs. The design flow rate for fish collection operations is 4,500 cfs. The 5,600 cfs flow rate is an extreme condition, which the Corps estimates to occur less than 5% of the time. Providing passage between 1,000 and 5,600 covers an adequate range of flow conditions for downstream passage because flow through the FSS is expected to be less than 5600 cfs 95% of the time, and above 1,000 cfs 100% of time (with pumps), including key months for downstream passage. • The Corps would design the FSS to integrate provisions for the future installation of attraction pumps, should the Corps determine the need for fish collection during periods when the turbines are not operated and when no

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flow is passing from the FSS to the SWS. Future provisions for pumped attraction flow would accommodate 1,000 cfs. • Fish would be transported a minimum of one trip per day, however, the design assumes that off-loading will occur more often during peak migration days. Depending on the time of year, fish will need to be acclimated from water temperatures at the collection site to temperatures at the downstream release site. One option is to transfer the fish into the Minto Fish Facility to be acclimated in the existing holding ponds before being released into the North Santiam River through the existing juvenile fish release pipe below Minto Dam. However, various options will be further evaluated as the FSS design progresses. Because data indicates the turbine route provides poor passage conditions with 54.1% survival (48 hour) for surface acclimated fish, the FSS and SWS would exclude the existing turbine intakes as a route of passage (Duncan and Carlson, 2011; Normandeau, 2011). In addition, study data shows a significant number of juvenile-sized targets (Khan et al., 2012) and proportions of Juvenile Salmon Acoustic Telemetry System (JSATS) tagged fish (Kock et al., 2015) entered this route under existing operations, and did so especially during the fall study period in 2013 (Beeman and Adams, 2015). Khan et al. (2012) reported approximately 86.5% of the fish passed through the turbines during the study period of February 2011 to February 2012. The Corps would design the placement of the FSS to avoid this in the future.

The FSS would be compatible with the SWS connected to the dam with minimal disruption to the existing turbine operations. The design would be compatible with trap-and-haul of fish downstream to the Minto Fish Facility and the provision to add 1,000 cfs pumped flow in the future. Turbine operation during power peaking hours would be the primary flow regulating mechanism for fish collection and temperature control. Pumped flow on the FSS would allow it to operate for fish collection when not power peaking, if necessary, based on post-construction biological performance test results. The Corps would connect the FSS to the two SWS HIWs and the FSS would move vertically with the annual forebay fluctuation cycle (rule curve). The FSS would collect fish from the surface water flow that enters the SWS. The FSS would safely filter collected fish from passing through the SWS and the two Francis turbine units. A penstock bifurcation would allow the passage of flow outside of power peaking hours when needed for flood control or when a turbine unit is out of service.

The SWS design provides operational flexibility for temperature control by allowing the HIW access to surface water from 1,425 to 1,570 ft elevation in the reservoir. The SWS and FSS would screen the surface water that enters the SWS,

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meeting (the 90th percentile of annual) power peaking flow rates. The FSS design flow range for meeting NMFS screen criteria is 1,000 to 4,500 cfs with the ability to operate up to 6,200 cfs. This design flow range would maximize the hydraulic signature in the forebay and minimize competing flow since the turbine route would be excluded and large volumes of surface water would pass through the collector into the SWS, encouraging attraction and high fish collection efficiency. However, during storm events, at full pool, it may be necessary to pass water either through the spillway or the ROs, which may lead to competing flows. Once fish enter, the Corps would design the FSS to screen them from most of the water and divert them into to holding pods. The pods could be moved on to a truck for transporting the captured fish downstream for release at the Minto Fish Facility.

The Corps assumes the SWS and FSS performance target for downstream fish passage is to achieve 95% fish collection efficiency (FCE) and 98% survival for fish transported below Big Cliff. This is a widely recognized industry standards that has been shown to be achievable when following the fish passage facility design criteria as specified in the NMFS facility design guidelines (NMFS 2001) and these targets were specifically negotiated for the Cougar Downstream Fish Passage project in the WVS. It should be noted that how FCE and survival are measured has not been specifically defined and will require additional regional discussion with state, federal, tribal, and other stakeholders. The Corps would measure the FCE as the proportion of fish that are collected by the fish passage facility divided by the total number of fish in the “FCE measurement zone”. The FCE measurement zone is an area upstream of the collector entrance in the Detroit Dam forebay which currently hasn’t been defined. The goal of the SWS is to provide operational flexibility so that the Corps can meet temperature targets while also meeting the dam’s other authorized purposes. The goal of the FSS is to provide an attractive surface route to maximize fish collection efficiency and survival. The fish passage criteria and these project goals have been significant design drivers for operations and designing of the systems to be interconnected.

Period of operations, inspections, and maintenance The FSS would operate over the annual cycle with a proposed maintenance from July 1 - August 31. The Corps may extend or shorten the annual maintenance period depending on the scheduled maintenance and environmental conditions. The maintenance period could be shortened if fish collection numbers support continued operations of the FSS after July 1st. Shortening or extending the maintenance period would require coordination with the Willamette Fish Passage Operation and Maintenance team.

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The amount and type of maintenance would vary from year to year and the Corps would adjust the scheduled maintenance period accordingly. The maintenance period takes advantage of the warmer reservoir temperature, which tends to push fish deeper in the water column; thus, fewer fish would be at the FSS depth for collection. During the maintenance period, the FSS would be deballasted for inspections and maintenance and dive inspections may be required to complete inspections below the waterline. In this position, the FSS draft would be small (approximately 6 ft) and all fish system equipment would be above the reservoir elevation and accessible for maintenance. The Corps expects hull maintenance to be minimal over time due to the relatively benign water conditions and limited movement of the FSS. The Corps may accomplish maintenance or repair, depending on the location and nature of the hull work, via barges located adjacent to the FSS with the FSS in the maintenance position (minimum draft). If hull bottom or low-elevation maintenance or repair are required, the Corps would perform work using divers. Daily inspections would be required during fish collection operations. These would consist of trash rack inspections and raking operations for debris at the entrance of the FSS and within the FSS. The Corps would configure the entrance with an adjustable weir with a 2-ft hydraulic drop to achieve capture velocities at the entrance under any flow scenario. Water elevation at this location would be adjusted by the weir through program logic controllers and would be periodically measured for accuracy. The dewatering screens, and possibly elsewhere downstream in the system, would have elevation sensors or points for observation of debris buildup and differentials to ensure proper operation. Visual inspection of the fish holding pods would also occur regularly to ensure fish safety and removal of debris.

FSS Effectiveness Monitoring and Evaluation Short and long-term field studies of juvenile and adult fish would be necessary to evaluate performance of the SWS and FSS. These may consist of active tag studies to evaluate route specific passage and behavior, passive studies with technology such as hydroacoustic and/or DIDSON cameras, and direct capture of juvenile and adult fish at locations to estimate species composition, run timing, and abundance. The Corps would develop the post-construction performance evaluations and monitoring through the regional Willamette Action Team for Ecosystem Restoration (WATER) Research, Monitoring, and Evaluation (RM&E) Team, as required in the 2008 Willamette BiOp, as appropriate. Members of the RM&E program work groups include fish managers with representatives from the Corps, Bonneville Power Administration (BPA), NMFS, ODFW, USFWS, the Confederate Tribes of the Grande Ronde, and the Columbia River Inter-Tribal Fish Commission.

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b. Figure 18. a. Conceptual FSS Design in plan/birds-eye view (numbers denote ft), b. Conceptual FSS Design in profile/cross section

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Fish Transport Operation Under trap and haul operations, at a minimum, operators would off-load fish held on the FSS for transport at least once every 24 hours. This is to ensure that the Corps holds fish for less than one day. During peak migration days, off-loading would occur more often. Using a crane, operators would off-load the transport pods, containing fish held for downstream release, onto a truck and drive the pods to the Minto Fish Facility. The Minto Fish Facility is equipped to temporarily hold and safely release the transported fish to the North Santiam River. Depending on the results of current RM&E studies, fish collected in the FSS may require acclimation before their release into the North Santiam. If the Corps determines there is a need for acclimation, the operators would discharge the fish in the pods into stress relief ponds for temporary holding and temperature acclimation prior to release into the river below Minto. However, other potential options for holding and temperature acclimation may need to be developed.

Continued Operations of the Minto and Marion Forks Fish Facilities

Minto Fish Facility Under all alternatives, the Corps would continue to collect adult spring Chinook salmon and steelhead needed for ongoing fish management activities in the North Santiam subbasin at the Minto Fish Facility, 4 miles downstream of Big Cliff Dam (Figure 1). In addition to collecting adult upstream migrating salmonids, the facility would also continue to sort and handle other resident fish. The Corps owns the Minto facility and ODFW operates the facility under contract with the Corps. The Minto Fish Facility consists of a fish ladder, presort pool and crowder, sorting flume, eight post-sort holding ponds fed by pumps, and many other features that accommodate both holding adult salmon and steelhead as well as acclimation of juveniles. This Project effectively expands spawning and rearing habitat, and would help restore biological connectivity for migrating fish between upstream and downstream habitats. The Minto Fish Facility is a complex system that must be operated carefully to maintain hydraulics for efficient fish passage and holding. Many features of the facility are automated, but can also be operated manually. The Minto Fish Facility operates most of the year except during shutdown, if necessary, for maintenance or other activities. However, the transport period is from 1 April to 15 October (Table 6).

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Table 6. Minto Fish Facility adult transport period and hauling frequency Transport Period Hauling Frequency April 1 – May 15 2 times per week May 16 – June 30 3 times per week July 1 – October 15 2 times per week

Marion Forks Hatchery Once temperature control is operational, the continued operations at Marion Forks would remain unaffected and fish production currently performed would continue uninterrupted (see Section 1.6.1.2). Once downstream passage is established, and natural-origin adult salmonids are routinely placed above Detroit Dam, operations at Marion Forks will require adjustment. Thus far, only hatchery- origin spring Chinook have been outplanted above Detroit. The details of this operation along with the outplanting sites utilized are discussed in sections 2.12.2 and 2.13.1.7. The hatchery draws water from, and is adjacent to, Marion Creek and Horn Creek. Both of these creeks are large enough for adult salmonids to migrate into the area above the hatchery intake. This makes the hatchery’s water supply susceptible to any pathogens the adult fish may be carrying. This concerning breach of biosecurity at the intakes has prompted ODFW to barricade the creeks, downstream of the hatchery intakes, when outplanted adult spring Chinook are present in the system. This period is usually from July to early October when flows in both creeks are relatively stable and lacking major debris. This strategy would be challenged when winter steelhead and natural-origin spring Chinook adults are present above Detroit for much of the calendar year. The flow and debris load in both Marion and Horn creeks would not allow for barricades or weirs to be in place year-round. Consequently, other measures would need to be taken to ensure the biosecurity at Marion Forks remains intact. In 2017, this topic was discussed among subject matter experts at the Hatchery Management Team meetings. A report (Bjork, 2017) was produced that describes the risks and recommended solution.

Construction The following construction elements would be the same for all action alternatives.

SWS Construction Site Preparation Construction of the SWS tower would require foundation preparation including removal of overburden and loose rocks, rock excavation by blasting, cleaning of excavated surface, and concrete placement. Under CA4 and CA5, concrete would need to be piped for placement underwater. The Corps would use the excavated material as fill in the construction of the boat ramp and access road described in Section 2.7.2.3. The Corps would place any remaining material from excavation on

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the reservoir slope and in the deepest water where it would not affect present or future operations of the project (Figure 19).

Figure 19. Proposed excavation and in-reservoir material placement areas adjacent to the SWS site

The Corps would then construct the attached SWS concrete tower (see Section 2.4.1 for details). The Corps could complete the foundation construction by installing formwork like super sacks, concrete blocks, or steel, and then place concrete. The Corps would complete the remainder of the tower construction in a similar fashion. Under CA3, CA4, and CA5, Corps may assemble the formwork at the staging area and float it to the SWS for installation (as described in Section 2.6). It is likely that at some point the Corps would build up the SWS high enough to allow the Corps to build the remainder of the tower in the dry. At that point, in-the-dry construction would occur from the deck of Detroit Dam and from barges or modular flexi-floats adjacent to the dam and SWS. As a BMP, the Corps would install silt fences made of neutral buoyancy geotextiles during excavation, material placement, and construction activities.

Excavation Construction would require three phases of rock and sediment excavation. During all phases of excavation, the Corps would install silt fencing from the dam to the shore to enclose the excavation area in order to contain any resulting turbidity. The first phase of excavation would be on the abutment near North Santiam Highway (OR-22) (Figure 19). The purpose of this excavation would be to remove as much of the loose rocks and soils on top of the weathered rock surface as possible in order to prevent material from eroding and/or sliding down in the future. This

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excavation would avoid the accumulation of sediment at the toe of the slope that could potentially endanger the safety/operability of the floating FSS. The abutment excavation area is away from the penstock intakes and, once complete, the Corps does not expect this excavation to effect dam operations. When the reservoir elevation is lowering, as is typical during the summer conservation season, excavation activities could proceed down the slope utilizing long-reach track hoes as the water recedes. When the pool is rising, as it would in the spring, the Corps would utilize underwater excavation by dredging. The Corps would leave the slope in a natural irregular condition and, within a few years, it would likely become indistinguishable from nearby natural slopes. The second major excavation phase would be the excavation of a benched area for the FSS to float in over the full range of pool variations (Figure 19). The Corps estimates excavating 4,770 cubic yards (CY) for the bench area, of which 7,830 CY is rock requiring blasting. The removal of 4,000 CY of overburden, loosened rocks, and weathered rock is not contingent upon pool level and can be done during winter flood season when the reservoir is normally drawn down to minimum conservation pool (elevation 1,450). Excavation of the rock would likely occur year-round due to the large quantity of material the Corps would need to remove. The Corps could accomplish some of the material removal in the dry (during low pool) utilizing long- reach track hoes. Otherwise, the Corps would remove the material by underwater excavation. The third and final excavation phase would be for the SWS tower foundation (Figure 19). This would require an excavation area of approximately 30 ft maximum by 108 ft. The Corps would likely start at the top of the slope (north end) by blasting and removing rock in small 20-ft benches. The Corps would design blasts to be correspondingly smaller. The main difference with this excavation is that the foundation would be fully prepared for placement of piped concrete over the rock. The Corps would shape the foundation into a series of small benches separated with vertical cuts. The removal of all loose rocks, sand, and silt may require a suction dredge in order to get a clean surface.

Blasting The Corps expects rock excavation to be difficult due to the relatively high unconfined compressive strength of the rock, the steep nature of the deep underwater slope, and the depth of the water (>300 ft). Blasting is the most practical method to remove the necessary rock in a timely fashion. Because of the water depth and the parameters surrounding the rock excavation, the Corps does not expect conventional blasting techniques to be viable under CA4 and CA5. The Corps would have to consult underwater blasting specialists to develop a successful blasting plan and approach specific to Detroit Dam. This blasting plan would have to

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meet all Corps dam safety regulations. In general, the Corps would perform drilling and blasting from a floating plant and, therefore, would have to perform these activities during periods when the pool is relatively stable (e.g. May-November when the pool is near maximum depth). The current rock excavation concept is to blast the bedrock, lowering it in 5 to 10- ft increments. This would require doubling the number of blast holes and a longer period of drilling, however, the tradeoff is that each blast would be smaller with less energy impulse imparted into the water. The Corps would likely begin blasting on the east and south side of the excavation and perform blasting once or twice a day. Once the rock is fragmented and loosened, the Corps would dredge the rock away and dispose of it in a nearby disposal area. The final excavation may appear as a series of underwater benches wrapping around the excavation and the Corps would leave the rock surface in a rough state with no loose rocks. Blasting would require the Corps to continuously monitor and assess dam safety and incidents of aquatic species injuries to refine blasting over time. The Corps may blast in as small increments as practicable to reduce vibration and water impulse shocks. Additionally, the Corps would employ a small precursor blast to scare fish away (as practicable) to mitigate the pressure of underwater shock waves on aquatic species (Keevin 1998).

Excavated Material Disposal The Corps would use the excavated material as fill in the construction of the boat ramp and access road described in Section 2.7.2.3. The Corps would place any excess remaining material from excavation in the reservoir. The Corps would transport the excess excavated material to below elevation 1,350 and dispose of it on the steep slope or in deeper water. Coarser rock fragments (gravel to boulder- size) would settle to the bottom of the reservoir quickly. However, the finer sand, silt, and possibly clay-sized material would take more time to settle out, resulting in localized turbidity. Silt fencing would be set up within the same fenced area described above or in a separate smaller ring around the disposal site to address turbidity resulting from disposal. The material would be disposed of in the center of the silt fence ring to sink to the lake bottom. It is uncertain how deep a floating silt fence would function in the water depth required. The silt fencing may only function for the top 100 feet of water column, which would reduce turbidity at the surface only.

Construction Access and Road Improvements The Project is accessible by Oregon Route (OR-22)/North Santiam Highway No. 162 (No. 162), which extends through the area. Construction activities would require temporary closure of access to Kinney Creek Road (NF-2212) and the forest south

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of Detroit Reservoir across the top of the dam (Detroit Dam Road) for an extended period. The Corps has an agreement with USFS that covers USFS’s right to repair, maintain, use, control, and improve Kinney Creek Road. The Corps also has an agreement with logging companies to provide access across Detroit Dam Road to the forest south of Detroit Reservoir. Detroit Dam Road would be an essential construction site and maintaining access across Detroit Dam Road would significantly reduce the benefit of this site. The Corps needs to maintain regular access to the area south of Detroit Reservoir for USFS and Oregon Department of Forestry (ODF) personnel for fire suppression, emergency response, and forest and road management. Therefore, the Corps must make an alternate route south of the dam onto NF-2212 accessible during construction. The only viable option near Detroit Dam is an old construction road (Southshore Road) located near the southern abutment on the downstream side of the dam (Figure 20). The Corps would need to realign and rehabilitate the Southshore Road to provide alternative access to NF-2212 for emergency vehicles and logging trucks up to the size of interstate semi-trailers (WB-62). The Corps estimates that the rehabilitation of Southshore Road would require 3,450 CY of cut and 10,700 of fill, for a net total of 7,250 CY of fill. The Corps needs a majority of the fill to construct two switchbacks and to repair an eroded slope near the midpoint of the roadway. To access the Southshore Road, a driver must take a road on Corps property to the powerhouse yard. This road junctures with OR-22 on the north side of the North Santiam approximately 1.25 miles downstream of the dam crest. The Corps would need to provide access through a security gate on this road. A bridge west of the powerhouse yard provides access across the North Santiam River. The Corps has determined that the bridge structure is safe for infrequent use by non-permit USFS vehicles, but may require further investigation if it is to be used for the mobilization of logging equipment, large firefighting equipment, or daily construction traffic. Site work may be required due to the limited space and steep vertical curves of the two bridge approaches.

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Figure 20. Southshore Road Improvements

Boat Ramp and Access Road The nearest boat ramp is at Mongold State Park, over 4 lake-miles away from the project location, which is heavily utilized by the public. Therefore, the Corps may construct a new, project-dedicated boat ramp near the dam that would not be accessible to the public. The Corps would use this boat ramp for site access during construction as well as maintenance and crew access once the FSS is operational. The proposed boat ramp follows the alignment of an old construction access road on the south side of Detroit Reservoir (Figure 21). Access to the proposed boat ramp begins over a mile from the Northwest Visitors Parking Lot along USFS road NF-2212. The old construction access road intersects NF-2212 approximately 1,000 ft to the southeast from the edge of the reservoir where the elevation is approximately 1,695 ft. This portion of the road would be cleared of trees, vegetation, and debris and widened to a width of 15 ft. The Corps may place gravel or other wearing course, as necessary, to provide stability and traction. Both the rehabilitated road and proposed boat ramp would require cut and fill to attain the appropriate slope. The Corps would not place fill on existing slopes greater than 60%.To minimize earthwork and construction costs, the proposed grades would mimic the existing topography of the old construction access road, where feasible.

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Upon entering the reservoir at elevation 1,575, the Corps would construct a boat ramp on top of the old construction road. The boat ramp would consist of a 6-inch sub-base below an 8-inch thick reinforced concrete wearing course with 1-inch deep V-grooves for traction and drainage. Wherever feasible, the Corps would contain both sides of the boat ramp by reinforced concrete retaining walls 1-ft thick to prevent undercutting. The boat ramp would follow the topography of the Cumley Creek ravine for the final 650 ft. The elevation of the boat ramp terminus would coincide with the minimum power pool at elevation 1,425 ft. The Corps would construct over-widened turnouts to the boat ramp, cut into the existing surface every 25 vertical feet to allow for vehicle turnaround, and assist in debris removal. These would include an over-widened turnout at the terminus of the boat ramp. During low pool elevations, Cumley Creek would need to cross the boat ramp to enter the reservoir. The Corps would install a series of small diameter half- pipe culverts below the boat ramp in the Cumley Creek ravine to allow for low volumes of water to flow beneath the ramp. Additionally, the Corps would reinforce the boat ramp in this area to allow for high volume flows to pass overtop the ramp and enter the reservoir when the pool elevation is below 1,465 ft. The Corps would need approximately 3,200 CY of cut and 500 CY of fill material to rehabilitate the old construction access road and grade the proposed boat ramp. Additionally, roughly 475 CY of sub-base and 925 CY of reinforced concrete would be required to construct the boat ramp per Corps Engineering Manual (EM) 1110-1-400. Visual inspection of the boat ramp would occur on a regular, ongoing basis once completed. The upper, rehabilitated access road section of the boat ramp that is above the maximum water surface elevation of Detroit Reservoir would remain gravel. This section would require maintenance on an as-needed basis to clear debris and eliminate localized low points through placement of supplemental gravel. Periodic maintenance, including grading of the wearing surface and stabilization of side slopes, may be necessary every 5-10 years. The lower, concrete section of the boat ramp with Detroit Reservoir may require periodic maintenance of the concrete wearing surface every 5-10 years. Maintenance in this section may include concrete patching, joint sealing, crack sealing, or slab stabilization.

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Figure 21. Proposed Boat Ramp and Construction Access Road.

Construction Traffic The Corps anticipates an average of one semi-truck of material or equipment per hour for 8–10 hours per day, up to 16-hour days during high activity times. There would also be 10–30 passenger vehicles for the workers every day. The Corps would take measures to minimize impact on the local traffic and recreational uses of the area. Construction traffic and haul roads would comply with the Corps of Engineers safety manual, EM 385-1-1. This manual specifies use of the “Manual of Uniform Traffic Control Devices” for highway construction signage. The Corps would prepare and implement a traffic control and safety plan that would address access into the project site and staging areas, as well as construction traffic entry and exit points onto OR-22 and other public roads.

Staging and Concrete Batch Plant Areas Construction staging areas are locations used for the storage of construction related equipment and materials, such as vehicles and material stockpiles as well as construction workers’ offices and parking areas. A concrete batch plant would also be required to avoid the need for transporting large quantities of concrete from the nearest urban area for the construction of the SWS. The topography of the area both upstream and downstream of Detroit Dam is a steep canyon, making it difficult to find staging areas. The only work area directly adjacent to the proposed structure is the roadway on top of the dam and the parking lot to the north. The Corps would have to close those two areas to public access during construction. Other possible staging and construction yard areas include the Minto North area, the Detroit Dam operations yard, and the Cumley Creek confluence area, described below.

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Staging areas for construction equipment and material storage are common for all action alternatives. The Corps would utilize these areas for vehicle staging, cleaning, maintenance, fuel storage, and refueling. The Corps would return all disturbed areas to their pre-construction condition at the completion of construction. The staging locations would avoid all designated historic properties and archaeological sites. The Corps would implement BMPs and other spill prevention measures (see Section 2.7.2.6 for details) to prevent and minimize any releases to the environment. During construction, the Corps would install temporary security fencing or other security measures including signage and mobile lighting around the established staging and construction areas to prevent public access and theft. Security measures might also be required around the construction area to keep the public out.

Minto North The Corps purchased the 5-acre property north of the Minto Fish Facility (Figure 22) in 2010 to provide staging, earth disposal, and a septic location for the facility. There is one acre of usable space for staging material. The property is adjacent to Highway 22, 6.5 miles west of Detroit Dam.

Figure 22. Minto North Staging Area

Detroit Dam Operations Yard The Detroit Dam Operations Yard is located downstream of Detroit Dam in an area outside of the powerhouse security fence (Figure 23). Approximately 2 acres would be available for staging. To prepare the site for staging, the Corps may need to make some road improvements and perform site clearing and grading. The yard is located approximately 2,000 ft west of Detroit Dam; however, driving distance from this area to the job site is over 2 miles as the access road from this staging area to OR-22 is approximately 0.8 miles, and the dam crest is another 1.25 miles from the junction.

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Figure 23. Detroit Dam Operations Yard Staging Area.

Detroit Dam Visitor Parking Lot and Detroit Dam Road. The Detroit Dam Northwest Visitor Parking Lot, located immediately adjacent to OR-22 and Detroit Dam Road, is the most useful staging area to support construction (Figure 24). Directly connected to the Detroit Dam Road, the Northwest Visitor Parking Lot provides approximately 0.55 acre for offices, parking, and equipment storing and staging. There would be minimal site improvements needed to ready the site for construction staging use. However, the Corps may widen the parking lot and extend it on the eastern end to provide a platform for fish transport equipment or electrical equipment storage. The Corps would likely use the Detroit Dam Road to position cranes, concrete pump trucks, forklifts, and other material handling equipment. Trucks could then deliver material ready for installation.

Figure 24. Northwest Visitor Parking Lot and Detroit Dam Road Staging Area

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Cumley Creek Confluence The staging area used during the original dam construction was located where Cumley Creek enters Detroit Reservoir southeast of the dam, approximately 1,500 to 2,000 ft south of the SWS construction area (Figure 25). As the reservoir bottom in this area varies from 1,575 to 1,475 ft, a large portion of this area is typically dry during the fall/winter pool levels. There may be more than 6.5 acres available for staging in this area, though the actual space available is dependent upon water levels. Moreover, the area has steep slopes, which would also limit the available area for construction staging to roughly three acres or less without a major regrading effort. The Corps would need to perform road improvements and site clearing and grading to prepare the site for staging. In addition, the Corps would need to construct a temporary cofferdam to isolate the staging area from the reservoir and to prevent flooding of the area. The Corps would dewater the area inside the cofferdam, if it were to be built, and perform fish salvage prior to grading.

Figure 25. Cumley Creek Confluence Staging Area

Marine Equipment The Corps anticipates that marine equipment would be required to support construction. The Corps could use barges or modular flexi-floats to provide staging areas adjacent to the dam and materials staging closest to the jobsite; however, unless just-in-time material deliveries are closely coordinated, this would still require an intermediate staging area.

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Temporary Environmental Controls The Corps would implement erosion and sediment control BMPs to stabilize exposed areas and contain runoff, such as the installation of silt fencing to prevent sediment from construction activities entering wetlands or the surrounding water bodies. BMPs would collect stormwater and remove sediment before the stormwater returns to the reservoir or river. The Corps would mulch disturbed work areas and cover inactive material stockpiles during rains that produce runoff. If the Corps holds any disturbed ground and stockpiles over the winter, they would be protected with fiber-bonded mulch or similar methods to prevent erosion. The Corps would maintain and replace these sediment and erosion control measures as necessary until construction is complete and permanent vegetation and storm runoff control measures are established and effective. Other BMPs that would likely be implemented include containment of equipment fueling areas and locating these areas as far from wetlands or waters as possible to prevent discharges in a spill event. Daily inspections of the fueling area and construction equipment would occur to ensure there are no leaks. The Corps would place oil-absorbing pads, drip pans, or similar devices beneath the equipment when working in waters or staged overnight to catch any leakage. Fuel spill control devices, such as a Wiggins Fast Fuel system or equivalent, would be used. The Corps would substitute equipment hydraulic fluids with biodegradable fluids as appropriate. Special construction measures would be required when working above/near water to prevent pollutant discharges. The Corps would restore areas disturbed during construction to existing conditions upon the completion of work unless stated otherwise in the drawings and specifications The Corps would procure a National Pollution Discharge Elimination Systems (NPDES) construction permit from the Oregon Department of Environmental Quality (ODEQ) to address stormwater discharges from construction sites of 1acre or more. As a part of that permit, an Erosion and Sediment Control Plan (ESCP) would be prepared before construction begins. The ESCP would be prepared in accordance with ODEQ guidance (ODEQ, 2013a and 2013b). The ESCP describes the measures, including BMPs, implemented during construction to control erosion, prevent sediment discharges in stormwater, and minimize the potential for hydrocarbon or chemical contamination of site soils and water bodies. The ESCP would address all areas of disturbance from the construction activities, including equipment staging, material stockpiling, and the concrete batch plant. The contractor must comply with all conditions of the permit and implement the ESCP. The Corps would keep the ESCP on the site and would update it as needed.

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Monitoring Currently, the Corps funds the USGS to monitor/measure continuous TDG, temperature, and flow data downstream of Detroit Dam6. The Corps also continuously measures temperature at various depths in the reservoir. All data is telemetered to a real-time network and available instantly on the web7. This monitoring would continue before, during, and following project construction

Flexibility to Accommodate Volitional Pipe Bypass Fish passage conveyance principally falls into two categories; trap-and-haul (also referred to as truck transport) and volitional bypass. The Corps considered both transport alternatives for how the fish, once collected at the FSS, would be moved downstream of Detroit and Big Cliff Dams. The Corps already utilizes trap-and-haul to transport migrating adults upstream from the Minto Fish Facility, which the Corps sees as a feasible alternative for fish transport. However, there are risks associated with the handling and transportation of juvenile migrants, as well as the potential interruption of maintenance and collection operations and transportation facilities given the long-term nature of these programs. The process of trapping, holding, and transporting the fish can be stressful and recent research on the condition and performance of fish from Cougar Reservoir (Monzyk 2015 and Herron 2017) have raised concerns about the ability of trap-and-haul systems to convey fish safely around the dam. In response to these concerns, the Corps is investigating the feasibility of conveying fish through the dam via a volitional bypass pipe. In order to evaluate the feasibility and applicability of a volitional bypass, the Corps’ Portland District formed the High Head Bypass Team. This team is has developed a draft design parameters document, which would guide the development of bypass alternatives in a separate engineering evaluation. Given that the study is underway and data are currently insufficient to determine whether volitional high head bypass at Detroit and Big Cliff dams is biologically safe or technically feasible, the Corps eliminated this alternative from further consideration for this EIS. However, as discussed in Section 2.6, the Corps would construct the FSS in the second phase of the Project. Therefore, while the Corps completes the SWS in the first four years of project construction, the High

6 https://waterdata.usgs.gov/nwis http://www.nwd-wc.usace.army.mil/dd/common/dataquery/www/

7 http://www.nwd-wc.usace.army.mil/nwp/wm/wq_reports.html https://or.water.usgs.gov/cgi-bin/grapher/graph_setup.pl

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Head Bypass Team would evaluate the feasibility and design concepts with the Detroit SWS/FSS team to determine if volitional bypass would be a viable alternative at Detroit Dam. When the Detroit FSS design effort re-starts following the completion of the SWS, the Corps would update the configuration of the Detroit FSS based on the recommendations of the High Head Bypass Team and incorporate lessons learned from the Cougar FSS. If new information determines volitional bypass is safe and effective, the Corps will work with the WATER partners to determine whether to incorporate volitional bypass. If volitional passage is pursued as a result, the Corps would perform additional NEPA analysis under a supplemental EA to assess any additional environmental impacts of implementing volitional bypass.

Ancillary long-term project operations

Road Maintenance If the boat ramp access road’s surface remains gravel, periodic maintenance of supplemental gravel and regrading every 5–10 years to maintain a suitable wearing surface may be required.

Debris Management Debris such as logs, branches, needles, trash, etc. would be harmful to the operation of the SWS and FSS. Therefore, active and ongoing debris management is critical for the FSS to operate as intended. Debris management on Detroit Reservoir currently consists of a single floating boom to block surface debris from reaching the dam. The existing debris boom is in poor condition and in need of replacement. This debris boom does not extend below the water surface, so debris can move under the boom and float downstream until it reaches the upstream dam face. The current primary method of removing debris from Detroit Reservoir that gets past the existing debris boom is to open the spillways during high pool and allow the debris to pass through the dam. Using the spillway would also be detrimental to the operations of the SWS and FSS. Therefore, the Corps would need to replace the existing debris boom. The Corps may also need to relocate the debris boom or divide it into multiple booms in order to allow for boat access to the FSS. To provide added debris removal, the Corps may include an auxiliary debris boom further downstream near the FSS. Figure 26 shows the proposed locations for new debris booms.

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Figure 26. Proposed Debris Boom Locations

The Corps would replace the existing log boom with a primary debris boom and a Cumley Creek debris boom. The Corps would install the primary and Cumley Creek debris booms during the SWS construction to ensure they are working before installation of the FSS. The primary debris boom would be equipped with a gate to allow the passage of boats. The Corps would remove debris stopped by the log booms from the reservoir using a barge. Operators would drive the barge to the new boat ramp located on the south side of the reservoir. Once at the boat ramp, operators would off-load the debris onto a truck and drive it to the quarry that is located above Cumley Creek for storage (Figure 26). The Corps assumes operators would need to remove debris from the reservoir once a week. Frequency may increase after storm events and decrease during the summer months. Once the FSS is constructed and in operation, operators would place large woody debris collected at the FSS entrance on a debris barge, drive the barge to the new boat ramp, and remove the debris from the reservoir, as described above. Onboard the FSS, operators would collect the smaller floating surface debris caught in the FSS and offload it using the fish transport hoist to be disposed of at a proper facility.

Power The total amount of combined power needed for the SWS and FSS would be approximately 2.4 MW. The FSS would account for 1.9 MW of the total load with the

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remaining 500kW needed for the SWS. The Detroit Dam powerhouse would supply this power.

Operational Environmental Controls The Corps would mitigate the risk of an oil/grease spill into the river during operations of the SWS where feasible. When practicable, the Corps would employ Environmentally Acceptable Lubricants. Floating oil containment booms would be located in close proximity to the SWS to minimize reservoir contamination.

2.8 SUMMARY COMPARISON OF ALTERNATIVES

Table 7 presents a summary of the impacts for the action alternatives the helped drive the decision making process when identifying the preferred alternative. Section 3 of the EIS describes the impacts of the No Action/No Project Alternative for comparison to those of the action alternatives in detail. Table 8 and Table 9 summarizes the environmental effects of the proposed construction and staging activities of each SA and CA, respectively.

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Table 7. Environmental Decision Drivers

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Water Water Supply: Supply: Recreation: Agriculture: Agriculture: Recreation: Recreation: people at estimated indirect direct indirect direct Jobs lost risk of cost to Construction impact Construction impact1 to impact1 to impact due to losing construct Fish and Alt Cost visitor complexity cropland agricultural visitor’s visitor municipal alternative Wildlife Comparison spending irrigators industry willingness spending and water foregone (rounded) (rounded) to pay2 forgone industrial supply (rounded) water facilities availability (millions)3 Minor Extremely impacts to High - listed construction species of large and CA5 CA2 +$100M $0 $0 $3,150,000 $0 0 0 $0 structure aquatic attached to habitat in dam entirely Detroit in the wet Reservoir only 1Direct impact to agriculture are those effects to individual farmers who may experience reductions in irrigation. Indirect impacts are secondary economic impact because of the impact to the local agricultural economy (impacts to labor, services that support farmers, suppliers, food processing, etc.). Totals are computed in Appendix I. Other social effects from direct and impacts to agriculture are described in Appendix K. 2Willingness to pay is the value of recreation to recreation visitors based on a unit day value for fiscal year 2019 (see Corps Economic Guidance Memorandum 19-03). Totals are computed in Appendix H. Other social effects from direct and impacts to recreation are described in Appendix K. 3High risk the City of Salem could not implement design, permitting, financing, and construction of alternative water supply facilities in the timeline of the Project.

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Table 8. Assembly staging area alternative summary matrix IMPACT SA1. Mongold State Park t SA2. Oregon State Parks Maintenance SA3. Detroit Lake State Recreation Area Yard - PREFERRED ALTERNATIVE

Air Quality MINOR - Small, localized reduction in air MINOR - Small, localized reduction in MINOR - Small, localized reduction in quality. air quality. air quality. Noise MODERATE - Moderate, localized MODERATE - Moderate, localized MODERATE - Moderate, localized increases in noise. increases in noise. increases in noise. Geology/ Soils/ Seismology No impacts to seismology No impacts to seismology No impacts to seismology MINOR - Localized, short-term impacts. MINOR - Localized, short-term impacts. MINOR - Localized, short-term impacts. Hydrology/ Hydraulics MINOR - Localized, short-term impacts. MINOR - Localized, short-term impacts. MINOR - Localized, short-term impacts. Sediment Transport/ Turbidity MINOR - Localized, short-term impacts. MINOR - Localized, short-term impacts. MINOR - Localized, short-term impacts. Water Quality MINOR - Localized, short-term impacts. MINOR - Localized, short-term impacts. MINOR - Localized, short-term impacts. Vegetation MINOR - Localized, short-term impacts. MODERATE - Localized, short-term MODERATE - Localized, short-term impacts to vegetation, including tree impacts to vegetation, including tree removal. removal. Fisheries/ Hatcheries NONE NONE NONE

Fish and Wildlife (including MODERATE - Localized, short-term MODERATE - Localized, short-term MINOR - Localized, short-term impacts. Threatened and Endangered impacts. impacts. Species) Water Supply NONE NONE NONE Hydropower NONE NONE NONE Agriculture NONE NONE NONE Recreation SIGNIFICANT - Reduction or cessation of NONE MODERATE - Reduction of visitor visitor access at highly visited location access to campground. Aesthetics MODERATE - Localized, short-term MODERATE- Localized, short-term MODERATE impacts. impacts. Localized, short-term impacts.

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IMPACT SA1. Mongold State Park t SA2. Oregon State Parks Maintenance SA3. Detroit Lake State Recreation Area Yard - PREFERRED ALTERNATIVE Transportation/ Circulation MODERATE - Localized, short-term MODERATE- Localized, short-term MODERATE- Localized, short-term impacts. impacts. impacts. Cultural, Archeological, and The Corps would be required to The Corps would be required to The Corps would be required to Historical Resources perform a cultural resource inventory at perform a cultural resource inventory perform a cultural resource inventory site prior to project implementation. at site prior to project at site prior to project The Corps will consult with State implementation. The Corps will implementation. The Corps will Historic Preservation Office and consult with State Historic consult with State Historic affected tribes to ensure all Preservation Office and affected tribes Preservation Office and affected tribes construction/staging zones are to ensure all construction/staging to ensure all construction/staging inventoried. Any newly documented zones are inventoried. Any newly zones are inventoried. Any newly resources would be evaluated for listing documented resources would be documented resources would be in the National Register. evaluated for listing in the National evaluated for listing in the National Register. Register. Other Social Effects SIGNIFICANT - impacts to recreation at a NONE MODERATE - impacts to recreation. highly visited site Public Health and Safety NONE NONE NONE Climate Change NONE NONE NONE

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Table 9. Construction alternatives summary matrix IMPACT CA2. 2 year drawdown to CA3. 1 year drawdown to CA4. 1 year variable drawdown CA5. Normal Rule Curve elevation 1,300 feet elevation 1,300 feet Operation PREFERRED ALTERNATIVE

Air Quality MINOR MINOR MINOR MINOR Small, localized reduction in Small, localized reduction in Small, localized reduction in Small, localized reduction in air quality. air quality. air quality. air quality. Noise MINOR MINOR MINOR MINOR Small, localized increases in Small, localized increases in Small, localized increases in Small, localized increases in noise. noise. noise. noise. Geology/ Soils/ No impacts to seismology No impacts to seismology No impacts to seismology No impacts to seismology Seismology MINOR MINOR MINOR MINOR localized, short-term impacts localized, short-term impacts localized, short-term impacts localized, short-term impacts to geology and soils to geology and soils to geology and soils to geology and soils Hydrology/ Hydraulics SIGNIFICANT SIGNIFICANT MODERATE NONE Greatly reduced spring and Greatly reduced spring and Variable reductions in summer flows in the North summer flows in the North reservoir pool during Santiam during the 28-month Santiam during the 28-month drawdown. proposed drawdown. proposed drawdown. Greatly reduced reservoir Greatly reduced reservoir pool. pool. Sediment Transport/ SIGNIFICANT SIGNIFICANT SIGNIFICANT MINOR Turbidity Substantially raised and Substantially raised and Substantially raised and Short term increases in persistent sediment load and persistent sediment load and persistent sediment load and reservoir turbidity due to associated suspended associated suspended associated suspended blasting and excavated sediment concentrations and sediment concentrations and sediment concentration and material placement. turbidity. turbidity. turbidity.

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IMPACT CA2. 2 year drawdown to CA3. 1 year drawdown to CA4. 1 year variable drawdown CA5. Normal Rule Curve elevation 1,300 feet elevation 1,300 feet Operation PREFERRED ALTERNATIVE

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IMPACT CA2. 2 year drawdown to CA3. 1 year drawdown to CA4. 1 year variable drawdown CA5. Normal Rule Curve elevation 1,300 feet elevation 1,300 feet Operation PREFERRED ALTERNATIVE

Fish and Wildlife MODERATE to SIGNIFICANT MODERATE to SIGNIFICANT MODERATE MODERATE (including Threatened Significantly reduced Significantly reduced Dewatering of redds Localized, short-term impacts. and Endangered mainstem aquatic habitat. mainstem aquatic habitat. Reduced spawning habitat Long-term beneficial impacts Species) Reduction in upstream Reduction in upstream Water quality (turbidity) and to ESA-listed salmonids from passage. passage. habitat degradation enhanced downstream Dewatered floodplain habitat Dewatered floodplain habitat (sedimentation) passage and temperature (important for chub). (important for chub). Increased stress levels and control. Dewatering of redds. Dewatering of redds. mortality in Chinook and Decreased spawning habitat. Decreased spawning habitat. reservoir fish populations with Delayed upstream migration Delayed upstream migration limited cold water refuge area of adult Chinook salmon, shift of adult Chinook salmon, shift (less than Alts 2&3) in fry emergence, and in fry emergence, and Increased stress levels due to increased stress / mortality of increased stress / mortality of crowding of fish into smaller salmonids in warm water salmonids in warm water areas years. years. Noise and pressure waves Water quality and habitat Water quality and habitat from blasting may displace, degradation (sedimentation) degradation (sedimentation) injury, or kill fish for aquatic environment, for aquatic environment, Long-term beneficial impacts including ESA listed species including ESA listed species to ESA-listed salmonids from habitat and recently delisted habitat and recently delisted enhanced downstream chub habitat. chub habitat. passage and temperature Increased stress levels and Increased stress levels and control. mortality in Chinook and mortality in Chinook and reservoir fish populations with reservoir fish populations with limited cold water refuge limited cold water refuge area. area. Increased stress levels due to Increased stress levels due to crowding of fish into smaller crowding of fish into smaller areas. areas. Noise and pressure waves Noise and pressure waves from blasting may displace or from blasting may displace or injury fish. injury fish.

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IMPACT CA2. 2 year drawdown to CA3. 1 year drawdown to CA4. 1 year variable drawdown CA5. Normal Rule Curve elevation 1,300 feet elevation 1,300 feet Operation PREFERRED ALTERNATIVE

Potential for amphibian Potential for amphibian stranding, a temporal loss of stranding, a temporal loss of wetlands, a decrease in wetlands, a decrease in available waterfowl foraging available waterfowl foraging habitat acreage within Detroit habitat acreage within Detroit Reservoir during drawdown. Reservoir during drawdown. Long-term beneficial impacts Long-term beneficial impacts to ESA-listed salmonids from to ESA-listed salmonids from enhanced downstream enhanced downstream passage and temperature passage and temperature control. control.

Fisheries/ Hatcheries MODERATE MODERATE NONE NONE Increased turbidity will result Increased turbidity will result in stress to fish at the Minto in stress to fish at the Minto Fish Facility Fish Facility Vegetation MINOR MINOR MINOR NONE Short-term increase in in- Short-term increase in in- Short-term increase in in- reservoir wetland species. reservoir wetland species. reservoir wetland species. Short-term sedimentation of Short-term sedimentation of Short-term sedimentation of wetland species downstream wetland species downstream wetland species downstream Short-term desiccation of Short-term desiccation of downstream wetlands. downstream wetlands.

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IMPACT CA2. 2 year drawdown to CA3. 1 year drawdown to CA4. 1 year variable drawdown CA5. Normal Rule Curve elevation 1,300 feet elevation 1,300 feet Operation PREFERRED ALTERNATIVE

Water Supply SIGNIFICANT SIGNIFICANT SIGNIFICANT NONE Reductions in ability of Reductions in ability of Reductions in ability of municipal and industrial and municipal and industrial and municipal and industrial water irrigation water supply irrigation water supply supply providers to serve their providers to serve their providers to serve their customers due to turbidity customers due to low flows customers due to low flows impacts on intake structures. and turbidity impacts on and turbidity impacts on intake structures. intake structures. Hydropower MODERATE MODERATE MODERATE MODERATE Cessation of power Cessation of power Cessation of power Cessation of power production during SWS production during SWS production during SWS production during SWS construction resulting in a construction resulting in a construction resulting in a construction resulting in a value of the energy and value of the energy and value of the energy and value of the energy and capacity loss of $19.09 million capacity loss of $19.09 million capacity loss of $19.09 million capacity loss of $19.09 million annually. annually. annually. annually. Agriculture SIGNIFICANT SIGNIFICANT NONE NONE Reductions in ability of Reductions in ability of irrigation water supply irrigation water supply providers to serve providers to serve 17,000acres of agricultural 17,000acres of agricultural lands due to low flows lands due to low flows Recreation SIGNIFICANT SIGNIFICANT SIGNIFICANT NONE Drawdown levels will make Drawdown levels will make Drawdown levels will make boat ramps inaccessible boat ramps inaccessible boat ramps inaccessible resulting in the loss of water resulting in the loss of water resulting in the loss of water based recreation based recreation based recreation opportunities. opportunities. opportunities. Aesthetics MODERATE MODERATE MODERATE MINOR Short-term impacts due to construction activities.

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IMPACT CA2. 2 year drawdown to CA3. 1 year drawdown to CA4. 1 year variable drawdown CA5. Normal Rule Curve elevation 1,300 feet elevation 1,300 feet Operation PREFERRED ALTERNATIVE

Low levels will result in Low levels will result in Low levels will result in dewatered reservoir would dewatered reservoir would dewatered reservoir would result in the short-term result in the short-term result in the short-term degradation of views at degradation of views at degradation of views at Detroit Reservoir. Detroit Reservoir. Detroit Reservoir. Short-term impacts due to Short-term impacts due to Short-term impacts due to construction activities. construction activities. construction activities. Transportation/ MODERATE MODERATE MODERATE MODERATE Circulation Short-term increases in traffic Short-term increases in traffic Short-term increases in traffic Short-term increases in traffic due to construction activities due to construction activities due to construction activities due to construction activities Detroit Dam Road would be Detroit Dam Road would be Detroit Dam Road would be Detroit Dam Road would be closed over the duration of closed over the duration of closed over the duration of closed over the duration of construction. construction. construction. construction. Cultural, MODERATE TO SIGNIFICANT MODERATE TO SIGNIFICANT MODERATE TO SIGNIFICANT MODERATE TO SIGNIFICANT Archeological, and Attachment of conduits to Attachment of conduits to Attachment of SWS to Detroit Attachment of SWS to Detroit Historical Resources Detroit Dam results in impacts Detroit Dam results in impacts Dam results in impacts to Dam results in impacts to to structure eligible for listing to structure eligible for listing structure eligible for listing in structure eligible for listing in in the National Register. in the National Register. the National Register. the National Register. Exposure during the Exposure during the Exposure during the drawdown of cultural drawdown of cultural drawdown of cultural resources typically inundated resources typically inundated resources typically inundated (risk of degradation and (risk of degradation and (risk of degradation and looting). looting). looting). Other Social Effects SIGNIFICANT SIGNIFICANT SIGNIFICANT NEGLIGABLE Impacts to business and communities from Salem to Idanha that depend on summer recreation tourism

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IMPACT CA2. 2 year drawdown to CA3. 1 year drawdown to CA4. 1 year variable drawdown CA5. Normal Rule Curve elevation 1,300 feet elevation 1,300 feet Operation PREFERRED ALTERNATIVE

Impacts to residents, Impacts to residents, businesses and communities businesses and communities from Salem to Idanha, from Salem to Idanha, including impacts to including impacts to agricultural, food processing agricultural, food processing operations, water supply and operations, water supply and water quality, recreation, water quality, recreation, tourism, businesses, schools, tourism, businesses, schools, and social services. and social services. Public Health and MODERATE MODERATE NONE NONE Safety Low flows during drawdown Low flows during drawdown would negatively impacts the would negatively impacts the ability to provide water for ability to provide water for fire protection to the Cascade fire protection to the Cascade School District. School District. Climate Change MINOR MINOR MINOR MINOR Increased greenhouse gasses Increased greenhouse gasses Increased greenhouse gasses Increased greenhouse gasses during construction due to during construction due to during construction due to during construction due to forgone hydropower forgone hydropower forgone hydropower forgone hydropower production resulting in a production resulting in a social production resulting in a social production resulting in a social social cost of carbon of cost of carbon of cost of carbon of cost of carbon of approximately $11,000. approximately $11,000. approximately $11,000. approximately $11,000.

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Environmentally Preferable Alternative According to the CEQ’s regulations for implementing NEPA (40 C.F.R § 1505.2 (b)), an EIS must identify the alternative or alternatives considered to be environmentally preferable. Ordinarily, this means the alternative(s) that causes the least damage to the biological and physical environment; it also means the alternative(s) which best protects, preserves, and enhances historic, cultural, and natural resources (CEQ 40 Most Asked Questions number 6(a)). The selected alternative does not have to be the environmentally preferable alternative but must demonstrate whether all practicable means to avoid or minimize environmental impacts are included in the selected alternative or that the selected alternative reasonably minimize adverse environmental effects. The Corps considered impacts to all resources and on balance, CA5 is the environmentally practicable alternative. CA5 would have the least environmental effects associated with impacts on aquatic habitats and listed fish species. Conversely, CA2 has the highest impacts on aquatic habitat and listed fish species. Under CA2, the 2-year drawdown to elevation 1,300 would dramatically decrease flow in the North Santiam below Detroit and Big Cliff dams in the spring and summer, especially in hot, dry years. Low flows would reduce instream and floodplain aquatic habitat, impede upstream passage by anadromous fish, and degrade water quality (increased temperatures, turbidity, and sedimentation).

Relationship of Short-term Uses and Long-Term Productivity The short-term uses of the environment described in Section 3 and summarized in Table 8 and Table 9 would result in long-term increased productivity of ESA-listed UWR Chinook salmon and steelhead.

Irreversible and Irretrievable Commitment of Resources Irreversible commitments are those that cannot be reversed, except perhaps in the extreme long term. Irretrievable commitments are those that are lost for a period. Under all alternatives, the Corps would make irreversible and irretrievable commitments of materials (concrete, steel, etc.), funds, labor, and energy in constructing and operation of the SWS, FSS, debris booms, and boat ramp construction as well as in the removal and placement of excavated materials for the SWS and FSS foundation, access road improvements, and boat ramp construction.

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SECTION 3 - AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES The sections below describe the existing conditions of resources that the Corps could affect by implementing the project alternatives described above. The resource descriptions provided below serve as the environmental baseline with which to compare the potential effects of the project alternatives considered in this EIS. The Corps only evaluated those resources potentially affected by the alternatives. Other resources, including land use, mineral resources, public services (i.e. sewer waste, water lines, etc.), and hazardous materials were considered but not carried forward for detailed analysis because these resources would not be impacted through the implementation of the alternatives. Dam safety issues will be addressed during the Project’s final design to meet the Corps’ Engineering Regulation 1110-2-1156 (Safety of Dams, Policy and Procedures) and the Corps’ North Western Division Regulation NWDR 1110-1-3 (Modifications at Existing Corps-Owned Civil Works Projects). This EIS assumes that appropriate dam safety mitigation would be fully addressed in the final design and are not further assessed in this EIS. The EIS evaluates the potential effects for the following resources (the list includes the associated EIS affected environment and environmental consequences section): • 3.1 Air quality • 3.2 Noise • 3.3 Geology, seismology, and soils • 3.4 Hydrology and hydraulics • 3.5 Sediment transport and turbidity • 3.6 Water quality • 3.9 Threatened and endangered species • 3.7 Wildlife • 3.8 Fish and aquatic species • 3.9 Adult fish facilities, hatcheries, and fisheries • 3.11 Vegetation • 3.12 Water supply (including municipal and industrial (M&I) and irrigation for agriculture) • 3.13 Hydropower • 3.14 Transportation/circulation • 3.15 Aesthetic resources • 3.16 Cultural, archeological, and historic resources • 3.17 Recreation • 3.18 Socioeconomics

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• 0 Other social effects (OSE), includes Environmental Justice • 0 Public health and safety • 3.21 Climate change The EIS discussed the range of potential environmental consequences with respect to the context and intensity that the No Action Alternative and the various action alternatives would have on each of the above listed resources in the project area. The Corps evaluated impacts as two categories of effects: (1) direct effects, which occur at the same time and in the same place as the action; and (2) indirect effects, which occur later or at a location away from the action. The EIS describes the intensity of effects as negligible, minor, moderate, and significant. Existing or baseline conditions are used to evaluate and predict the potential effects, both short and long term, resulting from implementing the No Action Alternative or the action alternatives. The period of analysis for direct and indirect effects begins with the construction activities and extends for a duration of 50 years following implementation, the Corps’ prescribed planning horizon. Section 4 discusses cumulative effects, which are additive and include those effects which occur in the past, present, and reasonably foreseeable future. The Corps’ construction of the Detroit Dam initiated fundamental changes to the North Santiam watershed and the Santiam River subbasin, including blocking fish passage between the lower rivers and upstream spawning habitats. In addition, construction of the dam altered stream flows, which affect downstream water quality and the quantity and quality of in-stream and riparian habitats. The resource descriptions provided below serve as the baseline condition (current condition, not pre-dam condition) against which the potential effects of the project alternatives are evaluated in the following sections. For each of the resource categories listed above, the EIS begins with a general description of conditions at the site followed by the potential environmental consequences of staging and each construction alternative. The Corps evaluated the environmental consequences of the No Action Alternative under the assumption that no changes to existing dam operations continue into the future. Environmental consequences under the alternatives describe the state of the project site assuming the Corps implements downstream passage and temperature control actions as described in SECTION 2 - .

3.1 AIR QUALITY The Environmental Protection Agency (EPA) has established human health- based National Ambient Air Quality Standards (NAAQS) for six air pollutants (criteria pollutants): particulate matter (PM10 and PM2.5; particulate matter less than or equal to 10 or 2.5 microns), ozone (O3), carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2) and lead (Pb). For each of the six criteria pollutants, EPA defines the NAAQS and State Ambient Air Quality Standards (SAAQS) as a

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maximum concentration above which adverse effects on human health may occur. EPA classifies geographic areas in which the ambient concentrations of a criteria pollutant exceed the NAAQS as non-attainment areas. Federal regulations require states to prepare statewide air quality planning documents called State Implementation Plans that establish methods to bring non-attainment areas into compliance with the NAAQS and to maintain compliance. EPA refers to non- attainment areas that return to compliance as maintenance areas. No part of the project area is a designated as a non-attainment or maintenance area for criteria pollutants (ODEQ 2013).

Environmental Consequences

Staging Areas All the staging areas described in Sections 2.7.2.5 and 2.6 would experience the environmental consequences on air quality localized to construction areas described below for each of the construction drawdown alternatives.

CA1. No Action The No Action Alternative would have no direct or indirect on air quality.

CA2. SWS and FSS Constructed with a Two-year Deep Drawdown Under CA2, there would be a small, localized reduction in air quality due to emissions from construction equipment. These impacts would be minor and temporary in nature, and would cease once construction is completed. The drawdown proposed under CA2 may have minor effects on air quality in highly localized areas. These would include areas with high organic content in the exposed sediments, thick mucky vegetation or detritus that would exist in areas not usually exposed to oxygen, or newly eroded sediments that overlay organic matter (e.g. mud that moves off an old river bench that had lots of vegetation). Effects would be for a very short-duration (dissipates in less than week). The Total Organic Carbon (TOC) from the 2018 Detroit sediment testing (Appendix C) ranged from 1.00 to 1.82%, indicating relatively low organic content in the surface sediments immediately exposed during a drawdown. The grab sample data forms from 2018 (Appendix C) did note one location (DE-14) with leaves, but they were likely recent settlers and not indicative of mucky, organic sediments over time. For CA2, with a drawdown proposed for multiple seasons/years, the Corps does not expect the aroma to worsen beyond the first drawdown. Reduced generation of hydroelectric power resulting from the drawdown of Detroit Reservoir and a reduction in river flow might indirectly cause additional air

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emissions from thermal power plants8. These facilities, however, would not impair the air quality in the region because they are subject to New Source Performance Standards and permitting requirements that restrict the air emissions from such facilities to ensure that air quality is not degraded.

CA3. SWS and FSS Constructed with a One-year Deep Drawdown Impacts to air quality under CA3 would be similar to those described under CA2.

CA4. SWS and FSS Constructed with a One-year Variable Drawdown Impacts to air quality under CA4 would be similar to those described under CA2.

CA5. SWS and FSS Constructed with No Drawdown Impacts to air quality under CA5 would be similar to those described under CA2 except those air quality effects resulting from exposed sediment, as the Corps is not proposing a drawdown beyond normal operations under the Water Control Diagram under CA5.

3.2 NOISE Marion County Code Chapter 8.45 prohibits noise that exceeds 55 A-weighted decibels (dBA) at any time between 10:00 p.m. and 7:00 a.m. or 65 dBA at any time between 7:00 a.m. and 10:00 p.m., except if the sound producing device is an off- road vehicle. Generally, the ordinance allows the use of construction equipment at normal operating levels between the hours of 7 a.m. and 7 p.m. In the action area, noise does not typically exceed these standards.

Environmental Consequences

Staging Areas All the staging areas described in Sections 2.7.2.5 and 2.6 would experience the environmental consequences by noise localized to construction areas described below for each of the construction drawdown alternatives.

CA1. No Action

8 According to the Northwest Power and Conservation Council’s 7th Power Plan, the most likely thermal generating plant would be a Combined-Cycle Generating Station for On-Peak generation, which is produced at Detroit, Lookout Point, and Green Peter. The remaining Willamette Valley plants operate as Base Load (run-of-river) where the emissions come from a different mix of thermal generating plant types which are powered by a mix of fuels.

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The No Action Alternative would have no direct or indirect on noise conditions.

CA2. SWS and FSS Constructed with a Two-year Deep Drawdown Under CA2, there would be localized increases in noise levels from construction equipment. These impacts would be minor and temporary in nature, and would cease once construction is completed.

CA3. SWS and FSS Constructed with a One-year Deep Drawdown Under CA3, there would be localized increases in noise levels from construction equipment. These impacts would be minor and temporary in nature, and would cease once construction is completed.

CA4. SWS and FSS Constructed with a One-year Variable Drawdown Under CA4, there would be localized increases in noise levels from construction equipment. These impacts would be minor and temporary in nature, and would cease once construction is completed.

CA5. SWS and FSS Constructed with No Drawdown Under CA5, there would be localized increases in noise levels from construction equipment. These impacts would be minor and temporary in nature, and would cease once construction is completed.

3.3 GEOLOGY, SEISMOLOGY, AND SOILS Appendix O provides details on the regional and general site geology as well as the site seismicity and summarized in Sections 3.3.1-3.3.2.

Geologic Setting Detroit Dam is located within the Western Cascades geologic province of Oregon. Western Cascades is an older Oligocene-Miocene range of volcanoes much like the modern day High Cascades to the east. The dam site is located in the North Santiam River canyon. The volcanic rocks in the canyon are mapped as poorly stratified volcanic lava flows, volcanoclastic sediments and tuffs of the Lower Member of the Sardine formation. During dam construction, the Corps excavated and removed all of the overburden and a few feet of weathered rock from the concrete foundation footprint of the dam. Two buried river channels were uncovered during foundation excavation.

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The main river channel thalweg9 was a narrow, deeply incised channel about 60 ft in depth. The Corps removed all gravels and boulders from the channel beneath the dam. A second channel was uncovered at about elevation 1,410 ft on the right abutment. The northern wall of the channel was vertical to overhanging. The Corps filled the channel with glacial deposit. The Corps removed this deposit by blasting and reshaping the overhanging rock. In addition, the relocation of OR-22 involved deep rock cut at the north side of the dam. The Corps used the rock material excavated elsewhere as fill in creek crossings or excess material cast over the side of the road alignment (Figure 27).

Figure 27. Construction photo of right (north abutment) of Detroit Dam

Site Seismicity The three primary seismic sources for Detroit Dam include the Cascadia Subduction Zone (CSZ) Interface, CSZ intraplate, and Shallow Crustal. The most recent major CSZ earthquake occurred in 1700 (Goldfinger et al, 2012). In the relative near term, the moderate magnitudes 5 to 6 earthquake occurring near the site is relatively important, as is the possibility of a large CSZ. However, over a much longer period the CSZ is the dominant source that drives design. For Detroit Dam, a new site-specific seismic hazard study is under contract and the Corps expects its completion by the end of 2019. The Corps would use this study in the seismic design

9 A thalweg is a line connecting the lowest points of successive cross-sections along the course of a valley or river.

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of new work and modifications to existing portions of the dam affected by proposed work.

Reservoir Landslides A few landslides have occurred in proximity to Detroit Reservoir (Figure 28). The largest landslide area is a series of slides in Blowout Creek on the south side of the reservoir. These ancient slide deposits had historic movements that have since ceased. Only two landslides are of significance to this analysis. Both are small slides that directly affect OR-22. The Oregon Department of Transportation (ODOT) has named these slides the Sunken Grade (MP 46) and Mongold landslide (MP 46.32- 46.47). ODOT has documented these slides in various maintenance and study reports. Information is not available to determine if direct winter precipitation on the hill slope above the road or existing Detroit Reservoir pool fluctuations aggravate the slides.

Figure 28. Landslide deposits around Detroit Reservoir (Modified from OR Department of Geology, 2018)

OR-22 Sunken Grade Slide The OR-22 Sunken Grade slide is a small slide that is periodically active during the winter months. GeoStabilization International, Inc. investigated the slide and designs for road stabilization in 2014 for ODOT (Figure 29 and Figure 30).

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Figure 29. OR-22 Sunken Grade Landslide (plan view) (GeoStabilization International, Inc. 2014)

Figure 30. Highway 22 Sunken Grade landslide cross-section (GeoStabilization International, Inc. 2014). Shows repair design

Mongold Slide The Mongold slide is another periodically seasonally active slide that requires constant maintenance. ODOT awarded a contract in 2007 to improve drainage at the Mongold slide as well as other highway improvements. Drainage improvements included a subsurface drain below the existing ditch and installation of 21 horizontal drains drilled into the slide mass below the road. The ODOT completed this work in 2007.

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Environmental Consequences

Staging Areas All the staging areas described in Sections 2.7.2.5 and 2.6 would experience the environmental consequences localized to construction areas described below for each of the construction alternatives resulting in minor to moderate impacts to geology, seismology, and soils. Construction activities at the chosen assembly- staging site would require grading, cuts, and placement of fill. The Corps expects potential slope instability induced by soil cuts to be localized and small scale. Cuts into native soil could induce small localized slope instability if cut too steeply. The Corps expects this hazard to be short term. The Corps would moderate any hazard by minimizing allowable height and angle of cut slopes.

CA1. No Action The No Action Alternative would not change the current geology, the geologic processes would remain the same, and the project area would experience no direct or indirect on geology, seismology, and soils.

CA2. SWS and FSS Constructed with a Two-year Deep Drawdown Under CA2, the Corps expects no impacts to seismology. Neither construction nor operation would affect the earthquake probability, nor would drawdown for construction result in additional impacts should an earthquake occur. The drawdown would reduce the likelihood of downstream flood damage should a structurally damaging earthquake occur during construction. Under CA2, the Corps expects primarily minor, short-term impacts to geology and soils localized to areas where active construction is occurring, including at the staging area. There would be minor impacts to rock slopes adjacent to Detroit Dam, as the drawdown of the reservoir would remove stabilizing hydrostatic forces, potentially inducing instability of the steep rock slopes. Rock fall from unwatering is a higher hazard in jointed and fractured rock. Rock and rock fill excavation could also produce localized instability, particularly within the vicinity of the dike and fault zone. The effects of construction activities on rock stability are short-term (during construction only) and the Corps would mitigate these effects with the installation of both temporary and permanent rock reinforcement. As such, the Corps does not expect construction to produce long-term instability effects in the area. Under CA2, the Corps expects that potentially moderate impacts may occur in areas around the reservoirs edge that have the potential for landslide reactivation due to drawdown. Specifically, the drawdown of the reservoir may temporarily increase the risk of instability of OR-22 and the slide at Mongold. This instability is

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due to the rate of drawdown required and depth of drawdown. Reservoir rim slopes have never experienced deep drawdown of the magnitude that this construction would require. Therefore, there are uncertainties in slope performance. These impacts include landslides or rock falls resulting from the drawdown that require road repair. Damage would probably be limited to horizontal and vertical movements of a few inches to several feet. Landslides within the reservoir area normally move in a relatively slow progressive manner with the initial movement occurring near the toe and progressing upslope over time. The reservoir drawdown rate for the construction drawdown would be limited to 3 ft per day, which would reduce the risk of landslide reactivation. The Corps considers impacts only moderate because the Corps anticipates being able to easily repair any damage to the road if a landslide were to occur.

CA3. SWS and FSS Constructed with a One-year Deep Drawdown Impacts to seismology, geology, and soils under CA3 would be similar to those described under CA2. However, CA3 would reduce the landslide risks compared to CA2 due to the reduced length of time the Corps would keep the reservoir drawn down.

CA4. SWS and FSS Constructed with a One-year Variable Drawdown Impacts to seismology, geology, and soils under CA4 would be similar to those described under CA3. The Corps does not expect blasting activity to cause lands slides and rick slides due to the limited extent and the amount of explosives expected for use.

CA5. SWS and FSS Constructed with No Drawdown Impacts to seismology, geology, and soils under CA5 would be similar to those described under CA2. However, CA5 would eliminate the risk of the reactivating existing slides on OR-22 and Mongold or causing new slides because there is no drawdown proposed beyond normal operations under the Water Control Diagram under CA5. The Corps does not expect blasting activity to cause lands slides and rick slides due to the limited extent and the amount of explosives expected for use.

3.4 HYDROLOGY AND HYDRAULICS

Basin Hydrology The North Santiam basin is in a mountainous region on the western slope of the Cascades (Figure 31). The 435 square mile drainage area above Detroit Dam is composed of terrain ranging in elevations of 1,200-10,495 ft (NAVD 88). The Detroit

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Dam watershed is part of the North Santiam River basin. From Detroit Dam, the North Santiam River flows west approximately 48.5 river miles until it meets the South Santiam River, and becomes the mainstem of the Santiam River. The Santiam River is a tributary to the Willamette River (USACE 2016). With a climate characterized by wet, cold winters and dry, warm summers, the area is subject to frequent winter storms. Peak flows into the reservoir occur because of heavy rains from frequent winter storms augmented by snowmelt on the upper North Santiam River basin. Peak annual one day average flows into Detroit Reservoir have occurred as early as October and as late as June. About 88% of the largest single day, average flow of record has occurred during the months from November through February; about 55% of the annual precipitation occurs during this period. By contrast, less than 10% of the annual precipitation occurs June through September. During the summer months, thunderstorms occasionally occur in the mountains but do not result in significant discharges into Detroit Reservoir (USACE 2016). Figure 32 presents average daily inflows (1960-present) to Detroit Reservoir (USACE 2018a). Detroit Dam is a multi-purpose storage project that operates to meet the authorized purposes of flood risk management, irrigation, power generation, recreation, navigation, fish and wildlife habitat, and downstream water quality improvement. Table 1 provides the pertinent dam data. Big Cliff Dam, which acts as a reregulation project, is 2.8 miles downstream of Detroit Dam. The Corps uses Big Cliff Dam to capture power generation water releases from Detroit Dam in order to control downstream river level fluctuations. The Corps bases regulation of Detroit Reservoir for flood risk management upon maintaining flows below flood stage at Mehama and Jefferson in the Santiam River and at Salem in the Willamette River (USACE 1953). When not executing flood risk management operations, the Corps operates Detroit Dam to meet minimum and maximum flow requirements to support ecosystem and biological functions below Big Cliff Dam in accordance with the 2008 BiOp. Table 10 summarizes flow requirements from the 2008 BiOp. Maximum flows during spawning are 3,000 cfs, if possible. Maximum down-ramping rate guidelines below Big Cliff Dam are 0.1-ft/hour during nighttime and 0.2-ft/hour during daytime (USACE 2018b).

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Table 10. North Santiam 2008 BiOp Flow Requirements Timeframe BiOp Requirement Flow (cfs) March 16 to May 15 Spring spawning flows for winter 1,500 steelhead May 16 to July 15 Winter steelhead incubation flows 1,200 July 16 to August 31 Minimum outflow from Big Cliff 1,000 Dam September 1 to October 15 Spring Chinook salmon spawning 1,500 October 16 to January 31 Spring Chinook salmon incubation 1,200 flows

While the Corps does not specifically draft Detroit Reservoir with the specific goal of meeting BiOp flow targets at Salem since the Corps operates all projects as a system, outflows from the project do contribute to this basin-wide objective. Changes to Detroit’s outflow may affect how the Corps operates the other reservoirs in the WVS to meet the Salem flow target. Figure 32 shows the historical regulated outflows (1960-present). Figure 33 shows daily historical maximum, minimum, and average reservoir elevations (1971-present), along with the annual target elevation (rule curve) (USACE 2018a). The Corps operates Detroit Dam together with the system of twelve other dams in the WVS, and changes to normal operations at Detroit Dam affect how the Corps operates the other dams in order to meet the basin-wide objectives listed above.

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Figure 31. Map of Santiam Basin, including hydropower projects, population centers, and control points

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Figure 32. Detroit Reservoir Daily Average Inflow and Regulated Outflow

Figure 33. Detroit Reservoir Pool Daily Elevation Statistics

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Environmental Consequences Appendix P provides the hydrology and hydraulics simulation results for the alternatives assessed in this EIS including details on how the Corps simulated alternatives and what the modeling assumptions were used. The following sections sumarizes the environmental effects on hydrology and hydraulics for each alternative and includes the results provided in Appendix P by reference.

Methodology and Scale of Analysis The Corps assessed impacts to regulated river flows and reservoir elevations within the Willamette basin using the HEC-ResSim computer model. HEC-ResSim simulates reservoir operations under various hydrologic conditions. The Willamette basin HEC- ResSim model includes all thirteen WVS reservoirs along with the operational rules and constraints at each location, which are designed to achieve both project-specific and system-wide objectives as specified in the project and system Water Control Manuals. For all alternatives, operational conditions and requirements were simulated using historical hydrology over a period of 73 years (1935-2008) on a daily time step. Each simulation applies the same operating rules to all years, and is not meant to reproduce actual data, but rather represent what would have happened every year from 1935-2008 if all thirteen reservoirs existed and operated consistent with a particular alternative’s operational plan for each of those years. The study area includes all thirteen of the Corps dams within the WVS, all river reaches with Corps dams including the North and South Santiam, Middle Fork Willamette, Long Tom, and McKenzie rivers, and selected control points from the southern end of the basin to Oregon City above Willamette Falls. The flow dataset used for analysis includes all of the surface water from the southern end of the basin to (and including) Oregon City above Willamette Falls (RM 26.8). The portion of the Willamette River flowing through Portland, Oregon, is downstream of Willamette Falls and is not included in the reservoir model, and neither is any flow coming into the river downstream of Willamette Falls. The Willamette River below Willamette Falls has a tidal influence that cannot be modeled in ResSim. The analysis compares the ResSim model output for each alternative to those from the No Action Alternative. Outputs analyzed include Detroit Reservoir outflows and river flows at Mehama on the North Santiam River. Operations at other reservoirs mitigate impacts to flows at Salem, therefore, elevations at projects throughout the basin are compared. The analysis looked at whether a change in outflows at Detroit Dam would result in changes to outflows and resulting reservoir elevations at the other WVS dams to maintain flows at Salem. The

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daily average reservoir elevations throughout the basin are compared to the No Action Alternative daily average. To describe the likelihood of future flow and elevation conditions given the implementation of operations described in each alternative, the Corps computed the daily non-exceedance values for Detroit and Mehama flows and Detroit Reservoir elevations at the 5, 10, 25, 50, 75, and 90th percentiles. The simulated pool elevation and outflows in the figures in this section show the target elevation (rule curve) and simulated 5, 10, 25, 50, 75, and 90th percentile elevations at Detroit Reservoir for each day of the years. The probability of non-exceedance curves give the probability that a flow or elevation would not be exceeded on a particular day. For example, the 25th percentile non-exceedance flow value represents the value at which there is a 25% probability that future flow will be less than the given value. Similarly, there is a 75% probability that a flow is equal to or above the value.

Staging Areas No staging areas described in Section 2.7.2.5 would experience hydrology or hydraulic impacts, as they are located above the high water mark. The staging areas described in Section 2.6 would experience the environmental consequences described below for each of the construction drawdown alternatives.

Construction Alternatives System Impacts The WVS is operated as a system to meet flow targets along the Willamette River mainstem. Therefore, changes to a single dam’s operation in the system may result in changes to reservoir levels and outflows at other dams. Figure 34 shows a high-level summary of system operations indicated by the average daily pool elevation at each of the thirteen Willamette Valley Project reservoirs. Each reservoir’s rule curve is shown in black, and the No Action Alternative median daily elevations are shown as a light blue dotted line. The figure shows that the simulated daily average reservoir elevation is generally not exactly on the rule curve. Daily elevations from all alternatives studied are included on this diagram, but details on the other alternatives are provided in later sections.

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CA1. No Action Alternative The No Action Alternative simulation represents current operational conditions. In this simulation, all reservoirs follow regulation rules consistent with current project and system objectives and practices as specified in the Water Control Manuals. There would be no change to reservoir elevation or outflow at Detroit Dam. Appendix P provides details on Dam operations and resulting reservoir elevation and outflows under CA1.

CA2. SWS and FSS Constructed with a Two-year Deep Drawdown Under CA2, there would be significant impacts to hydrology and hydraulics in the North Santiam River due to reduced summer flows in the spring and summer during the 28-month proposed drawdown. CA2 is simulated using operational conditions during construction of the SWS, where the Corps draws down Detroit Reservoir to elevation 1,300 ft to facilitate construction. In this simulation, the Detroit drawdown begins September 6 with refill to the normal rule curve beginning January 5—three calendar years later, for a total drawdown period of 28 months. Compared to the No Action Alternative, reservoir elevations are much lower throughout the year under CA2 (Figure 35). The Corps would maintain flood risk management operations, but minimum flow targets would be reduced from those in the BiOp (which are at least 1,000 cfs) to run of river (outflow would equal inflow). As a result, under CA2, flows in the North Santiam River below Detroit Dam could go as low as 400 cfs in the summer months under the simulated 5th percentile (analogous to the driest years) (Figure 36).The powerhouse is not available, so the Corps would make all releases through the ROs and the spillway. All other Willamette Valley reservoirs would maintain operational rules similar to the No Action Alternative. Winter pool elevations are lower than the No Action Alternative due to the drawdown, generating more space for flood operations. Spring outflows (February through April) would be higher than the No Action Alternative. Under the No Action Alternative, spring flows will be limited in order to facilitate filling the reservoir to meet the Water Control Diagram for the conservation season. Under CA2, the Corps will attempt to maintain the reservoir at elevation 1,300 (Figure 35), therefore the flows that the Corps would hold back for storage in the No Action Alternative are sent downstream in CA2. However, the Corps will limit the increased flows to avoid increasing flood risk downstream.

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Figure 35. Simulated pool elevation at Detroit Reservoir during one year of the 1,300 ft drawdown period (Jan-Dec). These conditions persist for one additional year during the drawdown operations occurring in CA2. The colored lines represent results from each alternative, while the shaded area represents the results from the No Action Alternative.

Figure 36. Simulated North Santiam flow at Mehama during one year of the 1,300 ft drawdown period (Jan-Dec). These conditions persist for one additional year during the drawdown operations occurring in CA2. The colored lines represent results from each alternative, while the shaded area represents the results from the No Action Alternative. 3-122

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Refill back to the normal winter rule curve elevation begins on January 5. If the minimum winter outflow of 750 cfs is maintained during refill, the probability of achieving full refill by May 5 is no less than the No Action Alternative. If minimum winter outflows return to BiOp minimum targets, the probability of refill following the drawdown is 66%, which is a 9% reduction from the No Action Alternative.

System Storage Figure 4 shows a high-level summary of system operations indicated by the average daily pool elevation at each of the thirteen WVS reservoirs. The figure indicates little difference in system operations between the No Action Alternative and CA2. However, during the spring and summer, average pool elevations during the summer are slightly higher (between 0 and 4.4 ft) than the No Action Alternative throughout the basin (except at Detroit, Dexter and Big Cliff). Because Detroit outflows are higher during the spring, other projects in the basin release less water for the purpose of meeting Salem BiOp flow targets, which allows these projects to maintain higher elevations on average.

CA3. SWS and FSS Constructed with a One-year Deep Drawdown Under CA3, there would be significant impacts to hydrology and hydraulics in the North Santiam River similar to CA2 due to reduced flows in the spring and summer but only during the 16-month proposed drawdown. Operationally, the first 15 months of CA3 are identical to CA2. As such, impacts on flow and elevation during the year of drawdown to elevation 1,300 (January through December) are the same as described for CA2 and are compared to the No Action Alternative. See the description of impacts for CA2. Refill in CA3 is also similar to CA2, except it occurs 1 year earlier. Refill back to the normal winter rule curve elevation begins on January 5. If the Corps maintains a minimum winter outflow of 750 cfs during refill, the probability of achieving full refill by May 5 is no less than the No Action Alternative. If minimum winter outflows return to BiOp minimum targets, the probability of refill following the drawdown is 66%, which is a 9% reduction from the No Action Alternative. The regulated flows at Mehama on each day of the year for CA3 compared to the No Action Alternative are identical to CA2 (Figure 36).

System Storage Effects to system storage are the same as those for CA2 but for a single year.

CA4. SWS and FSS Constructed with a One-year Variable Drawdown

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Under CA4, there would be moderate impacts to hydrology and hydraulics due to the variable reduction in pool elevations. CA4 is simulated using operational conditions during construction of the SWS, where the Corps would drawdown Detroit Reservoir initially to elevation 1,400 ft to facilitate construction. The drawdown would start on September 6 followed by a partial spring refill (starting February 1 of the next calendar year) to a target elevation of 1,455 ft by May 1. The Corps would maintain this target elevation until December 1 when the reservoir returns to the normal winter rule curve elevation of 1,450 ft. Reservoir refill occurs in the spring of the following year along the normal rule curve. In this simulation, the minimum flow target is a constant 1,000 cfs, which is a reduction from minimum BiOp flow targets in spring and early summer. All other Willamette Valley reservoirs maintain operational rules from the No Action Alternative. In order to better compare CA4 with the No Action Alternative, Figure 37 and Figure 38 show simulation results for 1 year of operations (January through December), extracted from the 16-month drawdown period and plotted with the No Action Alternative. The gray shaded areas indicate the No Action Alternative results and the colored lines indicate the CA4 results. Compared to the No Action Alternative, reservoir elevations are lower throughout the year. Winter pool elevations are lower than the No Action Alternative due to the drawdown generating more space for flood operations. Spring outflows (February and March) are generally higher than the No Action Alternative, when a portion of the inflows held back for storage in the No Action Alternative are sent downstream in CA4. Model results show there is less than 5% probability that outflow is below 1,000 cfs on any one day. After returning to the normal winter rule curve elevation on December 1, refill begins as usual on February 1. At the initiation of refill, the CA4 pool elevation is likely less than the normal rule curve elevation of 1,450 ft but higher than the elevation at the initiation for drawdown for CA2 and CA3. Therefore, the probability of achieving full refill in the following summer is between that of the No Action Alternative and CA2 and CA3 (between 73% and 66%, respectively).

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Figure 37. Simulated pool elevation at Detroit Reservoir for CA4

Figure 38. Simulated outflows at Detroit for CA4

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Figure 39 shows simulated 5, 10, 25, 50, 75, and 90th percentile regulated flows at Mehama on each day of the year for CA4 compared to the No Action Alternative. For reference, the dashed line shows a flow of 750 cfs. A daily flow above 750 cfs is simulated above 95% of days throughout the year.

Figure 39. Simulated flow on the North Santiam at Mehama for CA4

System Storage Figure 34 indicates little difference in system operations between the No Action Alternative and CA4. However, during the spring and summer average pool elevations are slightly higher (between 0 and 3.1 ft) than the No Action Alternative throughout the basin (except Detroit, Dexter, and Big Cliff). Because Detroit outflows are higher during the spring, other projects in the basin are obligated to release less water for the purpose of meeting Salem BiOp flow targets, which allows these projects to maintain higher elevations on average.

CA5. SWS and FSS Constructed with No Drawdown Under CA5 there would be negligible impacts to hydrology. CA5 is simulated using operational conditions during construction of the SWS, where Detroit Reservoir operates at its normal rule curve with the same operations as in the No Action Alternative, but no flows are released through the powerhouse. All other WVS reservoirs maintain operational rules from the No Action Alternative. 3-126

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There is very little difference between CA5 and the No Action Alternative pool elevation and outflow simulations. Slight differences are a result of the change in total outlet capacity, since no flows go through the penstock to the powerhouse in CA5. Simulations also show very little difference in flows at Mehama between CA5 and the No Action Alternative.

System Storage There is very little difference in system operations between the No Action Alternative and CA5 (less than 0.6-ft at all reservoirs).

3.5 SEDIMENT TRANSPORT AND TURBIDITY

Sediment Transport Construction of Detroit Dam was completed in 1952 and for the past 66+ years the water surface elevation has never been below elevation 1,426 ft during the summer. A considerable amount of sediment has settled in the reservoir since the dam became operational and has never been exposed to erosive velocities. Recent glaciers have cut and eroded, and pulverized rock on the steep volcanic slopes of the basin above Detroit Reservoir. The sediment yield from the upper basin in very high for a Western Cascade stream - the annual yield from Blowout Creek is 600–1000 ton/mi2 and the yield for the Breitenbush River is 300–500 ton/mi2 (Anderson, 1954; Bragg et. al., 2007). In addition, a sizeable fraction of fine-grained sediments in the basin, notably in Blowout Creek basin, are Montmorillonites (high swelling clays that cause high turbidity at relatively low concentrations in surface water). The U.S. Soil Conservation Service estimated annual sediment yield and annual transport rate from the North Santiam Basin at 220 tons/mi2 and 150,000 tons (WBTF, 1969), (USACE, 1954). Using the previous annual load estimate and including a bed load fraction, the approximate mass of sediment trapped by Detroit Dam since 1953 would be 9,000,000 tons. Based on a surface difference calculation (2013 DEM minus 1948 DEM), there is 34,000,000 tons of sediment deposited in the reservoir. Although speculative, much of the volume difference could be attributed to a massive inflow of sediment to the reservoir over a 5-week flood period in late December 1964 to late January 1965. During the December 1964 and January 1965 floods, the USGS calculated the peak suspended sediment discharge of the Santiam River at Jefferson at 255,000 tons/day - with 223,000 tons/day from the South Santiam and the remainder of the instantaneous peak from the North Santiam River. However, recent observations of turbidity suggest that average annual sediment discharges are sensitive to the frequency and magnitude of storms in the basin in any given year. Regardless of inflow to the reservoir, Detroit and Big Cliff Dams prevent the transportation of bed load and

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partially suspended bed material, including fine- and very fine- sands, downstream. Dam outflows only transport fully suspended sediments, silts and clays downstream.

Turbidity When the reservoir is drawn down in the fall, in preparation for flood season, some of the finer grained sediments (silts and clays) deposited in the reservoir can be re- suspended and exported downstream resulting in increased suspended sediment concentration (SSC) and turbidity levels in the North Santiam. The USGS conducted an investigation of major turbidity events in the North Santiam basin from 1999-2004 (USGS, 2007). During a 5-year period, the USGS measured high and persistent turbidity and concomitant high SSCs in three of the largest streams discharging into the reservoir: North Santiam River, Breitenbush River, and Blowout Creek. Investigators calculated the mean annual SSC in the North Santiam River downstream of Detroit Dam at Mehama at 45 parts per million (ppm). While the Corps reported that SSC into Detroit Reservoir would be small (USACE, 1954), subsequent investigators have determined that SSC entering the reservoir can be high, especially during periods of high runoff from the basin caused by rainfall- and rainfall-snowmelt storms. The measure SSC for the North- and South- Santiam were 393 ppm and 2,200 ppm during the 1965 event. As the Corps had not built Green Peter Dam and Foster Dam at the time on the South and Middle Santiam, respectively, Detroit/Big Cliff Dam may be inferred from the USGS data collected at Jefferson during the historic floods. During normal conditions, the Corps draws down Detroit Reservoir from summer pool elevation to the minimum conservation pool (elevation 1,450) at about 3 ft/day. The slow rate minimizes high discharges downstream and mitigates rapid dewatering of side slopes. The pool is at flood control elevation by mid-November or sooner when lowered at the rate described above. In Detroit Dam’s operational history, lake levels have dropped, as result of drought, to just above minimum power pool elevations (1,425 ft) on five occasions – 1969, 1972, 1989, 1997, and the latest in 2015. However, the reservoir has never been drawn down from normal summer pool elevation, about 1,564 ft to very low levels (1,400 ft or less) since the dam began operating in 1953.

Detroit Reservoir Sediments Results of the 2018 sediment sampling physical analysis (Appendix C) indicated that all samples are “elastic silt,” with a median grain size of 4.3, 3.7, and 4.6 micrometers, and a calculated mean grain size of 5.6, 4.73, and 6.03 micrometers, respectively. The Corps measured the percent fines (silts and clay passing a 230 sieve) for the samples at 98.4, 98.2, and 99.0. Overall, no screening levels for metals, polycyclic aromatic hydrocarbons (PAHs), Polychlorinated Biphenyls (PCBs), or pesticides were exceeded at the three sampling

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locations, with the exception of Bis(2-ethylhexyl) phthalate, discussed below. Three compounds were detected for which no screening levels have been established. These include: 1. Benzoic Acid, a common laboratory contaminant, detected at low levels, and flagged as an estimated value at all 3 stations; 2. 4-Metholphenol, detected at a low level at one sample location; and 3. 1,4-dichlorobenzene, detected at low levels at all 3 stations as well as in the laboratory blank. Bis(2-ethylhexyl) phthalate is the only compound that detected above established screening levels, and was found only at one sample location and in the laboratory blank. Multiple lines-of-evidence suggest that this detection is an artifact of the analysis (see Appendix C for details).

Environmental Consequences

Methodology Scale of Analysis The Corps performed hydrodynamic simulations using the numerical model Adaptive Hydraulics (AdH) Model Version 4.6 for North Santiam River at Detroit Reservoir. In addition, the Corps used the Mobile Bed module of AdH to assess the mobility and transport potential of suspended sediment in the reservoirs. Appendix F provides a detailed report on the results of this analysis, including analysis assumptions. To use the AdH, the Corps created a digital elevation model of Detroit Reservoir, Big Cliff Pool, and a short reach of the North Santiam River downstream of Big Cliff Dam. Figure 40 shows the area modeled and a detail of the downstream end of the mesh is presented on the same figure. The upper model region extends from the axis of Detroit Dam to 8–9 river miles upstream, or the approximate backwater limits of the maximum conservation pool.

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Figure 40. Computational mesh domain for Detroit Reservoir (at Detroit Dam), Big Cliff Pool and Dam, and a short segment of the North Santiam River below Big Cliff Dam

The median size bed material below the confluence of the North Santiam and Breitenbush Rivers, from samples collected prior to dam construction, was 120 mm. The sediments in Detroit Reservoir are largely clays and silts and some fine- and very- fine sand. To identify the presence of potential contaminants of concern in Detroit and Big Cliff reservoir sediments, the Corps performed sediment sampling in both reservoirs in 2013 and in 2018. The collected sediment samples were characterized in accordance with the Clean Water Act 404(b)(1) guidelines and the regional dredged material testing protocols found in the 2018 Sediment Evaluation Framework (SEF). In the Pacific Northwest Region (Oregon, Washington, and Idaho), the SEF is used to evaluate the suitability of dredged materials for unconfined, aquatic disposal. Although the release of sediments via a dam drawdown is not “dredging,” the SEF can be used to perform an ecological assessment of the discharge. In a drawdown scenario, the presumption is that released sediments are comparable to an aquatic release of dredged material, and freshwater receptors would respond to contaminants in the same manner. Chemical concentrations in the sediment are compared to regionally accepted benthic toxicity screening levels. The Corps compared the results of the chemical analyses to the Freshwater Screening Levels (screening levels) from the 2018 SEF. For the 2018 sampling effort, particular focus was in the area of the Detroit Reservoir that may be exposed between the minimum conservation pool elevation (1,450 ft) and the lowest alternative proposed drawdown elevation (1,310 ft). Appendix C provides details on sampling methodology, location, and results.

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staging areas described in Section 2.6 would experience the environmental consequences described below for each of the construction drawdown alternatives.

CA1. No Action Under a No Action Alternative, the downstream effects from sediment transport below Big Cliff Dam would be unchanged from current conditions.

CA2. SWS and FSS Constructed with a Two-year Deep Drawdown Under CA2, there would significant impacts to sediment transport and turbidity. During the initial drawdown and the following period of lowered reservoir level operation, deltaic sediment would be suspended and transported downstream. During storms, runoff and fluctuating pool elevations may cause sloughing and sliding (mass wasting), and incision and denudation of exposed reservoir slopes. As exposed reservoir sides consist of much coarser material than found in the reservoir bottom and bedrock, most of the side slope material carried to the lowered pool would settle, or it would be transported short distances as bed load. The area of deltaic sediment deposits newly exposed to erosive forces is 1,307 acres. During drawdown, the sediment load, and associated SSC and turbidity would be substantially raised above baseline levels and those high levels of turbidity would persist for long periods downstream of Big Cliff Dam. For flood control operations, sediment discharge from the dam would be moderately elevated above normal winter operations. Table 11 summarizes the model outputs. Table 11. CA2 sediment transport model outputs Description SSC SSC Persistent Sediment Sediment Sediment Sediment Mean Max Turbidity Discharge Discharge Discharge Total Discharge (ppm) (ppm) Max (FTU) Turbidity Average Outflow Mass Fraction Duration Mass Rate (tons) Discharge

(days) (tons/day) (Sedout/Sedin) Drawdown 758 3211 400 65-70 2900 242,000 - Flood Control 45 278 37 5 718 19,900 0.20 Operations

In lowering the reservoir level to elevation 1,300, the total sediment discharged downstream is 242,000 tons; maximum persistent turbidity is 400 Formazin Nephelometric Unit (FNU) with turbidity elevated above 10 FNU for 65-70 days. The trap efficiency of the dam is 80% when the winter operating pool is elevation 1,300, and turbidity values and duration are moderately higher and longer than during normal winter flood operations. Although the North Santiam is a high gradient stream (32 ft/mile) from Big Cliff Dam (RM 58.1) to near Mehema (RM 39), high to extremely high levels of siltation of inlet 3-131

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works and turbidity affects would occur at the Minto Fish facility (RM 54) during drawdown to elevation 1,300. Low to moderate siltation10 would occur during flood control operations at this pool elevation. Low siltation would be a fractional inch to a few inches while moderate siltation would be up to 1-ft and high to severe siltation would be greater than 1-ft and up to several feet. Because of the North Santiam high gradient, coupled with the discharge of wash load only, channel deposition may be low to moderate irrespective of the large volume of material released during drawdown. Turbidity levels would be very high and of long duration for drawdown and moderate level for a short period during winter operations. If a turbidity event (e.g. bank sloughing, slope failure) were to occur in the summer during a period of minimum releases (750 cfs), the discharge of high SSC (turbidity) downstream is unlikely. Although the hydraulic residence time for CA2 is short (16 days), model results suggest that the trap efficiency of the reservoir remains high even at a very low operating pool elevation. From Mehema to near Stayton (approximately RM 29.5) the stream gradients decrease to about 20 ft/mile. Deposition of silt and clay in the channel, side channels, and diversion may occur. Floodplain and off-channel habitats would likely be more prone to siltation than riverine habitats. Given the low- to no water velocity present in these habitats, sediment is likely to fall from suspension and may accumulate within these locations, as it did in the initial drawdowns of Fall Creek Reservoir. Sedimentation may be particularly high approaching Geren Island. The Cities of Salem and Stayton as well as the Santiam Water Control District (SWCD) have water supply intakes at this location. High to severe siltation and high-to-severe persistent turbidity of long duration would adversely affect these intake works and the associated treatment plants. Additionally, operating the reservoir for flood control at the lower proposed level would cause low to moderate siltation and turbidity affects in the Mehema-Stayton reach. As the North Santiam approaches the confluence with the South Santiam (RM 11.3), and the mainstem Santiam joins the Willamette River, the stream gradient flattens to 10 ft/mile or less. Potentially high to extremely high sedimentation may occur for CA2. Moderate to high turbidity may occur at the confluence and in the mainstem Santiam as well. This sedimentation and turbidity would affect the Sydney Irrigation Collective (SIC) intakes for agricultural water supply located in this area. In this reach, and those reaches upstream, any material settling in the channel will likely become re-suspended

10 Herein, siltation refers to accumulation of sediment in inlet works, such as sumps and pipes; deposition refers to settling of material in the main channel, and side channels. Relative magnitudes (high, low etc.) are qualitative, for comparison only, and subjective. To illustrate the latter, a few inches of siltation (classified as low impact in this report) at a water intake structure could be regarded as a severe problem by an operator. 3-132

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in subsequent years with only backwater and overbank sediments staying in the Santiam long term. Short-term deposition in the lower North Santiam may have an associated short-term increase in flood risk. The increase in flood risk would be limited as high flows would mobilize and transport fine grained material that settled in this reach. Based upon the sediment quality data generated in the 2018 sampling effort (Appendix C), the Corps does not believe the sediment in the forebay of the Detroit Reservoir poses a potentially unacceptable environmental impact due to sediment quality. The Corps does not expect the release of sediment under the drawdown proposed under CA2 to increase dissolved metals or pesticide concentrations downstream of the dam. The Corps did not detect pesticides during the 2018 sampling event. Due to their low concentrations, the Corps expects metals to remain bound to fine-grained sediments. During blasting activities, there would be no impacts other than possible erosion of existing material in the blasting/construction area during rain events or potential flooding. BMPs would be employed to erosion.

CA3. SWS and FSS Constructed with a One-year Deep Drawdown Under CA3, the drawdown, flood control operations, and summer turbidity affects are as described for CA2. An exception to note is that a winter flood/turbidity event is less likely to occur because these conditions will persist over 2 years under CA2. For example, a flood with a 10-year return period has a 10% change of occurring for CA3 and a 19% chance of occurring during the Alterative 2 construction window.

CA4. SWS and FSS Constructed with a One-year Variable Drawdown In order to maintain 1,000 cfs outflows during the summer months of the drawdown proposed under CA4, the reservoir elevation would again go below minimum conservation pool (1,450 ft), reinitiating the suspension and transport of deltaic sediments downstream. Table 12 provides a summary of mass rates, total mass, and maximum suspended sediment concentration turbidity for the North Santiam immediately downstream of Big Cliff Dam under CA4. The results of the model runs shown in Table 12 assume that the Corps would lower the pool to elevation 1,400 ft and maintain it at this level as feasible. However, the Corps would try to raise the pool to at least elevation 1,450 in the spring to maintain required summer outflows of 1,000 cfs. Table 12 represents these conditions under the starting pool elevations (1,400 ft and 1,450 ft). The final pool elevations in Table 12 represent various conditions depending on whether a wet or dry year is experienced.

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The model results for run 1 simulates sediment transport during the initial drawdown. The model result for runs 2a and 2b simulate sediment transport during a low runoff year (dry year), where outflow exceeds inflow to the reservoir and the Corps cannot sustain pool levels over the summer while meeting the 1,000 cfs outflow prescribed under CA4. The model simulates the final pool elevation under this dry year scenario as being between elevations 1,300 and 1,320 ft and estimates suspended sediment discharge for both final pool elevations. Run 3 estimates suspended sediment discharge downstream of Big Cliff during a storm event (sediment inflow event) with Detroit Reservoir at normal winter level. Regardless of construction pool elevation, the Corps would operate the dam for flood control during the late fall and winter. Run 4 captures the sediment transport response of the reservoir at water surface elevations proposed under CA4 during a storm and high sediment inflow (wet year). Table 12. CA4 sediment transport model outputs. Run Description Starting Final pool SSC SSC Persistent Sediment Sediment Sediment pool elevation Mean Max Turbidity Discharge Discharge Discharge elevation (ft) (ppm) (ppm) Max (FTU) Turbidity Average Total (ft) Duration Mass Rate Outflow (days) (tons/day) Mass (tons) 1 Initial 1450 1400 690 3610 440 65-70 2900 242,000 Drawdown 2a Summer 1450 1300 138 490 58 12-14 820 25,000 2b outflow 1455 1320 83 2230 290 18,40,17 1800 109,000 exceeds inflow (dry year) 3 Winter storm 1455 1440 17 36 5 NA 280 4,900 event 4 Summer storm 1400 1390 42 166 23 4 580 16,000 event (wet year)

Drawing down the reservoir to elevation 1,400 exports 25,000 tons of sediment downstream of Big Cliff Dam. The maximum persistent turbidity is 58 FNU persisting for a duration of 12-14 days. During a drought year (run 2b in Table 12), an additional 109,000 tons of fine grained sediment is exported downstream as the reservoir level decreases in response to required summer outflow (1000 cfs) exceeding inflows. Several high turbidity pulses occur over the summer and Table 12 reports the duration of those pulses in run 2b. During flood control operations when the lake elevation is at 1,400 ft, 16,000 tons of sediment is discharged downstream – or about 70% more than for flood operations at normal winter pool elevation. During a turbidity event, the trap efficiency of the dam/reservoir is approximately 84%; and at normal winter pool

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elevations Detroit Dam would retain 95% of incoming sediment. The maximum persistent turbidity is 23 FNU and the duration of elevated turbidity is 4 days. Under CA4, siltation at the Minto Fish Facility would be similar to that under CA2 and CA3. Deposition in the channel, side channels, and diversions may occur, especially approaching Geren Island. Low levels of siltation may occur at water intakes near Stayton and low to moderate persistent turbidity may affect water treatment plants in the Mehama-Stayton reach. The sedimentation impacts of maintaining summer flows in a low runoff year might be nearly as severe as CA2 and CA3. Operating the reservoir for flood control would cause low to moderate siltation and turbidity affects in the Mehama- Stayton reach. In the reach as the North Santiam approaches the confluence with the South Santiam (RM 11.7) and the mainstem Santiam joins the Willamette River, low levels of deposition are possible. Turbidity levels would be commensurate with suspended sediment quantities exported to this reach. During underwater blasting activities, fine material (either overlaying the blasting site or from rock fragmentation) would be suspended in the water column by the blast and carried upward into the water column to the surface by the blast gas bubbles, temporarily increasing turbidity.

CA5. SWS and FSS Constructed with No Drawdown Although the initial construction processes (such as blasting) may mobilize low levels of sediment, the downstream SSC, sedimentation, and turbidity affects would be similar to the No Action alternative. Blasting turbidity impacts would be the same as for CA4.

3.6 WATER QUALITY

Basin Water Quality Detroit Reservoir is a warm monomictic lake that lacks ice cover in the winter, has an extensive single stratification period during the warmest parts of the year, and mixes to become nearly isothermal (possessing a constant temperature) during the coldest part of the year. The ODEQ has designated the North Santiam River as core cold-water habitat to help protect threatened salmonid habitat. Total Maximum Daily Loads (TMDLs) exist on the North Santiam and Santiam Rivers to help minimize negative effects of anthropogenic-sourced discharges that lead to the following: • Unnaturally warm water temperature (not to exceed 16.0 degrees Celsius year- round and 13.0 degrees Celsius during salmon and steelhead spawning [September 1 - June 15] as the 7-day-average maximum). • Extremely low dissolved oxygen values (not less than 11.0 mg/L or 95% of saturation during salmon spawning September 1 - June 15) (ODEQ, 2006).

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Water Temperature Since the construction of Detroit Dam in 1953-1954, the seasonally-filled Detroit Reservoir has affected water temperature downstream as solar radiation is absorbed in the summer and heat is released downstream later in the fall. This alteration (delay/shift) of the natural thermograph has negative consequences for threatened UWR Chinook salmon and steelhead. Water temperatures in Detroit Reservoir depend largely on lake level (pool area), outflow operations, tributary inflow/temperature, and meteorology. Since 2009, the Corps has used the spillway gates (elevation 1,541) to release warm water during the summer, to help minimize unseasonably warm temperatures later in the fall (Figure 41). Prior to 2009, releases from Detroit Dam were primarily from the power penstocks (invert elevation 1,395.5 ft) year-round, which typically led to cooler releases in the summer. The Corps has performed temperature control operations on the North Santiam River over recent years using water temperature targets based on those developed and implemented on the South Fork McKenzie River at Cougar Dam. These target temperatures were originally developed only for UWR spring Chinook salmon since no winter steelhead are present in the McKenzie subbasin. A review of these targets, in comparison to literature-based thermal preferences for winter steelhead, indicate that these temperature targets are appropriate for the North Santiam River and meet the needs of both winter steelhead and spring Chinook in the North Santiam basin (Table 5- 1 in USACE, 2018c). Beginning in 2017, a multi-agency team including ODFW and NMFS developed and adopted new temperature targets (Table 13). These newer targets are cooler than the older targets during June-September. The ODEQ’s Total Maximum Daily Load (TMDL) Monthly Median Target Temperatures exist and are slightly cooler than these newer targets from April through June and in September, but are within the same range for the remainder of the year.

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Figure 41. Long-term 7-day mean of daily max temperature immediately below Detroit Dam, Oregon

Table 13. Detroit / Big Cliff Dams Downstream Water Temperature 2017 Interim and Original Resource Agency Targets (Daily Average)* and ODEQ’s 2006 TMDL Targets (Seven-Day Average) 2017 Interim 2017 Interim Resource Resource ODEQ 2006 TMDL Resource Resource Agency Agency Target Temperatures °F Agency Target Agency Target Target Target Month Temperature Temperature Temperature Temperature Range Range Range Range Maximum °F * Minimum °F * Maximum °F Minimum °F January 42 38 40.1 40.1 No Allocation Needed February 42 38 42.1 41.0 No Allocation Needed March 44 42 42.1 41.0 No Allocation Needed April 46 42 45.1 43.2 41.7 May 50 46 49.1 46.0 45.1 June 54 48 56.1 51.1 49.5 July 55 52 61.2 54.1 55.0 August 55 52 60.3 54.1 55.0 September 54 48 56.1 52.3 51.6 October 52 46 <50.0 <50.0 45.9 November 46 42 <50.0 <50.0 45.9 December 46 41 41.0 41.0 No Allocation Needed

In this EIS, the Corps used within the CE-QUAL-W2 model a hypothetical temperature target based on long-term upstream temperature data (top of the gray- 3-137

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shaded area in Figure 42) to evaluate the relative ability of each alternative to meet a more normative water temperature immediately downstream of Detroit Dam. This hypothetical target represents temperatures that likely occurred prior to the construction of Detroit Dam.

Figure 42. Comparison of the estimated no dam temperature range upstream (“UpstreamMix1977- 2017”: light blue shaded region) and historic temperatures downstream of Detroit Dam (USGS 14181500; “Niagara2008-2017”: pink shaded region). Purple and Green dots are the maximum temperature targets used in this study and operationally 2017-2019, respectively.

Algae production, Dissolved Oxygen, and pH Detroit Reservoir is generally oligotrophic (relatively biologically unproductive), with low nutrient levels available for aquatic plant growth. However, blue-green cyanobacteria blooms dominated by Dolichospermum (Anabaena flos-aquae) can occur May through July and can complicate drinking water quality for the municipal and industrial (M&I) water supply for which there are intakes in the North Santiam River downstream near Stayton, OR. ODEQ has designated Detroit Reservoir to be water quality impaired due to algae. Algal toxins can lead to Oregon Health Authority (OHA) advisories for drinking water and recreational uses, which have been issued for Detroit Reservoir 3 of the last 10 years (2018, 2017, and 2015). OHA advisories are issued based on algal toxin sampling, which has historically been City of Salem, USACE, and

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USGS. In 2018, OHA advisory thresholds became more stringent to match those of the EPA (USEPA, 2015; OHA, 2018). The DO levels in Detroit Reservoir can depend on sediment oxygen demand and biologic productivity (algae growth) and can vary with depth, season, meteorology, and dam operations. The DO concentration generally increases with depth, reaching its maximum concentration at around 100 ft deep, which typically stays constant toward the lakebed. ODEQ has also determined the North Santiam River to be water quality impaired by algae from river miles 47.9 to 56.4 with guidelines stating DO should not fall below 11.0 mg/L or 95% of saturation during salmon spawning (September 1 – June 15). Figure 43 shows the average DO downstream of Detroit Dam (at Niagara). Downstream of Detroit Dam, DO saturation is typically near 100% but can exceed 100% when the spillways are used to release near-surface water for temperature operations.

. Figure 43. 7-day average DO immediately downstream of Big Cliff Dam at Niagara (USGS 14181500) on the North Santiam River.

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North Santiam Point Source Discharges Table 14 lists industrial and domestic surface water discharge permits in the North Santiam basin and Middle Willamette areas affecting the Salem, Oregon vicinity. Dilution is a tool used to mitigate the effects of point source pollution. During extreme low flow conditions, when flow falls below the 7Q10 (lowest 7-consecutive-day average flow event expected to occur once every 10 years, on average; see Table 15), less water is available for dilution to occur (ODEQ 2006).

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Table 14. Point Source Surface water permits in the North Santiam and Middle Willamette basin potentially affecting water quality under extreme low flows in the North Santiam River Legal Name City Facility Type Permit Description Stream Name River Mile City of Gates Gates air/water/solid waste Industrial Wastewater; North Santiam 39.37 Treatment Plant programs NPDES filter backwash River ODFW Idanha operating fish Dairies, fish hatcheries and Horn Creek 72.1 hatchery other confined feeding operations on individual permits Frank Lumber Co., Lyons sawmills and Timber and Wood Products - North Santiam 32.5 Inc. planning mills Sawmills, log storage, River instream log storage. Jefferson, City Of Jefferson sewerage systems Sewage - less than 1 MGD Santiam River 9.3

Stayton, City Of Stayton sewerage systems Sewage - 1 MGD or more North Santiam 14.9 but less than 2 MGD River RainSweet Inc. Salem canned fruits and Industrial Wastewater; Willamette 83 vegetables NPDES cooling water River Oregon Fruit Salem canned fruits and Industrial Wastewater; Willamette 84.6 Products LLC vegetables NPDES cooling water River Oregon Salem correctional All facilities not elsewhere Mill Creek 2.5 Department Of institutions classified which dispose of Corrections process wastewater (includes remediated groundwater) - Tier 2 sources NorPac Foods, Inc. Stayton frozen fruits, juice, Food/beverage processing - Mill Creek 18.5 vegetables Medium. Flow between 0.1 MGD and 1 MGD, or flow greater than or equal to 1 MGD for less than 180 days/year RainSweet, Inc. Salem frozen fruits, juice, Industrial Wastewater; Willamette 78.2 vegetables NPDES cooling water River Holiday Salem management Industrial Wastewater; Unknown 0.24 Retirement Corp services NPDES cooling water

First Premier Salem nonresidential Industrial Wastewater; Unknown 0.79 Properties construct, nec NPDES cooling water

Saif Corporation Salem other business Industrial Wastewater; Pringle Creek 3 services NPDES petroleum hydrocarbon cleanup

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AmeriCold Salem refrigerated Industrial Wastewater; Claggett Creek 4.9 Logistics, LLC warehousing NPDES cooling water

Covanta Marion, Brooks refuse systems All facilities not elsewhere Willamette 71.7 Inc classified which dispose of River non-process wastewaters City of Aumsville Aumsville sewerage systems Sewage - less than 1 MGD Beaver Creek 2.5 with discharging lagoons Marion County Brooks sewerage systems Sewage - less than 1 MGD Willamette 71.7 and Brooks with discharging lagoons River Community Sewer District

Table 15. ODEQ defined 7Q10 Streamflow values in which the dilution from point source discharge permits for the North Santiam, Santiam, and Willamette Rivers TMDL 7Q10 7Q10 7Q10 16 Jun- 16 May- 15 Oct- Critical Period 31 Aug 14 Oct May 15 Stayton (North Santiam River; USGS 14183000) 863 - 1090 Jefferson (Santiam River; USGS 14189000) 1010 1010 1960 Salem (Willamette River; USGS 14191000) 5630 5630 6540

Environmental Consequences Appendix E provides the water temperature simulation results for the alternatives assessed in this EIS including details on how the Corps simulated alternatives and what the modeling assumptions were used. The following sections detail the environmental effects on water quality for each alternative and includes the results provided in Appendix E by reference.

Methodology and Scale of Analysis The Corps assessed current water quality conditions through analysis of historic measurements and studies concerned with Detroit Reservoir as well as the North Santiam River downstream of Big Cliff Dam. Water temperature is assessed quantitatively using 2-dimensional hydrodynamic models (CE-QUAL-W2) of Detroit Reservoir (Sullivan et.al, 2007; Buccola, et.al, 2016) and North Santiam-Santiam River (Sullivan and Rounds, 2004) downstream to evaluate and highlight the major differences among alternatives in this EIS. The CE-QUAL-W2 models have been previously developed and calibrated to observed conditions. While a CE-QUAL-W2 model of Big Cliff Reservoir exists, the Corps did not use it in this study due to time and resource constraints. The thermal effect of the re-regulating Big Cliff Reservoir is 3-142

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generally minor. The Corps used a daily average of outflow discharge and water temperature from Detroit in place of the Big Cliff model. The Corps assessed dissolved oxygen (DO) qualitatively, based on ancillary information from sediment transport discussions in Section 3.5. The study area includes Detroit Reservoir and the North Santiam River downstream of Detroit Dam. The Corps’ analysis of thermal effects from Detroit Dam operations in this EIS covers the North Santiam River from Detroit Reservoir to the confluence with the South Santiam and Willamette Rivers. The analysis covers primarily three downstream locations (N. Santiam River at Niagara [USGS 14181500 RM 57.3], N. Santiam River at Mehema [USGS 14183010 at RM 37.6], N. Santiam River at Greens Bridge [USGS 14184100 at RM 14.6], and Santiam River at Jefferson [USGS 14189050 at RM 9.6], (USGS, 2019)) where long-term datasets are available at USGS gaging stations. The Corps used two representative calendar years to assess thermal affects in a cool-wet year (2011) and a drought year (2015) in which extremely warm air temperatures existed, especially during June. These two hydrologic and meteorologic boundary conditions allow an upper and lower bound of what might be expected with the operational and structural changes at Detroit Dam and Reservoir proposed within the alternatives of this EIS. The Corps has addressed algal growth and DO effects qualitatively in this document.

Staging Areas No staging areas described in Section 2.7.2.5 would experience water quality impacts, as they are located above the high water mark. The staging areas described in Section 2.6 would experience the environmental consequences described below for each of the construction drawdown alternatives.

CA1. No Action

Water Temperature Under the No Action Alternative, dam operators would continue to maintain outflows and reservoir levels in accordance with requirements described in the Water Control Manual (USACE, 1964b) and continue temperature control operations described in Section 3.6.1.1. Thermal impacts to Chinook and steelhead (delays in upstream spring migration timing; earlier egg emergence compared with pre-dam conditions) would continue.

Algae production, Dissolved Oxygen, and pH Under the No Action Alternative, impacts to algae production, DO, and pH are similar to those described in Section 3.6.1.2.

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North Santiam Point Source Discharges Under the No Action Alternative, there would be no impacts to point source discharges.

CA2. SWS and FSS Constructed with a Two-year Deep Drawdown Under CA2, there would be moderate impacts to water quality due to increases in downstream temperatures, greater diurnal variation of DO and pH in the reservoir and downstream, increase risk of toxic algae blooms, and downstream water quality degradation from point source discharges in the form of temperature, nutrient, and biochemical oxygen demand pollution.

Water Temperature CA2 would have moderate effects on reservoir water temperatures and water temperatures downstream during the 2-year drawdown. Under CA2, a lower reservoir level of about 1,300 ft (smaller volume of water stored in Detroit Reservoir) and reduced streamflow downstream of Detroit Dam compared with the No Action Alternative would result in warmer conditions in summer, especially in a low-flow year such as 2015 (see Appendix E for detailed results). However, due to the reduced volume in Detroit Reservoir, it may “turn-over” sooner than at normal pool elevations. A reservoir turn over would result in cooler release temperatures from Detroit Dam in the fall, especially in low-flow years. Lower flows under CA2 compared to the No Action Alternative would likely result in faster equilibration with ambient air conditions downstream, so downstream warming could be exacerbated in CA2 in an extremely warm fall. Conversely, downstream warming in CA2 could be less than the No Action Alternative in an extremely cool fall. The timing of warmer temperature releases in the fall (September-November) would likely coincide with fall storm events. These impacts would persist into the second year of the drawdown proposed under CA2

Algae production, Dissolved Oxygen, and pH Under CA2, increased suspended sediment derived from increased scour at lower pool levels could lead to persistent turbidity as described in Section 3.5. The addition of fine sediments to Detroit Reservoir could provide an additional nutrient source (Phosphorus) for blue-green algae (blue-green algae Nitrogen limited). This could result in greater diurnal variation of DO and pH in the reservoir and downstream. Downstream from Detroit and Big Cliff dams, water quality would likely be the lowest of the alternatives in this EIS due to low streamflow during late summer and fall. These impacts would persist into the second year of the drawdown proposed under CA2

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North Santiam Point Source Discharges Under CA2, permitted surface water discharge may negatively affect water quality in the North Santiam region (i.e., Mill Creek), and Middle Willamette River in the form of temperature, nutrient, and biochemical oxygen demand pollution if streamflow in the North Santiam River falls below the 7Q10 values in Table 15 (ODEQ 2006). Extreme low flows in the North Santiam River and Mill Creek may negatively affect operations for facilities/permittees in Table 14 and operations for facilities with stormwater permits not listed in this document, should North Santiam River flow fall below the 7Q10 values.

CA3. SWS and FSS Constructed with a One-year Deep Drawdown Under CA3, water quality impacts would be identical in detail to water quality impacts in CA2, but lower in total due to the limitation of a 1-year drawdown.

CA4. SWS and FSS Constructed with a One-year Variable Drawdown Under CA4, there would be moderate impacts to water quality due to increases in downstream temperatures, greater diurnal variation of DO and pH in the reservoir and downstream, and an increased risk of toxic algae blooms.

Water Temperature Under CA4, water quality impacts would be similar in detail to water quality impacts in CA3, but with minor differences. A 1,400-ft Detroit Reservoir elevation would have a greater surface area and volume compared to a 1,300-ft Detroit Reservoir elevation, thereby capturing more solar energy in summer comparatively. Under CA4, the Corps would draft the reservoir beginning in September. During late summer and early fall, this would lead to unseasonably warm water temperatures. The timing of this warm surge could be exacerbated and, dependent on the timing of fall storm events, likely earlier in the fall (September-October) and higher in magnitude than the No Action Alternative. This could lead to a greater number of days above 60° in August-September compared to the No Action Alternative. Water temperatures under CA4 would likely be near or below No Action Alternative temperatures during November-May.

Algae production, Dissolved Oxygen, and pH Impacts to cyanobacteria, DO, and pH would be assumed to be similar to CA2 and CA3. Downstream from Detroit and Big Cliff dams, water quality would likely be lower than the No Action Alternative, but not as detrimental as CA2 and CA3 based on streamflow values during late summer and fall (Appendix E).

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North Santiam Point Source Discharges Under CA4, there would be no impacts to point source discharges as stream flows would remain above the 7Q10 values in Table 15 (ODEQ 2006).

CA5. SWS and FSS Constructed with No Drawdown Under CA5, water quality impacts would likely be identical to the No Action Alternative.

3.7 WILDLIFE The North Santiam River and its floodplain historically consisted of a multitude of aquatic and terrestrial habitat types that sustained rich assemblages of wildlife species. These assemblages include species that live year-round in its waters and associated floodplains, migratory species which the ecosystem provides seasonal habitat (e.g. breeding, wintering), wildlife movement corridors, and non-breeding/foraging habitats. For the purpose of this review aquatic habitats include open water (i.e. reservoir, main channel, secondary channels, backwaters, oxbows, and lakes/ponds) of varying depths. Terrestrial habitats generally include wetlands, forests, oak-savannahs, grasslands, and shrublands. Open water habitats (i.e. reservoir, main channel, secondary channels, backwaters, oxbows, and lakes/ponds) provide a diverse range of flows and depths, which provide habitat for various species including amphibians (e.g. northern red-legged frog (Rana aurora), reptiles (e.g. western pond turtle (Actinemys marmorata)), fish, migratory birds, resident waterfowl, and furbearers (e.g. beaver). Habitat needs encompassed under the open water habitat class include feeding and breeding habitat for migratory birds and resident waterfowl; feeding and breeding habitat for furbearers; habitat for macroinvertebrates consumed by aquatic species; and feeding and breeding habitat for reptiles and amphibians. A variety of species, including migratory birds, forage in open water habitat within Detroit Reservoir and the North Santiam River. Wetland habitat provides foraging, breeding, rearing, nesting, and shelter habitat for assemblages of species including reptiles and amphibians (e.g. northern red-legged frog, western pond turtle, various bird species (e.g. waterfowl, neo-tropical migrant birds), fish, macroinvertebrates, and mammals. Habitat needs encompassed under the wetland habitat class include amphibian breeding, rearing, and foraging habitat; breeding and foraging habitat for waterfowl; foraging habitat for semi-aquatic mammals (e.g. muskrat); and breeding and foraging habitat for shorebirds. Wetlands located along the fringe of the Detroit Reservoir provide breeding and foraging areas for amphibians, birds, and fish. The upland habitats found within the geographic scope of the Project include grasslands, riparian forest, mixed conifer forest, agricultural lands, and oak-savannah 3-146

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habitats. Near Detroit Dam the main habitats observed are mixed coniferous forest and a mixed deciduous and conifer riparian forests. The variable canopy structure and diversity of the understory within these habitat classes provide a variety of different habitats and food sources specific to individuals or species. These habitat classes include nesting, denning, roosting, basking, breeding, shelter, and foraging for many wildlife species. Upland grassland habitat provides grazing and browsing for native ungulates (e.g. blacktail deer (Odocoileus hemionus columbianus)), grassland birds (e.g. western meadowlark (Sturnella neglecta)), rodents, and reptiles (e.g. western pond turtle (Actinemys marmorata)). The oak-savannah habitat provides grazing and browsing for native ungulates (e.g. blacktail deer), various bird species (e.g. white- breasted nuthatch (Sitta carolinensis)), rodents, and invertebrates (e.g. various butterfly species). Forty-eight wildlife special-status species were identified that may occur in the Project area (Table 16). These species are designated at either the state or federal level. Of those species identified 10 are amphibians and reptiles, 26 are birds, and 12 are mammals. Seven of the special status-species are either federally listed under the ESA or are proposed to be listed under the ESA.

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Table 16. Wildlife Sensitive Species List for North Santiam Subbasin from Detroit Reservoir to the confluence with the South Santiam River. (Data source: Species information compiled using geospatial data provided by Oregon Biodiversity Information Center (2016). This list does not include fish species considered sensitive which are covered under the aquatic species section). Common Name Scientific Name Federal Status State Status Amphibians/Reptiles Clouded salamander Aneides ferreus Sensitive Vulnerable Western pond turtle Actinemys marmorata Under Review Sensitive Critical Northern red-legged frog Rana aurora SOC Sensitive Critical Coastal tailed frog Ascaphus truei SOC Sensitive Vulnerable Cascade torrent salamander Rhyacotriton cascadae Sensitive Vulnerable Painted turtle Chrysemys picta Sensitive Critical Oregon slender salamander Batrachoseps wrighti SOC Sensitive Critical Foothill yellow-legged frog Rana boylii SOC Sensitive Vulnerable Cascades Frog Rana cascadae SOC Sensitive Vulnerable Birds Northern spotted owl Strix occidentalis caurina Threatened Bald eagle Haliaeetus leucocephalus Sensitive Vulnerable American peregrine falcon Falco peregrinus anatum Sensitive Vulnerable Aleutian cackling goose Branta hutchinsii leucopareia Northern goshawk Accipiter gentilis atricaupillus SOC Sensitive Vulnerable Olive-sided flycatcher Contopus cooperi SOC Sensitive Vulnerable Pileated woodpecker Dryocopus pileatus Conservation Strategy Harlequin duck Histrionicus histrionicus SOC Sensitive Vulnerable Greater sandhill crane Antigone canadensis tabida Sensitive Vulnerable Golden-crowned kinglet Regulus satrapa Conservation Strategy Oregon vesper sparrow Pooecetes gramineus affinis SOC Sensitive Critical Barrow’s goldeneye Bucephala islandica Conservation Strategy Purple martin Progne subis SOC Sensitive Critical Bufflehead Bucephala albeola Conservation Strategy Common nighthawk Chordeiles minor Sensitive Critical Little willow flycatcher Empidonax traillii brewsteri Sensitive Vulnerable Yellow-breasted chat Icteria virens SOC Sensitive Critical Acorn woodpecker Melanerpes fornicivorus SOC Sensitive Vulnerable Mountain quail Oreortyx pictus SOC Band-tailed pigeon Patagioenas fasciata SOC Western bluebird Sialia mexicana Sensitive Vulnerable Slender-billed nuthatch Sitta carolinensis aculeata Sensitive Vulnerable Western meadowlark Sturnella neglecta Sensitive Critical Grasshopper sparrow Ammodramus savannarum Partial Status Sensitive Critical

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Mammals Yuma myotis Myotis yumanensis SOC Western gray squirrel Sciurus griseus Sensitive Vulnerable Long-eared myotis Myotis evotis SOC Long-legged myotis Myotis volans SOC Sensitive Vulnerable White-footed vole Arborimus albipes SOC Pacific marten (interior) Martes caurina (pop. 1) Sensitive Vulnerable Hoary bat Lasiurus cinereus Sensitive Vulnerable Townsend’s big-eared bat Corynorhinus townsendii SOC Sensitive Critical Fringed myotis Myotis thysanodes SOC Sensitive Vulnerable Little brown myotis Myotis lucifugus Conservation Strategy Along with the sensitive status species listed above, a variety of common small mammals occur in various project area habitats, including several species of squirrels, chipmunks, mice, and rabbits. Small populations of waterfowl inhabit the river, reservoir, and riparian areas, including mallards, common mergansers, and wood ducks. In compliance with the National Forest Management Act, the WNF has a forest management plan that includes consideration of sensitive species and biological diversity. Eleven sensitive wildlife species are known to occur in the WNF. Five of these species, red-legged frog, bald eagle, American peregrine falcon, northern spotted owl, and harlequin duck can reasonably be expected to occur near the project or in immediate downstream locations. Many species of birds inhabit the area. Various salamanders and frogs, including the northern red-legged frog (also a candidate species under ESA), inhabit the North Santiam River.

Northern Spotted Owl The northern spotted owl (Strix occidentalis caurina), listed as threatened under the ESA, occurs primarily in late seral stage conifer forest with structure that meets requirements for prey, cover, and nesting. The typical habitat consists of moderate to high canopy closure with a multilayered, multispecies canopy dominated by large overstory trees greater than 30 inches diameter at breast height (dbh) with the presence of large cavities and broken tops (Forsman et al. 1984). Northern spotted owl pairs occupy the same territories year after year provided that suitable nesting habitat remains present. The nesting cycle begins in late February to early March when the pair begins to roost together. Northern spotted owls produce one to three eggs in March or April. Incubation lasts for approximately 30 days, and juvenile owls leave the nest 3 to 5 weeks after hatching, in May or June. Juveniles remain near the nest and are dependent on adults for food until August or September before becoming independent and dispersing from the nesting area (Marshall et al. 2003; Thomas et al. 1990). Although a pair would continually occupy the same territory, home

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range expands during winter when individuals wander extensively (Forsman et al. 1984). Northern spotted owl habitat is classified as: • suitable habitat that provides for nesting, roosting, and/or foraging and dispersal; • dispersal-only habitat that provides for protection from avian predators and at least minimal foraging opportunities during dispersal and colonization periods; and • non-habitat. The general home range of breeding northern spotted owls is estimated as a 1.2 mile circle around the nest tree and a core area defined as a 0.5 mile radius around the nest tree. An area measuring 300 meters in radius around the nest tree is known as the Nest Patch. At least 40% of the home range and 50% of the Core Area should be suitable habitat to support nesting and rearing of young (USFS 2018). A search through the ORBIC 2016 database indicates historical northern spotted owl nesting occurs in the vicinity of Detroit Dam and Reservoir. The closest historical nesting location is approximately 1 mile to the northeast of Detroit Dam and was last observed in 1989. Two additional historical nest observations are within 2 miles of Detroit Dam. Designated critical habitat (77 Fed. Reg. 71875) is located in lands adjacent to Corps administered lands. Two patches of designated critical habitat are located approximately 1.5 miles northeast and 4 miles southeast of Detroit Dam. Noise and human activities that generate noise levels of 92 dBA or greater can result in adverse effects to northern spotted owls by causing an adult or a nestling to flush from its nest, or a fledgling to miss a feeding (USFWS 2003, p. 273). Northern spotted owls are more likely to be susceptible to disturbances in the early breeding season (March 1 to July 15) when young are in the nest, but are less likely to be disturbed during the late season (July 16 to September 30) when young are able to move away from disturbances without fitness consequences. The USFWS (2011b, p. 43) identified a 65-yard distance as a threshold for ground-based disturbances with motorized equipment. This distance is based on two studies, Delaney et al. (1999, pp. 66-68) and Delaney and Grubb (2003, p. 22).

Red Tree Vole The red tree vole is a small arboreal mammal endemic to conifer forests within western Oregon and northern California. While the species does use second growth forests for foraging and breeding, they tend to be more abundant in and select older forests. While they can feed on a variety of conifer needles, they tend to select Douglas fir for both foraging and nesting.

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Red tree voles construct their nests of branchlets, discarded resin ducts and other tree materials shaped into a sphere with interior tunnels. Nests grow in size as long as red voles actively occupy them. Litter sizes are small relative to other small mammals with just three young per litter. Red voles can raise multiple litters at one time. Young red tree voles do not disperse until 47 to 60 days old. Red tree voles have a limited home range, less than half an acre, and dispersal distance is often less than 100 yards (73 Fed. Reg. 63919-63926).

Bald Eagle and Migratory Birds The bald eagle (Haliaeetus leucocephalus) was delisted from the ESA in August 2007 (72 Fed. Reg. 37346) and is still protected under the Bald and Golden Eagle Protection Act (BGEPA) and under the Migratory Bird Treaty Act (MBTA). Many of the migratory birds found within the project area are protected under the MBTA. The protection provided by the BGEPA is similar to the protection provided by the ESA in that no person or organization without a permit from the Secretary of the Interior can “take” a bald eagle, where “take” is defined by pursue, shoot, shoot at, poison, wound, kill, capture, trap, collect, molest, or disturb. The BGEPA also protects active and previously active bald eagle nest sites. The North Santiam River and Detroit Reservoir provide ample foraging, loafing, migration, and nesting habitat for bald eagles. The bald eagle is a predatory raptor species that feeds on fish, birds, reptiles, carrion, and small mammals. Bald eagles can be readily observed along the North Santiam and Detroit Reservoir. Bald eagles prefer mature trees for nesting and roosting. Within Detroit Reservoir, two nests have been identified and an additional four nests have been identified within the riparian forests of the North Santiam River. The two nests within Detroit Reservoir are located at Piety Knob (approximately 4 miles to the east of Detroit Dam) and along the south side of the Detroit Reservoir (approximately 2.5 miles to the southeast of Detroit Dam). The other four known bald eagle nest locations are located along the North Santiam River from Stayton to the confluence of the North and South Santiam Rivers.

Environmental Consequences

Methodology and Scale of Analysis The Corps analyzed impacts based on anticipated changes in habitat under each alternative compared to existing habitat conditions. The Corps estimated changes in habitat, and the impacts to wildlife species, associated with the proposed construction methods and operations of the SWS and FSS under each of the five construction alternatives using available habitat and wildlife species spatial information to determine direct, indirect, and cumulative impacts.

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In addition to cited references, the Corps used the following sources of information to identify the potential impacts of the alternatives on wildlife in the study areas: • USFWS Information for Planning and Conservation (IPaC) online database (USFWS, 2018). • Oregon Biodiversity Information Center (ORBIC) 2016 list of known occurrences of rare plants in Linn and Marion Counties, Oregon, and details regarding their occurrence, habitat, and range • Oregon Biodiversity Information Center 2016 spatial data provided by Institute for Natural Resources The geographical analysis for the alternatives includes the area of construction of the SWS tower and FSS, staging areas, Detroit Reservoir and adjacent terrestrial habitats, and downstream habitats within and adjacent to the North Santiam River from Detroit Dam to the confluence with the South Santiam River. The downstream areas under review would include those areas within the active channel of the North Santiam and off-channel habitats that have connectivity to the North Santiam River. Temporal scale analysis for the alternatives would include the duration of construction of the SWS and FSS, the duration of any proposed drawdown of Detroit Reservoir and the resulting duration of the reduced flows within the North Santiam River downstream of Detroit Dam, and the operation of the SWS and FSS.

Staging Areas The following provides a description of the habitat and environmental consequences of the project at the potential staging areas described in Sections 2.7.2.5 and 2.6. The staging areas described in Section 2.7.2.5 would experience the environmental consequences described under all action alternatives.

Minto North This location is downstream of Big Cliff Dam near the Minto Fish Facility along the North Santiam River and is the location of the spoils from construction of the Minto Fish Facility. The Corps has seeded Minto North with native grasses and forbs as part of the restoration portion of the Minto Fish Facility Project. This site is adjacent to OR-22. Total area of potential impact is approximately 2.5 acres. The surrounding habitat to the north consists of second growth mixed coniferous forest. While the Corps does not actively manage this area for wildlife habitat there is evidence (e.g. tracks) that deer use the area for foraging and movement. Various migratory songbirds also use the area for foraging on vegetation that the Corps planted for reclamation of the site following construction of the Minto Fish Facility. Overall, this area provides limited habitat for wildlife and impacts would be minimal.

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Post impact re-vegetation would provide early seral habitat, which would benefit migratory songbirds and small mammals. Species selection for replanting should be coordinated with Corps WVS botanists.

Detroit Dam and Parking Lot This location is adjacent to OR-22 and Detroit Dam. Habitat to the north consists of mixed coniferous forest and a large rock wall. The staging site is a paved parking lot adjacent to the highway. Noise from construction activities may affect migratory birds nesting in the adjacent forested areas. Impacts to wildlife would be minimal.

Detroit Dam and Operations Yard and Access Road This location is directly downstream of Detroit Dam and includes gravel parking areas adjacent to the Detroit Dam access road. The locations have limited vegetation as they have poor soils and are predominately compacted gravel. Some trees, predominately Douglas fir (Pseudotsuga menziesii) and big-leaf maple (Acer macrophyllum), are located within adjacent areas. Understory vegetation is predominately invasive Scotch broom (Cytisus scoparius). Due to human activity in the area and lack of suitable habitat, impacts to wildlife within the Detroit Dam, operations yard, and access road are minimal. Post impact re-vegetation would provide early seral habitat which would provide a benefit for migratory songbirds and small mammals. Species selection for replanting should be coordinated with Corps WVS botanists.

SA1. Mongold State Park SA1 is located 2.9 miles southeast of Detroit Dam within the Mongold Day Use Area. This location is an existing recreation area with multiple boat launches, docks, parking area, picnic areas, restrooms, and public swim beach. The proposed staging area would be located to the northeast of the parking area. This staging area would include the construction of a cofferdam and would require grading and excavation of the staging area due to the existing gradient. Adjacent habitat includes a small amount of Douglas fir and big-leaf maple forest and open water of Detroit Reservoir. Mongold Day Use Area has a high number of visitors during late spring/summer and does not provide adequate wildlife habitat. Noise from construction would likely result in wildlife not using the adjacent forested areas. The nearest known bald eagle nest is located at Piety Island, approximately 1.5 miles to the east. Construction activities would likely not result in an impact to nesting bald eagles. Grading within the lakebed would likely result in a loss of benthic invertebrates within the area.

SA2. Oregon State Parks Maintenance Yard

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This location would require clearing of vegetation to access the lakebed. Some of the vegetation would include large coniferous trees, which provide nesting and foraging habitat for a variety of migratory bird species. The area where the Corps would remove trees is not considered prime habitat and is fragmented due to the level of human disturbance and the location of the habitat between the highway and Detroit Reservoir. The removal of trees and understory vegetation would constitute a loss of available nesting habitat for migratory songbirds, small mammal breeding and foraging habitat, and terrestrial amphibian foraging habitat. The Corps considers the impacts to wildlife through construction of this staging area to be minor due to the size of the impact and the fragmented nature of the habitat. Post impact re-vegetation would provide early seral habitat, which would benefit migratory songbirds and small mammals. Placement of large woody debris within the upland areas would provide additional habitat for small mammals and amphibians as the material decays. Species selection for replanting should be coordinated with Corps WVS botanists and USFS personnel to identify appropriate planting regimes and timing.

SA3. Detroit Lake State Recreation Area This location is similar in impact to habitat as the Oregon State Parks Maintenance Yard site. The Corps would remove some vegetation within the forested area of the proposed site. Due to the limited available habitat and use of the area as a campground, impacts to wildlife are minimal. The Corps would construct a road/slipway for access to the lake for launching the FSS. This construction would affect benthic invertebrates. The Corps would remove road/slipway after construction is complete. Post impact re-vegetation would provide early seral habitat, which would benefit migratory songbirds and small mammals. Placement of large woody debris within the upland areas would provide additional habitat for small mammals and amphibians as the material decays. Species selection for replanting should be coordinated with Corps WVS botanists and USFS personnel to identify appropriate planting regimes and timing.

CA1. No Action Potential impacts to wildlife would not occur under the No Action Alternative.

CA2. SWS and FSS Constructed with a Two-year Deep Drawdown Under CA2, there would be a moderate impact on wildlife species due to potential for amphibian stranding, a temporal loss of wetlands, and a decrease in available waterfowl foraging habitat acreage within Detroit Reservoir during the proposed drawdown. Blasting may cause temporary displacement of wildlife. Sedimentation in off- channel wetland areas may moderately affect wildlife utilization of this habitat. The

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temporary loss of floodplain habitat due to low spring and summer flows may also moderately affect wildlife that utilize this habitat. The drawdown of Detroit Reservoir to an approximate elevation of 1,300 ft would affect two breeding seasons for many species found within Detroit Reservoir and downstream along the North Santiam River.

Detroit Reservoir The drawdown would result in a temporal loss of wetlands within Detroit Reservoir. Wetland areas impacted are predominately Palustrine emergent (38.98 acres) and Palustrine scrub/shrub (8.46 acres). These wetland areas provide habitat for macroinvertebrates; breeding, rearing, and foraging areas for amphibians (e.g. red- legged frog); and breeding and foraging for various bird species (e.g. waterfowl, shorebirds, aerial insectivores). Removal of hydrology from these wetland areas would result in a potential loss of a minimum 2 years of breeding by amphibians within these sites. The Corps expects that for the duration of CA2 the wetlands found within the Detroit Reservoir would not have adequate hydrology during the active growing season to facilitate growth of wetland dependent species. These wetland areas provide habitat for pond-breeding amphibians (e.g. red-legged frog and rough-skinned newt (Taricha granulosa)). During the initial drawdown of the reservoir, there is a potential for stranding of neotenic salamanders and other amphibians that would be present within the reservoir. The stranding would most likely occur within the shoreline fringe habitat and would be relatively accessible to staff to conduct rescue/recovery efforts of individuals. The timing of the extended drawdown in the fall would decrease the potential of this impact. Waterfowl and piscivorous birds (bald eagle and osprey) would see a decrease in available foraging habitat acreage. This decrease in available acreage would have negligible adverse impacts on bald eagles and osprey as prey items (fish) would be further concentrated within the remaining available areas. Impacts to species within the forested areas surrounding Detroit Reservoir are not anticipated as the drawdown to 1,300 ft would not result in change to the upland habitat. Red tree voles would not be impacted under CA2.

Blasting Construction activities related to the SWS and FSS would include the use of explosives in the first year of the drawdown. Use of explosives could cause temporary displacement of wildlife within the project vicinity. However, due to the extensive construction activity already occurring, additional impacts from blasting would likely be minor. The two bald eagle nests located within Detroit Reservoir are outside of the 1- mile buffer (4 and 2.5 miles from the blasting area) required under the BGEPA. Historical nesting of northern spotted owls has occurred near Detroit Dam. The two 3-155

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nests are within 1 and 2 miles of the dam. Observations of northern spotted owls in this area were in the late 1990s with no other observations noted within the ORBIC database. USFS did note that no known northern spotted owl nests occur near any of the proposed staging areas. Because of the high impedance barrier to sound transmission through the air–water interface, the risk to birds is very low, except for diving birds that may be underwater within the immediate vicinity at the time of the blast. However, exposure of diving birds to impulsive underwater sound from an explosion would require millisecond timing on the part of the bird. Consequently, the Corps considers the likelihood of such an exposure to be very small, particularly if deterrence measures are taken when the Corps observes diving birds of concern in the blast area. The Corps has little information regarding the likelihood of occurrence of protected birds in the impact area during the work period. The likelihood of exposing a bird to impulsive-underwater-sound appears to be very low. T The blaster will undoubtedly use methods (i.e., heavy stemming or blast mats) to control fly rock which would have the potential to injury or kill flying birds in the vicinity of the blasting. It is anticipated that the blasting site is far enough away from open-water utilized by diving birds that pressures would be greatly attenuated and impacts to diving birds would be minor or nonexistent. In addition, construction activities and noises would likely exclude birds from the immediate blasting zone. However, unnecessary and avoidable complications to the project are likely to occur if protected birds are impacted. So, the Corps proposes using loud noises (i.e., gas-operated exploders, air horns, sirens, or sonic devices) just prior to the blast to scare birds from the area. This technique has been successfully used at other blasting projects (Keever 1998). The Corps expects impacts to salamanders (adult and neotenic) to be minor with a potential of some individuals located within the blast zone. Although the literature on blasting impacts is limited for amphibians, Keevin and Hempen (1997) indicated that impacts to individuals with lungs (adult stage) would have similar mortality as fish with swim bladders, and individuals without lungs (neotenic) would probably be immune to underwater explosions.

North Santiam (Detroit Dam to Confluence with South Santiam) The initial drawdown of Detroit Reservoir to a pool elevation of 1,300 ft would release sediment that has built up within Detroit Reservoir into the North Santiam River (see Section 3.5 for details). Comprised of fine clay, the majority of the sediment would likely precipitate out of the water within the lower sections of the North Santiam River, from approximately Stayton, OR to the confluence of the North and South Santiam Rivers. This deposition would likely impact freshwater mussel species, benthic invertebrates, and amphibians, which breed in off-channel, backwaters, or connected

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oxbows to the North Santiam River. Depending on the depth of sedimentation, the impacts to wildlife due to sedimentation would range from minor to moderate. During the proposed 2-year drawdown, flows downstream of Detroit Dam would be equal to flows coming into Detroit Reservoir and would be approximately 400 cfs. Low flows would likely result in desiccation of wetlands and other off-channel habitats in the 2 years that low flows would be occurring. This loss of habitat temporally would moderately affect pond-breeding amphibians, waterfowl, migratory songbirds, shorebirds, reptiles (western pond turtle and western painted turtle), and some aquatic mammals (e.g. beaver, muskrat). Studies have shown that pond-breeding amphibians would move to suitable habitat during drought conditions (Church, 2007; Price et al., 2012). If there is no available habitat for adults in the area, it has been shown that the adults would forgo breeding until suitable habitat conditions are present. It is unlikely that the dewatering of the off-channel habitats would result in mortality of adults. A study of coastal giant salamanders (Dicamptodon tenebrosus) in the McKenzie River basin found that body mass declined but abundance were not significantly different between drought conditions and non-drought conditions (Kaylor et al., 2019). The coastal giant salamanders were also found to have recovered to pre-drought condition (body mass) and abundance within 2 years after the drought conditions. This movement of the adult amphibians could result in the loss of breeding up to 2 years within these areas. Impacts to the two native turtle species, western painted turtle (Chrysemys picta bellii) and western pond turtle would be to available foraging and to rearing habitat. Adult western pond turtles have been observed in off-channel habitat from Geren Island downstream to the confluence of the North and South Santiam Rivers (ORBIC, 2016). No observations of western painted turtles have been documented within this portion of the North Santiam but this section of river and off-channel emergent habitat are within the historical range of the western painted turtle. The off-channel habitat has not been surveyed for available nesting habitat for turtles so it is unknown if any breeding is occurring in these locations. Based on a review of aerial imagery there is a potential for nesting habitat adjacent to some of the off-channel habitat. The decrease in available water to the off-channel habitats would result in the loss of rearing habitat for hatchlings and would be considered a moderate impact. Adult turtles within riverine systems are known to move throughout the system depending on availability of habitat (Bury et al., 2012) and impacts to adults using the mainstem of the North Santiam would be minor. Impacts to nesting would likely be the loss of 2 years of nesting within the affected off- channel habitats. Turtles typically have high site-fidelity and a limited home range (Bury 1979). Adults would likely stay near the off-channel habitat and would seek foraging areas where adequate water and emergent vegetation are present. The reduction in available habitat could result in higher predation of species as they would be concentrated in the remaining available habitat along the North Santiam River

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and other off-channel habitats not influenced by flow of the North Santiam River. More mobile species (e.g. avian species) would likely move to more adequate habitat within the area. Impacts to the two native turtle species would be predominately on hatchlings, where found.

Operation of the FSS The operation of the FSS may result in entrapment of amphibians moving near the FSS as they attempt to cross from one shoreline to the other. This is a minor impact, as FSS operators would be able to release entrapped individuals within suitable shoreline habitat. The location of the FSS is not within habitat that would provide the appropriate thermal gradient for amphibians and the Corps does not consider it an attractant for the species present within Detroit Reservoir. The increase in fish within the North Santiam system would provide a long-term benefit for species that rely on fish as a prey item (e.g. bald eagle, osprey, and river otter). The operation of the FSS would not affect terrestrial wildlife species or arboreal (e.g. red tree vole) species.

Operation of the SWS The operation of the SWS would not likely impact wildlife within Detroit Reservoir directly. Downstream flows would be similar to what is currently observed on the North Santiam. Water temperatures would change from observable current conditions. Native wildlife species that use the North Santiam River would likely adjust to the change in temperature. The impacts of the operation of the SWS to wildlife downstream of Detroit Dam would likely be minor. The operation of the SWS would not affect terrestrial wildlife species or arboreal (e.g. red tree vole) species.

CA3. SWS and FSS Constructed with a One-year Deep Drawdown Under CA3, impacts to wildlife would be the same as those experienced under CA2. However, there would be reduced impacts, as wildlife would experience these for a shorter duration (1 year as opposed to 2 years under CA2). Under CA3, the drawdown of Detroit Reservoir to an approximate elevation of 1,300 ft would affect one breeding season, for many species found within Detroit Reservoir and downstream along the North Santiam River. The operation of the FSS and SWS would have the same impacts as those described in CA2.

CA4. SWS and FSS Constructed with a One-year Variable Drawdown

Detroit Reservoir

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The drawdown of Detroit Reservoir to an approximate elevation of 1,400 ft would result in similar impacts under CA3 in and around Detroit Reservoir.

Blasting Under CA4, construction activities related to the SWS and FSS would include the use of explosives underwater. Use of explosives would cause temporary displacement of wildlife within the project vicinity and has the potential for injury or mortality to individuals. Under CA4, the blasting would occur underwater and would not affect terrestrial wildlife due to the high impedance barrier to sound transmission through the air-water interface. The risk to terrestrial wildlife is very low, except for diving birds, aquatic mammals, and amphibians that may be underwater within the immediate vicinity of the blast at the time of blast. There is no potential for wildlife injury or mortality from fly rock because it would not breach the surface. Diving birds could be injured or killed if they were in the act of diving during the blast. Exposure of diving birds to blast pressures from an explosion would require millisecond timing on the part of the bird. Construction activities and noise would likely exclude diving birds from the immediate blasting zone. In addition, he Corps proposes using loud noises (i.e., gas-operated exploders, air horns, sirens, or sonic devices) just prior to the blast to scare birds from the area. This techniques has been successfully used at other blasting projects. The Corps has little information about the likelihood of occurrence of protected birds, aquatic mammals, and amphibians in the impact area during the work period. The likelihood of exposing wildlife to impulsive underwater sound appears to be very low. To limit exposure of diving birds and aquatic mammals to the impacts of blasting, surveys of the project area should occur prior to the blasting to determine if any species are present near the blasting location. The monitoring plan should include monitoring tasks to survey for protected birds, aquatic mammals, and amphibians prior to blast and report their presence to responsible parties. The Corps expects impacts to salamanders (adult and neotenic) to be minor with a potential of some individuals located within the blast zone. There currently no published information on blasting impacts to amphibians. It has been suggested by Keevin and Hempen (1997), that impacts to individuals with lungs (adult stage) would have similar mortality as fish with swim bladders and ones without lungs (neotenic) would probably be comparatively immune to underwater explosions.

North Santiam (Detroit Dam to Confluence with South Santiam) Under CA4, because the Corps would maintain 1,000 cfs in the summer months, there is no change to flows released from Detroit Dam throughout construction of the SWS and FSS. Therefore, off-channel and mainstem habitat impacts due to low flow 3-159

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would not occur. Sedimentation and turbidity effects within the North Santiam River under CA4 would be similar to those experienced under CA2.

Operations of the FSS and SWS The operation of the FSS and SWS would have the same impacts as those described in CA2.

CA5. SWS and FSS Constructed with No Drawdown

Detroit Reservoir Under CA5, Detroit Reservoir would not have a change to reservoir water levels and would result in no impacts to wildlife within the reservoir or the surrounding upland habitats. Wetlands identified in previous alternatives would continue to exist in their current form with no change to the hydrology.

Blasting Under CA5, construction activities related to the SWS and FSS would include the use of explosives underwater that would have the same impacts as those described in CA4.

North Santiam (Detroit Dam to Confluence with South Santiam) Under CA5, there is no change to flows released from Detroit Dam throughout construction of the SWS and FSS. This would result in no direct or in-direct impacts to off-channel or mainstem habitats and wildlife along the North Santiam River. Additionally, off-channel habitat impacts from the proposed action due to low flow would not occur. Sedimentation within the North Santiam River would not occur under CA5, as there would be no deep drawdown of Detroit Reservoir for construction.

Operations of the FSS and SWS The operation of the FSS and SWS would have the same impacts as those described in CA2.

3.8 FISH AND AQUATIC SPECIES The North Santiam River supports diverse populations of anadromous and resident fish species and aquatic organisms. These fish species are a mix of native and non- native (i.e., introduced) species. Table 17 list the species found in the basin and their protected status.

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Table 17. Fish species found in the North Santiam Watershed (Snyder et al. 2006 and ODFW, personal communication) Common name Scientific name Federal status State status Native or Introduced Steelhead Trout Oncorhynchus mykiss Threatened Sensitive-Critical Native Chinook Salmon Oncorhynchus tshawytscha Threatened Sensitive-Critical Native Chiselmouth Acrocheilus alutaceus Native Largescale Sucker Catostomus macrocheilus Native Mountain Sucker Catostomus platyrhynchus Native Blackside Dace Chrosomus cumberlandensis Native Prickly Sculpin Cottus asper Native Mottled Sculpin Cottus bairdii Native Paiute Sculpin Cottus beldingii Native Shorthead Sculpin Cottus confusus Native Riffle Sculpin Cottus gulosus Native Reticulate Sculpin Cottus perplexus Native Torrent Sculpin Cottus rhotheus Native Pacific Lamprey Entosphenus tridentatus Sensitive Native Threespine Stickleback Gasterosteus aculeatus Native Western Brook Lamprey Lampetra richardsoni Sensitive Native Peamouth Mylocheilus caurinus Native Coastal Cutthroat Trout Oncorhynchus clarkii Native Rainbow Trout Oncorhynchus mykiss Native Oregon Chub Oregonichthys crameri Native Sand Roller Percopsis transmontana Native Mountain Whitefish Prosopium williamsoni Native Northern Pikeminnow Ptychocheilus oregonensis Native Longnose Dace Rhinichthys cataractae Native Leopard Dace Rhinichthys falcatus Native Speckled Dace Rhinichthys osculus Native Redside Shiner Richardsonius balteatus Native Brown Bullhead Ameiurus nebulosus Introduced Western Mosquitofish Gambusia affinis Introduced Pumpkinseed Lepomis gibbosus Introduced Warmouth Lepomis gulosus Introduced Bluegill Lepomis macrochirus Introduced Smallmouth Bass Micropterus dolomieu Introduced Largemouth Bass Micropterus salmoides Introduced Coho Salmon Oncorhynchus kisutch Introduced Kokanee Oncorhynchus nerka Introduced White Crappie Pomoxis annularis Introduced Black Crappie Pomoxis nigromaculatus Introduced

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Anadromous Fish The North Santiam subbasin supports two independent native populations of anadromous salmonids: UWR Chinook salmon and UWR winter steelhead. Historically, Pacific lamprey were present above Detroit Dam and are currently present downstream of Minto Dam. In addition to the native salmonids and lamprey, introduced coho salmon, fall Chinook salmon, and summer steelhead are present.

Upper Willamette River (spring) Chinook Salmon Figure 44 shows the seasonal life stages and species activity periodicity of UWR Chinook salmon in the North Santiam River basin. The mainstem North Santiam River is free of natural barriers up to its headwaters, approximately 35 mainstem miles above Detroit Dam (WNF DRD 1995). Before the Corps dams were constructed, adult Chinook salmon spawned in the upper reaches of the North Santiam River and in headwater tributaries such as the Marion Creek, the Breitenbush River, and Blowout Creek (WNF DRD 1994, 1996, 1997), as well as in the mainstem below the dam sites and in Little North Santiam River (Parkhurst et al. 1950). Historical estimates of the abundance of these fish in the North Santiam subbasin range from 8,250 adults escaping to spawn upstream of Detroit Dam in 1934 (Wallis 1963) despite intense downstream fisheries, to 2,830 spawners throughout the entire subbasin in 1947 (Mattson 1948). Parkhurst et al. (1950) estimated that there was sufficient habitat in the North Santiam to accommodate at least 30,000 adults. Mattson (1948) estimated that 71% of the spring Chinook production in the North Santiam subbasin occurred in areas that have since been blocked by Detroit and Big Cliff Dams. Based on habitat loss with the construction of the Big Cliff and Detroit dams (including the reservoir pools) and habitat loss and degradation below the dams, current spawner (egg) capacity is estimated at approximately 11,500 adult spawners (assuming 2,250 eggs per adult), with 72% of that capacity (for 8,100 adults) above Detroit Reservoir (Zabel et al. 2015). Additionally, Bond et al. (2017) compares estimates of spawning capacity based on habitat availability, similar to Parkhurst, et al. (1950) and Zabel et al. (2015), including climate change impacts (i.e., temperatures greater than 16 degrees Celcius) resulting in declining spawner capacity. The North Santiam population of UWR Chinook salmon is considered to be at a high risk of extinction (with considerable certainty) based on an assessment of its abundance, productivity, spatial structure, and diversity (McElhany et al. 2000, NMFS 2016). Chronically unfavorable conditions within a reduced geographic distribution create much of this risk, but the potential for catastrophic events such as landslides, hatchery-related disease outbreaks, or volcanic events, is also a contributor (NMFS 2008).

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Life Stage/Activity/Species Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Upstream Adult Migration Adult Holding Adult Spawning Egg Incubation through Fry Emergence1 Juvenile Rearing All Life Stages Fry2 Subyearling3 Fall Migrant4 Yearling5 Downstream Juvenile Migration6 Fry7 Subyearling Yearling smolt Fall migrants Periods of peak use* Periods of lesser level of use** Information based on field data and direct knowledge (otherwise based on professional opinion) Legend Critical periods when flow fluctuations should be avoided to prevent disruption of spawning , to minimize disturbance of eggs during early incubation, and to minimize stranding or displacing newly emerged fry.

*The peak period shown is the timeframe during which 90% of the life-stages activity occur (based on professional opinion). **The lesser used period shown is the timeframe during which 10% of the life-stage activity occurs (based on professional opinion). 1Emergence based on field observations and TU Calculations 2Peak Periods of rearing based on trapping (1998) and field data (2011-2012) 3Primary rearing period based on seining data 4Subyearlings that do not migrate in first summer 5Fish that remain through first summer and winter 6Migration data based on PIT tag data, except fry movement 7Fry movements based on field data (2011-2012)

Figure 44. Periodicity Table for UWR spring Chinook salmon in the North Santiam River below Big Cliff Dam taken from the WFOP (2018)

Hatchery-origin spring Chinook salmon are currently outplanted above Detroit Dam in the North Santiam and Breitenbush rivers. Adult counts at the Minto trap 2002-2007 and Bennett Dam 2001-2005 (Table 18), indicate less than 500 naturally produced (NOR) Chinook salmon adults return to the North Santiam River annually. Figure 59 summarizes adult migration timing, including other life history stages, which occurs from Mid-April to Mid-September.

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Table 18. Estimated numbers of wild and hatchery-origin adult UWR Chinook passing upstream at Bennett Dam, North Santiam River, 2001-2005, as determined by analyses of otoliths in non-fin- clipped fish and coded wire tags in fin-clipped fish (McLaughlin et al. 2008). Year Number of wild adults Number of hatchery- origin Total adults passing upstream at Percent wild adults Bennett Dam 2001 220 6,566 6,786 3%

2002 604 7,036 7,640 8% 2003 271 12,561 12,832 2% 2004 489 13,042 13,531 4% 2005 667 4,216 4,883 14% 5- year 450 8,684 9,134 6% average

In recent years, abundance of returning adult naturally-produced Chinook salmon has increased (Table 19). It appears spill operations since 2007 has increased the number of juveniles effectively passing Detroit and Big Cliff dams, likely contributing to increased adult returns. Genetic pedigree analysis of returning adult Chinook salmon to Minto trap found that most NOR salmon sampled in 2013 (59%) and 2014 (66%) were progeny of salmon outplanted above Detroit dam (O’Malley et al. 2015a). This analysis also estimated, for salmon outplanted in 2009, that female fitness was approximately 5× (2.72:0.52 progeny) that of the male cohort. The replacement rate was 1.07 as estimated from female replacement. Table 19. Fish counts at Lower and Upper Bennet Dams are included*. Number of unclipped Number of clipped Total adults passing upstream at Percent Year adults (hatchery-origin) adults Bennett Dam unclipped 2013 1,181 3,294 4,513 26% 2014 1,630 5,593 7,223 23% 2015 1,074 6,791 7,865 14% 2016 921 4,021 4,942 19% 2017 842 4,223 5,065 17% 2018 573 3,050 3,623 19% 6- year 1,037 4,495 5,539 19% average *The numbers of unclipped fish are either natural origin fish or mismarked hatchery fish. The hatchery –origin fish included Jacks. The data included in this table does not look at otoliths to determine hatchery versus natural origin fish. Data from 2013 – 2016 is from ODFW at https://myodfw.com/willamette-falls-fish-counts. The 2017 data is from current count data collected and compiled by ODFW and provided by the University of Idaho. The increase in adult abundance in the North Santiam in recent years, and replacement rate >1, is likely influenced by surface spill operations which are only possible in average to wet year conditions. Surface spill allows juvenile fish to pass a higher survival route, as compared to passage through the Francis turbines, and

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provides the best opportunity to achieve temperature targets downstream aiding adult migration, environmental, and rearing conditions in the lower river (Duncan and Carlson, 2011; Normandeau, 2011, Beeman 2015) From 2012 to 2014, USGS collected fish behavior at the dam with acoustic telemetry in an effort to provide information in support of the design of temperature control and fish passage structures. Groups of hatchery origin Chinook and summer steelhead were released in the two main tributaries upstream of the reservoir. Hydrophones were placed throughout the reservoir and at the dam. Detection probabilities were high for both species. Results included fish behavior in the reservoir, forebay distributions, and factors (e.g., diel period and seasonal dam operating conditions) affecting dam passage rates. The movement of both species were directionally persistent in the reservoir and fish tended to accumulate in the forebay of the dam. In general, fish depth varied by species, reservoir elevation, and diel period. Fish densities within 25 meters of the dam were most concentrated near the dam during the spring when the spillway was operating, and were least concentrated near the dam in the fall when the spillway was not operating. The spring behavior is likely due to fish responding to surface flow when available. Steelhead tended to be shallower than Chinook and were at similar depths during the day and night. Chinook were deeper during the day than night with more variability in depth during the study period. Dam passage occurred primarily during periods of elevated discharge and was most pronounced during the spring study period when spill occurred. Data and modeling support that the passage rate increased as spillway discharge increased. Both species were at shallow depths throughout the study period which suggests they would be available for passage if a properly designed surface route were available. Data on the poor passage conditions through the turbine route support the design goal for an interconnected SWS and FSS configuration that excludes the existing turbine intakes as a route of passage (Duncan and Carlson, 2011; Normandeau, 2011). In addition, study data shows significant numbers of juvenile-sized targets (Khan et al., 2012) and proportions of JSATS-tagged fish (Kock et al., 2015) entered this route under existing operations, and did so especially during the fall study period in 2013 (Beeman and Adams, 2015). Khan et al., 2012 conducted a hydroacoustic evaluation of juvenile salmonid passage and distribution at Detroit Dam during the study period Feb. 2011– Feb. 2012. Over the study period, when spill bay 5 was operated simultaneously with the turbines, 72% of the fish passing the dam used the spillway and 28% used the turbines. Approximately 86.5 % of the fish passed through the turbines during the study period. In dry years, like 2015, no surface spill occurred and juvenile fish did not have the opportunity to pass through the higher survival surface route downstream of Detroit Dam.

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Moreover, the effective population size of Chinook salmon, as measured from genetic pedigree analysis, is small and therefore the population is at risk of inbreeding effects unless the population increases. In Figure 60, for below Big Cliff Dam/Minto Fish Facility, in recent years (2012–2016), the percent of hatchery origin spawners (pHOS) has ranged from about 60-80%, and is currently 100% above Detroit Dam since only hatchery fish are currently being transported upstream. An exception happened in 2015 (due to low river flow and high temperature levels) when unclipped fish were moved above Detroit Dam (pHOS approximately 73%).

Figure 45. Spawner abundance estimates based on redd count expansion and pHOS estimates based on carcass recoveries through 2016 (Sharpe et al. 2017) The ODFW has conducted intensive monitoring of the spawning grounds of UWR Chinook salmon in the North Santiam and Little North Santiam rivers. Monitoring results from 2001 in the North Santiam (mean = 59%) and Little North Santiam (mean = 51%), show that an average of 90% of the spawners along the mainstem and 49% of those in the Little North Santiam were of hatchery origin (McLaughlin et al. 2008). More recently, pre-spawn mortality (where the fish dies before it spawns) in the North Santiam was as low as 3% and 5% below and above Detroit Reservoir, respectively. This is likely due in part to the upgrade of Minto Fish Facility and ladder completed in 2013, however, environmental conditions such as low flow and high temperatures play a significant role in pre-spawn mortality. In 2015, a low flow year, pre-spawn mortality was substantially higher at 63% and 12% below and above Detroit Reservoir. Extended over the long term, the combination of low abundance of wild adults, high pre-spawn mortality, and high percentages of hatchery fish in spawning areas, would make it improbable that the river’s “wild” run could include many individuals more than a few generations removed from the hatchery. Recent counts of UWR Chinook salmon redds (nests) in known spawning areas above and below Detroit Reservoir are higher than the average from surveys in 1997- 2006. An average of 302 redds (range: 144- 661) has been counted annually in the two rivers from 1997 through 2006, with nearly 90% of these redds seen in the North Santiam (ODFW 2008). In 2015 (characterized by a below average water year) the

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peak redd count above Detroit Reservoir was 293 and below was 239 (total 532 redds). In 2016 (characterized as an above average water year) the peak redd count above Detroit Reservoir was 481 and below was 410 (total 891 redds). More recently, in 2018, 196 redds were counted below Minto Dam and 245 redds were counted between Big Cliff and Minto Dams (total below dam redd count was 441). The intensity of UWR Chinook salmon use of spawning areas within the North Santiam itself is strongly skewed toward the reach of river immediately below the barrier dam at Minto Dam (Sharp et al. 2017). The concentration of spawners in areas relatively closer to Big Cliff would seem to increase the potential for the Corps dams and their reservoirs to affect fish survival (hence productivity) by influencing water quality, flow, or physical habitat conditions.

Upper Willamette River (winter) Steelhead Surveys conducted in 1940, before the dams were constructed, led to estimates of at least 2,000 steelhead spawning in the mainstem North Santiam, with additional runs to the Breitenbush River, Marion Creek, Pamelia and Blowout creeks, and the Little North Santiam (Parkhurst et al. 1950). The species also used many smaller streams in these and other tributary drainages (BLMS 1998; Olsen et al. 1992; WNF DRD 1994, 1995, 1996, 1997). After construction of the dams, Thompson et al. (1966) estimated that the entire North Santiam subbasin supported a population of 3,500 winter steelhead, including an unknown proportion of hatchery fish, in the 1950s and early 1960s, including adults trapped at Minto. UWR steelhead (also referred to below as winter steelhead) are limited by degraded habitat across much of their historic range. Generally, UWR steelhead move upstream toward spawning grounds from Mid-November to the end of June (Figure 46). Most UWR steelhead spawn in tertiary tributaries to the North and South Santiam rivers, which are streams not affected by the operation of WVP dams, and they select the upper reaches of these streams to spawn (Mapes et al. 2017). Habitat in the areas used by UWR steelhead for spawning, typically from March to Mid-July (Figure 46), are degraded by local land use practices (NMFS 2008, ODFW/NMFS 2011 recovery plan). UWR steelhead are also blocked by culverts and fish passage barriers from accessing portions of tertiary tributaries downstream of the WVP dams in the North and South Santiam rivers for spawning (Andersen 2009; Mapes et al. 2017 pg. 13). The abundance target for the N. Santiam winter steelhead population in the Upper Willamette Conservation and Recovery Plan for Chinook salmon and Steelhead is 8,362 fish (ODFW and NMFS 2011).

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Life Stage/Activity/Species Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Upstream Adult Migration Adult Holding Adult Spawning Egg Incubation through Fry Emergence1 Juvenile Rearing Downstream Juvenile Migration 2 Periods of peak use Periods of lesser level of use Information based on field data and direct knowledge (otherwise based on professional opinion) Legend Critical periods when flow fluctuations should be avoided to prevent disruption of spawning , to minimize disturbance of eggs during early incubation, and to minimize stranding or displacing newly emerged fry.

1Emergence based on field observations and TU Calculations 6Migration data based on PIT tag data, except fry movement

Figure 46. Periodicity Table for UWR winter steelhead in the North Santiam River below Big Cliff Dam taken from the WFOP (2018). Currently, no production of UWR steelhead occurs above Detroit Dam. However, The Upper Willamette River Conservation and Recovery plan call for reintroduction of a self-sustaining winter steelhead population above Detroit Dam (ODFW 2011). McElhany and others (2007) provided a current geometric mean of short-term abundance of 2,109 adults based on 1990-2005 data for the North Santiam. Since this estimate, the adult abundance trends for winter steelhead in the Willamette basin in general have been declining based on the Willamette Falls fish ladder counts, published by ODFW. The majority of winter steelhead passing above Willamette Falls originates from the North Santiam. McElhany et al. (2007) classified the winter-run steelhead population in the North Santiam subbasin as facing a low extinction risk based on its abundance and productivity, though they expressed a high degree of uncertainty. The population is relatively large, with a long-term (1980-2005) geometric mean abundance of 2,722 natural-origin spawners and a short-term (1990-2005) geometric mean abundance of 2,109 (McElhany et al. 2007). The number of adult late-winter steelhead passing over Willamette Falls declined between 2009 and 2017 . The geometric mean of adult late- winter steelhead counted at Willamette Falls over the last 5 years (2013-2017) was 2,441. The geometric mean for the last 10 years (2008-2017) was 2,953. The decline is driven foremost by very low returns in 2017. Returns in 2018 increased substantially from 2017; however, they are still lower than the geometric mean of the last 10 years. The ODFW believes the significant decline in 2017 was due to poor outmigration, poor

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ocean conditions, and sea lion predation (Wright et al. 2016; Falcy 2017; Statesman Journal). Additionally, poor outmigration conditions for juveniles in 2015 may have contributed to the lower returns. Falcy 2017 predicts higher extinction rates due, in part, to sea lion impacts. Conditions in the North Pacific Ocean for juvenile salmon and steelhead entering in 2014, 2015, and 2016 were warm and with overall reduced productivity resulting from El Niño, which impacted food availability for salmon and steelhead (NWFSC). Ocean conditions are influential on survival rates of both steelhead and salmon and are beyond the Action Agencies control. This project to improve temperature control and downstream passage in the North Santiam responds to the 2008 NMFS BiOp and will aid in avoiding jeopardy by improving the freshwater environment, and may be critical during unproductive ocean cycles. Though the most recent status review discussed concerns about the continued downward trend in the population, their listing status remains unchanged as Threatened (NMFS 2016).

Summer Steelhead Trout The ODFW releases summer steelhead trout smolts (first introduced in 1966) in the North Santiam River downstream of Big Cliff Dam. Proposed releases are a maximum of 121,000 smolts from the fish facility at Minto Dam. These fish are part of a larger program to support popular sport fishery in the Lower Columbia and Willamette Rivers. The following information is from the Final Hatchery and Genetic Management Plan (HGMP) submitted to NMFS by the Corps and ODFW for review. Over the past 12 years, an average of 595,600 smolts have been released annually in the Upper Willamette River, the average 2-salt return rate is 2.9% (minimum is 0.7% and maximum is 4.1%), or generally around 18,500 adult fish. The current program releases fewer than 595,000 smolts, reflecting changes requested in the BiOp and a desire to avoid impacts on winter steelhead while still providing angling opportunities. Since 2009, there has been a concerted effort to reduce the potential impacts of hatchery fish on wild fish. However, there has often not been sufficient time to evaluate the results of management changes largely due to the time it takes to adequately evaluate complete cohorts. Studies that look at genetic mixing and the impacts it has on fitness between hatchery fish and wild fish require samples from juveniles and adults. To get complete cohorts can take up to 5 years. The paragraphs below discuss the actions that have been taken to date to decrease the risks posed by hatchery steelhead to wild steelhead in the UWR. The summer steelhead hatchery program has created popular recreational fisheries that have extended the duration of the steelhead angling season. However, since the summer steelhead being used are not native to the upper Willamette certain practices have been implemented and other actions identified to reduce and/or avoid impacts to listed species.

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The spawning success of Skamania summer steelhead stock in the wild is unknown due to difficulty in conducting redd counts during the peak spawning season. Genetic analyses have been conducted on some juvenile and adult O. mykiss samples providing information on levels of hybridization and pure summer steelhead reproduction success (Johnson et al. 2013). A more rigorous randomized survey was conducted by ODFW in 2014 and the genetic results are similar to those from the 2013 study. The 2013 study indicated that naturally produced (unmarked) summer steelhead are believed to account for less than 10% of the juvenile O. mykiss over Willamette Falls (Johnson et al. 2013) with a similar rate for hybridized juveniles (summer and winter steelhead parents). Summer steelhead production in the Santiam basin appears to be low, however hybridization rates of 11% in the North Santiam basin and 14.9% in the South Santiam basin were indicated in the analysis. It is unclear how much of the hybridization is current as opposed to a legacy effect of past hatchery steelhead practices. The majority of juveniles produced in the McKenzie basin (73%) are unsurprisingly summer steelhead since winter steelhead do not naturally occur there. Because clipped steelhead are not passed above Foster Dam on the South Santiam River, any natural spawning by hatchery steelhead would occur below the dam. On the North Santiam River, summer steelhead thought to be excluded by Minto Dam are finding their way into the Minto to Big Cliff reach. Little work has been done on this reach but roughly 300-400 summer steelhead in 2014 were estimated to have made it into this reach (University of Idaho and ODFW unpublished data). Steelhead spawning surveys were conducted in the South Santiam River in 2015–2017 and results are pending. In addition to the suite of actions taken to reduce the impacts of hatchery fish (Table 1.16.1-2; HGMP), ODFW conducted a triploid steelhead study in 2014 to assess the potential success of a triploid summer steelhead program to eliminate hybridization or introgression concerns regarding winter steelhead. Study results indicate that triploid steelhead experience slower growth and higher mortality in saltwater than diploid steelhead. Additionally, only 41% of the outmigrants from the study detected at Willamette Falls were triploid fish. Results from the steelhead triploid study include that adult triploid steelhead returns were 16.3% that of adult diploid returns.

Potential Risks of Program Every effort is made to separate summer and winter steelhead in time and space. For a more in-depth discussion of potential ecological interactions, see Section 3.5 of the HGMP. Co-occurring natural winter-run steelhead populations in the UWR and ESA-listed salmon and steelhead populations in the mainstem Columbia River could be negatively impacted by co-mingling with program fish in migration corridors. Impacts could potentially occur from competition for food, predation, disease transmission, or density

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dependent effects. In order to minimize the potential for any of these effects to occur, program fish are released as full-term yearling smolts (promoting immediate downstream migration to the ocean). Releases of hatchery summer steelhead could increase competition for food and space with naturally rearing salmonids, including wild spring Chinook and winter steelhead. Therefore, all program hatchery releases are coordinated in time and space to minimize this risk. Theoretically, the hatchery smolts would be inclined to move rapidly downstream to estuarine waters, thus minimizing intra- and inter-specific competition with naturally rearing Chinook and steelhead. However, this is not always the case. Fish that are not ready to migrate upon release may stay in the river for a longer period. Hatchery smolts that do not migrate to the ocean (residual fish) may have a size advantage over naturally produced Chinook and steelhead, and thus may out- compete naturally produced juvenile salmonids for food and/or space. Returning adult hatchery summer steelhead could amplify the rate of Infectious Haematopoietic Necrosis (IHNV) infection among naturally produced salmonids. In subbasins such as the McKenzie River, returning adult hatchery steelhead tend to be positive for IHNV. Furthermore, because not all hatchery fish are removed from each subbasin upon return, the likelihood exists for the transmission of IHNV to other natural fish species in the subbasin, which may negatively affect production of both wild and hatchery stocks. It should be noted that wild salmonids are also carriers of IHNV and have been responsible for causing outbreaks in the hatcheries. The exact impacts of IHNV on listed salmon and steelhead are currently unknown.

Pacific Lamprey Pacific lamprey (Entosphenus tridentatus) are present in the Willamette basin and are an important cultural resource to local tribes. Pacific lamprey have been in severe decline and in several areas have been extirpated (CRITFC 2011). However, the Willamette River has one of the largest known adult returns with Willamette Falls supporting one of the last traditional tribal harvest locations. More specifically, spawning adults and redds have been documented in the Santiam River just downstream of Jefferson, Oregon and in 2013 spawning occurred from late April through mid-June (Mayfield et al. 2014). However, Pacific lamprey are not presently in Detroit Reservoir but have the potential to be present in the accessible range of salmonids, which includes the lower North Santiam River. Historically, the range extent for Pacific lamprey prior to dam construction did include the headwaters of the North Santiam River and associated tributaries (Luzier 2011). The Corps is a signatory to a number of conservation efforts for lamprey taking place, such as the USFWS Pacific Lamprey Conservation Agreement (UFWS 2012). Tribal partners have implemented reintroduction programs, with success, in the Columbia and Snake Rivers (CRITFC

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2011) with similar projects potentially expanding in to the Willamette River basin to include above Detroit Dam. A pilot level reintroduction program has occurred above Fall Creek Dam in the Middle Fork Willamette subbasin. The life history of Pacific lamprey is similar to salmonids with adults returning from the ocean moving into freshwater in the spring. They can spend from 1 month up to 2 years in freshwater before continuing upstream into spawning habitats (Mayfield et al. 2014). However, in the Columbia River most are thought to overwinter before moving. Lamprey spawn in habitat with coble and gravel substrate similar to salmon and steelhead spawning habitat substrate. Lamprey create redds and, also similar to salmonids, spawn at temperatures from 10–15 °C (CRITFC 2011), which in the Willamette basin generally occurs from March to July. After spawning, adult Pacific lamprey die. Once the larvae hatch, they drift and settle in fine sediments and filter feed for up to 7 years. They then transform from larvae (ammocoetes) to macrophthalmia in which they form a defined oral disk, dentition, and eyes. At this stage they out-migrate to the ocean where they are parasitic, feeding on other fish and mammals. They spend 2 to 4 years in the ocean before returning to freshwater to complete their life cycle. Therefore, the North Santiam River provides rearing habitat for ammocoetes and spawning habitat for adult fish, which also acts as a migratory corridor to the ocean for both juveniles and adults.

Resident Fish There are many native resident fish species as well as several introduced species found in the North Santiam subbasin (Table 17). Only managed species or those with special status are discussed below.

Bull Trout Bull trout are native to the Willamette River basin but currently are not present in the North Santiam subbasin. They were listed as threatened in June 1998 and populations currently exist in the McKenzie River and Middle Fork Willamette River basins. However, historically, bull trout populations occupied portions of the North Santiam River and were last observed in 1945. The USFWS is exploring the feasibility of expanding bull trout distribution into the North Santiam River (Hudson 2017) but first must determine if and where viable habitat exist before moving forward and, therefore, it is not reasonable to assume they would be present in the foreseeable future.

Oregon Chub Oregon chub is a native cyprinid that is found in the Willamette River basin primarily in floodplain habitats with little or no water flow. The USFWS listed Oregon chub as endangered in 1993 and reclassified as threatened in 2010. When listed in 1993 there were only 1,000 known individuals. However, thanks to conservation efforts, the 3-172

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population grew to over 140,000 fish in at least 80 habitats by the time of delisting in 2015. The USFWS officially de-listed Oregon Chub on February 17, 2015 (USFWS 2015). The ODFW has been implementing the Post-Delisting Monitoring Plan for the Oregon Chub (USFWS 2014). The purpose is to track changes in distribution, abundance, habitat conditions, and threats after delisting. Relevant information for the North Santiam subbasin is included below and is from the 2017 Oregon Chub Investigations Report (Bangs and Meeuwig 2018).

In sites sampled in 2017, Oregon Chub were found in the North Santiam River and surveyed areas are largely near Mehama downstream to the mouth of the North Santiam River (Figure 47). There are 26 known populations of Oregon chub in the Santiam River Basin, with 11 of those populations ≥500 adult Oregon chub. The ODFW estimated the population abundance of Oregon Chub at nine locations in the Santiam River Recovery Area. There were seven populations in the Santiam Recovery Area with ≥500 Oregon Chub (Table 20). They were unable to capture Oregon Chub at Santiam I‐ 5 Side Channels, where Oregon Chub were captured in 2016. The ODFW noted significant increases in Oregon Chub abundance at Geren Island North Channel, Stayton Public Works Pond, South Stayton Pond, and Pioneer Park Pond. They also noted a significant decline in Oregon Chub abundance at Chahalpam Slough.

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Table 20. Oregon Chub population abundance estimates from 2013‐2017, listed by Recovery Area*. Santiam Location name First Range 2013 2014 2015 2016 2017 Recovery discovered/ through Area introduced 2012 Basin NS Geren Island North Channel 1996 210 - 8,660 2,280 1,370 610 770 1,640 NS Stayton Public Works Pond 1998 0 - 1,100 1,530 260 22 300 1,300 NS South Stayton Pond 2006 54 – 6,230 1,100 1,370 620 610 1,020 NS Mehama Slough 2010 15 – 1,240 1,380 2,800 1,030 1,240 910 SS Foster Pullout Pond 1999 85 – 2,640 3,410 2,420 5,050 970 900 NS Pioneer Park Pond 1997 0 – 2,710 1,630 3,880 2,220 280 600 NS Birdhaven Slough 2014 5,350 5,980 3,780 500 NS Santiam Conservation Easement 1994 0 – 1,250 310 300 930 920 490 NS Green's Bridge Slough 1993 0 – 610 670 510 690 170 70 NS Chahalpam (Gray) Slough 1995 0 – 700 2,430 2,200 680 90 10 SANT Santiam I-5 Side Channels 1997 2 – 350 420 30 3 1 0 NS Budeau North Pond 2010 310 – 5,730 8,350 11,260 480 NS Budeau South Pond 2010 312 – 4,160 2,810 6,180 (200) 0 SS Rummel Pond 2016 (92) NS Boomer Slough 2014 6 0 0 NS Koenig Slough 2011 443 – 2,410 1,780 1,640 NS North Stayton Pond 2010 300 – 4,370 3,720 50 1,090 NS Buell-Miller Slough 2010 2 – 710 760 730 NS Taloali Slough 2013 4 581 NS Stout Creek 2013 39 54 420 NS Eck Slough 2015 43 NS Hatch Side Channels 2015 33 NS Harris Slough 2011 18 – 80 30 30 19 NS Trexler Farm Ponds 2013 53 28 4 NS Alder Creek 2015 1 NS Logan Slough 1997 0 – 1 0 0 SS Foster Reservoir 2014 9 SS Hospital Slough 2009 10 NS Cold Creek Slough 2011 0 – 59 SS Menear's Bend 2000 *Basins: NS= North Santiam, SANT= Mainstem Santiam, SS= South Santiam. Also includes a summary of data prior to 2013, including the years when ODFW first discovered or introduced each population and the ranges of abundance. Abundance was calculated using a mark‐recapture model, except where numbers are shown in bold, which only represent the number of fish captured. Location names in bold italics are locations where Oregon Chub were introduced. The numbers of fish stocked at introduction locations are shown in parentheses (table from Bangs and Meeuwig, 2018).

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Figure 47. All known Oregon Chub population in the Willamette River basin in 2017. Green circles indicate locations where Oregon Chub were detected during sampling. Red circles indicate locations where Oregon Chub were not detected during sampling but were observed previously. Overlapping symbols represent multiple locations occurring at or near the same survey location. Figure is from ODFW 2017 Oregon Chub Investigations (2018).

Coastal Cutthroat Trout Coastal Cutthroat trout (Oncorhynchus clarkii clarkii) can be found in the entire North Santiam drainage into the headwaters of most tributaries (such as Stout, Ayers, and Shellburg Creeks) as well as a fluvial population in the mainstem North Santiam River Detroit and Big Cliff dams (BLM 2006). This watershed does not include any anadromous coastal cutthroat trout, as they are not found above Willamette Falls. The species management unit above Willamette Falls is considered ‘not at risk’ due to its wide distribution, relatively high abundance, and resilience to events that reduce abundance (ODFW 2005).

Rainbow Trout Native rainbow trout (Oncorhynchus mykiss) are river dwelling in the mainstem North Santiam River, Detroit Reservoir and larger tributaries, which provides habitat for

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all life stages. In addition to the native population, triploid (sterile) hatchery rainbow trout are released at various locations in the North Santiam to provide for sport fishing opportunities. These hatchery fish come from various facilities (Leaburg, Willamette, Roaring River, Wizard Falls, Marion Forks, and Desert Springs) and current Detroit trout stocking is 250,000 fingerlings by ODFW and between 60,000 and 100,000 trout 8" or larger provided for anglers by the Corps and ODFW from April through October with peak stocking in June/July. Current (planned) annual rainbow trout stocking upstream of the dam are: 115,403 in the reservoir, 10,760 in the North. Santiam River, and 6,456 in Breitenbush River. The fishery is year round with spring being the optimal time to fish when the reservoir is near full pool and stocking is nearing its peak. Trout depth distribution in the spring and fall when it is cooler tend to be relatively shallow but would be found deeper during the hot months.

Kokanee Kokanee (Oncorhynchus nerka) are a non-migratory sockeye salmon and are currently stocked in Detroit Reservoir to support popular sport fishery. Kokanee are not native to the North Santiam and were first stocked by the Oregon fish commission in 1959 (Wetherbee and others 1965). They are raised at Wizard Falls Hatchery and current stocking in the reservoir is approximately 25,000 fingerlings in the fall during a September release. Local non-profit organizations of volunteers, such as Kokanee Power of Oregon (KPO) representing approximately 150 members, are devoted to the enhancement of kokanee, other salmon, and trout fisheries in the state and regularly work on projects with ODFW. Many hours and funding have been provided by KPO in the collection of ecosystem, biological, and creel census data at Detroit Reservoir. For the past 2 years, they have helped fund the raising and stocking of 27,000 kokanee (6 inches long) at Detroit Reservoir. While not native to the Santiam system, the Detroit Reservoir kokanee have become a major fishery for many anglers that contribute to the recreation attraction, local businesses, and livability of the area. There are two types of kokanee salmon – stream spawners and lake shoreline spawners. During rearing, they inhabit the lake. Sexual maturity usually occurs at age 3. Kokanee in Detroit reservoir naturally reproduce in the North Santiam River and tributaries, such as the Breitenbush, Tumble, French and Blowout Creeks, in the fall (Wetherbee, 1965). Kokanee compete for zooplankton with other species in the lake whether stocked or naturally spawned. Monthly zooplankton data collected by KPO volunteers in recent years at Detroit Reservoir indicates there is sufficient zooplankton to support a healthy kokanee population. Low food supply reduces the kokanee growth rate. Large rainbow trout have been known to feed on kokanee.

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Kokanee are most often found in deeper colder water and during the summer months are 80-100 ft below the surface in the reservoir but would change their depth depending on water temperature.

Land-locked Chinook The Corps and ODFW release adult hatchery Chinook above Detroit Reservoir to spawn, and their progeny may rear in the reservoir as an adfluvial population that returns upriver to spawn without migrating to the ocean. Anglers are not allowed to retain Chinook in or above Detroit Reservoir.

Wester Brook Lamprey Western brook lamprey are found in the Willamette River basin and is likely the second most common and widely distributed lamprey in Oregon after the Pacific lamprey (Kostow 2002 as cited in ODFW 2005). Western brook lampreys have no special state or federal status but are considered by the state as “at risk” (ODFW 2005). Overall little is known about western brook lamprey abundance and productivity in the Willamette River Basin.

Other Aquatic Species Other aquatic species found in the area of effect include Northern red-legged frog, foothill yellow-legged frog, western brook lamprey, Willamette floater, western pearlshell, and western ridged mussel.

Environmental Consequences

Methodology and Scale of Analysis The Corps analyzed impacts based on anticipated changes in aquatic habitat under each alternative compared to baseline habitat conditions. The Corps estimated changes in habitat, and the impacts to fish and aquatic species, associated with the proposed construction methods and operations of the SWS and FSS under each of the five construction alternatives using the baseline described in the NMFS 2008 BiOp Section 5.6, North Santiam Subbasin Effects, which outlines the effects under current operations and system configuration. However, spillway operations for downstream fish passage and temperature control were not part of the initial Proposed Action in the NMFS 2008 BiOp and, therefore, were not evaluated as part of Section 5.6 in the BiOp. Temperatures can have major impacts on salmon and steelhead and impacts vary based on life history stage. Richter and Kolmes (2005) summarized salmonid temperature thresholds and put together the following table describing upper optimal temperature criteria for salmonids (Table 21). The following analysis takes into consideration the temperature targets outlined by

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regional fish managers and compares the difference in temperatures from each alternative. The Corps considered the interim temperature control operations a part of the baseline conditions for this analysis and compared the differences of the alternatives to the base to make inferences of overall impacts to salmonids based on the upper optimal temperature criteria provided by Richter and Kolmes (2005). Table 21. Upper optimal temperature criteria developed for salmon and steelhead life history stages (Richter and Kolmes, 2005). These thresholds where used to compare alternatives to determine impacts to salmonids Life stage 7 – Day – average maximum daily Weekly mean temperatures temperatures Spawning and incubation 13°C (55°F) 10°C (50°F)

Juvenile rearing 16°C (61°F) 15°C (59°F)

Adult migration 18°C (64°F) 16°C (61°F)

Smoltification except steelhead 16°C (61°F) 15°C (59°F)

Steelhead smoltification at fourth level 14°C (57°F) 12°C (54°F) hydrologic unit code watershed The geographical analysis for the alternatives includes the area of construction of the SWS tower and FSS, staging areas, Detroit Reservoir, and downstream habitats within and adjacent to the North Santiam River from Detroit Dam to the confluence with the South Santiam River. The downstream areas under review would include those areas within the active channel of the North Santiam and off-channel habitats that have connectivity to the North Santiam River. Temporal scale analysis for the alternatives would include the duration of construction of the SWS and FSS, the duration of any proposed drawdown of Detroit Reservoir and the resulting duration of the reduced flows within the North Santiam River downstream of Detroit Dam, and the operation of the SWS and FSS.

Staging Areas Actions at the staging areas described in Sections 2.7.2.5 would have no direct or indirect impacts on fish and aquatic species except at Cumely Creek, if a cofferdam is required. A cofferdam at Cumely Creek would require the dewatering and fish salvage in the area within the cofferdam, potentially resulting in injury or mortality of a limited number of fish. Under all alternatives described in Section2.6, the cofferdam would require dewatering and fish salvage that could result in injury or mortality to a limited number of fish. Dewatering and earthmoving activity would disturb the benthic community within the cofferdam during construction, however; this area is typically dewatered in the winter during normal operations. The Corps would restore site to its preconstruction condition once the project is complete.

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CA1. No Action Below is a summary of the No Action Alternative, described in more detail in the 2008 BiOp Section 5.6. The No Action Alternative would likely see no measurable change to the abundance, habitat or behavior of resident fish like Oregon chub. Pacific lamprey would also see no measurable change to the abundance, habitat, or behavior. Pacific lamprey would continue to lack access to spawning and rearing habitat above Big Cliff and Detroit dams. The effects of the No Action Alternative on North Santiam populations of UWR Chinook Salmon and UWR steelhead would be essentially the same as NMFS determined in its baseline analysis from their 2008 BiOp (NMFS 2008). It was determined that Chinook salmon and steelhead ESUs would continue to decline and critical habitat would continue to be adversely modified. Further jeopardy of salmonids would have a major impact on the survival and recovery of UWR Chinook salmon and winter steelhead. These fish provide important economic, spiritual, recreational, and subsistence benefits to tribes, local community members, and others throughout the state, nation, and internationally. The No Action Alternative would continue to have a major impact on UWR Chinook salmon and UWR steelhead: • The dam would continue to provide the same temperature management capabilities that it does at this time, which is further discussed in Section 2.

o Degradation of water quality and physical habitat elements downstream from the dam complex would continue.

o Upstream run timing of adults would not change and continue to be impacted when environmental conditions and dam operations limit the ability to achieve downstream temperature targets as called for in the WFOP. Adult salmonid migration, spawning and incubation, and juvenile and kelt downstream survival would continue to negatively affect the productivity of listed salmon and winter steelhead in the lower North Santiam River. This has been identified as one of the most critical limiting factors for species recovery (NMFS 2011). • The dam would continue to provide the same fish passage capabilities that it does at this time.

o Accessible spawning and juvenile rearing habitat in these reaches and the reservoir would not be optimized for increased production upstream of the dam site. Habitat limiting factors such as food production would not be maximized due to lack of carcasses and release of nutrients that would support the aquatic ecosystem upstream of the dam. However outplanting of hatchery Chinook salmon above Detroit Dam helps mitigate some of the nutrient cycling concerns.

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o Natural origin fish trapped at Minto would continue to be limited into the short four mile Big Cliff to Minto reach. This reach is often exposed to high TDG.

o Fish passage through Detroit and Big Cliff dams would continue to be impaired by the available dam outlets and operational limitations during low, normal, and high flow years. Although the spillway, RO, and turbine outlets provide some passage benefit, these routes are not considered safe for fish.

o Resident fish such as coastal cutthroat trout and western brook lamprey exhibit migratory behavior or life history strategies that do so. Existing passage that would persist under the No Action Alternative retains lack of connectivity between/among populations above and below Detroit and Big Cliff dams. • Recreational fish such as rainbow trout and kokanee would not be affected. • Stream flows can be further reduced through existing water rights for irrigation purposes and can potentially have an impact on fish species of concern depending on water availability.

CA2. SWS and FSS Constructed with a Two-year Deep Drawdown

Impacts during Construction Resident aquatic species effects may include higher risk of predation, food scarcity, the failure of entire age-cohorts in some species, and the loss of spawning and rearing habitat. These effects could lead to widespread mortality, the spread of opportunistic disease, and a reduction in native fish populations for years following the action. Conditions would likely be more favorable to non-native fish species thereby increasing predation on and negative interactions with native fish species. Stranding of native fish in pockets or pools of water would likely also result in mortality. Under CA2, impacts to UWR Chinook salmon and summer steelhead would likely be moderate to significant because the Corps would not be able to meet flow targets below Big Cliff Dam, depending on water year. In addition, the Corps may not be able to meet temperature targets, which would lead to significant impacts such as delayed upstream migration of adult Chinook salmon, shift in fry emergence, and increased stress / mortality of salmonids in warm water years. Significant impacts may also occur from high turbidity and sedimentation resulting in additional stress to fish. Impacts to adult Pacific lamprey would generally be similar to salmonids; however, impacts due to temperature would likely be less extensive. Impacts to Oregon Chub would likely be significant due to low flows resulting in loss of habitat and loss of mainstem connectivity of off-channel habit.

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Downstream impacts Over all, downstream effects to resident aquatic species may include higher risk of predation, food scarcity, the failure of entire age-cohorts in some species, and the loss of spawning and rearing habitat. These effects could lead to widespread mortality, the spread of opportunistic disease, and a reduction in native fish populations for years following the action. Conditions would likely be more favorable to non-native fish species thereby increasing predation on and negative interactions with native fish species. Stranding of native fish in pockets or pools of water would likely also result in mortality. Increased turbidity and sedimentation would result in significant imapcts to off- channel habitat and the species found there as well as moderate to significant impact to maintsem habitat. Flow Operations during this alternative would alter flow conditions, both total flow and water quality, primarily temperature, TDG and turbidity. The NMFS 2008 BiOp requires specific flow regimes below Big Cliff Dam. These operations include minimum and maximum flow targets, increasing and decreasing flow rate targets (ramp rates), and recommendations for operations during high flow periods. The WFOP (USACE 2018a, Table 2) details the flow rate and ramp rate requirements for Big Cliff Dam. Under CA2, the Corps would maintain the elevation of Detroit Reservoir at a maximum of 1,300 ft during the 28-month drawdown and, as a result, outflows at Detroit/Big Cliff Dams would not follow current operations described in the No Action Alternative. Section 3.4.3 describes the flows under each alternative. This analysis shows that, under CA2, flows discharged at Big Cliff Dam would fall below 750 cfs more than half of the time, with these low flows occurring between mid- July and November. The effects of this would vary by reach with some of the greatest effects being downstream of the major diversions at Geren Island near Stayton, Oregon. If the withdrawals occur at the modeled 300-500 cfs for this reach, there would be flows in the lower reaches (between Stayton and the confluence with the South Santiam) even lower than historic pre-Project flows. These low flows could have major impacts to mainstem and off-channel aquatic habitat and their associated species. For instance, during the summer of 2009, flow in the North Santiam was severely reduced due to mechanical failures at Big Cliff Dam. Flow at the Mehama gage was reduced to 716 cfs. A number of Oregon chub populations were rapidly dewatered, and an important population was maintained by the Corps and ODFW through pumping. Low flow conditions persisted over a short period (approx. 7 days), but this event had a major impact on chub populations in the North Santiam for at least one year following the event. ODFW also observed high mortality of Pacific lamprey ammocoetes in off- channel habitats during the low water events in 2009. Off-channel habitats are preferred

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by Pacific lamprey ammocoetes over instream habitats. Therefore, low flows as a result of CA2 would likely have significant impacts on Pacific lamprey. Additionally, drought conditions in the summers of 2015 and 2016 demonstrate the effect of prolonged low flow conditions on Oregon chub habitats. ODFW observed lower water elevations during these drought years than during the Big Cliff event of 2009; off- channel habitats are sponge-like, and there’s a significant hysteresis between changes in in-stream flow and water elevation in off-channel habitats at most locations during low flow periods. Flow at the Mehama gage was at or above baseflow elevations through the summer months (1,000 cfs), but given the dry springs both years, ODFW saw lower water elevations than base flow conditions through summer months in normal water years. During a prolonged low/base flow period, as proposed, it is likely habitats will be further impacted due to the length of these reduced flow periods. As a result, there would be moderate to significant effects to many species of concern found in these habitats such as Pacific lamprey, Oregon chub and endemic freshwater mussels. The extremely low flows in this reach also have the potential to effect the anadromous fish of the North Santiam in the stretch below Stayton, Oregon. This includes some of the most intact and complex off-channel habitats in the Willamette system. This reach is a migratory corridor for adult UWR Chinook and UWR steelhead, introduced fall Chinook and coho salmon also use it heavily, and it serves as an important rearing habitat for all species and runs. The Corps used the flow targets outlined in Table 2 to compare the No Action Alternative with the 28-month drawdown proposed under CA2. The bulleted list below specifies how the Corps would meet or miss flow targets based on a wet and cool water year forecast and a dry and hot water year forecast. The Corps evaluates the flow impacts to UWR Chinook salmon and UWR steelhead based on life history present at specific times of the year in the reach between Big Cliff Dam and the city of Gates, Oregon (referred to as Reach 1). Figure 63 shows forecasted flows below Detroit Dam broken up into segments representing times of year when specific salmonid life history stages are present. The letters shown in the following paragraphs represent the life history stages labeled in Figure 63. It is important to note that this reach is the closest to Detroit and Big Cliff dams and that the effects described herein may differ significantly as one travels further downstream. In most years during the summer months, the water withdrawals at Geren Island would exceed the volume of flow from local sources, such as the Little North Santiam, near Mehama, Oregon. This could cause flows in the lower reaches to fall far below those discharged from Big Cliff Dam.

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Figure 48. Simulated outflows at Detroit Reservoir during 1 year of the 1,300 ft drawdown period (Jan-Dec). These conditions persist for 1 additional year during the drawdown operations occurring in CA2. Black dashed lines represent flows at 1,000, 1,250 and 1,500 cfs. The blue dashed lines break up the year into key periods of the year representing Chinook salmon and steelhead life history stages

1. Initial Drawdown (September 6th to Mid-November): In order to reach the target elevation of 1,300 ft, it would be necessary to increase discharges much higher than is typical under the baseline or No Action Alternative. These unusually high flows could affect the spawning success of the Chinook below Big Cliff and Minto dams. Flows peak between 6,000 and 9,000 cfs during peak spawning activity from mid-September to mid-October (see Appendix P). Shortly afterward, when the target forebay elevation is reached, flow is reduced dramatically to as low as approximately 700 cfs with roughly 1,500 cfs being the 50% exceedance. This would likely have a major impact on the egg survival for the 2021 brood year since most fish would probably spawn in higher elevation spawning gravels that would later be dewatered as flows were reduced. There is also likely an increased risk of stranding for all fish species and life stages under this operation. Even if the operation follows the established ramp rates, the overall

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change in flow is so great there is a good chance some habitats would become isolated and eventually de-watered. 2. (A) February 1 – March 15: The flow target below Big Cliff is 1,000 cfs and would be met except under the fifth percentile. In a water year where we see flows at the forecasted fifth percentile, the target flow would still be met except during the early part of February in which it is within 100 to 200 cfs of the target. Therefore, the impact to salmonids during this time would be negligible compared to the No Action Alternative. 3. (B) March 16 – May 31: The flow target during this period is 1,500 cfs for winter steelhead spawning. There is also regional guidance to keep flows below 3,000 cfs during salmonid spawning. Under the 25, 50, 75, and 95 percentile for forecasted outflow at Detroit Dam the flow target would be met below Big Cliff and, therefore, the impacts would be negligible compared to the No Action Alternative. The exception is during water years predicted at the fifth percentile where winter steelhead spawning impacts would be minor. Flows during this period in Reach 1 can range from 1,000 to 1,500 cfs and the percent of spawning habitat available varies from 90% (1,000 cfs) to approximately 97% (1,400 cfs) (Gagner et al. 2014). When forecasted water years fall within the 50th percentile the upper flow limit would not be exceeded. However, for the 75th and 95th percentile flows can exceed the threshold which can result in desiccation of redds when flows are reduced during the incubation period. In addition, under high flows the percent of available spawning habitat decreases as flows go up from 3,000 to 6,100 cfs with available habitat in Reach 1 going from 37% to 8%, respectively. However, these high flows can also occur under the No Action Alternative and therefore impacts are negligible compared to the No Action Alternative. 4. (C) June 1 – July 15: The flow target during this period is 1,200 cfs for winter steelhead incubation. During this period, flow targets would likely only be met through most of July based on 50% of the forecasted water years. Water years in the 25th percentile would only be met in the first week of June. Reduced flows have the potential to dewater steelhead redds if spawning habitats that were available during higher flows are dewatered prior to the eggs hatching and fry swim-up stage. 5. (D) July 16 – Sept 4: The flow target during this period is 1,000 cfs for rearing of juvenile fish. For water years in the 5th, 25th, and 50th percentile the flow target would not be met. However, based on Gagner et al. (2014), in Reach 1, fry and juvenile rearing habitat approaches 100% as flows drop from 1,000 cfs to 500 cfs (Table 22).

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6. (E) Sep 5 – Oct 31: The flow target during this period is 1,500 cfs for Chinook salmon spawning. For water years in the 5th, 25th, and 50th percentile the flow target would not be met. For water years expected 50% of the time, spawning habit would be reduced from approximately 99% to roughly 65% in Reach 1. Flows during this period are not expected to go above 3,000 cfs as they did during period C. 7. (F) Nov 1 – Jan 31: The flow target during this period is 1,200 cfs for Chinook salmon egg incubation. For water years, forecasted 50% of the time the target flow would be met, with the exception being in early November when flows would be slightly lower than the 1,200 cfs target. This could result in a reduction of up to 3% of the available spawning gravel for redds that is available when the flow target is met in Reach 1. 8. Post tower construction refill (January to June 2024): This would involve an unusually long period of minimum flows in order to refill the reservoir from the construction pool elevation. Since the volume of water required is greater, there is a chance that the reservoir would not completely fill to the spillway crest. Temperature operations using the newly constructed SWS cannot be implemented until completion of commissioning. The tower should be operational and fully commissioned by June, so any impacts due to temperature would be minor, unless commissioning is delayed due to a lack of refill or technical issues. There is also an increased risk of not being able to meet downstream flow targets.

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Table 22. Percent of maximum habitat area at specified flows (cfs) for spring Chinook salmon and steelhead life stages between Big Cliff and the city of Gates (Reach 1) on the North Santiam River, Oregon. Table from Gagner et al. 2014. Spring Spring Spring Spring Winter Winter Winter Winter Chinook Chinook Chinook Chinook Steelhead Steelhead Steelhead Steelhead Q (cfs) Adult Spawning Juvenile Fry Adult Spawning Juvenile Fry 500 62 49 100 100 64 48 100 99 600 66 59 91 90 77 59 96 100 700 70 65 83 87 87 66 93 96 800 73 73 77 89 93 74 90 97 900 77 81 73 81 97 83 87 91 1000 80 89 70 81 98 90 83 82 1100 83 96 67 78 99 97 80 72 1200 85 99 65 79 99 99 77 75 1286.3 87 100 64 81 100 100 75 80 1400 90 99 63 85 99 97 72 72 1600 94 95 63 83 98 91 68 61 1800 98 90 60 84 97 86 63 50 1927.6 99 87 58 88 94 83 59 48 2200 100 75 54 84 89 71 54 45 2400 100 64 52 82 83 61 50 45 2600 88 55 49 83 78 52 46 41 2800 98 47 47 83 73 44 43 37 3000 96 39 46 81 68 37 41 32 3146.3 95 34 45 80 66 34 39 32 3500 93 26 44 79 61 27 37 31 3800 90 21 42 79 56 22 35 29 4100 88 19 42 77 52 20 34 32 4500 85 16 40 75 48 16 32 31 4900 82 14 39 73 45 13 31 33 5300 79 13 38 70 41 11 30 31 5700 76 11 37 67 39 9 29 29 6100 73 11 36 64 37 8 28 25 6500 71 11 35 61 36 7 27 22 7000 69 11 34 57 35 7 27 20 7500 66 11 33 52 34 7 26 16

Water Quality: Temperature Operations during construction of CA2 would also have an impact on interim temperature control operations. The Corps implements temperature control operations to improve water temperatures downstream of Detroit Dam to benefit ESA-listed anadromous fish species, by providing temperatures that are warmer in the summer 3-186

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and cooler in the fall than what is typical from normal project operations (pre-2007). These goals are achieved by operating to the agreed upon resource agency (NMFS, USFWS, and ODFW) target temperatures that were originally developed for the McKenzie River below Cougar Dam, and modified for downstream of Detroit/Big Cliff dams. A review of these targets, in comparison to literature-based thermal preferences for winter steelhead, indicate that these temperature targets are appropriate for the North Santiam River and meet the needs of both winter steelhead and spring Chinook salmon in the North Santiam basin (Table 5 - 1 in the WFOP; USACE, 2018a). Beginning in 2017, a multi-agency team including ODFW and NMFS developed and adopted new temperature targets (Table 2-1 in the WFOP; USACE, 2018a). For the purposes of this EIS and because of the long-term implications of the SWS, the temperature targets used to simulate thermal effects were those that most closely resemble natural seasonal temperatures in the North Santiam River above Detroit Dam under which winter steelhead and spring Chinook evolved. Further comparisons of temperature targets and effects on Chinook behavior and survival is discussed in Keefer, et. al. (2019). The EIS discusses water quality parameters in detail in Section 3.6. The Corps compared temperatures under CA2 to the temperature targets and to temperatures under the No Action Alternative at Niagara (Table 23). The Corps also used total degree-days to determine differences in fry emergence for Chinook salmon and winter steelhead. It is important to remember that even if impacts to fish are negligible when compared to the baseline (i.e., similar to impacts under the No Action Alternative) impacts to fish may still be significant overall when temperature targets are missed. In wet years, temperatures under CA2 are closer to the temperature targets than under the No Action Alternative and, therefore, impacts to salmonids would be negligible if not beneficial compared to the No Action Alternative. In November, during salmon egg incubation, temperatures are colder under CA2 and hotter under the No Action Alternative than the targets. There are a number of ways in which low flows will create effects to water quality in off-channel habitats during low flow periods as well. Reduced flow into, and lower hydraulic head around, habitats may increase water temperature through summer months; many of these habitats are at or near critical temperature during these periods already. Vegetative growth begins to fill the water column of off-channel habitats in early spring; as water elevation is reduced, vegetation will be confined to a smaller volume of water. While this vegetation provides dissolved oxygen to the water column during the day, it uses it overnight, and combined with warm water temperatures can lead to a summer die-off event or low DO cascade (plants begin to die, limiting a source of DO, and when bacteria colonize, there’s greater DO need in a system, causing more plants to die, etc.). If sediment is transported into these habitats, summer habitat will be

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immediately reduced; during construction, this could occur immediately before a period of reduced summer flows, further exacerbating the impacts that either would cause on their own. Table 23. Comparison of modeled temperatures (see Section 3.15) at Niagara under CA1, CA2, and CA3. MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Niagara 2011 (wet / cool year; °F) Target 43.4 45.6 50.9 55.7 59.7 59.7 55.9 50.7 45.9 43.3 CA2 and 3 40.2 40.9 43.4 47.8 53.6 57.9 55.4 49.2 41.9 Difference 3.2 4.7 7.5 7.9 6.1 1.8 0.5 1.5 4 Niagara 2011 (wet / cool year; °F) Target 43.4 45.6 50.9 55.7 59.7 59.7 55.9 50.7 45.9 43.3 CA1 39.6 40.8 43.8 47.4 52 56 54.8 48.4 48.1 Difference 3.8 4.8 7.1 8.3 7.7 3.7 1.1 2.3 2.2 MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Niagara 2015 (dry /hot year; °F) Target 43.4 45.6 50.9 55.7 59.7 59.7 55.9 50.7 45.9 43.3 CA2 and 3 45.5 45.6 51 58.7 62.1 60.5 55 51.2 43.7 Difference 2.1 0 0.1 3 2.4 0.8 0.9 0.5 2.2 Niagara 2015 (dry /hot year; °F) Target 43.4 45.6 50.9 55.7 59.7 59.7 55.9 50.7 45.9 43.3 CA1 43.9 45.3 47.8 50.7 54.7 59.1 56.3 58 52 Difference 0.5 0.3 3.1 5 5 0.6 0.4 7.3 6.1 *Temperatures were modeled assuming a wet / cool year (2011) and separately a dry / hot year (2015). Blue highlighted cells represent temperature differences that are colder than temperature targets and the orange highlighted cells represent temperature differences that are warmer than targets

Table 24 and Table 25 summarize degree-days during the period when UWR Chinook salmon and winter steelhead (respectively) are spawning and egg incubation occurs . When temperature targets are met, the total degree-days in the months of September through November is 1,714. This is higher than both the No Action Alternative (1,675 total degree-days) and CA2 (1,533 total degree-days) resulting in emergence under CA2 being delayed compared to both the No Action Alternative and when temperature targets are met.

The total degree-days for winter steelhead, when temperature targets are met during months critical for spawning and egg incubation (May – July), is 2,156. Based on degree-days, emergence would be similar for both the No Action Alternative (1,448 total degree-days) and CA2 (1,497 total degree-days) during the same period, however, both are delayed compared to water years when temperature targets are met.

Temperature targets would not be met for both CA2 and the No Action Alternative in May–July, resulting in the delay of adult upstream migration. Migration delays coupled 3-188

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with lower flows could lead to significant impacts such as an increase in pre-spawn mortality.

In hot years, temperatures would be generally slightly over temperature targets under CA2 with a variance from the target ranges of 0.1 to 3°F hotter. The most impactful difference between the CA2 and the No Action Alternative is in July. Steelhead egg incubation and juvenile fish rearing is occurring during this time. With temperatures above 61°F (upper optimal temperature; Table 26), rearing fish would likely be stressed and more susceptible to disease and, as a result, predation. These impacts would be moderate to significant. Steelhead egg hatch may also be accelerated due to increased temperatures under CA2 and there is potential for egg mortality due to temperatures going above the 50 to 55 °F upper temperature threshold, with temperatures in June and July ranging from 58.7 to 62.1 °F. Emergence timing for Chinook salmon under CA2 (1,636) is closer to the timing when temperature targets are met (1,714). Under the No Action Alternative, emergence would occur earlier than both scenarios discussed above. Total degree-days for winter steelhead in May to July in water years when temperature targets are met is 2,156. Under the No Action Alternative and CA2, the total degree-days for winter steelhead in the same period is 1,752 and 2,326, respectively. Therefore, emergence would be earlier under CA2 than under the No Action Alternative. Table 24. Degree-days (summarized from Section 3.6) for periods when UWR Chinook salmon are spawning and eggs are incubating for CA1 – CA4 SEP OCT NOV SEP - NOV SEP OCT NOV SEP - NOV Target 716 580 418 1714 716 580 418 1714 Measured 663 559 514 1736 799 691 574 2064 CA1 684 509 482 1675 729 807 601 2137 SWS (interim op) 717 580 400 1697 716 660 576 1952 CA4 722 714 482 1918 886 705 535 2126 CA2 and CA3 703 534 296 1533 691 595 350 1636

Table 25. Degree-days (summarized from Section 3.6) for periods when UWR winter steelhead are spawning and eggs are incubating for CA1 – CA4 MAY JUN JUL MAY - JUL MAY JUN JUL MAY - JUL Target 584 712 860 2156 584 712 860 2156 Measured 355 495 638 1488 466 537 696 1699 CA1 366 461 621 1448 489 560 703 1752 SWS (interim op) 422 567 830 1819 585 711 857 2153 CA4 359 467 685 1511 577 712 860 2149 CA2 and CA3 353 473 671 1497 590 802 934 2326

The Corps also compared temperatures under CA2 to the temperature targets and to temperatures under the No Action Alternative at Mehama (Table 26). In wet years, 3-189

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temperatures are similar to the temperature targets under the No Action Alternative and, therefore, impacts to salmonids would be negligible. However, in August temperatures are above the optimal upper temperature for rearing fish and could result in increased stress, disease susceptibility, and mortality. Temperature targets would not be met under both CA2 and the No Action Alternative in May – July, resulting in the delay of adult upstream migration. Migration delay coupled with lower flows could lead to significant impacts such as an increase in pre-spawn mortality. In hot years temperature impacts in the Mehama reach would be similar to impacts described above below Big Cliff Dam at Niagara. Table 26. Comparison of modeled temperatures (see Section 3.15) at Mehama under CA1, CA2, and CA3*. Mehama 2011 MAR APR MAY JUN JUL AUG SEP OCT NOV DEC (wet/cool year; °F) Target 43.4 45.6 50.9 55.7 59.7 59.7 55.9 50.7 45.9 43.3 CA2 and CA3 41.7 42.2 45 50 58 62.5 59 50.4 Difference between 1.7 3.4 5.9 5.7 1.7 2.8 3.1 0.3 Target and CA2 and CA3 CA1 41.9 42.5 45.3 49.6 56.9 60.5 57.1 49 Difference between 1.5 3.1 5.6 6.1 2.8 0.8 1.2 1.7 Target and CA1 Mehama 2015 (dry/hot year; °F) Target 43.4 45.6 50.9 55.7 59.7 59.7 55.9 50.7 45.9 43.3 CA2 and CA3 47 47.1 53.9 63.7 67.5 64.8 57.8 53.2 Difference between 3.6 1.5 3 8 7.8 5.1 1.9 2.5 Target and CA2 and CA3 CA1 47.2 47.5 52.8 59.1 62.5 63.5 58.2 57.3 Difference between 3.8 1.9 1.9 3.4 2.8 3.8 2.3 6.6 Target and CA1 *Temperatures were modeled assuming a wet / cool year (2011) and separately a dry / hot year (2015). Blue highlighted cells represent temperature differences that are colder than temperature targets and the orange highlighted cells represent temperature differences that are warmer than targets

Sediment Transport (Turbidity) During the drawdown proposed under CA2, significant sediment may be exported downstream of Big Cliff Dam (see Table 11 in Section 3.5.4.4 for details). As a result, turbidity is expected to be elevated above 10 FNU with an expected maximum persistent turbidity of 400 FNU for 65–70 days (see Table 11 in Section 3.5.4.4 for details). Juvenile salmonids and other resident fish are likely to experience similar impacts to those experienced by hatchery fish (see Section 3.10.1.2 for details) with the exception that these fish are in rivers and not confined to a raceway. In the river environment, they would potentially have the ability to move and find areas where there

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is less turbid water and, therefore, be less impacted than the hatchery fish (see Section 3.10.1.2 for details). However, impacts are likely going to be moderate to significant due to irritation of the gills and increased stress. Large discharges of siltation can also have profound short-term and long-term effects on aquatic habitats. In the Fall Creek watershed, the Corps estimated that 50,300 tons of sediment was released during 2012 to 2013 over 6 days (Schenk and Bragg 2014). Novel beaches and gravel bars were immediately observable in the tailrace where there was sufficient sediment to require the Corps to shut down the screw trap located there. Although conditions will likely be different from those during the initial complete drawdowns of Fall Creek Reservoir, there is a risk that sediments may be transported into off-channel habitats. ODFW was not monitoring off-channel habitats downstream of Fall Creek prior to the first drawdown, although anecdotally landowners of monitoring sites report that rapid sedimentation occurred in off-channel habitats. Since initiating studies on Fall Creek following the first drawdown, ODFW observed sedimentation occurring annually during the subsequent drawdowns. In recent years (2015-2018), it appears that less sedimentation is occurring in the off-channel habitats from the drawdowns. However, after the initial drawdowns ODFW observed reed canary grass and willow quickly colonize areas where sediment was deposited, increasing the roughness of the channel and stabilizing the sediment. Despite the Corps running Fall Creek to the upper managed flow limit, much of the sediment in the off- channel habitat has remained in place; a new thalweg has been cut through the off- channel habitats with a smaller width and depth of the original channel, and less habitat is available at summer flow levels. Under current managed flows, the North Santiam River likely has reduced capacity to create and sustain off-channel habitat features, and the reduction in habitat quantity and quality may impact resident fish, juvenile anadromous fish, amphibians, and invertebrates that are obligate to these habitats. Although the Santiam is a much different basin, it is not fully understood where mobilized sediment may end up after transport through the reservoir. In Fall Creek, when sediment transport and scour occurred during low flow periods, when off-channel habitats were not connected to the river, sediment typically flushed down the river channel rather than being deposited in the floodplain; a management strategy that limits sediment transport into floodplain habitats be developed for the North Santiam. Changes to the mainstem are somewhat ephemeral with the finer sediments being washed downstream after the first few freshets. In the off-channel habitats, however, many of the new sand and silt bars were quickly colonized by riparian plants which helped stabilize them in place. Unlike Fall Creek, the sediment transported downstream of Big Cliff would be predominantly small sands and finer silts. The sheer volume poses a risk of deposition, which could degrade spawning habitats in slower velocity reaches as well as negatively impact operations of hatchery water supplies. Increases in turbidity

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and sedimentation could also affect any western pearlshell mussel populations downstream. The silting in of mussel beds would likely result in loss of those individuals. The North Santiam is a high gradient stream (32 ft/mile) from Big Cliff Dam (RM 58.1) to Mehama (RM 39). Under CA2, major siltation and turbidity effects are expected in the Mehama Reach during drawdown and, therefore, salmonids would be impacted at some level. In the reach from Mehama to near Stayton (approximately RM 28.4) the stream gradients decrease to about 20 ft/mile. Expected sedimentation is moderate-to-high with high-to-severe siltations. The Corps expects turbidity to be persistent and high-to- severe for a long duration. Therefore, salmonids would be impacted at some level. Significant impacts are likely to occur during September and November after the initial drawdown when Chinook salmon spawning and egg incubation occurs. Impacts would include gill irritation, potentially resulting in increased stress and pre-spawn mortality. In areas where siltation occurs, there is the potential that salmon redds would be covered, restricting oxygen transfer to incubating eggs. In the reach from Mehama to near Stayton, operating the reservoir for flood control at the proposed levels would cause low to moderate siltation and turbidity affects. From the confluence of the North Santiam with the South Santiam (RM 11.7) to the Willamette River, the stream gradient flattens to 10 ft/mile or less. Under CA2, potentially-high to extremely-high sedimentation may occur. Turbidity levels would be commensurate with suspended sediment quantities exported to this reach. Potential impact to salmonids in this reach are minor to moderate due to potential sedimentation of redds.

Reservoir Impacts The following sections provides impacts primarily to hatchery UWR Chinook, and their progeny, that are both part of the DPS and outplanted above Detroit (assuming this management strategy would continue). Fish managers will work together to develop an outplanting strategy plan during construction to minimize the impacts to transported fish. Although, this has not yet been developed it will be once a preferred alternative and construction plan is selected. Natural origin adult UWR Chinook and steelhead are not transported above Detroit at this time due to the lack of safe downstream fish passage. Construction would displace other reservoir fish (Table 17). Though impacts during construction of the action alternatives may be similar or worse in the short-term, the impact of the No Action Alternative is very significant for salmonids. The No Action Alternative has impacts to establishing new fish populations and the environment downstream. The No Action Alternative does not meet the purpose and need for this project to improve downstream temperatures and enhance

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downstream passage over the long-term while maintaining the authorized purposes of the Detroit and Big Cliff dams. Water Quality: Temperature A lower lake level at elevation 1,300 would result in a smaller volume of water being stored in Detroit Reservoir and reduced streamflow downstream of Detroit compared with No Action. This would result in warmer reservoir conditions in summer, especially in a low-flow year such as 2015. However, due to its reduced volume, the reservoir could “turn-over” (reservoir temperatures would more uniform and no longer be stratified by depth) sooner than at normal pool elevations, which would result in cooler release temperatures from Detroit Reservoir in the fall, especially in low-flow years. Higher water temperatures in the reservoir may result in increased stress levels and mortality in Chinook and reservoir fish populations with limited cold-water refuge area. During a low flow, hot/dry year, the Corps expects thermal impacts to be minor to moderate for Chinook and other fish in the reservoir at elevation 1,300 under CA2 compared to the No Action Alternative. If the “turn-over” of the reservoir occurs sooner than at normal pool elevations, this would result in cooler reservoir temperatures at Detroit in the fall. During a cool fall, the Corps expects thermal impacts to be neutral for Chinook and other fish in the reservoir at elevation 1,300 under CA2 compared to the No Action Alternative. Water Quality: DO The DO impacts are likely to be minor to major for Chinook and other fish in the reservoir under CA2 compared to the No Action Alternative. The DO levels in the Detroit Reservoir can depend on sediment oxygen demand and biologic productivity (algae growth). Reservoir DO can also vary with depth, season, meteorology, and dam operations. The DO concentration generally increases with depth, reaching its maximum concentration at around 100 ft deep, which typically stays constant toward the lakebed. Increased suspended sediment derived from increased scour at lower pool levels could lead to elevated turbidity as described in Section 3.5. The addition of fine sediments to Detroit Reservoir could provide additional nutrient source (Phosphorus) for blue-green algae. This could result in greater diurnal variation of DO and pH in the reservoir. Under CA2, DO would likely be the lowest of the alternatives in this EIS due to low streamflow during late summer and fall. During the drawdown proposed under CA2, fish may crowd into smaller areas potentially resulting in higher stress levels due to low DO levels, especially during a low flow hot/dry year. Water Quality: Sediment and turbidity Elevated SSC and turbidity in Detroit Reservoir during the drawdown proposed under CA2 is expected to have moderate to major impacts for Chinook and other fish in the reservoir compared to the No Action Alternative. The sediment effects analysis

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(Section 3.5, Appendix D) showed that during drawdown inflows may mobilize and transport downstream sediment not normally directly exposed to runoff and erosive flows on the reservoir bottom and banks, including the former channel and floodplain. The sediment deposition in the reservoir are largely clays, silts, and some fine- and very-fine sand. Reduced volume in the reservoir could also increase transport of incoming sediment loads from North Santiam and Breitenbush Rivers and Blowout Creek downstream. The elevated turbidity in the reservoir resulting from a drawdown to elevation 1,300 would undoubtedly increase stress on any juvenile Chinook subjected to it and is the most concerning impact to fish in the reservoir. The maximum allowable SSC for fish culture is 2,000 ppm (Wedemeyer, 2002). With an expected persistent turbidity of 250 FNU, as described in Section 0, the drawdown to elevation 1,300 would elevate persistent turbidity to 160% of recommended levels for fish culture. The recommended turbidity levels for fish culture primarily consider the impacts to juvenile fish, which are more susceptible to elevated turbidity than adults. Elevated suspended sediment concentrations cause irritation in the gills, increasing likelihood of disease contraction. Additionally, high turbidity decreases a fish’s ability to navigate waterways, limiting visibility and having detrimental effects on migration efficiency and predator avoidance. Rock Removal (Blasting) Blasting would be conducted completely in the dry. It is anticipated that the blasting site is far enough away from open-water that pressures would be greatly attenuated and impacts to fish would be minor or nonexistent. Fish immediately adjacent to the blasting areas could be temporarily displaced by the vibrations created by drilling or by noise and pressure waves from noise and pressure waves during construction blasting. Displacement would be temporary and fish would return to the area after construction.

Loose material removal Construction would require the removal of loose material through techniques such as clam shelling. The Corps expects the noise and vibration impacts during removal of loose material to, at a minimum, displace fish from the area. Fish injury or mortality from noise and vibrations resulting from material removal are uncertain but likely minor as fish will avoid areas with high noise and vibration. Hammer drilling Construction could include hammer drilling and grouting to fill voids as well as bond together the FSS mooring support structure. The Corps expects the resulting noise and vibration impacts during construction of the SWS base and the attachment of the SWS to the dam to, at a minimum, displace fish from the area. This would occur with both above water and underwater activity. Fish injury or mortality from noise and vibrations

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resulting from material removal are uncertain but likely minor as fish will avoid areas with high noise and vibration. Underwater concrete placement If not properly controlled, underwater concrete placement can have effects on water quality, especially pH. The Corps expects the noise and vibration impacts during underwater concrete placement to, at a minimum, displace fish from the area. Fish injury or mortality from noise and vibrations resulting from material removal are uncertain but likely minor as fish will avoid areas with high noise and vibration. Potential for isolation and stranding The lowering of Detroit Reservoir to levels not seen since the original construction has the potential to isolate fish in pools and expose them to stress, crowding, higher temperatures, and mortality due to poor water quality, increased risk of predation (see below) or even desiccation. Though not quantified, the stranding of both bull trout and Chinook salmon as well as other fish were observed during a similar drawdown for construction at Cougar Dam between 2002 and 2005 (Zymonas 2010). The annual drawdown operation at Fall Creek Dam is another example. Fish caught in the sediment plain could be at risk of isolation and stranding. There has been no direct measurement of mortality induced by stranding for Fall Creek, though it is widely believed that the operation has an overall benefit to the UWR Chinook and steelhead produced above the dam. Measuring mortality rates from stranding is notoriously difficult due to fish being difficult to survey in the drawdown zone, high rates of predation on isolated and stranded fish, and having an unknown number of fish that comprise the population of interest. Salvage efforts at Cougar were frustrated by challenging access conditions, where the salvage team could not reach many of the pools where fish were isolated (Zymonas 2010). It is likely there would be similar conditions in the Detroit Reservoir construction drawdown zone. Though there are no bull trout above Detroit and all of the Chinook are the progeny of hatchery outplants, the drawdown under CA2 could still have some profound effects on both resident fish and hatchery fish planted for recreation that are present in the reservoir. Competition Under CA2, the drawdown may crowd fish into smaller areas, resulting in higher levels of competition for space and food resources. There may also be a reduction in primary productivity of the river, particularly in the macroinvertebrate community and the food supply for fish during and after the drawdown could be significantly diminished. Predation ODFW studies in Detroit Reservoir in 2011 resulted in the capture of four potentially piscivorous fish species: rainbow trout, cutthroat trout, brown bullhead, and sculpin.

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Rainbow trout comprised 87.8% of the predatory fish captured in Detroit Reservoir and included both hatchery and natural origin fish (Monzyk et. al., 2012). The only potential Chinook predators collected for diet analysis during the spring (May-June) and fall (Oct- Nov) study periods were rainbow trout and brown bullhead. Macroinvertebrates and zooplankton had the greatest occurrence in diet analysis while prey fish occurred only 4% of the time. Only three of 64 rainbow trout with identifiable prey fish in their stomachs were identified as juvenile Chinook. Estimates of Chinook predation are considered conservative based on capture methods and study time periods. Total consumption of juvenile Chinook by predators depends on numerous factors such as spatial and temporal overlap in predator-prey habitat, prey diversity, and predator abundance. Under CA2, the drawdown may crowd fish into smaller areas, possibly resulting in higher rates of predation and mortality. Conditions are likely to be more favorable for non-native fish species thereby increasing predation on, and negative interactions with, native fish species. Predation could be by other fish but also by birds or mammals. Chinook fry may be more subject to increased predation due to their small size. Passage Under CA2, there would be no availability to release water through the spillway or powerhouse during construction. Flood risk management operations would be maintained with a 400 cfs minimum release target. The drawdown operations during construction would be through the southernmost lower RO at elevation 1,265 and fish may travel through the lower RO to pass. See information below in the Reservoir Impacts of Post Construction (Interim Operations) for CA2 for survival estimates of fish passing through the RO. Under this operation, survival impacts would be neutral or possibly improved with large gate openings due to the closer proximity to the surface elevation of the reservoir for passage and the lower RO elevation and outlet conditions in the stilling basin compared to only upper RO passage under the No Action Alternative. However, due to construction in the area, fish may avoid the area in response and may not pass and or wait to pass at other opportune times. In this case, the Corps expects impacts from migration delay to be minor to moderate for Chinook and other fish in the reservoir for CA2 compared to the No Action Alternative.

Post SWS Construction (Interim Operations) Impacts Downstream Impacts Following the construction of the SWS, the resulting temperature control operations would provide benefits to downstream fish and aquatic habitats. The Corps would meet temperature targets more frequently, allowing for more historical timing of fish emergence and upstream adult fish migration. More normative run timing of adults could get the pre-spawn fish to ideal holding habitats above the dam prior to them being 3-196

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exposed to the higher concentrations of hatchery fish and pathogens below Minto. This could have positive effects by reducing the frequency and intensity of pre-spawn mortality events. This would especially be the case for hot/dry years with low flow, similar to conditions experienced in 2015, where operational temperature control is limited or impossible due to the reservoir levels precluding the use of the surface spillways. Additionally, for marginal years, the Corps would not have to choose between meeting flow targets and maintaining a higher pool for operational temperature control. This new operational flexibility and ability to provide more idealized temperatures could become increasingly important under current climate trends. The ability to meet downstream temperature targets would meet the primary purpose and need of the SWS construction. Reservoir Impacts The ability to meet downstream temperature targets would meet the primary purpose and need of the SWS construction. However, in the interim between completion of the SWS and commissioning of the FSS, when reservoir elevations are above the spillway crest in summer, the Corps would not use the spillway for temperature operations and, therefore, the majority of Chinook that pass would enter the SWS HIWs and go through turbines. Hansen et al. (2017) describes results from studies conducted on downstream passage and survival of juvenile salmonids passing through the various outlets through Detroit Dam. Based on these results, which show poor passage conditions and survival through the turbine route, the Corps assumes that the interim operations of the SWS would have a moderate to significant impact on ESA-listed naturally spawned hatchery Chinook progeny attempting to pass downstream. When the reservoir elevations are below the spillway crest and flow is passed only through the SWS and turbine, survival impacts would be neutral compared to only turbine passage under the No Action Alternative. When the reservoir elevations are below the spillway crest and the Corps passes flow through the RO only, survival impacts would be neutral to the only RO passage under the No Action Alternative.

Post FSS Construction (project completion) Impacts Downstream Impacts Following construction of the FSS, both upstream and downstream passage for migrating fish would be available. The cumulative benefit should meet the RPA measure 4.12.3 and 5.2 for downstream passage and temperature control for ESA-listed salmonids per the NMFS 2008 BiOp.

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Reservoir Impacts Following construction of the FSS, both upstream and downstream passage for migrating fish would be available and improved. The operation of the FSS and SWS would achieve the benefits to dam passage and survival, meeting the RPA measures 4.12.3 and 5.2 for downstream passage and temperature control for ESA-listed salmonids per the NMFS 2008 BiOp. Kokanee impacts will be minimal, however, with more effective downstream passage there is the potential to collect kokanee and move them out of the reservoir and out of the popular fishery.

CA3. SWS and FSS Constructed with a One-year Deep Drawdown Impacts under this alternative are similar to CA2 except impacts resulting from the drawdown would be limited to a single year.

CA4. SWS and FSS Constructed with a One-year Variable Drawdown

Impacts during Construction The impetus of this alternative is to try to provide a much greater chance of meeting a minimum 1,000 cfs discharge rate over the entire construction period while reducing the depth of the reservoir to ease the complexity, hazards, and cost of SWS construction. While the alternative succeeds at this goal, it changes the nature of some other effects beyond just flow, including effects on temperatures and anticipated turbidity. For this alternative, impacts to UWR Chinook Salmon, winter steelhead, and summer steelhead would likely be less severe than under CA2 and CA3. However, under CA4, temperature targets would be missed resulting in significant impacts, including the delayed upstream migration of adult Chinook salmon, shift in fry emergence, and increased stress/mortality of salmonids in warm water years. Minor impacts may also occur from high turbidity and sedimentation resulting in additional stress to fish. Impacts to adult Pacific lamprey would generally be similar to salmonids. However, impacts due to temperature would likely be less extensive. Impacts to Oregon Chub would likely be major due to low flows resulting in loss of habitat and loss of mainstem connectivity of off-channel habitat.

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Downstream impacts Overall, downstream impacts from CA4 will be less extensive than under CA2 and CA3. Flow Refer to Figure 48 for time period distinctions. 1. Initial Drawdown (September – November in): In order to reach the target elevation of 1,400 ft, it would be necessary to increase discharges much higher than is typical under the baseline or no-action alternative (CA1). These unusually high flows could affect the spawning success of the Chinook below Big Cliff and Minto dams. Flows peak between 4,000 and 9,000 cfs during peak spawning activity in mid-September to mid-October (see Appendix P for details). Shortly afterward, when the target forebay elevation is reached, flow is reduced dramatically to approximately 1,000 cfs. This would likely have a major impact on the egg survival for the 2021 brood year since most fish would probably spawn in higher elevation spawning gravels that would later be dewatered as flows were reduced. There is also likely an increased risk of stranding for all fish species and life stages under this operation. Even if the operation follows the established ramp rates, the overall change in flow is so great there is a good chance some habitats would become isolated and eventually de-watered. 2. (A) February 1 – March 15: The 1,000 cfs flow target below Big Cliff would be met. Therefore, the impact to salmonids during this time would be negligible compared to the No Action Alternative. 3. (B) March 16 – May 31: The flow target during this period is 1,500 cfs for winter steelhead spawning. There is also regional guidance to keep flows below 3,000 cfs during salmonid spawning. Under the 50, 75, and 95 th percentile for forecasted outflow at Detroit Dam the flow target would be met below Big Cliff and, therefore, the impacts would be negligible compared to the No Action Alternative. Impacts during this period are similar to impacts described in CA2. 4. (C) June 1 – July 15: The flow target during this period is 1,200 cfs for winter steelhead incubation. During this period, flow targets would likely only be met through June based on 50th and 25th percentiles of the forecasted water years. Water years in the 5th percentile flow targets would not be met. Reduced flows have the potential to leave steelhead redds high and dry if spawning habitat that was available during spawning is dewatered later in the year prior to hatching. 5. (D) July 16 – Sept 4: The flow target during this period is 1,000 cfs for rearing of juvenile fish and would be met under all forecasted water years, impacts would be negligible.

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6. (E) Sep 5 – Oct 31: The flow target during this period is 1,500 cfs for Chinook salmon spawning. For all water years, the flow target would not be met except for a brief time in Mid-October under the 95th percentile. Chinook salmon spawning habitat would drop from approximately 99% to 89% (Table 22) having a moderate impact in reach 1. Flows during this period are not expected to go above 3,000 cfs as they did during period B. 7. (F) Nov 1 – Jan 31: The flow target during this period is 1,200 cfs for Chinook salmon egg incubation. For water years, forecasted 50% of the time the target flow would be met with the exception of November when flows would be slightly lower at 1,000 cfs. This could result in a reduction of 3% of the available spawning habitat / redds that is available when the flow target is met in reach 1. 8. Post tower construction refill (January 2021 - June 2023): This would involve a long period of minimum flows in order to refill the reservoir from the construction pool elevation. Since the volume of water required is greater, there is a chance that the reservoir would not completely fill to the spillway crest. Temperature operations using the newly constructed SWS cannot be implemented until completion of commissioning. The tower should be operational and fully commissioned by June, so any impacts due to temperatures would be minor, unless commissioning is delayed due to a lack of refill or technical issue. There is also an increased risk of not being able to meet downstream flow targets. Water Quality: Temperature

Table 27 shows the temperatures at Niagara under CA4. In wet years, temperatures are closer to the temperature targets than the No Action Alternative and, therefore, impacts to salmonids would be negligible if not beneficial. However, in October, temperatures are warmer (55 °F) and above the temperature target compared to the No Action Alternative with colder temperatures (48.4 °F). The warmer temperature would still remain under the upper optimal temperature criteria and, therefore, would have negligible impacts. In September to November, during spawning and egg incubation for Chinook salmon, the total degree-day accumulation i is 1,918 (Table 24). This would result in early emergence compared to the No Action Alternative, which is closer to the emergence timing when temperature targets are met. Total degree-day accumulation in May to July, during spawning and egg incubation for winter steelhead, is 1,511 (Table 25). This would result in major delays to emergence when compared to years when temperature targets are met. However, emergence under CA4 (1,511) and the No Action Alternative (1,488) are similar. In hot years, temperatures are closer to the targets than the No Action Alternative except in September. During this period, juvenile fish are rearing with an upper 3-200

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temperature limit of 61°F. Forecasted temperature for the month is 61.5°F, which may result in a minor impact to juvenile rearing fish. These monthly temperature values are average monthly values. However, the level of impact would be determined by duration of high temperatures and the fish’s ability to find cool water refugia. A moderate to major impact may result for adult Chinook salmon spawning during this time. The upper optimal temperature is exceeded by 6.5 °F compared to an exceedance of 0.4 °F under the No Action Alternative. Total degree-day accumulation in September to November during spawning and egg incubation for Chinook salmon is 2,126 (Table 24) this would result in early emergence compared to years when the temperature targets are met. However, emergence timing for the No Action Alternative (2,137) would be similar to CA4 and therefore impacts are negligible when comparing the No Action Alternative and CA4. Total degree-day accumulation in May to July during spawning and egg incubation for winter steelhead is 2,149 (Table 25). This would result in similar emergence timing when compared to years when temperature targets are met. In contrast, emergence under the No Action Alternative (1,752) would be delayed. Considering CA4 results in emergence similar to years when temperature targets are met CA4 provides a benefit to winter steelhead emergence. Table 27. Comparison of modeled temperatures (see Section 3.15) at Niagara under CA1 and CA4*. Niagara 2011 MAR APR MAY JUN JUL AUG SEP OCT NOV DEC (wet/cool year; °F) Target 43.4 45.6 50.9 55.7 59.7 59.7 55.9 50.7 45.9 43.3 CA4 39.8 41 43.6 47.6 54.1 58.6 56.1 55 48.1 Difference 3.6 4.6 7.3 8.1 5.6 1.1 0.2 4.3 2.2 CA1 39.6 40.8 43.8 47.4 52 56 54.8 48.4 48.1 Difference 3.8 4.8 7.1 8.3 7.7 3.7 1.1 2.3 2.2 Niagara 2015 (dry/hot year; °F) Target 43.4 45.6 50.9 55.7 59.7 59.7 55.9 50.7 45.9 43.3 CA4 44.9 46.2 50.6 55.7 59.7 60.5 61.5 54.8 49.8 Difference between Target 1.5 0.6 0.3 0 0 0.8 5.6 4.1 3.9 and CA4 CA1 43.9 45.3 47.8 50.7 54.7 59.1 56.3 58 52 Difference between Target 0.5 0.3 3.1 5 5 0.6 0.4 7.3 6.1 and CA1 * These monthly temperature values are average monthly values. Temperatures were modeled assuming a wet / cool year (2011) and separately a dry / hot year (2015). Blue highlighted cells represent temperature differences that are colder than temperature targets and the orange highlighted cells represent temperature differences that are warmer than targets.

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Table 28 shows the temperatures modeled for CA4 at Mehama. In wet years temperatures are similar to the temperature targets under the No Action Alternative (Alternative 1) and therefore impacts to salmonids would be negligible. However, in October temperatures are warmer (53.9 °F) and above the temperature target compared to the No Action Alternative with colder temperatures (49.0 °F). During this time Chinook salmon spawning occurs with slightly elevated temperatures. Impacts should be negligible considering forecasted temperatures would be below the upper optimal temperature guidance. In hot years, temperatures are over temperature targets for both the No Action Alternative and CA4. The variance from the target ranges from 2.1–6.1 °F hotter for CA4 and 1.9–6.6 °F for the No Action Alternative. The largest difference between the two alternatives is in June–October. Steelhead egg incubation and juvenile fish are rearing during this time. At temperatures above 60°F, rearing fish would be stressed and more susceptible to disease and, therefore, predation and other environmental stressors. Under CA4, temperatures would be above the 61°F threshold (Table 21) starting in June. These impacts would be moderate to significant. The Steelhead egg hatch may also be accelerated due to increased temperatures under CA4. Table 28. Comparison of modeled temperatures (see Section 3.15) at Mehama under CA1 and CA4*. Mehama 2011 (wet/cool year; MAR APR MAY JUN JUL AUG SEP OCT NOV DEC °F) Target 43.4 45.6 50.9 55.7 59.7 59.7 55.9 50.7 45.9 43.3 CA4 41.6 42.5 45.1 49.9 58.1 62.3 58.8 53.9 Difference between Target 1.8 3.1 5.8 5.8 1.6 2.6 2.9 3.2 and CA4 CA1 41.9 42.5 45.3 49.6 56.9 60.5 57.1 49 Difference between Target 1.5 3.1 5.6 6.1 2.8 0.8 1.2 1.7 and CA1 Mehama 2015 (dry /hot year; °F) Target 43.4 45.6 50.9 55.7 59.7 59.7 55.9 50.7 45.9 43.3 CA4 47 47.7 53.7 61.8 65.5 64.2 61.8 55.4 Difference between Target 3.6 2.1 2.8 6.1 5.8 4.5 5.9 4.7 and CA4 CA1 47.2 47.5 52.8 59.1 62.5 63.5 58.2 57.3 Difference between Target 3.8 1.9 1.9 3.4 2.8 3.8 2.3 6.6 and CA1

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*Temperatures were modeled assuming a wet / cool year (2011) and separately a dry / hot year (2015). Blue highlighted cells represent temperature differences that are colder than temperature targets and the orange highlighted cells represent temperature differences that are warmer than targets.

Sediment Transport (turbidity)

Under CA4, sediment transport impacts would be similar to those experienced under CA2 with additional impacts associated with the potential pulses sedimentation during the summer months (see Table 12 in Section 3.5.4.6 for details). These pulses could lead to higher sediment and turbidity throughout the proposed drawdown period.

Reservoir Impacts Water Quality: Temperature Temperature impacts would be similar to temperature impacts in CA3, but with minor differences. A 1,400 ft Detroit Reservoir elevation would have a greater surface area and volume compared to a 1,300 ft Detroit Reservoir elevation, thereby capturing more solar energy in summer comparatively. However, there would be more lake volume, potentially less stress from crowding and more potential for cooler water refugia deeper in the reservoir. Water Quality: Dissolved Oxygen Under CA4, the Corps assumes the impacts to fish from DO and pH to be similar to those described under CA2. Water Quality: Sediment and turbidity impacts to fish

Under CA4, sediment and turbidity impacts would be similar to those experienced under CA2. The Corps expects this impact to be minor for Chinook and other fish in the reservoir at elevation 1,400 ft compared to the No Action Alternative. Passage There would be no availability to release water through spillway or powerhouse during construction. The Corps would maintain flood risk management operations with a target release of 1,000 cfs. The 1,400-ft drawdown operations during construction would utilize the southernmost upper and/or lower RO to provide the safest hydraulic conditions for divers. The upper RO is at elevation 1,340 and the lower RO is at elevation 1,265. Fish would travel through the upper or lower RO to pass. See information in the Reservoir Impacts section of Post Construction (Interim Operations) Impacts under CA2 for survival estimates of fish passing through the RO. Survival impacts would be neutral to the only RO passage under the No Action Alternative. However, due to construction, fish may avoid the area in response and may not pass and/or wait to pass at other opportune times. In this case, the Corps expects the impact

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from delayed migration to be minor to moderate for Chinook and other fish in the reservoir under CA4 compared to the No Action Alternative. Potential Blasting impacts CA4 would require in-water blasting to prepare a foundation for the SWS. Underwater blasting could injure or kill resident fish and kokanee that are in the vicinity of a construction related blast (Keevin and Hempen 1997; Lewis 1996). Only 7-10% of the blast pressure from a well confined blast are actually transmitted into the water column, so fish injury and mortality would be restricted to the area in the immediate vicinity of the blasting. However, fish near the blast site would likely avoid these areas due to initial warning blasts and other construction related activities (e.g., loose rock removal, drilling and blasting preparation) occurring between blasting. The Corps plans to employ mitigation measures (Keevin and Hempen 1995; Keevin 1998) to avoid and minimize blast damage to fish and other aquatic organisms. These measure could include, but are not limited to: • a well-designed blasting design that reduces the amount of explosives used and the associated damage zone; • well stemmed bore holes to confine blast pressures; • the use of scare charges prior to blasting to move fish from the blast zone; and • the potential use of recorded noise to move fish from the blast zone. The mitigation program will be coordinated with the NMFS, USFWS, and ODFW. Post SWS Construction (Interim Operations) Impacts Same as described in CA2.

CA5. SWS and FSS Constructed with No Drawdown

Impacts during Construction Under CA5, impacts to UWR Chinook Salmon, winter steelhead, and summer steelhead would likely be minor due to temperature and flow targets largely being met downstream. Impacts to adult Pacific lamprey would generally be similar to salmonids; however, impacts due to temperature would likely be less extensive. The Corps expects no impact to Pacific lamprey as compared to the No Action Alternative. No impacts to Oregon Chub are likely to occur due to flow and temperature targets being met as compared to the No Action Alternative. The Corps expects minor impacts to resident fish and kokanee near underwater blasting. Fish near the blast site would likely avoid these areas due to initial the use of repelling charges and other construction activities (e.g. loose rock removal and blasting

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preparation) occurring between blasting. Repelling charges can be small and the injury/kill zone would be small compared to the main blast(s) (Keevin, T.M. 1998). In addition, it would be possible to use a repelling charge with a deflagration explosive product (low explosive) which would have minimal impact. Impacts would be negligible to fish present downstream of Big Cliff Dam from blasting upstream of Detroit Dam. Impacts from other sources, discussed in CA2, would be negligible.

Downstream impacts Flow Construction of the SWS and FSS would not affect flow and, therefore, there would be no additional impacts to fish during construction as compared to the No Action Alternative. Water Quality: Temperature Temperatures downstream during construction would be similar to the No Action Alternative and, therefore, there would be no additional impacts to fish during construction. Sediment Transport (turbidity) Under CA5, sediment transport effects on fish would be similar to those experienced under the No Action Alternative. Compared to the other action alternatives, construction of the SWS and FSS would result in considerably less sediment transport below Big Cliff and, therefore, there would be no additional impacts to fish during construction downstream of Big Cliff.

Reservoir impacts Impacts to resident fish such as rainbow trout, kokanee, and juvenile Chinook salmon would be negligible due to operations being similar to the No Action Alternative. However, there could be minor impacts to fish near rock excavation sites due to displacement related to drilling and blasting pressure, noises, and vibrations similar to the description in CA2. Flow Impacts Flow impacts to fish would be similar to the No Action Alternative. Water Quality: Temperature Water temperature impacts would be similar to the No Action Alternative. Thermal impacts to reservoir juvenile Chinook and the environment would not change. Water Quality: Dissolved Oxygen

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Impacts to DO are similar to the No Action Alternative. The DO impacts to reservoir juvenile Chinook and the environment would not change. Water Quality: Sediment and turbidity impacts to fish Although low levels of sediment may be mobilized during the initial construction process, turbidity affects would be similar to the No Action alternative. Blasting, excavation, and material placement would result in elevated turbidity near the dam but the Corps would minimized increases in turbidity with the use of silt curtains. Although low level of sediment may be mobilized during the initial construction process, reservoir sedimentation would be localized near the dam. Sedimentation impacts to fish would be localized near the dam and minor. Passage Under CA5, during construction the Corps would be able to release water through the upper RO or, potentially, the southernmost spillway gate, but not the powerhouse. RO operations during construction would be through the southernmost upper RO to provide the safest hydraulic conditions for divers. The upper RO is at elevation 1,340. Fish would travel through the upper RO or over the spillway (if used) to pass the dam. Reservoir elevation would be the same as normal rule curve elevations as under the No Action Alternative. With flow passed through only the RO, survival impacts would be neutral to only RO passage under the No Action Alternative. The majority of Chinook that pass would be forced to sound and use the upper RO. This would be a minor to moderate impact based on the variable RO passage conditions and survival through the RO route. See information in the Reservoir Impacts section of Post Construction (Interim Operations) Impacts under CA2 for survival estimates of fish passing through the RO and spillway. The need for fish to sound to find the RO may result in some delay in passage. Additionally, due to construction in the area, fish may avoid the area in response and may not pass and or wait to pass at other opportune times. In this case, the Corps expects the impact from delay migration to be minor to moderate for Chinook and other fish in the reservoir compared to the No Action Alternative. Potential Blasting impacts The potential impacts to fish are the same as for CA4 due to the of in-water blasting.

Post SWS Construction (Interim Operations) Impacts Same as described in CA2

3.9 THREATENED AND ENDANGERED SPECIES The ESA of 1973 (16 U.S.C. §§ 1531 et seq.), as amended, provides for the conservation and recovery of endangered and threatened species and the ecosystems

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upon which they depend. The USFWS and NMFS share joint jurisdiction for the administration of ESA-listed species. Under Section 7 of the ESA, federal agencies are required to evaluate the effects of actions they fund, permit, or authorize and consult with the USFWS and/or NMFS to ensure Federal actions would not jeopardize the continued existence of listed species or destroy or adversely modify designated critical habitat. Critical habitat is defined as specific geographic locations critical to the existence of a threatened or endangered species. The following sections describe the threatened and/or endangered species present in the action area, and the designated critical habitats upon which they depend.

Species under NMFS Jurisdiction Two Pacific salmonid species occur in the project area: UWR spring Chinook salmon and UWR winter steelhead. In September 2005, critical habitat was designated for these species (70 Fed. Reg. 52630) and critical habitat for UWR Chinook salmon and steelhead is found within the project area. The UWR Chinook ESU was listed as threatened on March 24, 1999 (64 Fed. Reg. 14308), and threatened status was reaffirmed on June 28, 2005 (70 Fed. Reg. 37160). The ESU includes all naturally spawned populations of spring-run Chinook salmon in the Clackamas River, as well as the populations in the Willamette River and its tributaries upstream of Willamette Falls, Oregon. The ESU also includes spring-run Chinook salmon from six artificial propagation programs, including the Marion Forks Hatchery/North Fork Santiam River Program (ODFW Stock #21). Historically, salmon inthis ESU spawned in several tributaries of the Willamette River, including the Clackamas, Pudding, Molalla, Calapooia, Santiam, McKenzie and Middle Fork Willamette River subbasins. Access to large swaths of historical spawning habitat was blocked by construction of the WVS dams, inclusive of Detroit Dam. The UWR steelhead DPS includes all naturally spawned anadromous steelhead originating below natural and manmade impassable barriers from the Willamette River and its tributaries upstream of Willamette Falls to the Calapooia River. The North Santiam population is one of four historical demographically independent populations for UWR winter-run steelhead delineated based on geography, migration rates, genetic attributes, life history patterns, phenotypic characteristics, population dynamics, and environmental and habitat characteristics (Myers et al. 2006). Section 3.18 provides a more detailed discussion.

Upper Willamette River winter steelhead Section 3.8 provides a description of UWR winter steelhead.

Upper Willamette River spring Chinook salmon

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Section 3.8 provides a description of UWR spring Chinook salmon.

Species under USFWS Jurisdiction The species listed, proposed to be listed, or candidate species under ESA by USFWS for Linn and Marion Counties can be found in Table 29 below. USFWS has designated or proposed critical habitat for nine of the species listed. Many species listed under the ESA for Linn and Marion Counties, Oregon, are not found within the project area due to habitat requirements or species that have been extirpated within the project area. As the habitat within the area of effect is a mixture of mixed coniferous forest and riparian corridor forests, the following species are not found within the project area due to inadequate habitat: • Fender’s blue butterfly (Icaricia icarioides fenderi), • Kincaid’s lupine (Lupinus sulphureus ssp kincaidii), • Willamette daisy (Erigeron decumbens), • water howellia (Howellia aquatilis), • golden paintbrush (Castilleja levisecta), • Nelson’s checker-mallow (Sidalcea nelsoniana), • Bradshaw’s desert-parsley (Lomatium bradshawii), • marbled murrelet (Brachyramphus marmoratus), • streaked-horned lark (Eremophila alpestris strigata), and • North American wolverine (Gulo gulo luscus). Historically, yellow-billed cuckoo (Coccyzus americanus) and Oregon spotted frog (Rana pretiosa) have been known to occur within the project vicinity. For the Oregon spotted frog, the only known locations are in high elevation lakes and wetlands located to the east of Detroit Reservoir in the upper Deschutes River basin, the Three Sisters Wilderness, and at Gold Lake (Middle Fork Willamette subbasin) to the southeast. Yellow-billed cuckoo historically were found throughout riparian areas of Oregon. The last recorded observations of this species in the project vicinity occurred in the late 1800s near Sweet Home, Oregon (part of the South Santiam River subbasin) and near Bend, Oregon (Deschutes River subbasin) in 1990. The Corps further analyzed four USFWS ESA-listed species that may occur within the vicinity of the project in this EIS. The four species are northern spotted owl (Strix

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occidentalis caurina - Threatened), red tree vole (Arborimus longicaudus - Candidate), bull trout (Threatened), and Oregon chub (Recovery delisted in 2015). Section 3.7 discusses Northern spotted owl and red tree vole and Section 3.8 discusses bull trout and Oregon chub.

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Table 29. Species listed, proposed to be listed, or are candidate species under the Endangered Species Act for Linn and Marion Counties. Information was obtained through USFWS Environmental Conservation Online System (ECOS), https://ecos.fws.gov/ecp/. Common Name Scientific Name Federal Status Critical Habitat Protective Regulations Amphibians Oregon spotted Rana pretiosa Threatened Designated 79 Fed. Reg. 51657 frog 81 Fed. Reg. 29335 Birds Yellow-billed Coccyzus americanus Threatened Proposed 79 Fed. Reg. 71373 cuckoo Northern Strix occidentalis caurina Threatened Designated 55 Fed. Reg. 26114 spotted owl 77 Fed. Reg. 71875 Streaked horned Eremophila alpestris Threatened Designated 78 Fed. Reg. 61452 lark strigata 78 Fed. Reg. 61506 Marbled Brachyramphus Threatened Designated 75 Fed. Reg. 3424 murrelet marmoratus 76 Fed. Reg. 61599 Fish Bull trout Salvelinus confluentus Threatened Designated 64 Fed. Reg. 58910 75 Fed. Reg. 63898 Oregon chub Oregonichthys crameri Delisted 80 Fed. Reg. 9125 Mammals North American Gulo gulo luscus Proposed

wolverine Threatened Red tree vole Arborimus longicaudus Candidate Insects Fender’s blue Icaricia icarioides fenderi Endangered Designated 65 Fed. Reg. 3875 butterfly 71 Fed. Reg. 63862 Plants Bradshaw’s Lomatium bradshawii Endangered 51 Fed. Reg. 38448 desert-parsley Nelson’s Sidalcea nelsoniana Threatened 58 Fed. Reg. 8235 checker-mallow Golden Castilleja levisecta Threatened 62 Fed. Reg. 31740 paintbrush Water howellia Howellia aquatilis Threatened 59 Fed. Reg. 35860 Willamette daisy Erigeron decumbens Endangered Designated 65 Fed. Reg. 3875 71 Fed. Reg. 63862 Whitebark pine Pinus albicaulis Candidate Kincaid’s lupine Lupinus sulphureus ssp Threatened Designated 65 Fed. Reg. 3875 kincaidii 71 Fed. Reg. 63862

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Environmental Consequences The EIS describes the alternatives’ effects to the wildlife and aquatic ESA-listed species in Sections 3.7.4 and 3.8.4, respectively. The Corps will submit a Biological Assessment to initiate formal ESA Section 7 consultation with NMFS. The Corps has determined that the Project is likely to adversely affect UWR Chinook salmon, UWR steelhead, and their designated critical habitat due to short-term impacts during implementation, but is not likely to jeopardize the species or adversely modify critical habitat in the long-term. The Corps has determined no alternatives are likely to affect red tree vole or the northern spotted owl, as there is a low likelihood of occurrence of either species in the project vicinity. Historical nesting of northern spotted owls has occurred near Detroit Dam. The two nests are within 1 and 2 miles from the dam. Observations of northern spotted owls in this area were in the late 1990s with no other observations noted within the ORBIC database. USFS did note that no known northern spotted owl nests occur near any of the proposed staging areas.

3.10 ADULT FISH FACILITIES, HATCHERIES, AND FISHERIES Congress authorized the construction of hatcheries to provide mitigation, in part, for habitat lost or made inaccessible by the construction of the WVP dams. There are also hatchery programs in the Willamette basin that the State of Oregon maintains to enhance sport fisheries and harvest opportunities. The ODFW operates the Corps’ mitigation hatchery program in the North Santiam under contract with the Corps. The program produces spring Chinook. The ODFW also has a hatchery program in the North Santiam that produces spring Chinook and summer steelhead. Both the Corps and ODFW’s spring Chinook program is an integrated program that supports both reintroduction of wild spring Chinook and harvest opportunities. The summer steelhead program is a segregated program intended to provide harvest opportunities and minimize impacts to wild winter steelhead. Marion Forks Hatchery and the Minto Fish Facility support both of these programs (described in Section 1.6.1.2, along with an overview of current operations). The North Santiam River and Detroit Reservoir supports several fisheries including Chinook salmon, steelhead, coho salmon, rainbow trout, smallmouth bass, and kokanee. State fishing regulations vary by river reach and time of year. The kokanee fishery is popular in the Detroit Reservoir and Section 3.8.2.5 discusses it in detail. In addition, rainbow trout are stocked into the Detroit Reservoir to provide expanded angling opportunity. Angling can occur from the shore, boat, and the Detroit Dam forebay deck.

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Environmental Consequences

CA1. No Action Under the No Action Alternative, no impact would occur to the adult fish facilities or hatchery programs currently operating in the North Santiam basin. Operations would continue as usual with no interruptions. Impacts to fisheries would be negligible.

CA2. SWS and FSS Constructed with a Two-year Deep Drawdown

Adult Fish Facilities and Hatcheries Under CA2, Detroit Dam operations during construction would directly affect the Minto Fish Facility and indirectly affect the operations at Marion Forks Hatchery. Impacts to fish facilities, which concern Minto Fish Facility, Marion Forks Hatchery, and adult outplant sites, are categorized into three parts. For CA2, the majority of the impacts are concentrated at Minto Fish Facility. 1. Impacts to the passage of natural-origin adult fish11 2. Impacts to the collection12 and holding of adult fish utilized for broodstock and outplanting activities13,14 3. Impacts to the release of juvenile hatchery-origin spring Chinook and summer steelhead15

11 Improved passage and handling of ESA-listed spring Chinook and winter steelhead is required in Reasonable and Prudent Action (RPA) 4.6 “Upgrading Existing Adult Fish Collection and Handling Facilities” in the 2008 National Marine Fisheries Service Biological Opinion for the Willamette Project. 12 “Collection” is used in this context to mean the collection of adult fish immediately at the Minto facility. This refers to the attraction water being adequately proportional to river flow, ladder entrance opening in criteria, and water flow within the ladder in criteria. The term does not include the downstream factors that may indirectly influence collection such as downstream river flow or temperatures. 13 Continuation and improvement of the outplanting program is required in RPA 6.2.3 “Continue Adult Chinook Outplanting Program” 14 Building genetic diversity by collecting and using local broodstocks is required in RPA 6.2.2 “Genetically Integrated Management of Spring Chinook Programs” 15 Juvenile hatchery-origin spring Chinook releases are currently being used for conservation purposes in the Willamette Basin. RPA 6.2.4 “Adjust Spring Chinook Release Strategy” notes that the Chinook hatchery program serves a dual purpose (fishery augmentation and population conservation) and must be conducted in a way that maximizes both natural (i.e. “wild-type”) growth rates, sizes and release locations and survival rates. This RPA requires these release practices continue with adaptive management utilizing the best facilities available (i.e. Minto Fish Facility for acclimation and release). 3-212

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These three categories are discussed in detail below. Impacts to the passage of natural-origin adult fish CA2 may affect fish facilities in the North Santiam. The drawdown of Detroit Reservoir to elevation 1,300 proposed under CA2 would decrease flows in the North Santiam River downstream of Big Cliff Dam during some periods throughout the year. This may affect the water intake system at the Minto Fish Facility but depends largely on the type of water year(s) experienced and other uncontrollable environmental conditions. The facility’s design criteria is based off a minimum river flow of 895 cfs (USACE 2016), which corresponds to a tailwater at Minto Fish Facility of about elevation 963.5. However, ladder criteria can still be accessed down to tailwater of elevation 962 ft, which occurs when river flows are around 300 cfs. Thus, Minto Fish Facility operations are unlikely to be affected if river flows do not drop substantially below 300 cfs. Under CA2, no substantial amount of water would be stored in the Detroit Reservoir. Instead, Detroit and Big Cliff dams would simply pass inflows. Figure 49 shows that the median inflows into Detroit Reservoir (yellow line) for water years 1935 to 2008 drop below 895 cfs in mid-July and remain below that level until the beginning of November. However, the lowest point for median flows does not drop below 600 cfs throughout the year. The 25th percentile (green line) shows that, for the years presented in the dataset, flow minimums occur around 500 cfs from mid-August to mid-October. For the same timeframe, the 5th percentile (purple line) shows minimum flows around 400 cfs. For periods after November, the 5th percentile graph shows highly variable flows for the period of record. Some flows do drop below 300 cfs but those occurrences are unlikely. It should be noted that 2015, one of the driest water years on record, is not included in this dataset. If future water years trend toward drier conditions, the dataset is biased in favor of higher flows. Observing the median flow (50 percentile, yellow line) for the dataset in Figure 49 below, it is likely that outflows from Big Cliff would remain above the 895 cfs level in late-fall, winter, and spring. Late spring, summer, and early-fall flows would be most impacted from the drawdown and lack of stored water normally used to augment flows during these times. It is during this season that operations at Minto Fish Facility are at risk of being affected. For all drawdown alternatives, it is highly unlikely that flows would drop to or remain at 300 cfs for any significant period of time; meaning, ladder criteria can reliably be met year-round. It should be noted that flows of this kind have not been observed at Minto Fish Facility since construction of the updated facility in 2013. As such, without field confirmation, it is difficult to say with complete certainty that no adverse operational conditions would exist at Minto Fish Facility. In summary, impacts to the passage of natural-origin fish should be minimal in respect to the ability to attract and collect them at Minto Fish Facility. Although flows in the river would be much less 3-213

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than normal, Minto Fish Facility’s ladder would likely remain in criteria with the ability to safely capture and release natural-origin fish upstream of the Minto Fish Facility barrier dam.

The other major consideration to the passage of natural-origin fish is that of turbidity. Under CA2, especially in the late-fall and early winter, inflow from the North Santiam would mobilize large amounts of sediment from Detroit Reservoir. Depending on the extent of the drawdown, turbidity would rise to an initial level, decrease, and then persist for some time. Maximum allowable suspended sediment concentrations for fish culture are 2,000 parts per million, or a persistent turbidity of 250 FNU (Wedemeyer, 2002). Under CA2, persistent turbidity would be elevated to 160% of recommended levels for fish culture. There are two caveats to this comparison: 1) persistent turbidity levels are modeled for outflow from Big Cliff Dam, which is 4 miles upstream of Minto Fish Facility, and 2) recommended turbidity levels for fish culture primarily consider the impacts to juvenile

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fish, which are more susceptible to elevated turbidity than adults. The elevated turbidity of a drawdown to elevation 1,300 is the most concerning and would undoubtedly increase stress on any returning adults subjected to it. Elevated suspended sediment concentrations cause irritation in the gills and increase the likelihood of disease contraction. Additionally, high turbidity decreases an adult fish’s ability to navigate waterways, limiting visibility and having detrimental effects on migration efficiency and predator avoidance. Fortunately, for the passage of natural-origin adults, the highest levels of turbidity would occur in late-fall and early-winter. By that time, the vast majority of spring Chinook would have finished their migration into the North Santiam and would have had the opportunity to spawn. Mean peak spawning in the North Santiam occurs on September 28th for years 2008 to 2014 and by mid-October, spawning has concluded (ODFW, 2017). Assuming turbidity levels increase at or after mid-October, even a drawdown to elevation 1,300 would have minimal impacts to the passage of natural- origin spring Chinook adults, or their spawning activities. Likewise, winter steelhead are not typically observed at Upper Bennett Dam in the lower North Santiam until mid- February. In summary, for all action alternatives, impacts to the passage of natural- origin fish at Minto Fish Facility are expected to be minimal. Impacts to the collection and holding of adult fish utilized for broodstock and outplanting activities Impacts to the collection and holding of adult fish used for broodstock or meeting outplanting targets are quite similar to those discussed above. All groups of fish discussed here must first be collected and identified at Minto Fish Facility before proceeding toward their ultimate disposition. The major difference is that adults held for broodstock would remain at Minto Fish Facility for up to 4 months and adults held for outplanting activities would be held for up to a month. It is not likely that flows in the North Santiam past Minto Fish Facility would reach 300 cfs but it is possible. During the typical low flow period in the summer and early fall, even the 5th percentile flows remain above 400 cfs and the median flows around 600 cfs (Figure 49). As such, major disruptions to the collection or holding of adults is unlikely, in respect to the ability to attract, collect, and hold them at Minto Fish Facility. Although flows in the river would be much less than normal, Minto Fish Facility’s ladder and holding ponds would likely remain in criteria with the ability to ultimately outplant or spawn adults. It is unlikely that turbidity would affect the collection or holding of adult fish utilized for broodstock or outplanting. Due to adverse turbidity levels peaking in late-fall and early winter, all adults would have completed their migration and entry into the Minto Fish Facility and spawning for spring Chinook would have concluded by the end of

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September. Additionally, all outplanting of spring Chinook occurs in June, July, and August and would have concluded by mid-September. In summary, for all action alternatives, impacts to collection and holding of adult fish utilized for broodstock and outplanting activities at Minto Fish Facility appear to be minimal. Impacts to the release of juvenile hatchery-origin spring Chinook and summer steelhead For the month of November, similar to the impacts to adults discussed above, it is possible that flows in the North Santiam could be suboptimal for operations at Minto Fish Facility when juveniles are on-station. Even if flows do fall below 895 cfs for a short period in early November, it should not significantly disrupt operations at the Minto Fish Facility as the facility can easily maintain 4 ponds, trapping and sorting activities, and ladder flow even at 700 cfs16. Turbidity could present an issue for this first group of juvenile fish being reared at Minto Fish Facility. Under CA2, high turbidity levels are expected in the late-fall and early-winter, which likely corresponds to this first cohort of fish. This persistent turbidity is likely to reach levels that are 160% of the maximum allowable level recommended for fish culture. The juvenile fish at Minto Fish Facility would be at a stage that is highly susceptible to gill irritation and disease contraction. As persistent turbidity is expected to remain high for an extended period of time, it is possible that a large portion of the fish in production would be affected negatively, resulting in high mortality and increased disease load. It would be advisable to keep this first group of fish at Marion Forks and delay transport to Minto Fish Facility until the high turbidity has resolved. Because Marion Forks has water that is much colder than the Minto Fish Facility and lower water temperatures retard growth rates, it is likely that delaying transport to Minto Fish Facility by 2-3 months would result in smaller sized fish at release. The impacts of this are not entirely certain but would likely result in an increased juvenile fish mortality upon emigration from the Willamette River and an associated decrease in adult returns. Retaining fish at the hatchery would likely complicate production schedules as fish grow and more ponds and raceways are necessary to allow for proper densities. Close coordination with ODFW would be required to ensure that the hatchery could provide adequate space for all fish. Fish could still be transferred to Minto Fish Facility in late January or early February after turbidity levels decreased but the juveniles would likely not hit the target size of 12 fish per pound. Currently, fish released at Minto Fish Facility are liberated at a size and time known to be associated with active smolt migration (ODFW, 2016). Releasing juveniles at less than target size may influence migration,

16 Analysis by Steve Schlenker on 12 October 2018, detailed in email to Griffith, Janes, Buccola and Rerecich. 3-216

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survival, adult returns and adult straying. It is possible that juveniles could be released later in the season, past the target date, but allowed to reach the target size. For the remainder of the juvenile fish rearing and acclimation season, from January to April, it is likely that minimum flow targets would be met and the facility could be operated as normal. Turbidity levels are not expected to be above normal during this time. Minimal impacts are expected on the later releases of juvenile hatchery-origin spring Chinook and on the release of juvenile summer steelhead. In summary, for all action alternatives, impacts are isolated to the initial group of spring Chinook juveniles transported to Minto Fish Facility from Marion Forks in November, and impacts are exacerbated by alternatives that draw the reservoir down to the 1,300 ft elevation. Continued operations of the adult fish facilities impacts on the hatchery program The continued operation of the adult fish facilities would result in placement of natural-origin adults above Detroit Dam, to include both spring Chinook and winter steelhead, having additional impacts to the hatchery program. Thus far, only hatchery- origin spring Chinook have been outplanted above Detroit. The hatchery draws water from, and is adjacent to, Marion Creek and Horn Creek. Both of these creeks are large enough for adult salmonids to migrate into the area above the hatchery intake. This makes the hatchery’s water supply susceptible to any pathogens the adult fish may be carrying. This concerning breach of biosecurity at the intakes has prompted ODFW to barricade the creeks, downstream of the hatchery intakes, when outplanted adult spring Chinook are present in the system. This period is usually from July to early October when flows in both creeks are relatively stable and lacking major debris. This system would be challenged when winter steelhead and natural-origin spring Chinook adults are present above Detroit for much of the calendar year. The flow and debris load in both Marion and Horn creeks would not allow for barricades or weirs to be in place year- round. Consequently, other measures would need to be taken to ensure the biosecurity at Marion Forks remains intact. In 2017, this topic was discussed among subject matter experts at the Hatchery Management Team meetings. A report (Bjork, 2017) was produced that describes the risks and recommended solution.

Fisheries impacts in the reservoir and downstream During and following construction, fishing from the Detroit Dam forebay deck would not be permitted. The kokanee and rainbow trout fishery would also be impacted see a detailed analysis in Section 3.8.4. Impacts to fisheries downstream of Big Cliff would potentially include the delayed migration of adults into fishable reaches as well as reduce the numbers. For reaches where fish are delayed, due to water temperatures and flows (see Section 3.8.4), there may be a benefit to anglers in specific lower reaches as fish are likely to stage prior to upstream migration. 3-217

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CA3. SWS and FSS Constructed with a One-year Deep Drawdown

Adult fish facilities and hatchery impacts CA3 would moderately impact operations at Minto Fish Facility and Marion Forks Hatchery. These effects are identical to CA2, but only occur for 1 year and one release group of juvenile spring Chinook. Impacts to the hatchery program as a result of continued operations of the adult fish facility would be the same as for CA2.

Fisheries impacts in the reservoir and downstream Impacts to fisheries would be identical to CA2 but limited to 1 year.

CA4. SWS and FSS Constructed with a One-year Variable Drawdown

Adult fish facilities and hatchery impacts Under CA4, Minto Fish Facility would not experience the flow impacts associated with CA2 and CA3. CA4 subjects this group of juveniles to turbidity levels that are 23% of maximum recommended levels. As a result, operations at Marion Forks Hatchery would be impacted by delaying the transfer of juvenile spring Chinook to Minto Fish Facility, due to high turbidity concerns. These effects are similar to CA2 and CA3. The Corps expects the effects to the hatchery program under this alternative to be minor as the delay in transfer of juvenile spring Chinook to Minto Fish Facility would likely be on the scale of weeks, not months. Impacts to the hatchery program as a result of continued operations of the adult fish facility would be the same as for CA2.

Fisheries impacts in the reservoir and downstream During and following construction, fishing from the Detroit Dam forebay deck would not be permitted. The kokanee and rainbow trout fishery would also be impacted see a detailed analysis in Section 3.8.4. Impacts to fisheries downstream of Big Cliff would be less severe than impacts under CA2 and 3. However, the impacts would be similar to those described under CA2. Impacts to the hatchery program as a result of continued operations of the adult fish facility would be the same as for CA2.

CA5. SWS and FSS Constructed with No Drawdown CA5 does not present any foreseeable impacts to fish facilities during construction. By building in the wet, reservoir operations would be relatively unaffected, and both flows and turbidity in the North Santiam past Minto Fish Facility would be normative. After construction is complete, CA5 exhibits similar impacts to adult fish outplanting and 3-218

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juvenile fish acclimation that the other alternatives present. The Corps expects no impacts to the hatchery programs or fisheries in the North Santiam River basin. Fishing from Detroit Dam would be restricted due to construction activities.

3.11 VEGETATION The study area (North Santiam subbasin from the upstream end of Detroit Reservoir downstream to the confluence of the North Santiam River and South Santiam River) is within the West Cascades Ecoregion, as defined by the Oregon Conservation Strategy (Oregon Conservation Strategy). This ecoregion extends from the summit of the Cascade Mountains to the foothills of the Willamette, Umpqua, and Rogue Valleys, and spans the entire length of the state of Oregon. Conifers almost entirely forest this ecoregion.

Uplands Uplands are considered undeveloped vegetated areas that do not contain characteristics observed within wetland areas. Uplands are broken into the following vegetation types: • Forested upland. The land cover type within the footprint of the SWS and FSS is considered open water/lakebed depending on the time of year. Above the full- pool elevation of Detroit Reservoir, the land cover type is predominately forested uplands. The dominant trees within the forested upland include Douglas fir (Pseudotsuga menziesii), with western hemlock (Tsuga heterophylla) as the climax species. Other trees expected within the project area include western red cedar (Thuja plicata), big-leaf maple (Acer macrophyllum), incense-cedar (Calocedrus decurrens), noble fir (Abies procera), and grand fir (Abies grandis). Pacific silver fir (Abies amabilis) can be found in higher elevations within the North Santiam subbasin. Typical shrubs found within the project vicinity include vine maple (Acer circinatum), salal (Gaultheria shallon), Cascade Oregon grape (Berberis nervosa), Pacific rhododendron (Rhododendron macrophyllum), huckleberries (Vaccinium species), sword fern (Polystichum munitum), twinflower (Linnaea borealis), bear grass (Xerophyllum tenax), and other various shrub, grass, and forb species. • Unmanaged herbaceous upland. This vegetation type is dominated by herbaceous vegetation including native and non-native grasses and forbs. This land cover type is typically not maintained or managed (e.g. mowed). Within the project area, this vegetation type is found within portions of the staging areas, roadsides, and areas below Detroit Dam within the Detroit Dam operations facilities.

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• Managed herbaceous upland. This vegetation type is typically found within managed recreation areas and near administrative buildings below Detroit Dam. The dominant vegetation present are non-native grasses and forbs.

Wetlands The hydrology regime found within Detroit Reservoir does not allow for development of wetland areas near the proposed SWS and FSS. Areas that meet wetland criteria (wetland vegetation, soil, and hydrology) as defined in the federal wetland delineation manual (EPA 1989) are typically found within the upper portions of the reservoir where the gradient of the reservoir bed decreases (Figure 50). The most prevalent wetland type within the Detroit Reservoir is herbaceous wetlands followed by scrub-shrub wetlands. Table 30 provides total acreage of wetlands identified through the National Wetland Inventory located within the project boundaries of Detroit Dam and Reservoir. The calculations do not take into account the open water area of the Detroit Reservoir.

Figure 50. Detroit Reservoir project boundary (white) and National Wetland Inventory identified wetlands within the footprint of Detroit Reservoir (blue)

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Table 30. Wetland types and acreage at Detroit Reservoir Wetland Type Acreage Littoral Aquatic Bed 5.89 Palustrine Emergent 38.98 Palustrine Scrub/Shrub 8.46 Palustrine Forested 0.34 Total: 53.66

Wetlands are prevalent downstream of Big Cliff Dam along the North Santiam River and consist of two main types of wetlands: Palustrine and Riverine. The Palustrine wetlands are defined as non-tidal wetlands dominated by trees, shrubs, and persistent herbaceous vegetation. Riverine wetlands are found within the active stream channel and typically do not contain permanent vegetation due to flooding disturbance.

Open Water Open water accounts for most of the impacts within the footprint of the SWS and FSS as the two structures’ proposed locations are within Detroit Reservoir. Open water within Detroit Reservoir is approximately 3,586 acres. Due to the steep bathymetry of Detroit Reservoir, emergent vegetation is limited to a narrow band along the reservoir edges and within the up-stream portions of the reservoir.

Special Status Plant Species As a portion of the proposed project occurs in lands adjacent to USFS administered lands, the Corps has chosen to evaluate impacts to species identified by USFS as ‘special status species’ within this review. Current USFS management mandates conservation of several categories of special status plants in the WNF. These include species from the Regional Forester Sensitive and Strategic Plant lists. USFS regulations and manual direction protect special status species (FSM 2672.4). Numerous plants on the Regional Forester Special Status Species list for the WNF have potential to occur in the area along the North Santiam River, which encompasses a wide range of western Cascade forest habitats. Thompson’s mistmaiden (Romanzoffia thompsonii), a small, flowering plant found in open, rocky, seasonally wet habitats ranging 750 to 6,000 feet elevation, occurs in the North Santiam Watershed, but not within the project area. Other plants known to occur in the North Fork Santiam subbasin include northern singlespike sedge (Carex scirpoidea) (USFS 2018). Carex scirpoidea is found in wet meadows, along streams, river terraces, lakeshores, tundra, slopes, seashores, gravel, sand, and peat moss (USFS 2018). Although potential habitat occurs for special status fungi in the project area, no surveys for these species occurred (except Bridgeoporus nobilissimus, which is a perennial conk found on noble fir snags and stumps) (USFS 2018). The sensitive fungi on the WNF species list are

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limited in distribution and their habitats are poorly understood (i.e. there are very general habitat characteristics listed in the literature) (USFS 2018). The Corps identifies special status species within Operating Projects such as the WVS under Engineering Regulation (ER) 1130-2-540. Sensitive status species include: • any species listed, or proposed for listing (as threatened or endangered) by the USFWS or NMFS under the provisions of the ESA; • any species covered under the migratory bird treaty act; any species designated by USFWS as a “candidate” or “listing” species or “sensitive species”; and • any species which is listed and protected by State statute in a category implying potential endangerment or extinction (ER 1130-2-540). lists the sensitive status plant (including fungus) species known to occur within or in the vicinity of the North Santiam River from the upstream terminus of Detroit Reservoir to the confluence of the North Santiam River with the South Santiam River (Oregon Biodiversity Information Center, 2016). Table 31. Plant Sensitive Species List that may occur near the North Santiam River from Detroit Reservoir to the confluence with the South Santiam River. Species described are listed as 1 or 2 on the Oregon species list are included within this table; species ranked 3 or 4 are not included within this table Common Name Scientific Name Federal Status State Status Vascular Plants Mountain grape-fern Botrychium montanum SOC Sensitive Cold-water corydalis Corydalis aquae-gelidae SOC Candidate Willamette Valley larkspur Delphinium oreganum SOC Candidate Peacock larkspur Delphinium pavonaceum SOC Endangered Three-colored monkeyflower Diplacus tricolor Sensitive Gorman’s aster Eucephalus gormanii Sensitive Shaggy horkelia Horkelia congesta ssp. congesta SOC Candidate Thin-leaved peavine Lathyrus holochlorus SOC Sensitive Adder’s tongue Ophioglossum pusillum Sensitive Thompson mistmaiden Romanzoffia thompsonii Sensitive White-topped aster Sericocarpus rigidus SOC Threatened Fungus Fungus sp. Hydropus marginellus Sensitive Cabbage lung lichen Lobaria linita Sensitive Shingle lichen Pannaria rubiginella Sensitive Fungus sp. Phaeocollybia gregaria Sensitive Charred matchstick lichen Pilophorus nigricaulis Sensitive Lichen sp. Pseudocyphellaria mallota Sensitive Chalk foam lichen Stereocaulon spathuliferum Sensitive

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Invasive Species Within the North Santiam subbasin, invasive plant species can be found throughout the entire study area. Some of the species found include Himalayan blackberry, Scotch broom, Reed canary grass, English Ivy, false brome, Japanese knotweed, purple loosestrife, yellow-flag iris and ludwigia spp. Invasive species impact food chains within the affected habitats, change habitat composition, and compete with native plant species.

Environmental Consequences

Methodology and Scale of Analyses The Corps analyzed impacts based on anticipated changes in habitat under each alternative compared to existing habitat conditions. The Corps estimated changes in habitat, and the impacts to vegetation, associated with the proposed construction methods and operations of the SWS and FSS under each of the five alternatives using available habitat and wildlife species spatial information to determine direct, indirect, and cumulative impacts. The area of analysis includes Detroit Reservoir, staging areas within Detroit Reservoir and the potential staging areas located downstream of the Detroit/Big Cliff Dam Project areas, and the North Santiam River downstream of Detroit Dam to the confluence with the South Santiam River. In addition to cited references, the Corps used the following sources of information to identify the potential impacts of the proposed downstream fish passage project on vegetation in the study areas: • USFWS IPaC online database (USFWS, 2018); • Oregon Biodiversity Information Center (ORBIC) 2016 list of known occurrences of rare plants in Linn and Marion Counties, Oregon, and details regarding their occurrence, habitat, and range; and • Oregon Biodiversity Information Center 2016 spatial data provided by Institute for Natural Resources The geographical analysis for the proposed action includes the area of construction of the SWS tower and FSS, staging areas, and downstream habitats within and adjacent to the North Santiam River from Detroit Dam to the confluence with the South Santiam River. The downstream areas under review would include those areas within the active channel of the North Santiam and those areas that have connectivity to the North Santiam River. Temporal scale analysis for the proposed action would include the duration of construction of the SWS and FSS, the duration of the drawdown of the Detroit

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Reservoir, and the duration of the reduced flows within the North Santiam River downstream of Detroit Dam.

Minto North This location is located downstream of Big Cliff Dam near the Minto Fish Facility along the North Santiam River and is the location of the spoils from construction of the Minto Fish Facility. The Corps has seeded Minto North with native grasses and forbs as part of the restoration portion of the Minto Fish Facility project. This site is adjacent to OR-22. Total area of potential impact is approximately 2.5 acres. The surrounding habitat to the north consists of second growth mixed coniferous forest (Douglas fir and big-leaf maple). While the Corps does not actively manage this area for habitat, it is a previously completed restoration site. Overall, this area provides limited native vegetation and impacts would be considered minimal. Post impact re-vegetation would provide early seral habitat, which would benefit for migratory songbirds and small mammals. Species selection for replanting should be coordinated with Corps WVS botanists.

Detroit Dam and Parking Lot This location is adjacent to OR-22 and Detroit Dam. Habitat to the north consists of mixed coniferous forest and a large rock wall. The staging site is a paved parking lot adjacent to the highway. Impacts to vegetation would be minimal. There would be no need to restore this location with native vegetation post construction.

Detroit Dam and Operations Yard and Access Road This location is directly downstream of Detroit Dam and includes gravel parking areas adjacent to the Detroit Dam access road. The locations have limited vegetation as they have poor soils and are predominately compacted gravel. Some trees, predominately Douglas fir and big-leaf maple, are located within adjacent areas. Understory vegetation is predominately invasive Scotch broom and various blackberry species. Impacts to vegetation would likely be minor and limited to the access road right-of-way and gravel parking lots. The proposed areas are within active operations areas and would not be preferred areas for restoration of native vegetation. Due to the amount of vehicle traffic and

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location adjacent to many invasive plant species, it is recommended that pre- and post- treatment of invasive plants be conducted. The Corps would seed areas where soils are exposed post construction with a native seed mix to reduce potential erosion and to prevent further establishment of non-native plant species. Species selection for replanting and seeding would be coordinated with Corps WVS botanists.

SA1. Mongold State Park Under this alternative staging area, the proposed work area would be located to the northeast of the parking area. This staging area would include the construction of a cofferdam and would require grading and excavation of the staging area due to the existing gradient. Adjacent habitat includes a small amount of Douglas fir and big-leaf maple forest and the open water of Detroit Reservoir. Some emergent vegetation would be impacted in the construction of the cofferdam and the associated grading and filling within the lakebed. After construction activities are completed the portion of the lakebed that would be impacted should be seeded with a native seed mix appropriate for the location. Species selection for replanting and seeding would be coordinated with Corps WVS botanists.

SA2. Oregon State Parks Maintenance Yard This location would require clearing of vegetation to access the lakebed. Some of the vegetation would include large coniferous trees (Douglas fir predominately), deciduous trees (big-leaf maple), and understory vegetation. The Corps has not determined the number, species, or dimensions of the trees that would be removed in the construction of this staging area and its access points. The Corps considers the impacts to vegetation to be moderate in this location. After construction activities are complete, the Corps would seed the impacted areas with a native seed mix along with plantings of native trees and shrubs to form a complex native plant community. Post impact re-vegetation would provide early seral habitat, which would provide a benefit for wildlife. Placement of large woody debris within the upland areas would provide additional habitat for wildlife and nutrients for native vegetation as the material decays. Species selection for replanting should be coordinated with Corps WVS botanists and USFS and OPRD personnel to identify appropriate planting regimes and timing.

SA3. Detroit Lake State Recreation Area This location is similar in impact to habitat as the Oregon State Parks Maintenance Yard site. The Corps would remove some vegetation within the forested area of the proposed site. Vegetation is currently limited at this location due to human use of the area for camping. The Corps considers impacts to vegetation to be moderate, as the Corps would remove some large second growth trees for access to the staging area.

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Post impact re-vegetation would provide early seral habitat, which would provide a benefit for migratory songbirds and small mammals. Placement of large woody debris within the upland areas would provide additional habitat for wildlife and provide nutrients to native vegetation as the material decays. Species selection for replanting should be coordinated with Corps WVS botanists and USFS personnel to identify appropriate planting regimes and timing.

CA1. No Action Potential impacts to vegetation would likely not occur under the No Action Alternative.

CA2. SWS and FSS Constructed with a Two-year Deep Drawdown Under CA2, there would be minor impacts to wetland vegetation due to reduced reservoir elevations and low flows and sedimentation downstream. The Corps would draw Detroit Reservoir down to elevation 1,300 to facilitate construction of the SWS and FSS, allowing the Corps to complete construction in the dry. The Corps would keep the reservoir at this elevation for 2 years. Due to the steep bathymetry of Detroit Reservoir, there is no emergent vegetation within the proposed SWS and FSS locations. The 2- year drawdown of the reservoir to elevation 1,300 would result in a temporal loss of the emergent vegetation along the fringe of the reservoir and within the wetland areas shown in Figure 50 and Table 30.

Detroit Reservoir Wetland areas impacted are predominately Palustrine emergent (38.98 acres) and Palustrine scrub/shrub (8.46 acres). It is expected for the duration of CA2 that the wetlands found within the Detroit Reservoir would not have adequate hydrology during the active growing season to facilitate growth of wetland dependent species. The Corps anticipates that the wetland areas that currently have reed canary grass (Phalaris arundinacea) would have an increase in occurrence of this species. Reed canary grass has a wetland indicator status of Facultative Wetland17. Reed canary grass can be periodically inundated throughout the growing season but may not tolerate water depths greater than 3 ft (W. Messinger, personal communication, 2018). Due to the lower reservoir levels under CA2, the Corps anticipates that any reed canary grass present would expand in acreage into areas that would have previously been inundated with water deeper than 3 ft. Upon completion of construction, the overall footprint of reed

17 U.S. Department of Agriculture, Natural Resources Conservation Service. 2010. PLANTS Database, [Online]. Available: https://plants.usda.gov / 3-226

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canary grass within Detroit Reservoir would increase resulting in a potential monoculture of reed canary grass in areas that were previously vegetated with native emergent vegetation.

Blasting Due to the gradient of the bottom of the reservoir, depth, and reservoir elevation proposed under CA2, aquatic vegetation is not present within the project area where the Corps proposes to blast rock. As the blasting would occur underwater, there would be no expected impacts to terrestrial vegetation outside of the wetted shoreline of Detroit Reservoir.

North Santiam (Detroit Dam to Confluence with South Santiam) The initial drawdown of Detroit Reservoir to elevation 1,300 would release sediment that has built up within the Detroit Reservoir into the North Santiam River (see Section 3.5 for details). Comprised of fine clay, the majority of the sediment would likely precipitate out of the water within the lower sections of the North Santiam River, from approximately Stayton, Oregon to the confluence of the North and South Santiam Rivers. This deposition would likely impact emergent vegetation within the North Santiam mainstem and within off-channel habitats. Depending on the depth of sedimentation within the emergent vegetation areas, sediment could cover vegetation. While the covering of native vegetation may occur, it is likely that subsequent high-water events would mobilize much of the freshly deposited sediment and redistribute it further downstream. The Corps anticipates that during the two growing seasons low flows within the North Santiam would be present, that off-channel habitat (e.g. wetlands, oxbows, backwaters, etc.) could experience loss of water earlier in the growing season than during normal flow regimes. Depending on local precipitation events in the spring and summer, the off-channel habitats could experience drought-like conditions that would affect emergent vegetation found in these areas. Encroachment by non-native species (e.g. reed canary grass) could occur in these areas. Reed canary grass has been shown to form dense monocultures when left untreated. When typical flow regimes are re-established in the North Santiam, the monocultures of reed canary grass may be reduced over time in areas where water depths exceed 3 ft in depth. In the off-channel habitats, which do not typically see open water conditions, the Corps expects that reed canary grass would be the dominant vegetation. Another invasive plant species that is a concern within the North Santiam subbasin is water primrose (Ludwigia spp.). This species is present in some of the off-channel habitats within the North Santiam downstream of Detroit Dam. Ludwigia spp. are typically found in water depths less than 1.9 meters and can form dense monocultures. This species has been shown to change DO within systems where they occur (Ludwigia spp. have been shown to colonize areas 3-227

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where water levels have decreased due to drought (Fox and Haller, 2000; Lan et al. 2010). The species has also been observed to have high mortality in drought conditions in areas that were shallow water in typical water regimes (Mosaic Ecology, 2017). The Corps expects the reduction in flows within the North Santiam River under CA2 to facilitate increased growth of ludwigia spp. in areas where water depth has decreased and the species is present. The off-channel habitats with shallow water areas would dry-out which could result in an increase in mortality of ludwigia spp. that are present.

Operation of the FSS and SWS The Corps does not expect operation of the FSS and SWS to affect vegetation within Detroit Reservoir or within the North Santiam.

CA3. SWS and FSS Constructed with a One-year Deep Drawdown Under CA3, impacts to vegetation would be the same as those experienced under CA2. However, there would be reduced impacts, as vegetation would experience these impacts for a shorter duration (one growing season as opposed to two under CA2). Under CA3, the drawdown of Detroit Reservoir to an approximate elevation of 1,300 ft would affect one breeding seasons for many species found within Detroit Reservoir and downstream along the North Santiam River.

Operation of the FSS and SWS The Corps does not expect operation of the FSS and SWS to affect vegetation within Detroit Reservoir or within the North Santiam.

CA4. SWS and FSS Constructed with a One-year Variable Drawdown Under CA4, impacts to vegetation would be the same as those experienced under CA3 except that, because the Corps would maintain flows of 1,000 cfs out of Detroit, vegetation would not experience low flows and resulting summer dewatering of the North Santiam (Detroit Dam to the confluence with South Santiam).

Operation of the FSS and SWS The Corps does not expect operation of the FSS and SWS to affect vegetation within Detroit Reservoir or within the North Santiam.

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CA5. SWS and FSS Constructed with No Drawdown

Detroit Reservoir Under CA5, the Corps would not drawdown Detroit Reservoir beyond normal operations under the Water Control Diagram, resulting in no impacts to vegetation within the reservoir. CA5 would not affect the emergent vegetation present along the shoreline of the reservoir during the growing season when the reservoir is at full pool or the wetlands identified in Section 3.11.2. Section 3.11.6.2 covers impacts to vegetation related to the construction of staging areas.

Blasting Due to the gradient of the bottom of the reservoir, depth, and reservoir level management, aquatic vegetation is not present within the project area where the Corps proposes to blast rock. As the blasting would occur underwater, there are no expected impacts to terrestrial vegetation outside of the wetted shoreline of the Detroit Reservoir.

North Santiam (Detroit Dam to Confluence with South Santiam River) Under CA5, there is no change to flows released from Detroit Dam throughout construction of the SWS and FSS. This would result in no direct or in-direct impacts to off-channel or mainstem habitats. Sedimentation within the North Santiam River would not occur under CA5, as there would be no deep drawdown of Detroit Reservoir for construction. Additionally, off-channel habitat impacts from the proposed action due to low flow would not occur.

Operation of the FSS and SWS The Corps does not expect operation of the FSS and SWS to affect vegetation within the Detroit Reservoir or within the North Santiam.

3.12 WATER SUPPLY The North Santiam River is a key source of water supply in the basin (Figure 1) and the Willamette Valley, for both M&I purposes as well as agricultural purposes. The State of Oregon considers water to be a public resource and requires a permit (water right) from the Oregon Water Resources Department (OWRD) to use the water, for both surface and groundwater sources. Water use in Oregon is governed by the law of prior appropriation, commonly referred to as “first in time, first in right”, meaning the entity with the oldest water right has seniority to available water, then the second oldest right and so forth, until no more water is available. There are two types of surface water rights in Oregon, based on the type of source of water, i.e. live flow and stored flow.

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Live flow water is the water that would be in the river without the regulation of dams and reservoirs. Stored water is the water held behind a reservoir and later released through an outlet structure18. The OWRD maintains a database of water rights, showing the “family tree” of water rights, as they are perfected, including transfers between entities. The database does not track if all water rights that are currently used, but simply indicates if the right is non- cancelled. A query of the database resulted in 294 points of diversion on the mainstem of the North Santiam River, downstream of Big Cliff Dam. Of these diversions, OWRD permits 248 to withdraw water year round. Other diversions range from the majority of the irrigation season (March – October), while others are only in the springtime. The largest withdrawals of water from the North Santiam River occur around Geren Island, near the City of Stayton (Figure 51). Table 32 summarizes the water average monthly water use of the largest water users in the North Santiam basin. Table 32. Large M&I water users average monthly water use (AWU). Company Name Facility AWU AWU AWU AWU AWU AWU AWU Apr May Jun Jul Aug Sep Oct City of Salem Middle Intake, 60 68 81 96 89 75 69 Geren Island City of Stayton Main Water 3 3 4 6 7 6 4 Plant Santiam Water Control Main Canal 386 402 448 460 469 473 414 District Sidney Irrigation Sidney Canal 0 36 43 39 38 44 2 Cooperative Oregon Department of Stayton Pond 50 37 30 20 16 16 21 Fish and Wildlife

Total 499 546 606 621 619 614 510

The two main withdrawals are the SWCD and the City of Salem. The City of Salem withdraws a portion of its water from the North Santiam North Channel into its water supply facilities at Geren Island and a portion for the North Santiam into the Salem Ditch Canal. The ODFW also withdraws water from the area of Geren Island to store in Stayton Pond, located south of the river, due south of Stayton. Downstream of Stayton and close to the confluence of the North Santiam River and the Santiam River is the diversion point for SIC. The State of Oregon maintains a water use reporting database, but only federal and state agencies, cities, counties, schools, irrigation districts, and other special districts

18 https://www.oregon.gov/owrd/programs/waterrights/pages/default.aspx 3-230

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are required to report their annual use of water; therefore the database does not provide a complete snapshot of water used in the basin. Another issue is that a single water use report may cover multiple water rights. For instance, the water use report for the SWCD in 2016 (Water Use Report ID 61988, 2016) shows the amount of water diverted from the North Santiam River into the Main Canal to supply water to 45 different water rights (certificates or permits). The report does not indicate how much water SWCD used to satisfy each right. There are multiple types of uses served by these rights, including irrigation, power development, municipal use, and commercial use. Complicating the issue further is that water used to satisfy the power development rights returns to the North Santiam River shortly downstream of the City of Stayton. So while the water is withdrawn, it is returned to the system in close proximity to the point of diversion. The second largest diversion of water from the North Santiam is the City of Salem. The water use report for 2016 covers four different water rights, one of which indicates the point of withdrawal is on the Salem Ditch/Canal (Figure 51). The SIC also reported water use for 2016 (Report ID 51435). This report covers one water right, but that right includes rates for live flow and stored water released from the Detroit Reservoir and under contract with BOR. The amount of live flow permitted for diversion is 27.92 cfs from March 1 through July 31 and September 1 through October 31. Stored water may be diverted between March 1 and October 31. While the water right listed with this water use report has a junior priority date, SIC has some of the most senior water rights in the North Santiam basin and was likely exercising their rights under the more senior water rights (Keith Johnson, personal communication, 2018).

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Figure 51. Water supply infrastructure at Geren Island

It is best to look at water use reports for the largest users directly withdrawing water from the North Santiam, namely SWCD, City of Salem, SIC, and ODFW to get a better understanding of the total withdrawal of water from the North Santiam River. This is because of the complications of clarifying how much water is being used to satisfy individual water rights. The sections below provide information on the largest water users in the North Santiam basin.

Municipal Ten cities draw their drinking water from the North Santiam River, or canals filled with water from the North Santiam River: Detroit, Gates, Idanha, Jefferson, Lyons, Mehama, Mill City, Salem, Stayton, and Turner. Many of these are small users of water and a few, like Mill City, draw water from wells, not directly from the river. The cities of Salem and Stayton are the largest municipal water users that withdraw water directly from the North Santiam River.

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Large Municipal Water Users

Salem The City of Salem provides water to 195,816 residential users in and around the city, along with nearly 3,000 commercial users. The City's residential users include the City of Turner, and a number of water districts. If needed, the City also provides water to the City of Stayton (meeting with Salem, May 11, 2018). The North Santiam River is the City of Salem’s primary source of M&I water supply. The North Santiam River splits into multiple channels around Geren Island, mainly due to the Upper Bennett Dam (Figure 51). The City of Salem constructed Upper Bennett Dam but now shares ownership with SWCD. Salem built the dam to channel flow into the North Channel along Salem’s intake system and the SWCD and Salem Canals (Figure 51). The City of Salem’s intake system is located at the upstream end of Geren Island in the North Channel. The intake requires a minimum of 2.5 ft of head at its intake structure to function. The filtration system also requires a minimum 2.5 ft of head to provide enough pressure to push water through the sand filters. Based on current channel geometry, the north channel only attains a minimum of 2.5 feet ft of head with a river flow rate of approximately 750 cfs, as measured at Mehama. Gravel accumulation in the north channel and near the intake currently results in the head limit being reached more often. The City of Salem has a permit and a plan in-place that could help their intake work at lower river flows. This plan entails dredging-type activities around the forebay area of Upper Bennett Dam so more water flows past their intake. Salem has not initiated these improvements due to the cost associated with the mitigation efforts required by the permits. Water withdrawn from the North Santiam River goes to sand filtration ponds, where a slow gravity process filters the water down through sand ponds (Figure 52). From there, the water is gravity fed into their distribution system. These slow sand filters initially have 3 ft of sand that provides this filtration, and acts as a biologic filter as well. However, these filters only work with the extremely low turbidity water that the North Santiam River contains. Prolonged high turbidity fills the sand filters with fine sediment, which requires Salem to replace the sand and allow time for the biological filter to reform before recommissioning the clogged filtration pond. In addition to a minimum requirement for treated water, Salem also has a fire protection flow requirement, which dictates how much water must be stored and available for use at any given time.

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Figure 52. Geren Island Water Treatment Facility on the North Santiam River Source: City of Salem website at https://www.cityofsalem.net/Pages/salem-water-source.aspx

Based on water use reports on the OWRD website, Salem withdraws between 60– 96 cfs from April through October (2001-2016 data), with the peak monthly use in July and August, depending on the water needs and weather conditions. The City of Salem also has a water right for 80 cfs that Salem uses to send water into Mill Creek, via the Salem Canal diverted off the North Channel above Lower Bennett Dam into Stayton (Figure 51). The purpose of this water is for aesthetics in the City of Salem; however, this stream has also been identified as important habitat for ESA-listed salmonids. This is one of the oldest water rights in the system, with a priority date of 1856 (10 cfs) and 1985 (70 cfs). The City also obtains groundwater and uses its Aquifer Storage and Recovery (ASR) system during emergencies, water quality events, and peak demands to supplement surface water. The ASR system wells store treated drinking water from the North Santiam, which Salem injects into the Columbia River basalt aquifer to be stored for later recovery. Salem uses the reclaimed water during emergencies, high turbidity events, and peak demands to supplement surface water. Recovery rates typically decline from a range of 11 to 12 cfs at the beginning of the recovery period to the range of 7 to 8 cfs by the end of the recovery period. The finite storage capacity of the aquifer also limits the City’s ASR system. Groundwater is also available from wells on Geren Island and within the City’s water service area. The City recognizes that maintaining a reliable water supply is critical to supporting its large, growing population. Appendix J provides additional details of each of the City’s water sources and their water treatment and distribution system. Salem can also obtain and treat groundwater at Geren Island. The facility was initially constructed in the 1930s as an infiltration gallery and a water collection chamber (the collector well), where surface and groundwater are mixed to feed a 36-inch diameter transmission line. Over time, the infiltration gallery was converted and the system expanded to the present day treatment facility. Salem can also obtain

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groundwater from three additional wells on Geren Island (the Middle, East, and West wells). Finally, a limited amount of groundwater is available from wells within Salem’s service area. Salem’s groundwater sources supplement surface water during emergencies, high turbidity events, and periods of peak demand. Salem has intergovernmental agreements with two other municipal drinking water systems: the City of Stayton and City of Keizer. The City of Stayton is located southeast of Salem, near Geren Island. The City of Keizer is adjacent to and north of Salem and is located within the Salem-Keizer Urban Growth Boundary. Under each of these agreements, the Cities of Stayton and Keizer can obtain water from the City during emergencies if surplus water is available. In addition, the City of Stayton must follow Salem’s curtailment plan if the plan is in effect at the time Stayton requests the emergency supply. Both agreements allow either city to provide water to Salem.

Stayton The City of Stayton withdraws water from the SWCD canal, which diverts from the north channel of the North Santiam River from the forebay of Lower Bennett Dam, at the downstream end of Geren Island (Figure 51). The City of Stayton’s maximum use ranges from 10-15 cfs, depending on the time of year (Lance Ludwick, personal communication, 2018). Based on the water use report available from the OWRD website, the average monthly use ranges from 3-4 cfs in April, May, June, and October, and 6-7 cfs July–September. The City of Stayton has seven water rights for use of water from the North Santiam River. Three of these rights allow for year round diversion of 17.6 cfs, three rights are only usable May through September (total 4 cfs), and one right is only usable from October 1 through April (25 cfs). The City of Stayton cannot use this last right until receiving approval of the updated Water Management and Conservation Plan (drafted March 2018). The five main user groups of M&I water supply from Stayton are residential (41%), commercial/industrial (5%), NorPac (42%), wastewater treatment plant (10%), and other (2%) (City of Stayton WMCP, March 2018). Some of the water reported in the SWCD water use reports is for the City of Stayton.

Small Municipal Water Users

Gates The City of Gates has water rights to 1.7 cfs from the North Santiam to serve a population of approximately 500 people. Gates typically uses less than 0.2 cfs during the summer months.

Mill City The City of Mill City has two groundwater wells used for water supply to the city. Mill City does not draw water directly from the North Santiam River. 3-235

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Turner The City of Turner buys treated water directly from the City of Salem and does not have a backup supply source. The City of Turner supplies water to approximately 2,000 people, a lumber mill, a retirement facility, and two conference centers (call with City of Turner, June 28, 2018).

Irrigation / Agriculture

Major Users

Santiam Water Control District SWCD is the largest single user of North Santiam River water. SWCD provides irrigation to approximately 17,000 acres within their district boundary, with the majority of these acres covered by live flow water rights as the primary source of irrigation water. Approximately 1,300 acres only have stored water as a supply of irrigation water (meeting with SWCD, June 7, 2018). SWCD typically diverts approximately 400 cfs into the main canal located above Lower Bennett Dam (Figure 51). The inlet works are gravity fed. Gravel deposition in front of the point of diversion influences how much flow SWCD needs in the river to ensure water enters the main canal. SWCD does not have a minimum flow rate that ensures viable operation of the main canal and assumes the same minimum flow rate at the City of Salem, 750 cfs at Mehama. SWCD submits an annual water use report to the OWRD detailing out the monthly withdrawal of water into the main canal. Based on the available reports (2012-2016), the average monthly diversion ranges from 386 cfs in April to 473 cfs in September. Water use report 61988 lists 45 rights that are satisfied with this diversion, including power development, Salem Ditch/Mill Creek, and City of Stayton. The water use report does not list how much water was provided to each of the water rights. As this one report covers many entities, summing all water use reports could result in an over estimate of diversion around Geren Island; therefore the effects analysis would use the water use reports for the three main diversions on the North Santiam, namely City of Salem, SWCD, and SIC. Water diverted by SWCD into the main canal is the source of the City of Stayton’s municipal water and for Mill Creek, which is a creek that flows through the City of Salem and provides water to various ponds within city parks (aesthetic water right). Salem indicates that they withdraw 102 cfs for this purpose. SWCD also provides the sole source of water for fire protection to the Cascade School District. In addition to irrigation and fire protection, SWCD has water rights to use 185 cfs for power development. SWCD has contracts with Pacific Power for a set

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capacity, requiring 140 cfs from the main canal into the turbine units. Water then returns to the north channel of the North Santiam River below Stayton.

Sidney Irrigation Cooperative SIC provides irrigation water supply to approximately 8,000 acres of agricultural land, through a system of canals fed by one diversion point on the North Santiam River. The diversion is located upstream from the USGS’ Greens Bridge gage. Sidney’s water rights are second in priority only to some of the City of Salem’s rights, with nearly 4,000 acres covered by two water rights with a priority date of 1870 and 1909. The Sidney Canal is gravity fed and relies on adequate flow in the North Santiam to feed the canal inlet. The canal splits into a myriad of branches, only one of which returns to the North Santiam River, with the main canal returning to the Willamette River. SIC indicated they have issues when the Mehama gage is below 3 ft (meeting with SWCD and Sidney, June 7, 2018). Based on the USGS field measurements for this gage, 3-ft gage height corresponds to a flow of 1,200 cfs or less, typically less than 1,000 cfs.

Stored Water Contracts As of June 2018, there are 29 contracts with BOR for use of 11,375 acre-feet stored water from Detroit Reservoir. The contracts with BOR states that water may be diverted from March 1–October 31, which corresponds to a total of 23.45 cfs per day. The four largest contract holders are SIC (4,237 acre-feet), SWCD (1,997 acre-feet), Queener Irrigation (1,950 acre-feet), and Kingston Irrigation District (825 acre-feet).

Commercial/Industrial

NorPac Based on the water use report tool on the OWRD website, NorPac uses less than 1 cfs of water withdrawn from the North Santiam. However, SWCD (per meeting with SWCD in June 2018) indicated NorPac requires approximately 30 cfs of water in Salem Ditch/Mill Creek for boiler cooling purposes. This need can be met with Salem’s aesthetic water right.

Fish and Wildlife

Minimum Perennial Streamflows The OWRD established minimum perennial streamflows (MPSF) in 1964. These MPSFs are a combination of live flow and water released from storage. Within the Willamette River basin, there are several MPSFs that have yet to be converted to instream water rights, as required by state law. Additionally, the 2008 BiOp RPA requires the conversion of MPSFs and additional stored water for the benefit of UWR Chinook and steelhead. These MPSFs specify that a certain quantity of live flow, along 3-237

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with an unspecified amount of water released from storage, must be maintained on major tributaries and at several points along the mainstem of the Willamette River to support aquatic life and to minimize pollution. MPSFs exist in tributaries below the WVP reservoirs, including on the North Santiam River below Detroit and Big Cliff Dams. Once converted to instream water rights, the MPSFs would carry a priority date of June 22, 1964. The MPSFs on the North Santiam River have not been converted to an instream water right, and, therefore, do not have a priority date for regulation purposes. The MPSF on the North Santiam River is 345 cfs.

Decreed 50 cfs Right While there are no official instream water rights in the North Santiam, there is one decreed water right for 50 cfs with a priority date of time immemorial, meaning all rights are junior to this right. This flow is measured at Upper Bennett Dam and must be satisfied.

Flows

Ten-year Average from USGS Gages (Niagara, Mehama, Greens Bridge) The Corps obtained flow data covering 2008 through 2018 from the USGS website. This data was form the three main gauges on the North Santiam River: Niagara, Mehama, and Greens Bridge, listed in order from upstream to downstream (Figure 53). The Niagara gage is considered to gage the outflow from Big Cliff Dam; Mehama is immediately downstream from the confluence of the Little North Santiam River with the North Santiam River; Greens Bridge is located upstream of the confluence with the Santiam River.

Figure 53. North Santiam USGS Gauge Stations

Environmental Consequences

Methodology and Scale of Analysis

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The OWRD has indicated that the agency has not required users to stop withdrawing water (regulating off) in the North Santiam basin, largely due to the flow augmentation provided by stored water released from the Detroit Reservoir. While live flow users do not technically have a right to use stored water, OWRD considers any stored water released from a reservoir that is not associated with a contract with the owner of the dam to be part of the live flow. The OWRD is in the process of determining a method for how the agency might handle live flow water rights and users in times of drought, or when stored water is not available to augment the naturally low flows in the summer months. Results of this work are not yet available. In the absence of how the state would specifically regulate water rights, this analysis would simply look at the range of possible flow regimes in each alternative, and compare to the water rights of record. The Corps did not make any assumptions on which rights are truly active and being used, unless this information is known from conversations with the specific entity. While there are numerous water rights on tributaries to the North Santiam River, tributary water rights are for very small quantities of water that would not likely make a difference in the overall flow in the mainstem of the North Santiam. The OWRD indicated that a drought declaration does allow the state to prioritize water for human health and safety and livestock. For the M&I analysis, the Corps estimated the number of people Salem would not be able to serve if Geren Island is inoperable due to low flows along the North Santiam at Geren Island. The Corps utilized the City of Salem’s projected future demand from the 2014 Water Management Conservation Plan to determine the Maximum Daily Demand during the period when the Project is likely to occur (2024). To account for uncertainty in the data and application of the trends, the City calculated range factors of +/-15% of projected maximum daily demand values to plan for a potential range in future water demands. The 2014 Water Management Conservation Plan projects that in 2024 the maximum daily demand (+15%) would be 66.6 million gallons per day requiring 103 cfs. The maximum authorized rates of the City’s North Santiam surface water rights are sufficient to meet the projected maximum daily demand, but it is important to note the current point of constraint is the transmission capacity from Geren Island to the City’s storage and distribution system, which is currently limited to 102 cfs. The City can also obtain approximately 7 to 12 cfs from its ASR system, which results in a current total supply of 109–114 cfs. However, there is serious concern whether both the Cities of Salem and Stayton can provide the quantity and quality of water they need for project alternatives where there could be flows as little as 400 cfs during the summer months. This is because 400 cfs is below the 750 cfs threshold the City assumes the intakes and sand filtration system would not function. This is also a concern for the drawdown alternatives during periods when the turbidity is expected to be elevated above the threshold the facilities are capable of managing. For purposes of analysis, the Corps assumes that when flows in the North Santiam River at the Mehama gage are as below 3-239

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750 cfs and when turbidity is elevated, the Cities’ of Salem and Stayton’s slow sand filters would not function correctly without well water augmentation, and would not be able to provide treated water to the City of Salem. Applying the U.S. Census data for 2010 and 2017, and assuming the same population growth rate is applied to the 2021 to 2024 time period, when construction of the SWS is expected to occur, it is assumed the population in 2022, the likely first summer during construction, would be 209,189. Using these populations, the Corps performed a water budget to determine the potential number of people that the City would not be able to serve if water from the North Santiam River was not available.

Staging Areas Work proposed at the staging areas described in Sections 2.7.2.5 and 2.6 would not affect water supply under any alternative.

CA1. No Action The No Action Alternative would have no direct or indirect on water supply.

CA2. SWS and FSS Constructed with a Two-year Deep Drawdown Under CA2, there would be significant impacts to water supply for both M&I and irrigation due to low flows and increased turbidity in the North Santiam River. During the proposed drawdown, flows downstream of Detroit Dam (and Big Cliff) would be less than 750 cfs more than 50% of the time (see Section 0 for details). Flows could drop below the 750 cfs threshold as early as mid-July and extend into November in very dry years. Dry years could see flows drop below 750 cfs starting in August and extend through October (Figure 36). Additionally, when the reservoir is being initially drawn down in the winter under CA2, the drawdown would raise turbidity levels well above baseline levels for over 60 days (see Section 3.5.4.4). This would require both Salem and Stayton to shut down their sand filtration facilities for weeks to months. This is because sand filtration systems are very sensitive to turbidity levels and can only function at turbidity levels over baseline for a few days to a couple of weeks at most. Under elevated turbidity levels for longer periods, the sand filters would fill with fine sediment, clogging the gravity fed system. This would require operators to replace the sand and allow additional time for a complex biological film that grows on the surface of the sand and helps filter the water to develop before they can continue water supply filtration and delivery from the system. At flows less than 750 cfs in the summer during the drawdown and with high turbidity levels in the first winter of construction, City of Salem would have difficulty operating the main intake on Geren Island, thus affecting users throughout the Salem Public Works distribution system, including municipal users, commercial and industrial entities, 3-240

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schools, and potentially fire suppression. The Corps estimates that Salem would not be able to serve between 49,000 people (Average Daily Demand) and 180,000 people (Maximum Daily Demand) during the winter of the initial drawdown and in summer months over the 2-year drawdown period. To address these shortages, Salem could construct new local groundwater wells at Geren Island along with appurtenant support structures, and improve the City's Aquifer Storage Recovery system. The Corps estimates it would cost upwards of $28,000,000 to implement the water supply mitigation measures to improve the City's water supply system (see Appendix J for details). As Salem has water rights on the Willamette River, Salem could alternatively construct a new water supply facility downstream of Geren Island on the Willamette River. This would also require Salem to reconfigure their delivery system to connect to the new plant downstream, which would require pumping as the current system of pipes connecting the Geren Island Facility to users is gravity fed. Salem estimated this to cost upwards of $100M to construct. Such a system would also have longterm economic impacts as it would require new, more expensive to run filtration systems as the Willamette River requires more treatment. There is a high risk that it would not be possible for the City to implement either mitigation measure in the timeline of this project. The Corps project is planning to start construction of temperature control in 2021. It would take years, perhaps a decade, to complete the design, permitting, financing and construction of either new water supply. Stayton would likely exercise its agreement with Salem to have water delivered from the Salem system to addres shortages. The SWCD’s inlet into the main canal is gravity driven and the exact operational elevation varies year to year based on gravel deposition upstream of Lower Bennett Dam; therefore, SWCD defaults to the City of Salem’s requirement of 750 cfs at Mehama. The SIC indicated that they have similar limitations at their intake. At river flows less than 750 cfs, the Corps assumes that SWCD and SIC would not be able to withdraw water, thus affecting irrigation users, the City of Stayton, NorPac (which uses flows in the Salem Ditch), hydropower generation contracts, and many others. SWCD does not have alternative sources of water supply. The State of Oregon, through the OWRD, is responsible for managing water supplies in the state. As there is not a list or plan on how users would be prioritized when flows reach historically low levels, no attempt has been made to quantify impacts to individual users. However, normal state water law follows the doctrine of prior appropriation, or first in time, first in right.

CA3. SWS and FSS Constructed with a One-year Deep Drawdown Impacts to water supply under CA3 are the same as for CA2, except for only 1 year, or more specifically, one summer and early fall. 3-241

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CA4. SWS and FSS Constructed with a One-year Variable Drawdown CA4 involves an initial drawdown to elevation 1,400 in the fall, but with the goal of raising to elevation 1,455 by the following spring, with a target release of 1,000 cfs during the summer months. Under this alternative, flows are not expect to go below 750 cfs, and flows less than 1,000 cfs are unlikely. Flows would be lower than the No Action Alternative in September through November, but would not go below 750 cfs, and rarely dropping below 1,000 cfs. With these flows, the Corps does not expect impacts to water supply (M&I and irrigation) as flows were recently very close to 1,000 cfs (and slightly below during the drought of 2015) and water supply providers did not experience problems with their ability to withdraw water. However, the water supply facilities at both Salem and Stayton would experience elevated turbidity levels during the summer months of the drawdown as discussed in Section 3.5.4.6, having similar impacts to water supply as those experienced during the initial winter of drawdown under CA2 and CA3. The Corps estimates that Salem would not be able to serve between 49,000 people (Average Daily Demand) and 180,000 people (Maximum Daily Demand) during the summer months over the 1-year drawdown period. To address these shortages, Salem could construct new local groundwater wells at Geren Island along with appurtenant support structures, and improve the City's Aquifer Storage Recovery system. The Corps estimates it would cost upwards of $25,700,000 to implement the water supply mitigation measures to improve the City's water supply system (see Appendix J for details). Stayton would likely exercise its agreement with Salem to have water delivered from the Salem system during shortages.

CA5. SWS and FSS Constructed with No Drawdown CA5 would have no direct or indirect on water supply, as the Corps would construct the project without changes to current operations relative to reservoir elevations and releases. CA5 would not have long-term effects to water supply as the SWS and FSS would be operated to meet BiOp minimum flows.

3.13 HYDROPOWER The Willamette Basin contains several federal and non-federal hydropower power- generating facilities that agencies utilize to generate electrical energy for local and regional consumption. BPA markets energy generated by the Corps' Willamette projects to help meet local and regional energy demand within the Federal Columbia River Power System. Any change in one reservoir’s operations may affect other projects in the Valley and system power production.

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The Flood Control Act of 1948 (Pub. L. No. 80-858, 62 Stat. 1175)) modified the Flood Control Act of 1938 to provide for the installation of hydroelectric power- generating facilities at Detroit Dam, and included the construction of Big Cliff Dam as a part of the Detroit project. Detroit and Big Cliff dams are two of eight Corps multiple- purpose projects throughout the WVS that contain power-generating facilities. Big Cliff is one of three re-regulating dams. The power plants at the peaking projects (Detroit, Green Peter, and Lookout Point) are used primarily to generate power during Heavy Load Hours (peaking hours). Projects downstream of the ”peaking” power projects (Big Cliff, Foster, and Dexter, respectively) perform a re-regulation function by generating power steadily each day through both the heavy load hours and the low load hours. Table 33 provides the estimated monthly WVS generation values in average monthly energy in megawatts (aMW) under existing conditions (Base Case). Currently, Detroit Dam reduces power generation when the reservoir elevation is above the spillway for interim temperature operations. The Corps estimates the current expected power value generated in the WVS for the Base Case at $42.18 million (at 2019 price levels). Three power projects in the WVS (Detroit, Green Peter, and Lookout Point) can be scheduled to provide energy that is shaped to meet morning and evening peak loads. They also provide standby capacity that be called up to provide more or less energy depending on the needs of the loads that BPA serves. Dam operations that result in significant reductions in monthly energy generation at Detroit, Green Peter or Lookout Point may result in lost capacity. When generation drops below 6 aMW at the peaking plants (Detroit, Green Peter, and Lookout Point) there is insufficient flexibility to meet system load and additional capacity is needed to maintain system reliability

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Table 33. Estimated Generation Values for the Base Case

Base Case Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sept TOTAL (current prices)

1 Generation (aMW) (aMW) (aMW) (aMW) (aMW) (aMW) (aMW) (aMW) (aMW) (aMW) (aMW) (aMW) (aMW) 2 Detroit* 45.3 67.8 64.2 64.5 51.1 43 32.3 28.2 21.8 17.2 16.9 31.2 40.2 3 Big Cliff 12 16 14.6 14.6 11.1 9.8 10.2 12.8 10.6 7.3 5.9 9.7 11.2 4 Cougar 14.2 5.1 2 2.2 5.9 10.5 14.1 18.1 16.2 12.8 14.1 12.1 10.6 5 Green Peter* 15.9 31.5 54.6 48.4 25.9 28.9 33 30.9 24.9 15.5 14.2 22 28.8 6 Foster 10.5 15.4 19.4 18.2 14.9 16.3 18.1 15.5 13.6 8 6.8 10.6 13.9 7 Hills Creek 19.4 24.2 21.2 22.3 12.6 12.8 18.3 23.9 20.3 13.5 15.7 16.7 18.4 8 Lookout Point* 43.9 59.9 47 48.1 29.3 27.2 35.2 53.5 45.4 27 29.7 35.9 40.2 9 Dexter 11.1 14 12.6 13.1 7.4 6.7 8.3 11.2 9.8 6.3 7 8.9 9.7 10 Total Generation (aMW) 172.3 233.9 235.6 231.4 158.2 155.2 169.5 194.1 162.6 107.6 110.3 147.1 173.2 11 Hours in Month (hours) 744 719 744 744 672 745 720 744 720 744 744 720 8760 12 Power Project (aMW) 105.1 159.2 165.8 161 106.3 99.1 100.5 112.6 92.1 59.7 60.8 89.1 109.3 13 Power Project ($ MIL) $2.33 $3.52 $4.04 $3.88 $2.42 $2.13 $1.77 $1.56 $1.17 $1.15 $1.44 $2.02 $27.43 14 Flat (aMW) 67.2 74.7 69.8 70.4 51.9 56.1 69.0 81.5 70.5 47.9 49.5 58.0 63.9 15 Flat ($ MIL) $1.42 $1.61 $1.64 $1.61 $1.14 $1.17 $1.19 $1.02 $0.76 $0.85 $1.09 $1.24 $14.75 Total Willamette Hydropower Current Annual Value of BASE CASE ($ Mil) $42.18

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The SWCD operates a small hydropower project at their facilities at Geren Island (less than 5 MW), and is in the process of licensing additional generation capacity. Approximately 236,000 acre-feet of water was used in 2015 by SWCD for hydropower production (SWCD 2015).

Environmental Consequences

Methodology and Scale of Analysis In this study, the Corps and BPA jointly estimated the impacts to hydropower potential. Reservoir operations at WVS hydropower generation projects are simulated under the No Action Alternative and under the Action Alternatives, and the expected value of potential hydropower production during the construction period is calculated for all Alternatives. A full report on this analysis can be found in Appendix F and is incorporated here by reference. The HEC-ResSim computer model is used to simulate daily reservoir operations in the Willamette basin under various hydrologic conditions. The No Action Alternative simulation represents current operational conditions for a 73-year period of record (1935-2008). In this simulation, all reservoirs follow regulation rules consistent with current objectives and practices including flood risk management, fish and wildlife, water quality, water supply, recreation, and hydropower production potential. The action alternative simulations represent operational conditions during construction of the FSS and SWS and any associated drawdowns. All other Willamette Valley reservoirs maintain rules from the No Action Alternative. To estimate the value of potential hydropower generation at federal projects, the Corps passed reservoir operation results from ResSim to BPA where the results are used with the HYDSIM model to determine the hydro-system generation potential at each of the eight federal projects. The HYDSIM analysis produces the amount of power potentially generated by each power project for each month in the 73-year period of record, and the average monthly potential generation is calculated. BPA and the Corps estimated market prices by the AURORA model that uses electricity demand, fossil fuel markets, generation capacity, and emissions to determine hourly clearing prices for electric power. Monthly prices are calculated from the hourly price data by taking a weighted average using historical generation information. Finally, the monthly prices are applied to the average monthly energy generated at each project, and the sum is taken to arrive at the average annual value of hydropower. Additionally, the Corps estimated the “opportunity cost” (power loss) associated with the long-term operation of the SWS and FSS with the penstock bifurcation. The Project would likely result in a difference in penstock system head losses between the existing system (CA1) and the future system with the FSS, SWS and RO-penstock bifurcation

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(CA2-5) and some loss to the power generating capacities. By determining the potential head losses, the Corps estimated the potential hydropower losses (opportunity costs) over the long-term operation of the Project. This analysis is detailed in Appendix F.

Staging Areas Work proposed at the staging areas described in Sections 2.7.2.5 and 2.6 would not affect hydropower under any alternative.

CA1. No Action Under the No Action Alternative (the Base Case) there would be no change to current potential hydropower production. The Corps would continue current operations, which divert releases from the powerhouse to the outlets or spillway as a means of regulating the temperature of water released from Detroit Dam. Table 33 shows the potential generation under Base Case current operations of 173.2 aMW, valued at $42.18m. There would be annual “opportunity cost” (power loss) under CA1.

CA2. SWS and FSS Constructed with a Two-year Deep Drawdown Under CA2, the Corps would halt all hydropower generation at Detroit Dam for the duration of construction of the SWS (expected to be 2 years) and during FSS installation at the SWS and during its commissioning. Hydropower at Big Cliff Dam would continue. Table 34 shows the expected generation under CA2. The Corps estimates the value of the WVS energy generated under CA2 to be $31.72 million. The impact of CA2 is quantified by taking the difference from the Base Case (CA1) and deducting the capacity loss shown in Table 35. The potential value of the energy and capacity lost under scenario CA2 is $19.09 million annually for the duration of SWS construction (for a total of $38.18 million over the construction period of this alternative). Over the long, the combination of future changes (FSS, internal SWS tower and RO- penstock bifurcation) will bring about additional head losses in the penstock and some loss to the power generating capacities. The majority of increased headlosses will be incurred upstream of the unaltered penstock intake by the FSS and SWS. Losses caused by the angled bifurcation wye will be comparatively modest. In general, the overall differences are about 4 to 7 ft depending on flow rates (Appendix F for details). The average annual “opportunity cost” (power loss) of the SWS and FSS would be about 1.3% (5 GWh of generation and about $200k of revenue).

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Table 34. Estimated Generation Values for the CA2

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sept TOTAL CA2 (current prices) Generation (aMW) (aMW) (aMW) (aMW) (aMW) (aMW) (aMW) (aMW) (aMW) (aMW) (aMW) (aMW) (aMW)

Detroit* 0.0 0.0 2.2 4.9 4.0 0.4 0.0 0.0 0.0 0.0 0.0 0.0 0.9

Big Cliff 5.6 10.0 12.1 12.2 13.1 13.6 14.7 14.5 10.8 6.0 4.1 4.1 10.0 Cougar 13.4 6.0 2.0 2.2 5.9 10.4 13.8 18.0 16.2 12.9 14.6 11.8 10.6

Green Peter* 15.9 31.4 54.5 48.5 26.1 28.9 33.0 30.9 24.9 15.5 14.2 22.0 28.9

Foster 10.6 15.4 19.4 18.2 15.0 16.3 18.2 15.5 13.6 8.0 6.8 10.6 14.0 Hills Creek 19.0 24.2 21.2 22.3 12.6 12.8 17.8 24.0 20.4 13.8 16.7 16.4 18.5

Lookout Point* 42.7 58.2 46.7 48.0 29.3 27.2 34.4 53.4 45.5 27.1 30.2 38.1 40.1

Dexter 11.0 13.7 12.6 13.1 7.5 6.7 8.1 11.2 9.9 6.3 7.2 9.5 9.7 Total Generation (aMW) 118.3 159.0 170.7 169.3 113.5 116.4 140.0 167.3 141.3 89.5 93.7 112.5 132.7 Hours in Month (hours) 744 719 744 744 672 745 720 744 720 744 744 720 8760 Power Project (aMW) 58.6 89.6 103.4 101.4 59.4 56.5 67.5 84.2 70.5 42.5 44.4 60.1 69.9 Power Project ($ MIL) $1.30 $1.98 $2.52 $2.44 $1.35 $1.21 $1.19 $1.17 $0.89 $0.82 $1.05 $1.36 $17.29 Flat (aMW) 59.6 69.4 67.3 68.0 54.1 59.9 72.6 83.1 70.8 47.0 49.3 52.4 62.8 Flat ($ MIL) $1.26 $1.49 $1.58 $1.56 $1.19 $1.25 $1.26 $1.04 $0.76 $0.84 $1.08 $1.12 $14.43 Total Willamette Hydropower Current Annual Value of Alt #2 ($ Mil) $31.72

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Table 35. CA2 – Hydropower Value (losses)

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sept TOTAL CA2 Losses (current prices) Generation (aMW) (aMW) (aMW) (aMW) (aMW) (aMW) (aMW) (aMW) (aMW) (aMW) (aMW) (aMW) (aMW) Detroit* -45.3 -67.8 -62.0 -59.6 -47.1 -42.6 -32.3 -28.2 -21.8 -17.2 -16.9 -31.2 -39.3 Big Cliff -6.4 -6.0 -2.5 -2.4 2.0 3.8 4.5 1.7 0.2 -1.3 -1.8 -5.6 -1.2 Cougar -0.8 0.9 0.0 0.0 0.0 -0.1 -0.3 -0.1 0.0 0.1 0.5 -0.3 0.0 Green Peter* 0.0 -0.1 -0.1 0.1 0.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.1 Foster 0.1 0.0 0.0 0.0 0.1 0.0 0.1 0.0 0.0 0.0 0.0 0.0 0.1 Hills Creek -0.4 0.0 0.0 0.0 0.0 0.0 -0.5 0.1 0.1 0.3 1.0 -0.3 0.1 Lookout Point* -1.2 -1.7 -0.3 -0.1 0.0 0.0 -0.8 -0.1 0.1 0.1 0.5 2.2 -0.1 Dexter -0.1 -0.3 0.0 0.0 0.1 0.0 -0.2 0.0 0.1 0.0 0.2 0.6 0.0 Total Generation -54.0 -74.9 -64.9 -62.1 -44.7 -38.8 -29.5 -26.8 -21.3 -18.1 -16.6 -34.6 -40.5 (aMW) Hours in Month (hours) 744 719 744 744 672 745 720 744 720 744 744 720 8760 Power Project (aMW) -46.5 -69.6 -62.4 -59.6 -46.9 -42.6 -33.0 -28.4 -21.6 -17.2 -16.4 -29.0 -39.4 Power Project ($ MIL) ($1.03) ($1.54) ($1.52) ($1.44) ($1.07) ($0.91) ($0.58) ($0.39) ($0.27) ($0.33) ($0.39) ($0.66) ($10.13) Flat (aMW) -7.6 -5.3 -2.5 -2.4 2.2 3.8 3.6 1.6 0.3 -0.9 -0.2 -5.6 -1.1 Flat ($ MIL) ($0.16) ($0.11) ($0.06) ($0.06) $0.05 $0.08 $0.06 $0.02 $0.00 ($0.02) ($0.00) ($0.12) ($0.32) No Value These Capacity ($ MIL) ($0.91) ($0.91) ($0.91) ($0.91) ($0.91) ($0.91) ($0.45) ($0.91) ($0.91) ($0.91) ($8.64) Periods Total Willamette Hydropower Current Annual (losses) of Alt #2 ($ Mil) ($19.09)

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CA3. SWS and FSS Constructed with a One-year Deep Drawdown Under CA3, the Corps would halt all hydropower generation at Detroit Dam for the duration of construction of the SWS and during FSS installation at the SWS and during its commissioning. Hydropower at Big Cliff Dam would continue. As such, hydropower impacts under CA3 would be the same as under CA2. The average annual “opportunity cost” (power loss) of the SWS and FSS would be the same as under CA2.

CA4. SWS and FSS Constructed with a One-year Variable Drawdown Under CA4, the Corps would halt all hydropower generation at Detroit Dam for the duration of construction of the SWS and during FSS installation at the SWS and during its commissioning. Hydropower at Big Cliff Dam would continue. As such, hydropower impacts under CA4 would be the same as under CA2. The average annual “opportunity cost” (power loss) of the SWS and FSS would be the same as under CA2.

CA5. SWS and FSS Constructed with No Drawdown Under CA5, the Corps would halt all hydropower generation at Detroit Dam for the duration of construction of the SWS and during FSS installation at the SWS and during its commissioning. Hydropower at Big Cliff Dam would continue. As such, hydropower impacts under CA5 would be the same as under CA2. The average annual “opportunity cost” (power loss) of the SWS and FSS would be the same as under CA2.

3.14 TRANSPORTATION/CIRCULATION The Detroit Dam Powerhouse and the top of dam are both accessible directly from OR-22. OR-22 is a primary route between Interstate 5 (I-5) in Salem, OR and Central Oregon. For the first 13 miles east of I-5, from Salem to Stayton, OR-22 is a four-lane divided freeway. After Stayton, OR-22 is a two-lane highway. For the remaining 30 miles, from Stayton to the Detroit Dam, the Federal Highway Administration and ODOT classifies OR-22 as a Rural Principal Arterial highway. Additionally, ODOT has designated OR-22 as a freight route, signifying that the annual tonnage hauled by truck on this route is moderate to high and the highway provides connectivity to freight generating areas. Therefore, the Corps expects that large trucks hauling materials and equipment to the project site would encounter similar vehicles along the route. The ODOT classifies OR-22 as a Group 1 highway. The largest trucks that can transit along this highway without a permit are 60-ft long truck-tractors with semi-trailers, 65-ft long truck-tractors with stinger-steered pole trailers, or 75-ft long truck-tractors with multiple semi-trailers. The maximum height and width of non-permit vehicles is 14 ft and 8.5 ft, respectively, while the maximum permissible weight is 80,000 pounds, with no

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more than 20,000 pounds on any one axle or 34,000 on any tandem axle. Exceptions can typically be made with an oversize vehicle permit on a case-by-case basis. A review of weight-restricted bridges has not revealed any impediments for hauling to the project site. The only restricted bridge along the haul route from I-5 to the Detroit Dam project site is over the Santiam River in Mill City; however, this bridge is located off the OR-22 mainline and does not restrict standard or permitted vehicles on the highway. Currently logging companies and emergency vehicles have access to the south side of Detroit Reservoir by way of the Detroit Dam Road. Logging companies utilize this road as the most direct route to access properties on the south side of the reservoir to harvest and manage their properties. The USFS and Oregon Department of Forestry (ODF) emergency vehicles use this road as the most direct route for accessing areas south of Detroit Reservoir for emergencies including fighting wildfires and performing missing person searches.

Environmental Consequences

Staging Areas Construction traffic traveling into and out of the Detroit construction sites, including all staging areas described in Sections 2.7.2.5 and 2.6, should have a minor, short-term impact to other traffic using OR-22. Traffic would be heavier during the drawdown work. Construction may require nighttime work. Approximately 10-30 other construction- related vehicles per day may need to access staging areas. A dozen or so oversize (permit required) loads are likely. The Corps expects any potential delays to be short- term and temporary. Lane closures, barriers, flaggers, and/or construction signs may be required. However, if traffic control is necessary, the Corps may deploy flaggers to halt traffic temporarily to facilitate safe entrance and/or exit of heavy equipment and vehicles at the site. Construction traffic and haul roads would be in compliance with the Corps safety manual, EM 385-1-119. This EM specifies use of the “Manual of Uniform Traffic Control Devices” for highway construction signage. The contractor’s traffic safety plan would address construction traffic entry and exit points onto public roads and traffic control into the site.

CA1. No Action The No Action Alternative would have no direct or indirect on traffic/circulation.

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CA2. SWS and FSS Constructed with a Two-year Deep Drawdown Construction traffic traveling into and out of the Detroit construction sites, including all staging areas described in in Sections 2.7.2.5 and 2.6, should have a minor, short- term impact to other traffic using OR-22. Traffic would be heavier during the drawdown work. The Corps does not anticipate nighttime work, but it remains possible. During the summer, when construction is at its peak, the Corps estimates that an average of one semi-truck of material or equipment per hour would need to access the Detroit Dam site for up to 16 hours per day for the duration of construction. Approximately 10-30 other construction-related vehicles per day may need to access and leave the Detroit Dam site. A dozen or so oversize (permit required) loads are likely. The Corps expects any potential delays to be short-term and temporary. Lane closures, barriers, flaggers, or construction signs may be required. However, if traffic control is necessary, the Corps may deploy flaggers to halt traffic temporarily to facilitate safe entrance and/or exit of heavy equipment and vehicles at the site. Construction traffic and haul roads would be in compliance with the EM 385-1-1. This manual specifies use of the “Manual of Uniform Traffic Control Devices” for highway construction signage. The contractor’s traffic safety plan would address construction traffic entry and exit points onto public roads and traffic control into the site.

Detroit Dam Road Under CA2, the Corps would close Detroit Dam Road to all but construction related traffic for the duration of the SWS construction (approximately 3 years) and for three months at the end of FSS construction when the FSS is towed to the dam commissioned.. When the Corps closes the road over Detroit Dam for construction, emergency response vehicles and logging companies would need to use an alternate route to access the lands south of the dam and reservoir. Fortunately, a bridge below Detroit Dam provides access across Big Cliff Reservoir to the Southshore Road. The Corps recently improved this alternate route during a road rehabilitation project completed in the summer of 2018. The Corps would provide emergency vehicles with access through a Corps security gate. The Corps would need to coordinate with local fire response agencies such as the USFS and ODF, so that emergency responders would know to call the Detroit Powerhouse control room to get access through the gate. Using Southshore Road would probably take about 5 minutes longer than going directly across the dam. Logging trucks (which weigh on average 40 to 44 tons loaded) are too heavy for the Southshore Bridge (rated for 36 tons) downstream of Detroit Dam crossing the Big Cliff Reservoir. Therefore, logging trucks would have to take a circuitous route on OR-22 around Detroit Reservoir or by way of USFS roads from Mill City. This would increase the driving distance for logging companies to reach their harvest areas south of Detroit Reservoir. The Corps assumes the normal distance and

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time to Gates using current routes are assumed 21.6 miles (1 hour and 35 minutes driving time). This is compared to a distance of 55.1 miles (2 hours and 22 minutes driving time) if using USFS roads (NF 2212 to NF 1133 to NF 1012 to NF 10 to Upper Divide Creek Road to Blowout Road to Hwy 22). The Corps assumes logging trucks would be able to use the Southshore Bridge on their return trip to a harvested parcel, since the trucks would be empty. For purposes of economic analysis, the Corps assumes logging trucks could not cross Detroit Dam to access Highway 22 for 3.25 years, and that 300 trucks would no longer use the dam on annual basis during this time. The impact to existing USFS roads could be moderate should the timber company elect to harvest during the construction period. Total economic impact could be on the order of $100,000, if the assumptions hold true and the timber company continues to harvest timber south of the dam.

Operation of the FSS The Corps does not expect fish transport to impact traffic in the project area. Once the Corps commissions the FSS and commences the associated truck and haul operations, transport trucks would be transporting fish multiple times a day, 7 days per week from January 1–June 30 and September 1–December 31. The fish transport trucks would haul fish from Detroit Dam to the Minto Facility for release. As OR-22 is a trucking route, the addition of one truck making multiple trips a day would not substantially increase traffic overall.

CA3. SWS and FSS Constructed with a One-year Deep Drawdown Under CA3, impacts to transportation and circulation would be the same as those described under CA2.

CA4. SWS and FSS Constructed with a One-year Variable Drawdown Under CA4, impacts to transportation and circulation would be the same as those described under CA2.

CA5. SWS and FSS Constructed with No Drawdown Under CA5, impacts to transportation and circulation would be the same as those described under CA2.

3.15 AESTHETIC RESOURCES The landscape of the North Santiam River Canyon and around Detroit Reservoir is composed of dense coniferous vegetation, varied terrain, an abundance of geologic features, lakes and rivers, wildlife, and snow-capped mountain peaks, which together

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form an outstanding scenic resource. This resource provides a broad range of natural and managed scenic experiences for both local and distant visitors. The quality of the scenic resource is important to the local tourist industry as well as the Pacific Northwest. Many residents of the Willamette Valley, and beyond, through their recreational pursuits, seek an overall natural appearing landscape in contrast to their normal surroundings of urban streets and agricultural lands. The scenery of the area is an important asset to the local communities, which are attempting to diversify their economic base in an effort to recover from recent declines in the wood products industry. The reservoir itself is approximately 9 miles long with 32 miles of shoreline and views of Mount Jefferson. Many drainages in well-defined ravines enter the lake on either side. Reservoir slopes are often steep on the western end near the dam but flatten out at the head of the reservoir near the town of Detroit. The North Santiam River below Detroit Dam flows through forested land valued for its mature, old growth vegetation and hardwoods providing fall color. The corridor has an overstory of Douglas fir, western red cedar, and western hemlock. The existing wetland and side-stream areas host tree communities of alder, cottonwood, and willow. Sedges, understory shrubs, and forbs also populate the river corridor. The scenic quality of the forest, along with visually appealing water features of pools, falls, riffles, meandering channels, and water clarity, contribute to the corridors aesthetic value. USFS manages much of the lands surrounding Detroit Reservoir according to their visual quality objectives (Forest Service, 1990). These include: • "retention" - in general, human activities not evident to the casual forest visitor, • "partial retention" - in general, human activities may be evident but subordinate to the characteristic landscape, • “modification” - human activities may dominate the characteristic landscape but must appear as natural occurrences when viewed in foreground or middle ground, and • “maximum modification” – human activity may dominate the characteristic landscape but should appear as natural occurrences when viewed in the background. Water in the North Santiam basin enhances resident and visitor experiences by providing an aesthetic value to their surroundings. The OWRD has identified aesthetics as a beneficial use for water rights, describing it as the use of water for scenic, beautification, and enhancing the appeal of an area. However, a water right is not required to generate aesthetic use value: instream flows in the North Santiam and its tributaries also support this use and value. Aesthetic values can sometimes be difficult

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to disentangle from demand for other amenities provided by waterways, such as passive recreation and fish and wildlife habitat. The North Santiam River also supports aesthetic uses in Mill Creek, which is a tributary to the Willamette River. Salem diverts water from the North Santiam River into Salem Ditch which enters Mill Creek upstream of Aumsville. During the dry summer season, water from the North Santiam River substantially augments flows in Mill Creek. Demand for aesthetics along Mill Creek are particularly strong, as it flows through Oregon’s capitol grounds and, via the Mill Race, through the campus at Willamette University. Employees, residents, and visitors to Salem enjoy these waterways, especially during the summer months when people spend more time outside. The timing of relatively higher demand coincides with the period when flows from the North Santiam River make up a greater share of Mill Creek’s flow.

Environmental Consequences

Staging Areas Under CA2, project construction may result in moderate, long-term impacts to large mature trees and short-term impacts to herbaceous vegetation in regards to scenery at the potential staging areas described in Sections 2.7.2.5 and 2.6 during construction. The staging areas described in Section 2.7.2.5 would experience the environmental consequences described under all action alternatives. The Corps will rehabilitate the staging areas with a mix of native species, which represent the historic forest composition to further soften the scenery effects of the disturbance. The use of understory plantings would increase wildlife diversity, including native pollinators, and would provide a more diverse vegetation aesthetic. Over time, either planted native trees or natural regeneration of trees would provide similar visuals as pre-construction conditions. It is anticipated that the visual aesthetic of the impacted sites would return to a natural appearance of the area and blend into the surrounding landscape within 5 years for understory vegetation and approximately 50 or more years for large trees.

CA1. No Action The No Action Alternative would have no direct or indirect effects on the current scenery conditions in the project area.

CA2. SWS and FSS Constructed with a Two-year Deep Drawdown

Detroit Reservoir Under CA2, project construction may result in moderate, short-term impacts to scenery during construction. The Detroit Reservoir drawdown during the 2 years of construction would expose denuded rock areas and mud banks that are visually 3-254

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degrading and make access difficult. However, once the Corps recommences normal operations, scenery impacts would be the same as those under the No Action Alternative. The new SWS tower and the barge-like FSS would be on a similar scale to Detroit Dam and would likely add to the visual interest the dam provides.

North Santiam (Detroit Dam to Confluence with South Santiam) and Mill Creek During the proposed 2-year drawdown, flows downstream of Detroit Dam would be equal to flows coming into Detroit Reservoir and would be approximately 400 cfs. Low flows would likely result in desiccation of wetlands and other off-channel habitats in the 2 years that low flows would be occurring, potentially effecting the visual aesthetics of these areas. Additionally, low flows may result in the cessation of withdrawals to Mill Creek for aesthetics. This would negatively affect the aesthetic conditions along Mill Creek at its highest use time of year.

CA3. SWS and FSS Constructed with a One-year Deep Drawdown Under CA3, impacts to aesthetic resources would be the same as those experienced under CA2. However, impacts resulting from the drawdown would be limited to 1 year.

CA4. SWS and FSS Constructed with a One-year Variable Drawdown Under CA4, impacts to aesthetics resources would be the same as those experienced under CA3.

CA5. SWS and FSS Constructed with No Drawdown

Detroit Reservoir Under CA5, project construction may result in moderate, short-term impacts to scenery during construction. The Corps would not drawdown Detroit Reservoir beyond normal operations during construction, therefore, the visual impacts of exposed denuded rock areas and mud banks experienced under Construction Alternatives 2, 3, and 4 would not occur under CA5. The new SWS tower and the barge-like FSS would be on a similar scale to Detroit Dam and would likely add to the visual interest the dam provides.

North Santiam (Detroit Dam to Confluence with South Santiam) and Mill Creek Under CA5, the Corps would not drawdown Detroit Reservoir during construction; therefore, there would be no impacts to aesthetic resources downstream of Detroit Dam.

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3.16 CULTURAL, ARCHEOLOGICAL AND HISTORICAL RESOURCES

Cultural Setting The text in Section 3.16.1 is taken from Oetting (2017) with minimal revision by Corps archaeologists. Internal references have been omitted. Appendix Q provides details on the archeological, ethnographic, and historical context of the project’s cultural resources area of effect. The record of human occupation in Oregon extends back 14,000 years or more. The earliest well-dated evidence has been found in the Paisley Caves in the desert east of the Cascade Range. Archaeological evidence of early human occupation in the Western Cascades and the Willamette Valley has been more difficult to find and date, but some evidence has been found suggesting the presence of Native Americans as early as the late Pleistocene. Radiocarbon ages indicate that Native Americans were in the Willamette Valley by 9,800 years ago. A considerable amount of archaeological research has been conducted in the Cascades and Willamette Valley, with most of the evidence found dating to the Middle and Late Archaic periods. At the time Euro-American explorers, trappers, and first settlers entered western Oregon, the Willamette Valley was inhabited by the Kalapuya Indians and the Western Cascades were home to the Molala. The North Santiam River in the vicinity of the current Detroit Reservoir area was likely used primarily by the Molala. Three federally recognized Indian nations including the Confederated Tribes of the Grand Ronde, Confederated Tribes of Siletz Indians, and Confederated Tribes of Warm Springs have ties to the Molala peoples who historically inhabited the Detroit Reservoir area.

Cultural Resources in the Project Area of Potential Effect (APE) Four classes of cultural resources have been identified in the area of potential effect (APE) including: 1. Native American artifacts and sites that predate non-indigenous settlement in the Detroit Dam and Reservoir vicinity, 2. historic objects and sites related to the community of Old Detroit and the Willamette National Forest Ranger Station, 1890s-1952, 3. historic objects and sites related to the construction and operation of the Detroit Dam and Reservoir, 1947-1969, and 4. the Detroit Dam infrastructure.

A total of 28 documented cultural resources that fall within these four classes are located within or overlap with the proposed project APE (Table 36). Of these, 12 are isolated finds that are not eligible for listing on the Natural Register of Historic Places

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(National Register) (OPRD n.d.). The remaining 16 cultural resources are either unevaluated for listing or are potentially eligible for listing in the National Register. Table 36. Cultural Resources Located within or overlapping with Project APE Cultural Resource Identifier National Register Eligibility 40-485 Not eligible 40-486 Not eligible 40-487 Not eligible 40-489 Not eligible 40-490 Not eligible 40-491 Not eligible D-IF1 Not eligible D-IF2 Not eligible DET-I-01 Not eligible DET-I-02 Not eligible DET-I-03 Not eligible DET-I-04 Not eligible C07 Unevaluated 18-04-353 Unevaluated 35MA00066 Unevaluated 35LIN00086 Unevaluated 35MA00089 Unevaluated 35MA00173 Unevaluated 35MA00174 Unevaluated 35MA00175 Unevaluated 35MA00224 Unevaluated 35MA00379 Unevaluated 35MA00380 Unevaluated 35MA00381 Unevaluated 35MA00382 Unevaluated 35MA00383 Unevaluated 35MA00384 Unevaluated Detroit Dam Potentially Eligible

The Corps has prepared a draft National Register multiple property nomination for the 13 dams within the Willamette Valley including the Detroit Dam as a contributing property. The dam would be included for its association with the conservation mission of the 1936 Flood Control Act and for the architectural design and engineering value of the hydroelectric components, powerhouse, embankment profile, spillway, and control gates. The 15 remaining cultural resources are currently unevaluated for listing in the National Register. The resource include pre-contact and historic archaeological objects and sites, and historic structures and remnants.

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The documented cultural resources provide insight into the past, including the deep history that Native American communities have to the area as well as the more recent history of Euro-American colonization and settlement of the Willamette Valley beginning in the late 19th century. These resources, however, have been identified only within a small portion of the APE. Background research indicates that much of the APE overlaps with portions of the South Pacific Railroad line, Old North Santiam Highway, Old Detroit, the Old Willamette National Forest Ranger Station, the Mongold Construction Camp, and various work zones used during the building of Detroit Dam and Reservoir. The inundation of the reservoir also overlies the original channel of the North Santiam River and its tributaries, which were used by Native American communities for thousands of years before the development of historic railroad and logging communities in the late- 19th century.

Environmental Consequences

Methodology and Scale of Analysis The term cultural resources refers to a variety of physical manifestations that represent the heritage of a place and the people who have historic connections to that place. For the purposes of this EIS, cultural resources include: • pre-contact and historic archaeological features and deposits located on or below the ground surface that are tangible evidence of prior human occupation or use in a particular area, • architecture or elements of the built environment, such as buildings or structures, or human-made objects and landscapes, and • places that a group of people consider culturally important because of events or practices that have occurred at the location.

Regulatory Framework During project planning, Corps cultural resource management is primarily guided by Section 106 of the NHPA (54 U.S.C. § 306108). The Corps implements Section 106 of the Act through the implementing regulations in 36 C.F.R. part 800. These regulations require the Corps to: 1. identify the APE or geographic area or areas within which the project may directly or indirectly cause changes to the character or use of historic properties, 2. identify historic properties that could be affected by the project, and 3. consult with appropriate stakeholders throughout the process. Stakeholders include the State Historic Preservation Office (SHPO) and Indian Tribes that have interests in and connection to the area where the proposed action 3-258

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would occur. The Corps has identified three federally recognized tribes with interests in the proposed project including the Confederated Tribes of the Grand Ronde, Confederated Tribes of the Siletz Indians, and Confederated Tribes of Warm Springs. Section 106 and 36 C.F.R Part 800 categorize cultural resources as historic properties if they are included in or eligible for inclusion in the National Register of Historic Places (National Register). Historic properties must be: 1. generally 50 years old, 2. retain integrity related to location, design, setting, materials, workmanship, feeling, or association, and 3. in association with significant historical events or people, represent a distinctive style of construction or retain stylistic elements representative of a master artisan, or likely to provide important information about the past through continued study (U.S. DOI NPS n.d.a.; U.S. DOI NPS n.d.b.). Historic properties significant to American history can be pre-contact or historic objects, sites, buildings, structures, or districts, and include artifacts, records, and material remains related to the property (54 U.S.C. § 300308, 36 C.F.R. § 800.16). Another category of historic properties include places of traditional religious and cultural importance to an Indian tribe or Native Hawaiian organization (54 U.S.C. § 300308, 36 C.F.R. § 800.16). 36 C.F.R § 800.4 organizes impacts to cultural resources into two categories: 1) No Historic Properties Affected, and 2) Historic Properties Affected. Projects that have no potential to affect historic properties would not have significant impacts (significant as defined by NEPA and NHPA, and their implementing regulations). Projects that have the potential to affect historic properties may cause significant impacts. These impacts are further categorized as: 1) No Adverse Effect to Historic Properties or 2) Adverse Effects to Historic Properties. If a cultural resource has not been formally evaluated during the planning process, the Corps would consider impacts to the site as if it were a historic property, until it can be formally evaluated. This measure allows the Corps to avoid inadvertently adversely affecting a potentially significant cultural resources that later would be defined as a historic property under Section 106. To comply with Section 106, the Corps would formally evaluate any cultural resources, assess affects to any historic properties, and develop mitigation efforts for any significant impacts within the APE prior to project implementation and in consultation with affected tribes and the SHPO.

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Identification of APE The APE was defined through consideration of direct and indirect effects that the proposed project could have on cultural resources. Defined impacts include the following: • proposed sediment-disturbing activities in staging, construction, blasting, and drawdown zones to buried cultural resources, • physical impacts that attaching the SWS for temperature control and FSS for juvenile fish collection would have to the built environment of Detroit Dam, and • visual impacts the attachment of new infrastructure could have on the visual integrity of Detroit Dam and the larger vista of the Detroit Dam and Reservoir within the North Santiam River drainage. Throughout the Section 106 process, the Corps will consult with affected tribes and the SHPO to ensure the APE continues to be adequately defined prior to project implementation.

Identification of Historic Properties Corps archaeologists used several lines of information to identify cultural resources that occur within or overlap with the APE including: • site forms, technical reports, and spatial data stored in the SHPO’s online Oregon Archaeological Records Remote Access (OARRA) database, • historic maps including United States Geological Survey topographic quadrangle maps and General Land Office plat maps, • Corps project files, historic aerial imagery of the Detroit Dam vicinity, and historic maps, photographs, and design plans related to construction of the Detroit Dam and Reservoir system, • regional cultural resource overviews, historical syntheses, and anthropological research, and • outreach and consultation with affected tribes. The background research indicates that numerous previous cultural resource inventories overlap with the project APE. The surveys covered stream terraces and flats that are seasonally inundated and within the maximum pool elevation of Detroit Reservoir, along the shoreline of the reservoir in the locations of localized proposed sediment-disturbing activities, and within large portions of the drawdown area. The majority of these surveys focused on forested lands managed by WNF in advance of timber harvest activities, mostly adjacent to the proposed project APE. Four notable

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exceptions that focused on large swaths of land or construction/staging zones within the APE include the following inventories: • the 2017 survey of 436 acres by Heritage Research Associates that recently covered portions of the proposed project APE (Oetting 2017) that overlap with the Detroit Dam Operations Yard and Road, both proposed construction/staging zones, and portions of the Detroit Reservoir shoreline that are within the max fill pool zone; • the 2015 survey of 546 acres by Harris Environmental that recently covered portions of the proposed project APE (Hannum et al. 2017) that overlap with the drawdown zone in the vicinity of the North Santiam arm of Detroit Reservoir and the town of Detroit; • the 2011 localized survey of the area that the proposed project identifies as the Minto North construction/staging zone (Rader 2011); and • the 2000 and 2001 survey of 372 acres by WNF Archaeologists that covered portions of the APE that overlap with the Mongold State Park, State Parks Maintenance Yard, and WNF Detroit Campground (McCulley Kelly 2001). All of these are proposed staging/construction zones. The background review identified 28 documented cultural resources and six localized areas that have high probability for cultural resources, but do not have previously documented resources, within the APE. It also provided an understanding of which parts of the APE have been adequately surveyed for cultural resources and which areas would require further survey prior to project implementation. In general, the review provided a sufficient understanding of what types of cultural resources to expect in the APE and where to locate them. To comply with Section 106, the Corps would conduct required on-the-ground surveys to locate undocumented cultural resources and evaluate any documented cultural resources for listing in the National Register before project implementation. The locational and descriptive data related to specific cultural resources in the proposed project APE would be recorded and kept on file with the Corps. The information would also be available to Section 106 consulting parties including SHPO and affected tribes. This information would not be provided for public review. The NHPA, the Archaeological Resource Protected Act and their implementing regulations (36 C.F.R. Part 800 and 43 C.F.R. Part 7, respectively) protect such information from public consumption. These two statutes prohibit the sharing of certain data to reduce human destruction to cultural resources.

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Consultation Stakeholders in the Section 106 process include the SHPO and affected tribes that may attach religious and cultural significance to historic properties within the APE. The Corps has invited the Confederated Tribes of the Grand Ronde, Confederated Tribes of Siletz Indians, and Confederated Tribes of Warm Springs to project-specific government-to-government consultation in letters dated November 13, 2017. Communication efforts are ongoing, including staff-to-staff email exchanges and conference calls (dated November 27, 2018, January 23, 2019, and February 21, 2019) and in person staff-to-staff meetings (dated January 9, 2019 and February 12, 2019). Consultation with SHPO is underway. Prior to implementation of any of the proposed actions in this EIS, the Corps would fully comply with Section 106. The Corps would consult with SHPO and affected tribes to identify and formally evaluate cultural resources, assess affects to historic properties, and develop mitigation efforts to avoid or minimize significant impacts within the APE. The Corps intends to meet Section 106 compliance requirements through entering into a programmatic agreement that will include a phased approach to identification, evaluation, and resolution of adverse effects (36 C.F.R. §§ 800.4 and 800.6).

Scale of Analysis For this project, the APE encompasses the Detroit Reservoir, up to the maximum pool elevation (1,574 ft), and the landforms and dam infrastructure where proposed sediment-disturbing activities and construction of the SWS and FSS would occur. The majority of proposed staging, construction, and blasting zones would be partially located within the maximum pool elevation zone, with the exception of Minto North, the western- most staging zone. Access routes between staging/construction zones are well established roads (rocked and paved) and no improvement or ground disturbing activities that have the potential to impact cultural resources are anticipated with the proposed project. The APE is a geographical footprint. The length of time of each impact must also be considered. Some impacts may be temporary: 1) short-term – months or a few years and restricted to the span of construction, or 2) longer-term – decades and restricted to the life of the SWS and FSS operation and maintenance. Some impacts may be permanent, and not necessarily associated with the timing of the activity that caused the impact. For the purposes of this analysis, the three time frames of impact – short-term temporary, longer-term temporary, and permanent are considered. In general, physical impacts to an archaeological site are permanent and irreversible. The destruction or removal of intact archaeological components (artifacts within a matrix of sediment and organic materials) cannot be repaired or recreated. The artifacts within the site matrix have cultural as well as research value, but the original 3-262

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placement of those artifacts is equally valuable to scientific research (it’s in situ context). The loss of integrity to in situ context destroys what makes many archaeological historic properties eligible for listing in the National Register (i.e. research potential). The removal of artifacts from the in situ context also devalues the artifacts because it is more difficult to identify their age, relevance to past and present people, and place of origination.

Staging Areas The following provides a description of the effects to cultural resources of the project at the potential staging areas described in Sections 2.7.2.5 and 2.6. The staging areas described in Section 2.7.2.5 would experience the environmental consequences described under all action alternatives.

Minto North Minto North has been previously inventoried for cultural resources with negative results (Rader 2011, SHPO concurrence dated 3/3/2011). Therefore, construction activities at this site would not result in impacts to cultural resources.

Detroit Dam and Parking Lot The Detroit Dam Road and Parking Lot is fully paved. The parking of concrete pump trucks, forklifts, cranes, and other types of equipment within the parking lot and road would be temporary and removed after the construction of the SWS. The Corps does not expect activities at this site to impact cultural resources

Detroit Dam and Operations Yard and Access Road The Detroit Dam Operations Yard and Road has been previously inventoried (Oetting 2017). Cultural resources have been identified in proximity to the Detroit Dam Operations Yard and Road, but do not overlap with where the proposed staging would take place. The Corps does not anticipate any impacts to these resources. The proposed use of this area would be to deliver equipment for semi-truck loading, which would then transport equipment to the top of the dam (within the Detroit Dam Road and Parking Lot area), staying within existing roads and parking areas. It is unlikely that ground disturbance would be required to improve staging or vehicle turnaround. If this were to change, the Corps archaeologists would work with contractors to ensure that cultural resources are avoided throughout the project.

SA1. Mongold State Park The Corps would be required to perform a cultural resource inventory at Mongold State Park prior to project implementation. The Corps will consult with SHPO and

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affected tribes to ensure all construction/staging zones are inventoried. Any newly documented resources would be evaluated for listing in the National Register.

SA2. Oregon State Parks Maintenance Yard The Corps would be required to perform a cultural resource inventory at the Oregon State Parks Maintenance Yard prior to project implementation. The Corps will consult with SHPO and affected tribes to ensure all construction/staging zones are inventoried. Any newly documented resources would be evaluated for listing in the National Register.

SA3. Detroit Lake State Recreation Area The Corps would be required to perform a cultural resource inventory at the Detroit Lake State Recreation Area prior to project implementation. The Corps will consult with SHPO and affected tribes to ensure all construction/staging zones are inventoried. Any newly documented resources would be evaluated for listing in the National Register.

CA1. No Action The No Action Alternative does not propose activities outside of normal operations and maintenance of Detroit Dam and Reservoir, and therefore, would not have any new impacts to cultural resources.

CA2. SWS and FSS Constructed with a Two-year Deep Drawdown

Direct Impacts –SWS for Temperature Control Under CA2, the proposed SWS would be a hollow, rectangular concrete structure that is attached directly to the upstream face of the dam (Figure 8). The SWS would cover approximately 6% of the existing face of Detroit Dam. The attachment of the SWS on the face of the Detroit Dam, which is potentially eligible for listing in the National Register, would result in a Historic Properties Affected determination. Depending on the level of modification, the determination could be a significant impact. This impact to Detroit Dam would be long-term over the operational life of the SWS. Accessing the SWS is unlikely to significantly affect Detroit Dam as a historic property. A fixed stair tower off the north face of the SWS would provide personnel access to and from the FSS, which would float in the reservoir and temporarily attach to the SWS when needed. (Figure 8). Under CA2, the Corps proposed dredging and rock blasting to create an adequate construction zone to build the SWS near the dam. The use of heavy equipment within this footprint would also be required to build the SWS. These activities would have the

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potential to significantly damage any previously undocumented cultural resources within the blast and construction zone. These impacts would be permanent and irreversible.

Indirect Impacts –SWS for Temperature Control and FSS for Juvenile Fish Collection The upstream face of Detroit Dam is visible from portions of the northwest and southwest banks of Detroit Reservoir, particularly along 2.6 miles of OR-22, as one drives northwest toward the upstream view of the dam, and on the south side of the reservoir, along Forest Service Road 2212, as one drives northwest toward the south side of Detroit Dam. Forest Service Road 2212 winds through forested lands and the view of the upstream face of Detroit Dam is more limited than the view from the OR-22. The long-term placement of the SWS on the upstream face of Detroit Dam has the potential to significantly impact the integrity of the property's location, design, setting, materials, workmanship, feeling, or association through the introduction of a modern or out-of-place visual element (SWS) as part of the Detroit Dam infrastructure and the larger North Santiam viewshed. This impact would exist throughout the life of the SWS. The suggested composition of the SWS is concrete, which is the same material as the Detroit Dam. The use of similar material could potentially reduce any visual impacts to the face of Detroit Dam. The total area of the SWS is also very small in comparison to the overall size of the upstream face of the dam and would be fully exposed for limited durations on an annual basis, during reservoir drawdowns that occur over the winter months or when non-routine maintenance would be required. Consideration of effects would also include review of the proposed FSS for juvenile fish collection. The Corps would moor the FSS adjacent to the SWS. The combined footprint of the SWS and FSS adjacent to Detroit Dam would have visual impacts.

Direct Impacts – Drawdown The 15 unevaluated cultural resources are located within the reservoir maximum pool elevation (1,574 ft). Throughout the construction schedule, continued fluctuation of reservoir water levels has the potential to affect documented cultural resources that are seasonally inundated through: • wave action that displaces artifacts and erodes intact cultural components within the site matrix, • burying or displacing cultural resources with sediment delivery that occurs through drawdown, • increased rate of deterioration of organic archaeological materials through repeated or prolonged exposure to an aerobic climate during drawdown, and

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• increased exposure of artifacts and sites to people who may illegally collect or damage artifacts and sites during drawdown. These human impacts would occur in drawdown areas of the reservoir bed as well as designated recreation sites that abut the reservoir. The sediment transport analysis conducted for the proposed project indicates that if the Corps were to drawdown the reservoir to below the average minimum conservation pool level (1,450 ft.), multiple factors would create a dynamic environment in the Detroit Reservoir that is different from the current conditions. This aspect of the proposed project has the potential to significantly affect archaeological sites that are located in the reservoir basin. With this change in environment, large volumes of sediments that have accrued in Detroit Reservoir (since it became operational) are likely to be mobilized and transported downstream into Big Cliff Reservoir. This sediment transport process may erode existing bed layers, and expose and potentially sweep archaeological sites contained in the bed layers downstream with the sediment load. The lowered pool level would also present a situation where incoming sediment loads during winter flooding from North Santiam River, Breitenbush River, and Blowout Creek would increase and move through Detroit Reservoir and eventually downstream into Big Cliff Reservoir. The sediment transport analysis also indicates that a 10-year flood event is likely to occur during proposed drawdown, which would greatly increase the potential dynamic and destructive nature of water movement and sediment transport through Detroit Reservoir. The proposed exposure of an unprecedented amount of the Detroit Reservoir bed (a difference of up to 150 ft. elevation change between the minimum conservation pool and proposed project minimum drawdown pool level) has the potential to expose and adversely affect previously undocumented archaeological sites. According to the sediment transport analysis, since its construction (1952) the Detroit Reservoir has never been lower than the 1,426-ft. elevation. A deep drawdown could expose archaeological sites that have been submerged and protected by anaerobic environments for 67 years, accelerating the deterioration of organic materials. This drawdown to elevation 1,300 could also increase erosion from wave action or sediment movement, and illegal artifact collection or human destruction of archaeological components. These impacts would result in permanent damage to archaeological sites, adversely affecting their integrity, either through partial or complete physical destruction. The Corps expects that the vulnerability of archaeological sites is significant when these sites would be exposed during a 28-month drawdown proposed under CA2. Portions of the reservoir bed that are between elevation 1,425 and 1,300 ft have never been surveyed for archaeological resources. One event of wave action, sediment transport, exposure to an anaerobic environment, human destruction can occur very quickly and multiple times within a drawdown, but have lasting impacts to the integrity of artifacts and archaeological sites.

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CA3. SWS and FSS Constructed with a One-year Deep Drawdown Impacts to cultural resources under CA3 are the same as for CA2. However, exposure of the archaeological site during the proposed drawdown would be reduced, as the drawdown would be 16 months as opposed to 28 months.

CA4. SWS and FSS Constructed with a One-year Variable Drawdown Impacts to cultural resources under CA4 are the same as for CA3.

CA5. SWS and FSS Constructed with No Drawdown As part of CA5, building the proposed SWS in the construction zone at the base of the Detroit Dam and operating the SWS and FSS would have the same direct and indirect impacts to cultural resources as those described in CA2, CA3, and CA4. However, CA5 would not use drawdowns during the construction period, and would therefore have no anticipated direct or indirect effect on the 15 unevaluated sites that are located within the reservoir maximum pool elevation. There are also no anticipated impacts to undocumented cultural resources that may exist throughout the reservoir outside of the SWS construction zone.

3.17 RECREATION Detroit Reservoir is one of the most frequently visited Corps-constructed lakes in Oregon. Based on a 2007 State survey of registered boats, Detroit Reservoir was ranked 4th out of 215 Oregon water bodies by boat-use days. According to the Detroit Lake Composite Area Management Guide, about 46% of visitors come from the Portland metropolitan area, and 43% from the mid-Willamette Valley. A popular summer recreation site, parts of the lake are very busy, especially on weekends. Recreation diversity is prevalent at the lake with above-average visitor comforts at the State Park and in the small community of Detroit nearby. Although development is prevalent in some areas and includes the 463-foot high dam, OR-22 on the north shore, the City of Detroit, and a State Recreation Area, with 3,500 acres at full pool and a length of about 9 miles, Detroit Reservoir affords the possibility to escape crowds and noise. The lake is large enough that visitors can be away from this development and enjoy the scenic qualities and natural ambiance that are present in the North Santiam Canyon Detroit Reservoir has extensive public recreation facilities operated by USFS and OPRD, as well as two private marinas (Figure 54). Recreational Facilities around Detroit Reservoir include: • There are two private, seasonal marinas where visitors can moor their boats as well as buy fuel and other supplies.

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• The Detroit Lake State Recreation Area campground offers 271 reservable campsites, flush toilets, hot showers, picnic tables, playground, amphitheater, overnight boat docks, swim areas, campfire rings and firewood for sale, wildlife viewing areas, exhibit information signs, and two boat ramps. The nearby visitor center has park area information, along with gifts, ice, soft drinks, souvenirs, and educational toys for sale. • Mongold State Park day-use area is 1.5 miles west of Detroit Lake State Park. It is the only public boat launch facility on the lake that features a swimming area, grass beach, picnic facilities, and restrooms. It has 58 single car parking spaces and three fully-accessible parking spaces near the swimming area, and another 25 single car parking spaces at the top of the parking lot. There are 120 vehicle/trailer parking spaces, and three that are accessible to people with disabilities. The ramp allows for low water use. • There are five USFS campgrounds with a total of 188 sites; three of which have boat ramps: 1. Cove Creek Campground is the largest National Forest Campground on Detroit Reservoir, with 63 campsites. The campground offers single and double-family campsites, as well as an accessible group site for up to 70 people. Amenities include flush toilets, drinking water and coin-operated showers, picnic tables, fire rings and boat ramp. 2. Hoover Campground (37 sites) and the adjacent Hoover Group Camp Site (holds up to 70 people) sit among Douglas fir and maple trees and large ferns at an elevation of 1,600 ft on the shores of Detroit Lake. An interpretive trail and a viewing and fishing platform are part of the campground. Each site has a campfire ring and picnic table. Flush toilets are available at the campground and the group campground has a vault toilet. Other amenities include a boat ramp, drinking water and firewood for sale. 3. Piety Island Campground (22 first-come, first-served tent sites) is located on Detroit Lake with easy boat-in access from the northeast side of the island. In the winter, depending on water levels and weather conditions sites are available on a walk-in basis. All of the campsites offer great views of Detroit Lake, and include picnic tables, fire wood, trash cans, and two vault toilets. 4. Santiam Flats Campground is located at the confluence of the North Santiam River along the shoreline of Detroit Lake. The campground offers 32 sites (27 single and 5 multiple), over half of which are reservable. Amenities include picnic tables, grills, with three vault toilets and drinking water spigots spread throughout the campground.

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5. South Shore Campground is located at an elevation of 1,604 ft. on the south shore of Detroit Lake, a little west and south of Pretty Knob Island. The campground offers 25 single and five double family campsites. Amenities include a boat ramp, picnic tables, drinking water, and six vault toilets. OR-22 and Forest Service roads (Blowout Road #10) provide access to these facilities. The town of Detroit also offers overnight accommodations and other services such as restaurants, grocery stores, and gas. There is a prevalent management presence with marine patrols, and state and federal rangers. Visitor services and conveniences are prevalent with restaurants, fuel, boat rentals, food stores, utilities, lighting, and communication services at the recreation area. The recreation activity associated with the lake is a major contributor to the local economy and is expected to take on greater importance in the future. There are many water-based and water-related recreation activities at Detroit Dam. Water-based activities include motorized and non-motorized boating, water skiing and wake boarding, jet boating, fishing, and swimming. Although Oregon Marine Board has changed it triennial survey techniques over the past decade, based on a 2008 state survey of registered boaters, Detroit Lake was ranked 4th out of 215 Oregon water-bodies by boat-use days and the highest ranked lake/reservoir overall with an estimated 71,672 boat-use days20. Detroit Reservoir remains among the most popular location for boaters within the Willamette Valley, according to the Triennial Survey of Boaters 2017 data. The Corps maintains Detroit Reservoir pool as high as possible through Labor Day, typically drafting it last of all 13 WVS dams in the summer for downstream flow augmentation, reflecting its high priority for recreation. Camping, sightseeing, picnicking, hiking and mountain biking are also common activities. ODFW heavily stocks the lake with trout and other species beginning in April and ending in October. The annual fall drawdown to minimum conservation pool (elevation 1,450 ft) for flood risk management operations results in a “sea of stumps” along OR-22. The boat ramp at Mongold State Park is usable down to low pool elevations but other facilities, particularly marinas, are high and dry during the low pool period. When the Corps draws the reservoir down for flood risk management operations in the fall and winter, there are also many boating hazards associated with submerged stumps, especially in shallow areas between the town of Detroit and Piety Island.

20 Boat Use Day (Use Day) – any portion of a 24 hour period in which a survey participant (recreator) is engaged in boating activities. 3-269

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Figure 54. Map of Detroit Reservoir with Location of Recreational Facilities

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Environmental Consequences

Methodology and Scope of Analysis The Corps used visitation counts provided by OPRD to assess recreation impacts to Detroit Reservoir and the surrounding area. The Corps estimated the USFS visitation using the number of campsites at each campground with each campground being assumed to be full 4 days out of 7 during the summer months.

Staging Areas The staging areas described in Section 2.7.2.5 are on Corps property and, with the exception of the Detroit Visitors Parking Lot, are not accessible to the public. Therefore, construction activities at Minto North and the Detroit Dam and Operations Yard and Access Road would not affect recreation. There would be a minor impact to recreational use (specifically access to the viewpoint) at the Detroit Visitors Parking Lot as this area would be temporarily inaccessible during the 3-year SWS construction period and for a short period when the Corps installs the FSS. The following provides a description of the impacts of the project on recreation at the alternative staging areas described in 2.6. The staging areas described in Section 2.7.2.5 would experience the environmental consequences described under all action alternatives.

SA1. Mongold State Park Under this staging area alternative, construction activities over the entire duration of both the SWS and the FSS construction (upwards of 8 years) would significantly reduce recreational access at Mongold State Park. The Corps would gate off much of Mongold State Park for safety, including the entirety of the swimming area. The Corps may be able to maintain access to the boat ramps during construction; however, this access may be restricted at times.

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provide construction access to the staging area. The Corps would gate off this area for safety.

CA1. No Action The No Action Alternative would have no direct or indirect on recreational resources in the project’s area of effect. Potential benefits to recreational fishing correlated to a healthier and more robust fish population would not be realized.

CA2. SWS and FSS Constructed with a Two-year Deep Drawdown

Detroit Reservoir Recreation As the drawdown proposed under CA2 would eliminate water access at Detroit Reservoir, CA2 would have a significant effect on shore use, swimming, fishing, and boating. Hiking and camping would also be impacted as the drawdown would result in a “sea of stumps” potentially resulting in a negative aesthetic experience not typical for the area. However, these effects would be short term and temporary in nature, lasting two summer seasons. Overall, the Corps estimates a reduction in visitation of 716,000 visitors during the 2-year drawdown period under CA2.

North Santiam River (downstream of Detroit Dam) Recreation As described in Sections 3.4.2.5, the Corps expects reduced flows to around 400 cfs in the North Santiam River below Detroit Dam in the summer months as Detroit Dam would only be passing inflow during the construction drawdown. Low flows may have moderate impacts to boating, fishing, swimming, and nature-viewing activities along the North Santiam River downstream of Detroit Dam for two summer recreation seasons. Additionally, as described in Sections 3.5.4.4, the drawdown would result in a plume of high turbidity below Detroit Dam in the winter months. The turbidity may have a moderate effect on fishing during the winter when the Corps would initially drawdown Detroit Reservoir. However, these effects would be short term and temporary in nature.

CA3. SWS and FSS Constructed with a One-year Deep Drawdown

Detroit Reservoir Recreation Under CA3, the impacts to reservoir recreation would be the same as under CA2 except only lasting for a single summer recreation season. Overall, the Corps estimates a reduction in visitation of 358,000 visitors during the 1-year drawdown period under CA3.

North Santiam River (downstream of Detroit Dam) Recreation

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Under CA3, the impacts to recreation along the North Santiam River downstream of Detroit Dam would be the same as under CA2 except only lasting for a single summer recreation season.

CA4. SWS and FSS Constructed with a One-year Variable Drawdown

Detroit Reservoir Recreation Under CA4, the impacts to reservoir recreation would be the same as under CA3.

North Santiam River (downstream of Detroit Dam) Recreation Under CA4, recreational users of the North Santiam River downstream of Detroit Dam would not experience uncommon low flows, as the Corps would maintain 1,000 cfs outflows at Detroit Dam. However, increases in turbidity would be experienced over the summer of the proposed drawdown over a longer period (as described under Section 3.5.4.6) resulting in moderate impacts to boating, fishing, swimming, and nature-viewing activities along the North Santiam River downstream of Detroit Dam. However, these effects would be short term and temporary in nature.

CA5. SWS and FSS Constructed with No Drawdown Under CA5, the Corps would maintain typical reservoir elevations and outflows. Therefore, there would be no additional impacts to recreation under CA5.

3.18 SOCIOECONOMICS

Regional Socioeconomics The economics portion of a socioeconomic analysis evaluates how elements of the human environment such as population, employment, housing, and public services in the area of effect are impacted. These are summarized below. Appendix H provides a detailed analysis of economics in the area of effect and is incorporated here by reference. As one travels east along OR-22, in general the communities are increasingly rural in nature, with very sparse social services. As of the 2010 census, the population for Marion County is 315,335, making it the fifth most populous county in Oregon. The county seat is Salem, the state capital. Linn County is the county to the south of Marion County, located within the Willamette Valley. As of the 2010 census, the population was 116,672. The county seat is Albany. The Detroit Reservoir is approximately 50 miles east of Salem, OR, along OR-22. Communities east of Salem along OR-22, from west to east, as one travels closer in

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proximity to Detroit Reservoir include the following communities, all of which are within the Salem Metropolitan Statistical Area: • Four Corners, a census-designated place in Marion County, just outside the city limits of Salem but within the city’s urban growth boundary. The population of the census designated place was 13,922 at the time of the 2000 census. • Macleay is an unincorporated community in Marion County, about 9 miles east of downtown Salem, north of State Highway 22 in the Waldo Hills near the Little Pudding River. • Turner is a city in Marion County, about 9 miles east of downtown Salem, south of State Highway 22. The population was 1,854 at the time of the 2010 census. • Shaw is an unincorporated community in Marion County on State Highway 214, about 10 miles east of Salem, Oregon between Macleay and Aumsville. According to the Marion County Comprehensive Plan, as of 2005, Shaw had 18 dwellings, a machine shop, a general store building, a warehouse and a church. • Aumsville is a city in Marion County, Oregon, about 12 miles east of downtown Salem. The population was 3,584 at the time of the 2010 census. • Sublimity is a city in Marion County, Oregon, about 15.5 miles east of downtown Salem, OR. The population was 2,681 at the time of the 2010 census. • Stayton is a city in Marion County, Oregon, located about 16.5 miles southeast of downtown Salem. It is south of Sublimity and east of Aumsville. Located on the North Santiam River, Stayton is a regional agricultural and light manufacturing center. • Kingston is an unincorporated community near Stayton, in Linn County, Oregon. • Mehama is an unincorporated community in Marion County, Oregon located on State Highway 22 and the North Santiam River. For statistical purposes, the Census Bureau has defined Mehama as a census designated place. • Lyons is a city in Linn County Oregon, south of Mehama, Oregon. The population was 1,161 at the time of the 2010 census. • Mill City is a city in Linn and Marion Counties, Oregon, about 32 miles south-east of downtown Salem. The population was 1,855 at the time of the 2010 census. The city straddles both the north and south side of the North Santiam River. • Gates, like Mill City, has portions of the city crossing the North Santiam River, and therefore, exists in both Marion and Linn Counties. The city is about 35 miles south-east of downtown Salem. The population was 471 at the time of the 2010

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census. A greater portion of Gates’ population is in Marion County and therefore the city is primarily under Marion County’s jurisdiction. • Niagara is an unincorporated community in Marion County, Oregon. It is the site of the historic Niagara County Park, the first park created by Marion County Parks and Recreation Commission. The park consists of a historic dam, begun in 1890 and abandoned in 1912. • Detroit is a city in Marion County, Oregon. It was named after Detroit, Michigan, in the 1890s because of the large number of people from Michigan in the community. The population was 202 at the time of the 2010 census. In general, population, employment, and personal income in the area of effect is growing. Table 37 provides an overview of these socioeconomic metrics. Table 37. Overview of Socioeconomic Metrics (Population, Employment and Personal Income) for both Marion and Linn Counties (the Region) Change Socioeconomic Metric 1970 2000 2016 2000-2016 Population Data Source: U.S. Department 224,664 388,431 459,165 70,734 of Commerce 2018 Census Bureau Employment (full & part-time jobs) Data Source: U.S. Department 95,229 212,622 246,677 34,055 of Commerce 2018 Bureau of Economic Analysis Personal Income (thousands of 2017 $s) Data Source: U.S. Department 5,158,289 13,517,572 17,918,046 4,400,474 of Commerce 2018 Bureau of Economic Analysis

Specifically for Marion County from 1970 to 2016, population grew from 152,077 to 336,316 people, a 121% increase; and in Linn County, the population grew from 72,587 to 122,849, a 69% increase. The long-term steady growth of population for Marion and Linn Counties suggests people are moving to the area for jobs, quality of life, or both. Although agriculture, food processing, lumber, manufacturing, and education are important to the Counties’ economies, government is the county’s main employer, serving its primary economic base. For Marion County, from 1970 to 2016, employment grew from 66,039 to 186,069, a 182% increase; and for Linn County, employment grew from 29,190 to 60,608 a 108% increase, for the same period. Employment here means all full- and part-time workers, wage and salary jobs (employees), and proprietors (the self-employed) reported by place of work. Personal Income for the two county region grew from $5,158.3 million in 3-275

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1970 to $17,918 million (in real terms) in 2016, a 247% increase. Specifically for Marion County, from 1970 to 2016, personal income grew from $3,635.6 million to $13,105.9 million (in real terms), a 260% increase, suggesting a diversified, relatively strong economy. Long-term, steady growth of population, employment, and real personal income is generally an indication of a healthy, prosperous economy. Understanding which industries are responsible for most jobs and which sectors are growing or declining is key to grasping the type of economy that exists, how it has changed over time, and evolving competitive strengths. This section organizes industries according to three major categories: non-services related, services related, and government21. Employment includes wage and salary jobs and proprietors. This section organizes employment data according to the Standard Industrial Classification system and reports by place of work. • Non-Services Related is the employment in industries such as farming, mining, and manufacturing. • Services Related is the employment in industries such as retail trade, finance, insurance and real estate, and services. • Government includes federal, military, state, and local government employment, and government enterprise. Figure 55 shows the growth of employment by industry for the two counties from 1970 to 2000.

Figure 55. Employment by Sectors within the Economy (Non-Service, Service, and Government) For the Two County Region (data source: U.S. Department of Commerce 2018 Bureau of Economic Analysis)

21 The terms “non-services related” and “services related” are not terms used by the U.S. Department of Commerce. They are used here to help organize the information into easy-to-understand categories. 3-276

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Table 38 and Table 39 below provide specifics for employment by industry for Marion and Linn Counties for the period from 1970 to 2000. Table 38. Employment by Industry, Marion County Change 1970 1990 2000 Industry 1990-2000 Total Employment (number of jobs) 66,039 128,615 159,985 31,370 Non-Services Related 16,899 30,601 35,730 5,129 Farm 5,012 7,345 7,336 -9 Agricultural services, forestry, fishing & 458 2,979 3,041 62 other Mining (including fossil fuels) 90 146 289 143 Construction 3,432 5,942 9,526 3,584 Manufacturing (incl. forest products) 7,907 14,189 15,538 1,349 Services Related 31,540 68,445 90,768 22,323 Transportation & public utilities 2,113 3,289 5,137 1,848 Wholesale trade 1,648 4,298 4,559 261 Retail trade 10,715 20,861 26,931 6,070 Finance, insurance & real estate 5,351 8,869 11,318 2,449 Services 11,713 31,128 42,823 11,695 Government 17,600 29,569 33,487 3,918 Data Source: U.S. Department of Commerce 2018 Bureau of Economic Analysis

Table 39. Employment by Industry, Linn County Change 1970 1990 2000 Industry 1990-2000 Total Employment (number of jobs) 29,190 44,792 52,637 7,845 Non-Services Related 14,021 17,104 19,007 1,903 Farm 2,704 3,387 3,192 -195 Agricultural services, forestry, fishing 375 833 1,445 612 & other Mining (including fossil fuels) 87 16 64 48 Construction 1,443 1,954 3,345 1,391 Manufacturing (incl. forest products) 9,412 10,914 10,961 47 Services Related 11,200 21,794 26,684 4,890 Transportation & public utilities 1,192 1,900 2,549 649 Wholesale trade 525 1,573 2,014 441 Retail trade 4,015 6,922 8,419 1,497 Finance, insurance & real estate 1,545 2,037 2,393 356 Services 3,923 9,362 11,309 1,947 Government 3,969 5,894 6,946 1,052 Data Source: U.S. Department of Commerce 2018 Bureau of Economic Analysis

As evidenced by the tables above, in many small rural communities such as in and around Detroit Reservoir, government employment (the USFS and BLM) represents an

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important component of the economy. However, other important economic drivers in the region, beyond providing for employment, include the recreational and agricultural sectors. Appendix H and Appendix I provide detailed analysis of the recreational and agricultural sectors in the region, respectively. These are summarized below.

Agriculture Marion County has a reputation of being a leader in agricultural production among all Oregon Counties. This analysis compares Marion County to Linn County, the county to the south, as well as to the rest of the nation, each serving as a benchmark to demonstrate the importance of agriculture to the local economy. An assessment of irrigated agriculture is limited to a southwestern portion of Marion County, within the bounds of the SWCD and the SIC, as this is the area of interest for impact of the project alternatives. Appendix I provides a detailed analysis of the agricultural sector in Linn and Marion Counties (incorporated here by reference). Although nationwide trends indicate that with gains in production efficiency, fewer people are working in farming; this is not the case for Linn and Marion County. Data from the U.S. Bureau of Economic Analysis demonstrate that within Linn and Marion Counties (the “Two County Region” or “County Region” in the tables below), farm employment, as a percentage of total employment, is more than twice the national average. This means the number of workers (full- and part-time) engaged in the production of agricultural commodities (which includes sole proprietors, partners, and hired laborers) in Marion County is more than two times the national average. Table 40 and Figure 56 below demonstrate how farm employment for Marion and Linn Counties compares to the U.S. Table 40. Farm Employment for Marion and Linn Counties Relative to the U.S. Marion County, Linn County, Two County Region U.S. FARM EMPLOYMENT OR OR Total Employment, 2016 186,069 60,608 246,677 193,668,400 Farm Employment 6,198 3,228 9,426 2,644,000 Farm Proprietors 2,223 1,913 4,136 1,824,000 Employment Non-Farm Employment 179,871 57,380 237,251 191,024,400 Percent of Total Farm Employment 3.3% 5.3% 3.8% 1.4% Farm Proprietors 1.2% 3.2% 1.7% 0.9% Employment Non-Farm Employment 96.7% 94.7% 96.2% 98.6% Data Source: U.S. Department of Commerce 2018 Bureau of Economic Analysis

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Figure 56. Ratio of Farm Related Jobs to Total Employment (Data Source: United States Department of Agriculture National Agricultural Statistics Service, 2017 Census of Agriculture 22)

In 2016, Marion County had the largest percent of total earnings from farm earnings when compared to Linn County and the U.S. average (Figure 57). Farm earnings as a percent of total earnings were 2.37% for Marion County, 1.7% for Linn County, and .6% for the U.S., again demonstrating the importance of farming for the two county region, and particularly important to Marion County.

Figure 57. Farm Earnings as a Percent of Total Earnings (2016 dollars) (Data Source: United States Department of Agriculture National Agricultural Statistics Service, 2017 Census of Agriculture) Table 41 represents business revenues minus expenses and operating costs. This is a different way to portray income than farm labor earnings (above), which are the wages and salaries of farm employees.

22 https://www.nass.usda.gov/Publications/AgCensus/2017/index.php 3-279

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Table 41. Gross Expense Ratio for All Farms Two

Marion County, OR Linn County, OR County U.S. Farm Business Income Region Total Cash Receipts & Other Income ($1000), 2016 631,978 242,808 874,786 413,092,884 Cash Receipts from Marketing 560,163 202,854 763,018 373,189,735 Livestock & Products 109,783 56,924 166,707 182,530,706 Crops 450,380 145,931 596,311 190,659,028 Other Income 71,814 39,954 111,768 39,903,149 Government Payments 2,503 812 3,315 13,252,250 Imputed Rent & Misc. Income 69,311 39,142 108,453 26,650,899 Total Production Expenses 565,117 241,405 806,523 371,770,568 Net Income: Receipts - Expenses 66,860 1,403 68,263 41,322,315 Value of Inventory Change -1,782 -373 -2,154 1,227,785 Total Net Income Including Corp. 65,079 1,030 66,109 42,550,101 Farms Ratio: Total Cash Receipts & Other 1.12 1.01 1.08 1.11 Income/Total Production Expenses Data Source: United States Department of Agriculture National Agricultural Statistics Service, 2017 Census of Agriculture

Table 41 suggests that, despite the volatility present in the commodities markets, farming in Marion County tends to be profitable, especially when compared to the U.S. and Linn County. Table 41 also suggests that despite the farm size being smaller than the national average (as demonstrated in Table 42 below), the profitability of the farm business is virtually identical to the rest of the nation. Even when agriculture is a small component of the economy, the industry can represent a large portion of the land base. The number of farms, acres in farms, average farm size, total acres, and percent of total acres in farms can show how agriculture contributes to local economic diversity. The information in Table 42 comes from the USDA’s Census of Agriculture, which is conducted every 5 years. The advantage of the Census of Agriculture is that it provides a high level of detail that makes it possible to see the role that farms play in the local economy and landscape, and to compare differences between locations. The disadvantage of this data source is that, like all forms of census, the accuracy of the data depends on the survey methods and the quality of the responses. In addition, with this data source it is not possible to display continuous long-term trends.

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Table 42. Percent of Land Area in Farms Marion County, Two County Linn County, OR U.S. Number and Size of Farms OR Region Number of Farms, 2012 2,567 2,083 4,650 2,109,303 Land in Farms (Acres), 2012 286,194 331,316 617,510 914,527,657 Average Farm Size (Acres) 107 159 133 434 Approximate Land Area (Acres) 756,691 1,465,659 2,222,350 2,260,583,852 Approximate Percent of Land Area in Farms 37.8% 22.6% 27.8% 40.5% Data Source: United States Department of Agriculture National Agricultural Statistics Service, 2017 Census of Agriculture

Although the data is a snapshot in time, Table 42 demonstrates a relatively large amount of land within Marion County devoted to farms despite the fact the average size of the farm within the county is typically much smaller than the average farms across the U.S. It demonstrates that farms continue to be important even as they increasingly operate alongside a larger, non-agricultural economy. They contribute to local economic diversity, as farming communities continue to provide a mix of amenities that attract and retain people and businesses across a range of industries; and arguably contribute an important part of the local culture and community vitality. Not all agricultural land is used in the same manner. How farmlands are used can have important economic, environmental, and policy implications. For example, cropland may require water from surrounding lands; woodland can provide important habitat and store water; and pasturelands may be associated with public grazing lands and can provide open vistas that are important for attracting tourists and new migrants. Some lands may be less valuable (e.g., pastureland) and therefore more vulnerable to conversion for urban and suburban uses. According to the USDA's Census of Agriculture in 2012, of the four geographic areas being compared in this analysis, Marion County had the largest percent of land area devoted to cropland (74.7%), while the U.S. had the smallest (42.6%), providing an additional metric of the importance of agriculture to the county. Different types of farms have different economic potential and relationships with other natural resources including water and wildlife. Table 43 describes the number and percent of all farms according to what they produce. It demonstrates the production on all private farms, all forms of agricultural production, including livestock operations but the data excludes leased public land from total land in farms. Table 43 demonstrates the relative importance of vegetable and melon farming; fruit and nut tree farming; greenhouses and nurseries; and sheep and goat farming to Marion County.

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Table 43. Comparison of Farm Products across Two Counties and the Nation. The Census of Agriculture data on farms by type are only reported by the number of farms. They are not reported by employment, income, or acreage Marion County, Two County Linn County, OR U.S. Types of Farms OR Region All Farms, 2012 2,567 2,083 4,650 2,109,303 Oilseed & Grain Farming 65 24 89 369,332 Vegetable & Melon Farming 103 56 159 43,021 Fruit & Nut Tree Farming 395 124 519 93,020 Greenhouse, Nursery, etc. 388 109 497 52,777 Other Crop Farming 429 528 957 496,837 Beef Cattle Ranch. & Farm. 671 734 1,405 619,172 Cattle Feedlots 9 11 20 13,734 Dairy Cattle & Milk Prod. 38 18 56 46,005 Hog & Pig Farming 39 44 83 21,687 Poultry & Egg Production 79 55 134 52,849 Sheep & Goat Farming 152 157 309 73,272 Animal Aquaculture & Other Animal 199 223 422 227,597 Prod. Percent of Total Oilseed & Grain Farming 2.5% 1.2% 1.9% 17.5% Vegetable & Melon Farming 4.0% 2.7% 3.4% 2.0% Fruit & Nut Tree Farming 15.4% 6.0% 11.2% 4.4% Greenhouse, Nursery, etc. 15.1% 5.2% 10.7% 2.5% Other Crop Farming 16.7% 25.3% 20.6% 23.6% Beef Cattle Ranch. & Farm. 26.1% 35.2% 30.2% 29.4% Cattle Feedlots 0.4% 0.5% 0.4% 0.7% Dairy Cattle & Milk Prod. 1.5% 0.9% 1.2% 2.2% Hog & Pig Farming 1.5% 2.1% 1.8% 1.0% Poultry & Egg Production 3.1% 2.6% 2.9% 2.5% Sheep & Goat Farming 5.9% 7.5% 6.6% 3.5% Aquaculture & Other Prod. 7.8% 10.7% 9.1% 10.8% Data Source: United States Department of Agriculture National Agricultural Statistics Service, 2017 Census of Agriculture

Santiam Water Control District and Sidney Irrigation Cooperative The SWCD is located in the southwest corner of Marion County. Formed in 1954, the District currently delivers irrigation water to over 17,000 acres (26.56 square miles) of agricultural lands, serving farmers with 90 miles of canals and ditches extending from Stayton to Salem. The SIC is a privately held company in Jefferson, OR, a single location business, categorized under Growers' Associations. Records show it was established in 1940 and incorporated in Oregon. Current estimates show this company

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has an annual revenue of approximately $59,456 and employs a staff of approximately two. There is very little information available online to ascertain details about this irrigation district. Figure 58 provides a map of Marion County, with the SWCD and SIC areas of interest (AOI) outlined.

Figure 58. Map of Marion County with Santiam Water Control District Outlined in Black

Based on available literature, the Corps assumes that a 50% increase in crop yield within the SWCD and SIC AOI occurs during the “summer” months (May-September and possibly April-October depending on the contract between the farmer and SWCD or SIC) (Powers, 1946). The irrigation season typically is from May 1 thru September 30 of each year. Extended seasons are possible from March 1 thru April 30 and October 1 thru October 31. Contracts are executed between the private property owners served by the district and SWCD or SIC. Figure 59 provides a map of the ditches and channels located within SWCD and demonstrates the extensive and expansive irrigation services provided by SWCD.

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Figure 59. Map of SWCD Channels and Ditches (data source: SWCD)

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The Cropland Data Layer (CDL) for Marion County shows there are 275,410 acres of crops within the county. The USDA Census of Agriculture reports 2,567 farms within the county. The average acreage per farm throughout the county calculates to be 107 acres. Figure 60 and Figure 61 provide maps of the cropland data layer for the SWCD and SIC.

Figure 60. Overview of Crops Found Within SWCD

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Figure 61. Overview of Crops Found Within SIC There are a total of 33,342 acres of crops located within SCWD with an estimated acreage of 20,569 for annuals, 2,096 acres for perennials, and 10,621 acres for locally determined crops23. Dividing these values by the 107 acres per farm (average farm acreage within the county), there are approximately 192 farms growing annuals, 20 farms growing perennials, and 99 farms growing crops where the crop is locally determined. Multiplying the number of farms for each category by $82,107, the estimated farm wages per farm, the Corps calculates the annual income to be $15,783,766 for farmers growing annuals, $1,608,380 for farmers growing perennials, and $8,150,009 for farms growing crops that are locally determined. Based on cropland data layer of crops located within SIC, there are 17,443 acres of crops located within the district. The acreage for annuals is estimated to be 8,286; for perennials 946 acres; and for locally determined crops 8199 acres. Dividing these values by the 107 acres per farm (average farm acreage within the county), there are approximately 77 farms growing annuals, 9 farms growing perennials, and 77 farms growing crops where the crop is locally determined. Multiplying the number of farms for

23 Based on the CDL for Marion County. Locally determined crops are assumed to have a potential of surviving beyond 1 year so long as the crops are irrigated; and harvest of the locally determined crops will depend on market conditions. 3-286

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each category by $82,107, the estimated farm wages per farm, the Corps calculates the annual income to be $6,358,305 for farmers growing annuals; $738,963 for farmers growing perennials; and $6,291,545 for farms growing crops that are locally determined.

Farmers Who Have Water Contracts with the Bureau of Reclamation The Corps assumes the contractors who have entered into water service contracts with BOR do not need to contract water from either the SWCD or the SIC. Although the point of diversion may be downstream of Detroit Dam, the irrigators who have entered into an agreement with BOR are obtaining water stored in the reservoir. The Corps used the same methodology employed to calculate agricultural impacts (above) to estimate impacts to these contractors. For purposes of analysis, the Corps assumes these contractors are cropland farmers who grow annuals. Based on data provided by BOR, the Corps estimates the total agricultural acres for these farmers to be 6,517 acres. Dividing these values by the 107 acres per farm (average farm acreage within the county), there are approximately 61 farms served by the water contracts.

Multiplier Effects: Secondary and Total Impacts Oregon State University Extension Service reports agriculture supports many local and regional businesses with millions of dollars spent on (Searle, 2012): • seed ($158 million); • fertilizer and soil conditioners ($245 million); • feed ($455 million); • hired labor (over $900 million); • fuels ($191 million); • chemical products ($166 million); • supplies, repairs and maintenance ($312 million); • construction and repair for farm buildings, animal housing, and equipment (approximately $50 million); • machine hire and custom work ($75 million); • veterinary services; transportation services, warehousing/storage and wholesale marketing ($225 million); • business services, such as accounting, legal services, payroll services, banking and financial services; crop consultants; farm equipment repairs and parts ($206 million); and • product inspection and certification services, licensing and other services ($50 million) and much more. Agricultural processing adds about $2 billion to the value of the farm products (packaging, labor, shipping, etc.). All values reported are in 2012 dollars, as reported in

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ODA, 2012. Much of Oregon’s agricultural and processed food products are shipped out of state (over 80%), thereby generating export dollars. The high percentage of agriculture products that are exported make the concept of Traded Sector Economics very important in evaluating the relative contribution agriculture provides to the Oregon economy. “New” dollars generated into the economy by exporting add real growth in Oregon’s economy. After considering these factors, most agricultural economists use a multiplier between 2 and 8, depending on the breadth of the reach used in the analysis. Farms in Marion County are largely single owner, proprietary, entrepreneurial operations. Individually, depending on their size, they may not affect Oregon’s economy much. Collectively, however, farm production, food processing, warehousing, transportation, marketing, and all other aspects of services and related functions in the industry contribute significantly to the overall economy.

Recreation Hundreds of thousands of people visit the Detroit Reservoir each year: most of them (about 358,000) arrive during the busy summer months when high water levels are maintained. Section 3.17 describes the recreational resources in the area of effect in detail. When considering the direct, indirect and induced impacts to the region, the Corps estimates that the total spending by campers and other overnight visitors in 2018 dollars amounts to about $11,300,000 annually. Appendix H provides a detailed analysis of the economic impact of recreation in the area of effect (incorporated here by reference).

M&I Water Supply As discussed in Section 3.12.1.1, the City of Salem provides water to 195,816 residential users and 3,000 commercial users. The City recognizes that maintaining a reliable water supply is critical to supporting its large, growing population. It is critical for Salem to implement a program to ensure that its customers continue to receive the same high-quality drinking water and adequate quantities they have grown accustomed to. The City provides water to its retail customers and three wholesale customers (Suburban East Salem Water District, City of Turner, and Orchard Heights Water District). The City’s retail customers include customers within city limits as well as customers outside city limits, such as the Jan Ree area located within the northeast portion of the service area. Salem's system also provides a desirable product to industrial users. The water is low in minerals and other constituents, making it suitable for canneries or electronics industries with a minimal amount of customer treatment. Figure 59 provides a map of the City’s current service area and wholesale customers. The City has nine customer categories: residential, multi-family, commercial, industrial, institutional, public, irrigation, wholesale, and fire services. Figure 63 displays

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annual average day consumption (ADC), the average amount of water consumed each day, from fiscal year (FY) 2012-2013 through FY 2016-2017. The average ADC during this period was 20.46 million gallons per day.

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Figure 62. City of Salem Service Area and Wholesale Water Customers (GIS, 2014)

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Figure 63. Annual average water consumption per day (GSI, 2019)

Like other Pacific Northwest cities, water use in Salem is highly seasonal. More water is used in the summer than in the winter because of irrigation. This difference is further heightened in Salem by the presence of food processing industries that use a lot of water during summer months. Compared to the present average use of around 20 million gallons per day (45 cfs), the highest use during the summer may reach more than 60 million gallons per day (111.5 cfs). The City uses ADC by class and in total for its revenue and demand projection calculations. Figure 64 shows the estimated monthly consumption by customer category for July 2012 through June 2017. As expected, consumption increased in the summer months on an annual basis, which can be attributed to outdoor water use for irrigation. The highest monthly consumption was 506.5 MG in June 2015 for residential water users, which is approximately 100 MG less than the highest monthly consumption for residential water users from FY 2007-2008 through FY 2011-2012 (602.6 MG in July 2007).

Figure 64. Monthly metered consumption by customer category, July 2012–June 2017 (GSI, 2019)

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As described Section 3.12.1.1, the City holds municipal water rights authorizing the use of water from the North Santiam River. The City also holds water rights on the Willamette River as well as groundwater rights. The following provides a brief discussion of the reliability of the water rights from each of these sources. A more complete list of the City’s water rights is provided in Appendix J. The City holds municipal senior water rights on the North Santiam River authorizing the use of up to 239.0 cfs. Typically, the North Santiam River basin produces a significant quantity of water even during the driest months. According to streamflow records on the North Santiam River at Mehama (upstream from the City’s authorized points of diversion), the minimum 7-day rolling average flow (by month) for the period 2000 and through 2017 was 861 cfs in July, 817 cfs in August, 898 cfs in September, and 914 cfs in October. The amount of water available to satisfy the City’s water rights is a function of water right priority date (seniority) and streamflow. The City’s water rights from the North Santiam River are senior and therefore typically reliable. However, as discussed in Section 3.12.1.1, the surface water intake on the North Santiam is vulnerable during very low flows in dry years and is susceptible to water quality concerns typically during summer months. For flows less than 750 cfs, there is insufficient water volumes and pressure (head) in the sand filter ponds for them to operate properly, and the water intakes to function as designed. Gravel accumulation in the North Channel at Geren Island and near the City’s intake currently results in the intake’s limit being reached more often. The City has a permitting and plan in-place that could help their intake work at lower river flows. This would entail some dredging activities around the forebay area of Upper Bennett Dam so more water flows pass their intake. Salem has not initiated these improvements due to the cost associated with the mitigation efforts required by the permits. In the recent past, when flow rates were greater than the 750 cfs, the Geren Island treatment plant could not effectively treat North Santiam River water during high turbidity events (which primarily occur during winter and spring) or during algal fouling events (which primarily occur during summer). To meet its demands during high turbidity events, the City used groundwater at Geren Island. Currently, the City only has access to its four Geren Island groundwater registrations, which total 22.23 cfs, to provide supply redundancy. The City’s other groundwater rights are currently not in use or are used only for emergency purposes due to water quality concerns. These other groundwater rights would not typically be used during a high turbidity or algal fouling event.

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Environmental Consequences

Methodology and Scale of Analysis

Agriculture To assess the needs and potential impacts of the various alternatives, the Corps used the USDA National Agriculture Statistical Service (NASS) CDL to identify the crops farmed within the SWCD and the SIC. The CDL is a geo-referenced, crop-specific land cover data layer created annually for the continental United States using moderate resolution satellite imagery with extensive agricultural ground truthing by the USDA National Agriculture Statistical Service’s Research and Development Division, Geospatial Information Branch, Spatial Analysis Research Section. For comparison purposes, the Corps first applied the CDL to Marion County and then applied to each of the SWCD and the SIC. Using the Marion County data for average annual cropland farm wages, the Corps estimated total farm employment and total number of farms within the County described above. The Corps estimated the net income lost due to a decrease in crop yield to annuals and perennials for each of the SWCD and the SIC. It is assumed the average size of the farm within the county can be applied to both water districts (SWCD and SIC). For purposes of analysis, it is assumed cropland wages within the county can be applied to each of the water control districts (SWCD and SIC). Appendix I provides a detailed description of the economic analysis of agricultural impacts for this project. For purposes of remaining conservative in the economic estimate for this EIS, the Portland District has used the Corps’ Regional Economic System (RECONS) software (a Corps certified model) to estimate the multiplier effects resulting from the potential economic impact because of the impact to the local agricultural economy. The Corps used a multiplier of 1.5813 to calculate secondary impacts. The Corps used a multiplier of 2.5813 to calculate the total impacts.

Recreation The Corps also utilized the RECONS economic impact modeling tool to provide accurate and defendable estimates of regional economic impacts associated with spending. RECONS automates calculations and generates estimates of jobs and other economic measures such as income and sales associated with direct, secondary and cumulative expenditures (as well as stemming from effects of additional economic activities such as water transportation and tourism spending) that is associated with Corps programs and projects. The Corps also uses RECONS to evaluate the economic contribution of industries and activities that are dependent on or benefit from Corps programs and infrastructure; these downstream effects are termed “stemming from effects” and have been applied to the Corps business lines, including recreation. The

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Corps measures stemming-from effects of recreation programs by the spending and associated economic activity generated by visitors to Corps lakes and reservoirs. The Corps can use the RECONS recreation module to estimate economic significance or impacts of existing recreation use or to estimate impacts of a change in use. Significance measures cover all visitor spending, while an economic impact analyses will focus on spending by visitors from outside the local region. The Corps used the following segments to capture differences in spending: • local visitors (boaters and non-boaters) – visitors living within 30 miles of the project; • non-local visitors on day trips – visitors from beyond 30 miles not staying overnight in the area for both boaters and non-boaters; • campers – visitors staying in campgrounds for boaters and non-boaters; and • other overnight visitors – visitors staying overnight in motels, campgrounds or private homes within 30 miles of the project for both boaters and non-boaters.

Appendix G provides a detailed report on the Corps’ regional economic impact analysis for recreation, including the data sources used, and is incorporated here by reference. Comparison of the financial effects of recreation to the community of Detroit can be compared with a Willingness to Pay (WTP) model that represents the value of the recreation experience to the recreator for visiting Detroit Reservoir. Using a Unit Day Value approach to estimate the recreator’s WTP, using Economic Guidance Memorandum 19-03 Unit Day Values for Recreation for Fiscal Year 2019 for guidance, reveals a value of $3,150,400 ($8.80 x 358,000 visitors), which compares well with the total labor income lost due to the potential draught scenarios discussed above.

M&I Water Supply To assess the economic implications of the alternatives’ effect on M&I water supply, the Corps utilized the City of Salem’s projected future demand from the 2014 Water Management Conservation Plan to determine the Maximum Daily Demand during the period when the Project is likely to occur (2024). To account for uncertainty in the data and application of the trends, the City calculated range factors of +/-15% of projected maximum daily demand values to plan for a potential range in future water demands. The 2014 Water Management Conservation Plan projects that in 2024 the maximum daily demand (+15%) would be 66.6 million gallons per day requiring 103 cfs. The maximum authorized rates of the City’s North Santiam surface water rights are sufficient to meet the projected maximum daily demand, but it is important to note the current point of constraint is the transmission capacity from Geren Island to the City’s storage 3-294

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and distribution system, which is currently limited to 102 cfs. The City can also obtain approximately 7 to 12 cfs from its ASR system, which results in a current total supply of 109 to 114 cfs. However, for project alternatives where there could be flows as little as 400 cfs during the summer months, there is serious concern whether the City can provide the quantity and quality of water they need. For purposes of analysis, it is assumed when flows in the North Santiam at the Mehama gage are as low as 400 cfs; the Geren Island Treatment slow sand filters would not function, and could not provide finished water to the City of Salem. Applying the U.S. Census data for 2010 and 2017 and assuming the same population growth rate is applied to the 2021 to 2024 period, when construction of the SWS is expected to occur, it is assumed the population in 2022, the first summer during construction would be 209,189. Using these populations, the Corps performed a water budget to determine the potential number of people that the City would be able to serve water if water through their sand filter systems from the North Santiam River were not available. The Corps calculated the potential lost revenue to the City and then interpolated the data to estimate the total induced economic effect not just to the City, but also to the region. To avoid the potential economic impact of low flows at the Geren island facility during the peak summer months, the City of Salem has given considerable thought, time and energy in developing potential mitigation measures should the City be unable to produce enough drinking water to meet the needs of its community. Beyond water customers having to face some level of water curtailment for a couple of years, the City has identified supplemental water supply projects, which include: • Further development of the Geren Island groundwater wells • Aquifer Storage and Recovery improvements • Distribution system improvements • Construction of additional wells in south Salem • Improve and/or rehabilitate wells within the city. Alternatively, as the City of Salem has water rights on the Willamette River, Salem could construct a new water supply facility downstream of Geren Island on the Willamette River. This would also require Salem to reconfigure their delivery system to connect to the new plant downstream requiring pumping, as the current system of pipes connecting the Geren Island Facility to users is gravity fed. The Corps, in discussion with the City of Salem public works staff estimated the range of costs to the City of Salem to implement these alternative water supply facilities. If should be noted that the risk to water supply is still high as it is unlikely the City pof Salem would be able to design, permit, finance, and construct the alternative water supply facilities within the Corps proposed timeframe of this Project.

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Staging Areas Work proposed at the staging areas described in Section 2.7.2.5 would not affect socio-economics under any alternative. The staging areas described in Section 2.7.2.5 are on Corps property. Therefore, construction activities at Minto North, Detroit Dam Visitor Parking Lot and Detroit Dam Road, and Detroit Dam and Operations Yard and Access Road 2.7.2.5 would not affect socio-economics under any alternative. The following provides a description of the impacts of the project on socioeconomics at the alternative staging areas described in 2.6. The staging areas described in Section 2.7.2.5 would experience the environmental consequences described under all action alternatives.

SA1. Mongold State Park Under this staging area alternative, activities over the entire duration of both the SWS and the FSS construction (upwards of 8 years) would significantly reduce recreational access at Mongold State Park where the boat ramp with the highest use on Detroit Reservoir is located. As a result, there would be a reduction in visitation and associated state income from day use permits. The socioeconomic impact of the impacts to recreation are generally captured in the impacts analysis for the construction alternatives described below.

SA2. Oregon State Parks Maintenance Yard The Oregon State Park Maintenance Yard is operated by OPRD and access to the area for OPRD would likely continue under all alternatives. Therefore, the use of this area would have negligible socioeconomic impact.

SA3. Detroit Lake State Recreation Area Under this staging area alternative, construction activities over the entire duration of both the SWS and the FSS construction (upwards of 8 years) would significantly reduce recreational access at Detroit Lake State Recreation Area. As a result, there would be a reduction in visitation and associated USFS income from camping permits. The socioeconomic impact of the impacts to recreation are generally captured in the impacts analysis for the construction alternatives described below.

Construction Alternatives Table 44 summarizes the total avoidable impact to the region’s economy in the area of effect for each alternative. A detailed discussion of the results can be found in Appendices H, I, and J. As discussed in Section 3.12.6, to address M&I shortages, Salem could construct new water supply facilities at a cost of between 3-296

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$28,000,000 and $100,000,000 to construct. However, such system could have long- term economic impacts as they may require new, more expensive to run filtration systems as the and there is a high risk that it would not be possible for the City to implement these measures in the timeline of this project. The Corps project is planning to start construction of temperature control in 2021. It would take years, perhaps a decade, to complete the design, permitting, financing and construction of either new water supply. Table 44. Summary of Alternatives’ Economic Impacts Alt Agriculture: Agriculture: Recreation: Recreation: Recreation: M&I water M&I water Direct Indirect Direct Indirect Indirect supply: supply: imapcts to impacts to impacts to impacts imapcts Direct Indirect Cropland agricultural recreational visitor jobs lost imapcts imapcts irrigators industry visitors spending due to City of Salem (WTP) forgone visitors rate payer spending fees forgone forgone CA1 $0 $0 $3,150,000 $0 $0 $0 $0 CA2 $54,000,000 $85,000,000 $6,300,000 $23,000,000 140 $12,300,000 $48,700,000 CA3 $19,500,000 $30,500,000 $3,150,000 $11,000,000 140 $6,100,000 $24,600,000 CA4 $2,500,000 $3,500,000 $3,150,000 $11,000,000 140 $6,100,000 $24,600,000 CA5 $0 $0 $3,150,000 $0 $0 $0 $0 Note: see TABLE 2 OF APPENDIX H FOR additional details, INCLUDING the total local labor income generated as a result of recreator spending.

3.19 OTHER SOCIAL EFFECTS (OSE) The potential social and economic impacts during project construction are analyzed to provide a clear picture as the Corps evaluates the various alternatives. The economics portion of a socioeconomic analysis evaluates how the alternatives might affect elements of the human environment such as population, employment, housing, and public services. Section 1508.14 of the CEQ Regulations states (40 C.F.R. § 1508.14) “When an environmental impact statement is prepared and economic or social and natural or physical environmental effects are interrelated, then the environmental impact statement would discuss all of these effects on the human environment.” The sociological analysis focuses on applying “Other Social Effects” (OSE) concepts as described in the Corps’ Planning Guidance Notebook (ER 1105-2- 100). Fully incorporating social well-being factors into the planning process in a substantive way has great potential value for better ensuring that water resources solutions address a broad array of issues and concerns that better meet stakeholder needs and expectations. The Corps develops and uses OSE information to help parties

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involved to understand the situation and issues and to develop a deeper understanding of the views, positions and underlying interests of those involved. The intent of this communication process is that stakeholders come to a deeper understanding of all views, as well, and that opportunities for shared interests and greater collaboration may be discovered and differences and choices crystalized. This means that communicating the socioeconomic implications of alternatives and helping stakeholders to understand them and explore the consequences of alternatives on their situations and interests can help differentiate the choices that alternatives present. The social analysis should help clarify issues and interests of the stakeholders and should form the foundation for collaborative problem solving while finding appropriate and acceptable solutions (Creighton et al. 1998). For socioeconomics, the affected environment may be larger than the study area as impact considerations include economic activities such as, employment, income, population, housing, public services, and social conditions that may exist outside of the project area. The baseline conditions should include the size of local population centers, the distance from a project site to these areas, and the nature of the local economies. With respect to socioeconomic effects, the Corps considered the socioeconomic affected environment to include the Detroit Reservoir and surrounding communities. The potential impacts could reach from Salem, Oregon and its economic and social structures all the way down OR-22 to Idanha, Oregon, which lies just past Detroit Reservoir. The Detroit Reservoir is approximately 50 miles east of Salem, Oregon, along State Highway 22. Communities east of Salem along OR-22 include the communities listed in Section 3.18.1 As one travels east along OR-22, in general the communities are increasingly rural in nature, with very sparse social services.

Environmental Consequences

Methodology and Scale of Analysis The Corps completed the Sociological Assessment using both qualitative and quantitative methodologies found in the Institute for Water Resources Handbook on Applying OSE Factors in Corps of Engineers Water Resources Planning (IWR-09-R-4). The OSE account has appeared in various forms and nomenclatures in federal guidance for many years. The Corps should use OSE information in a project planning process to help formulate and evaluate project objectives and alternatives as well as help stakeholders understand and explore the consequences of alternatives on their situations and interests. The OSE handbook provides tools and methods for developing OSE factors for water resources planning.

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There are a number of challenges in integrating OSE information into the NEPA process. The first challenge is that the meaning of OSE information is contextual. The OSE analyst must actively engage with stakeholders about the meaning of the social effects that are occurring or predicted. The second challenge is that the social conditions that an OSE analyst observes and describes are complex, multidimensional concepts produced by a multitude of causes. This means that it may be too difficult to distinguish levels of OSE impacts among alternatives in a quantitative way. For the sociological assessment of the Project, the Corps utilized several OSE tools. The first step was to help the study team gain a better understanding of the social landscape. To do this, the Corps identified who lives in the study area as well as who has a stake in the problem or issue and why it is important to them. The Corps collected this information by performing a profile of the area in terms of basic social statistics and identifying stakeholders (the groups that are likely to have a stake in the problem, issue or outcome). The team then provided an opportunity for these groups to present their views on problems, needs, opportunities and constraints, including what kinds of effects they were interested in achieving or preventing. The Corps did this by conducting a series of summer public meetings in August 2018. The Corps followed these meetings by performing historical analysis utilizing community profiling tools from the IWR 09-R-4, independent studies, interviews, secondary data collection techniques to create a picture of how the alternatives would impact the people and businesses in the area that depend on the watershed for their livelihood. The team conducted interviews, and performed multiple records searches to analyze the potential impacts from the project on the communities. Appendix K includes the community profiles. The Corps reviewed historical records online and through interviews with local residents, business owners, public officials, and Corps staff. Appendix K provides the complete Socio-Economics Impacts Assessment and Analysis for the North Santiam Watershed.

Views of the Local Government In May 2018, the Marion County Board of Commissioners wrote a letter to the Corps highlighting their concerns over the Project. The categories of concern the county identified included potential impact on local communities, impacts to health, safety, and welfare of communities, economies, and critical natural resources. The Board asked that the Corps show their process leading to the alternatives development and questioned if there were more than one alternative being offered. They were concerned with safety in regard to transportation and highway impacts. There was a concern that the low reservoir levels would impair the safety of OR-22 and could lead to slide impacts and road damage. They also requested that the Corps be mindful of sensitive cultural resources that could be uncovered when the reservoir is drawn down. The Corps

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responded with a plan to address each of the raised concerns and formulated a plan to make the public aware of the NEPA process in alternatives development. In addition to NEPA scoping, held over the winter of 2017/2018, the Corps carried this out through a series of public meetings that the Corps hosted in the summer of 2018. The Corps’ socioeconomic analysis team also met with several public officials in the North Santiam watershed about the Project. The Detroit City Mayor met with Corps team members several times throughout 2018 and voiced his concerns along with the concerns of the residents and business owners in Detroit. The Mill City Mayor and officials from the City of Stayton also met with the team to discuss their concerns for the communities expected to be impacted by this project. Finally, the City of Salem’s Mayor attended several of the public meetings and coordinated efforts to work with the Corps on collecting a large portion of the information used in creating the community profiles for this analysis.

Staging Areas The staging areas described in Section 2.7.2.5 are on Corps property and, with the exception of the Detroit Visitors Parking Lot, are not accessible to the public. Therefore, construction activities at Minto North and the Detroit Dam and Operations Yard and Access Road would not have OSE. There would be a minor impact to public access to the viewpoint at the Detroit Visitors Parking Lot as this area would be temporarily inaccessible during the four year SWS construction period and when the Corps installs the FSS. The following provides a description of the impacts of the project on recreation at the alternative staging areas described in 2.6. The staging areas described in Section 2.7.2.5 would experience the environmental consequences described under all action alternatives.

SA1. Mongold State Park Under this staging area alternative, construction activities over the entire duration of both the SWS and the FSS construction (upwards of 8 years) would significantly reduce public access at Mongold State Park. Those who do access Mongold State Park during construction would experience the noise and disturbance of construction activities rather than the expected peaceful reservoir access that is typical. The Corps would gate off much of Mongold State Park for safety, including the entirety of the swimming area. The Corps may be able to maintain access to the boat ramps during construction; however, this access may be restricted at times.

SA2. Oregon State Parks Maintenance Yard

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The Oregon State Park Maintenance Yard does not provide public access; therefore, construction activities under this staging area alternative would not affect OSE.

SA3. Detroit Lake State Recreation Area Under this staging area alternative, construction activities over the entire duration of both the SWS and the FSS construction (upwards of 8 years) would significantly reduce recreational access at Detroit Lake State Recreation Area. Specifically, the Corps would completely dismantle camp loops A and B for the duration of construction in order to provide access to the staging area. The Corps would gate off this area for safety. Those who do access the Detroit Lake Recreation Area during construction would experience the noise and disturbance of construction activities rather than the expected peaceful reservoir access that is typical.

CA1. No Action Under the No Action alternative, the communities identified would not be affected.

CA2. SWS and FSS Constructed with a Two-year Deep Drawdown During the initial drawdown and the following period of lowered reservoir level operation, communities would experience significant direct and indirect effects from the drawdown. The drawdown would affect every community from Salem to Idanha. Affected industry and residents would include agricultural, food processing operations, water supply and water quality, recreation, tourism, businesses, schools, and social services. Sections 3.6.2, 3.12.6, 0, and 3.18 describe the water quality, water supply, recreation, and economic effects of the alternatives, respectively.

Agricultural This industry would be one of the most directly impacted by CA2. Not only is the area a major agricultural industry, the communities and other businesses up and down the watershed rely on the economic inputs from agriculture. Marion County is the largest in the state of Oregon for irrigation and farming. There are food processing plants, wineries and other small businesses that depend on the agricultural industry for their livelihood. The direct impacts of CA2 would be to the farmers and the employees that they hire. Indirect impacts could include the service industry, recreation, and tourism. Thousands of people visit the area annually to enjoy the area’s vast and varied agricultural industries, creating jobs and contributing to the regional economic development. While a 2-year drawdown would not destroy the industry, it would have a major economic impact to the processing plants who depend on both the crops and the water for day-to-day operations as well as the hundreds of employees they hire. Section 3.18.5.3 summarizes the economic impacts to the agricultural industry in the region.

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Food processing operations Companies such as Yamasa Corporation, Oregon Fruit Products, NorPac Food Inc., Truitt Bros, and others have expressed a stake in this project as they fully expect to lose revenue if the Project affects the agricultural communities. Impacts to water supply and water quality under CA2 would have direct impacts to the food processing businesses. Impacts to the agricultural businesses in the region under CA2 would indirectly affect these businesses. Loss of crops would mean loss of products for processing. This would have a trickle-down effect because it could potentially result in layoffs at these businesses.

Tourism and Social Connectedness As discussed in Section 0, CA2 would have a significant impact on recreation during the 2-year proposed drawdown. Leisure and recreation is also an important part of social connectedness. Social connectedness refers to the social networks in which individuals interact. According to IWR 09-R-4, “social connectedness largely provides meaning and structure to life.” Participation and being able to interact with others and influence social outcomes is an important aspect to social connectedness. Having leisure time and being able to spend it in preferred recreational pursuits is an important aspect of well-being for most people. To the degree that water resource problems or solutions affect leisure time and recreational opportunities they are likely to be perceived as important considerations in selecting preferred solutions.

Tourism and Small Businesses The potential impacts to tourism and recreation from CA2 would be especially hard on the small businesses up and down the North Santiam River canyon from Salem to Idanha. Interviews with business owners, residents and government officials show that the impacts could also be long lasting and costly. Some businesses are so dependent on the tourism revenue that even one lost summer could have severe monetary consequences. During the 2015 drought when the reservoir was low (albeit not as low as would occur under CA2), profits and sales were down in some businesses as much as 35%. Businesses that depend on tourism would be the most directly impacted by the projected drawdown levels. According to many business owners and residents interviewed, the common belief is that the project would hurt the local economy and kill some businesses. While some businesses may have the resources to bounce back from the expected loss of revenue, in many of the small businesses the owners and employees depend on the profits generated for their day-to-day living.

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CA3. SWS and FSS Constructed with a One-year Deep Drawdown The OSE under CA3 would be similar to those identified in CA2 but on a smaller scale. While this alternative would have less impact than CA2, the potential impacts could be long lasting. For example, by comparing historical records, it is clear that even a 1-year drawdown could have long-term impacts. Additionally, there are agricultural crops that are sensitive to reductions in the water levels that can take up to 3 years to regenerate.

CA4. SWS and FSS Constructed with a One-year Variable Drawdown Under CA4, the OSE on the business and communities in the North Santiam Canyon from Salem to Idanha that depend on summer recreational tourism would be similar to those identified in CA3. However, the effects on agricultural crops that are sensitive to reductions in the water levels would not be realized under CA4 and the Corps would maintain typical minimum flows in the summer months.

CA5. SWS and FSS Constructed with No Drawdown Impacts from this alternative would be similar to the No Action alternative.

Environmental Justice Environmental justice is the fair treatment and meaningful involvement of all people regardless of race, color, national origin, or income with respect to the development, implementation, and enforcement of environmental laws, regulations, and policies. Fair treatment means that no group of people should bear a disproportionate share of the negative environmental consequences resulting from industrial, governmental, and commercial operations or policies. Meaningful Involvement means that: • people have an opportunity to participate in decisions about activities that may affect their environment and/or health; • the public’s contribution can influence the regulatory agency’s decision; • their concerns would be considered in the decision making process; and • the decision-makers seek out and facilitate the involvement of those potentially affected. In compliance with Executive Order 12898: Federal Actions to Address Environmental Justice in Minority Populations and low-Income Populations, the Corps must create an opportunity for minority and low income populations to provide input on the analysis, including demographic analysis that identifies and addresses potential impacts on these populations that may be disproportionately high and adverse. The

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public involvement process can also provide information on subsistence patterns of consumption of fish, vegetation, or wildlife. This information should be disclosed to potentially affected populations for proposed actions and alternative(s) that are likely to have a substantial effect and for Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) sites. The demographic information reported by the American Community Service Office, U.S. Department of Commerce for the affected area (Table 45 and Table 46) revealed that no group of people appears to bear a disproportionate share of the potential negative environmental consequences of the project. Table 45. Ethnicities within Marion and Linn Counties, 2016 data from U.S. Census Bureau Marion County, Linn County, OR Two County Region U.S. OR Total Population, 2016* 119,862 326,527 446,389 318,558,162 Hispanic or Latino (of any race) 10,054 83,659 93,713 55,199,107 Not Hispanic or Latino 109,808 242,868 352,676 263,359,055 White alone 103,248 218,448 321,696 197,362,672 Black or African American alone 591 3,547 4,138 39,098,319 American Indian alone 1,623 1,952 3,575 2,084,326 Asian alone 1,363 6,249 7,612 16,425,317 Native Hawaii & Other Pacific Islands alone 116 2,549 2,665 508,924 Some other race 69 249 318 676,003 Two or more races 2,798 9,874 12,672 7,203,494 Percent of Total Hispanic or Latino (of any race) 8.4% 25.6% 21.0% 17.3% Not Hispanic or Latino 91.6% 74.4% 79.0% 82.7% White alone 86.1% 66.9% 72.1% 62.0% Black or African American alone 0.5% 1.1% 0.9% 12.3% American Indian alone 1.4% 0.6% 0.8% 0.7% Asian alone 1.1% 1.9% 1.7% 5.2% Native Hawaii & Other Pacific Islands alone 0.1% 0.8% 0.6% 0.2% Some other race 0.1% 0.1% 0.1% 0.2% Two or more races 2.3% 3.0% 2.8% 2.3% Medium Reliability: Data with coefficients of variation (CVs) between 12 & 40% are in orange to indicate that the values should be interpreted with caution. Low Reliability: Data with CVs > 40% are displayed in red to indicate that the estimate is considered very unreliable.

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Table 46. Median Household Income for Linn and Marion Counties Compared to the Nation. Linn County, Marion County, Two County U.S. OR OR Region Per Capita Income (2016 $s) $22,934 $23,348 na $29,829 Median Household Income^ (2016 $s) $46,782 $50,775 na $55,322 Total Households, 2016* 45,378 115,196 160,574 117,716,237 Less than $10,000 3,278 7,277 10,555 8,243,664 $10,000 to $14,999 2,920 6,168 9,088 6,000,362 $15,000 to $24,999 5,442 12,544 17,986 12,053,642 $25,000 to $34,999 5,455 12,962 18,417 11,628,547 $35,000 to $49,999 6,832 17,795 24,627 15,588,725 $50,000 to $74,999 9,341 23,071 32,412 20,913,779 $75,000 to $99,999 5,834 15,351 21,185 14,361,853 $100,000 to $149,999 4,374 13,839 18,213 15,885,823 $150,000 to $199,999 1,271 3,788 5,059 6,369,156 $200,000 or more 631 2,401 3,032 6,670,686 Gini Coefficient^ 0.43 0.42 na 0.48 Percent of Total Less than $10,000 7.2% 6.3% 6.6% 7.0% $10,000 to $14,999 6.4% 5.4% 5.7% 5.1% $15,000 to $24,999 12.0% 10.9% 11.2% 10.2% $25,000 to $34,999 12.0% 11.3% 11.5% 9.9% $35,000 to $49,999 15.1% 15.4% 15.3% 13.2% $50,000 to $74,999 20.6% 20.0% 20.2% 17.8% $75,000 to $99,999 12.9% 13.3% 13.2% 12.2% $100,000 to $149,999 9.6% 12.0% 11.3% 13.5% $150,000 to $199,999 2.8% 3.3% 3.2% 5.4% $200,000 or more 1.4% 2.1% 1.9% 5.7% Medium Reliability: Data with coefficients of variation (CVs) between 12 & 40% are in orange to indicate that the values should be interpreted with caution. Low Reliability: Data with CVs > 40% are displayed in red to indicate that the estimate is considered very unreliable.

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The Corps also utilized the EPA Environmental Justice Screening and Mapping Tool24. to map the area of interest to compare with state and national data (Figure 65). EPA developed the e Environmental Justice Screening and Mapping Tool based on nationally consistent data and an approach that combines environmental and demographic indicators in maps and reports. Figure 66 display how substances of concern in the area highlighted compare with state and national values and shows that the project would not disproportionally effect a particular demographic group. The Corps has participated in a number of media events, public meetings, and regular briefings with specific stakeholder groups since scoping was initiated in November 2017. The Corps hosted three public meetings in the cities of Salem, Gates, and Stayton, Oregon, in August 2018 to brief the public on the process used to arrive at the alternatives assessed in detail in the EIS. Public involvement will continue to be provided by a 60-day public review of the Draft EIS. Should a particular demographic be identified to potentially be adversely effected by future Government actions, the review period would immediately stop and renewed analysis would commence until an appropriate alternative is in place to avoid or ameliorate any environmental consequence that disproportionally affects any one demographic group.

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Figure 65. Area of Interest to Compare with State and National Data from EPA Environmental Justice Screening and Mapping Tool

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Figure 66. Environmental and demographic indicators for the area of interest displayed in Figure 65 (Region) compared to State and National values from EPA Environmental Justice Screening and Mapping Tool

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3.20 PUBLIC HEALTH AND SAFETY During public scoping, several commenters expressed concern about how the project may affect fire response and the availability of water for fighting fires in the area of effect. Currently, fire response vehicles access fires around Detroit Dam using OR- 22. Additionally, the road over the Detroit Dam is the fastest way for emergency response vehicles, including fire trucks, to reach the south side of Detroit. Emergency personnel may utilize Detroit Reservoir as a source of water in aerial firefighting to fight wildfires in the area. In urban areas, emergency personnel use municipal water systems (USFS, personal communication, 2018). The SWCD also provides the sole source of water for fire protection to the Cascade School District (SWCD, personal communication, 2018). Scoping comments also highlighted a concern about boater safety. Currently Detroit Dam has booms that mark areas where boater access is prohibited approaching Detroit Dam.

Environmental Consequences

Methodology and Scale of Analysis To assess the impacts to health and safety, the Corps interviewed emergency response professionals at USFS and ODF.

Staging Areas The staging areas described in Section 2.7.2.5 are on Corps property and, with the exception of the Detroit Visitors Parking Lot, are not accessible to the public. Therefore, construction activities at Minto North and the Detroit Dam and Operations Yard and Access Road would have no effect on health and safety. The following provides a description of the impacts of the project on fire response at the Detroit Dam Road and the alternative staging areas described in 2.6. The staging areas described in Section 2.7.2.5 would experience the environmental consequences described under all action alternatives.

Detroit Dam Road Under all action alternatives, the Corps would block access to the Detroit Dam Road for public safety during the 4-year SWS construction period and when the Corps installs the FSS and mooring dolphins. The Corps would establish traffic control around the Detroit Dam Visitors Parking Lot described in Section 3.14.1 for public safety. When the Corps closes the road over Detroit Dam for construction, fire response agencies would need to use an alternate route to conduct routine fire prevention patrols and respond to fires in the forestlands south of the dam and reservoir. As discussed in 3-309

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Section 2.7.2.1, the bridge below Detroit Dam provides access across Big Cliff Reservoir to the Southshore Road. The Corps recently improved this alternate route during a road rehabilitation project completed in the summer of 2018. During construction, fire response vehicles would use this road, however, they would need to get access through a Corps security gate. The Corps would coordinate with local fire response agencies such as the USFS and ODF, so that emergency responders would know to call the Detroit Powerhouse control room to get access through the gate. Using Southshore Road would take about 10 minutes longer than going directly across the dam. ODF looked at the Southshore Road in spring 2018 and confirmed that the road would work as an alternate route for emergency vehicles to access the other side of the dam. In a phone conversation, the USFS Fire Management Officer agreed that the alternate route would be fine to respond to small fires ("initial attack fires") and to conduct routine fire prevention patrols. However, USFS expressed concern that the alternate route may not work in the case of a large fire that required an extended response. During an "extended attack fire," up to 200 vehicles per day would need to get access through the security gate and across the bridge to get to the other side of the dam. In addition, Colville was concerned that the bridge might not be rated for the heavy equipment that would be brought in to fight an extended attack fire. Some equipment would require a 60-ton rating, and the bridge is only rated for 36 tons and up to 1,000 people per day could be mobilized to fight an extended attack fire, and many of them are non-local USFS employees or contractors. This could create a security concern for the Corps when providing access through the gate to the powerhouse. To summarize, the road closure over Detroit Dam during construction would have a minor impact on routine fire prevention patrols and small fire response because there is an alternate route available. However, the road closure could have a major negative impact in the event of a large fire because the alternate route may not be satisfactory to conduct a massive extended response. In this case, the Corps would develop a contingency plan that would shut down construction to allow passage for emergency vehicles and personnel during an extended attack fire.

SA1. Mongold State Park Under this staging area alternative, construction activities over the entire duration of both the SWS and the FSS construction (upwards of 8 years) would significantly reduce public access at Mongold State Park. The Corps would gate off much of Mongold State Park for safety, including the entirety of the swimming area. The Corps would establish the traffic control described in Section 3.14.1 for public safety. The Corps would work with emergency personnel to provide access to all areas of Mongold in an emergency.

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The Corps may limit boater access at Mongold during construction to ensure boater safety.

SA2. Oregon State Parks Maintenance Yard The Oregon State Park Maintenance Yard does not provide public access; therefore, construction activities under this staging area alternative would not affect health and safety. The Corps would establish the traffic control described in Section 3.14.1 for public safety. The Corps would communicate with OPRD staff to ensure boater safety for OPRD staff utilizing the docks at this site.

SA3. Detroit Lake State Recreation Area Under this staging area alternative, construction activities over the entire duration of both the SWS and the FSS construction (upwards of 8 years) would significantly reduce public access at Detroit Lake State Recreation Area. The Corps would gate off the staging area including camp loops A and B for safety. The Corps would establish the traffic control described in Section 3.14.1 for public safety. The Corps would work with emergency personnel to provide access to all areas of Detroit Lake State Recreation Area in an emergency. The Corps may limit boater access at the Recreation area during construction to ensure boater safety.

CA1. No Action Under the No Action alternative, there would be no effect on health and safety.

CA2. SWS and FSS Constructed with a Two-year Deep Drawdown Under CA2, the low summer flows resulting from the 2-year drawdown may negatively affect SWCD’s ability to provide water for fire protection to the Cascade School District. The Corps assumes that the City of Salem would prioritize water delivery to fire response personnel in the event of a fire. There would be no boater access during the drawdown, ensuring boater safety at that time. Following the drawdown the boater restriction booms would continue to ensure boater s do not have access to the construction site.

CA3. SWS and FSS Constructed with a One-year Deep Drawdown

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Under CA3, the effects to health and safety would be the same as under CA2 but would only be experienced for a single summer season as opposed to two seasons.

CA4. SWS and FSS Constructed with a One-year Variable Drawdown Impacts to fire response from this alternative would be similar to the No Action alternative. Impacts to boater safety would be the same as CA2.

CA5. SWS and FSS Constructed with No Drawdown Impacts from this alternative would be similar to the No Action alternative.

3.21 CLIMATE CHANGE To date, the most comprehensive study of climate change in the Pacific Northwest is the “Pacific Northwest Hydroclimate Scenarios Project (2860)”, which is also referred to as the Columbia Basin Climate Change Scenarios Project, or simply the Climate Impacts Group analysis (Climate Impacts Group, 2010). Datasets generated as part of the Climate Impacts Group study were used by the Oregon Climate Change Research Institute (OCCRI) to write a report for the Corps’ Portland District titled, “Historical Trends and Future Projections of Climate and Streamflow in the Willamette Valley and Rogue River Basins” (OCCRI 2015). The OCCRI report describes general climate projections for 2030-2059 as having higher regional minimum and maximum temperatures, meaning that both winters and summers would be warmer, with a greater increase in summer temperatures than winter temperatures. Annual precipitation is not projected to change, but models generally suggest modest increases in winter precipitation and decreases in summer precipitation. (Mote et al. 2019). Climate models run for local conditions indicate lower June-August runoff, projected to decline 5.3% in the Pacific Northwest over 2011–2050 compared to 1966–2005 under a high emissions pathway (Dalton et al 2017). While regulated flows from Detroit reservoir could potentially partially compensate for these effects below the dam, reduced inflows will also limit reservoir refill, and therefore reservoir regulation's ability to meet BiOp flow targets or provide temperature operations. Willamette Water 2100 (Jaeger et al., 2017) examined the interactions of humans, hydrology, and ecology on water supply in the Willamette River basin. In the case of precipitation, the three climate scenarios evaluated by Willamette Water 2100 indicate that winters would become slightly wetter and summers slightly drier, but based on the examination of more than 40 climate models, there is no consensus about whether the Willamette River basin’s climate would become wetter or drier overall (Jaeger et al., 2017). Snowpack may be dramatically reduced, and areas where streamflow depends on snowmelt, would experience reduced flows that arrive earlier in spring and summer than has been the case historically. The increases in average wintertime flow (owing to

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reduced snow accumulation and more rapid runoff) also correspond to increases in flood risk in those basins. Summertime flow is reduced in many basins, by as much as 50% (in June) (Moet et a. 2019). Further risks arise from the loss of snowpack which acts as a natural reservoir to enhance summertime live flow, from both surface and groundwater supply. The net result of the modeled changes in precipitation for the proposed allocation’s period of increased diversions, May through September, is a large decrease in the streamflow for the Willamette River at Salem (Mote et al. 2019). Clear predictions of increasing instream temperatures, earlier spring runoff, and lower summer flows will all impact water quality in the North Santiam despite effects of reservoir management.

Environmental Consequences

Methodology and Scale of Analysis

Climate change impacts on ESA-listed species In 2018, the Corps contracted the Northwest Fisheries Science Center to utilize population-specific life cycle models to assess the potential influence of climate change on population viability under baseline (current) and proposed fish passage scenarios (Myers et al. 2018, currently under review). The life cycle model utilized two independently estimated data sets for spawner capacity: one data set was solely habitat-based and the other dataset utilized historical estimates of spawning capacity and escapement. The habitat-based model predicts habitat quality downstream of the Corps’ WVS dams, which could result in Chinook salmon population declines in abundance from spawning habitat loss and increased adult mortality in freshwater. The Corps used the results from this study to assess climate change impacts on population viability under the alternatives.

Green House Gas Emissions An environmental benefit associated with hydropower generation is avoided emissions. Emissions would be avoided by generating electricity from hydropower as opposed to generating electricity from a fossil fuel source. Quantifying these avoided emissions depends on the generating resource mix of the power that is displaced by the hydropower project. Although monetizing the value of these increased emissions is wrought with uncertainty, it does provide a way to compare consequences of unit outages across different regions and to compare the addition of both financial and environmental consequences. A unit outage may change emissions in two ways. First, a unit outage may cause a shift in the fuel generation mix, when capacity constraints cause the hydropower plant to shift from peaking to off-peak generation. Secondly, more thermal generation may be

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required when the capacity constraint due to the unit outage actually causes losses in gross hydropower generation. Calculating changes in emissions for the first case would require a detailed description of hourly regional generation mixes and some assumptions on how these would change given more demand. It is deemed beyond this study to qualify these changes in emissions; however, for the second case, regional emission factors supplied by the EPA’s eGrid25 database are suitable. For the EIS, analysis from only the second case is considered. Emission rates from the eGrid database are defined as pounds per megawatt hour (MWh) for three greenhouse gases: carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). These are further divided into baseload and non- baseload generating resources. Since WVS hydropower is often used to replace the generating resources on the margin, this study uses the non-baseload emission rates for the Power Projects and total output emission rates for the ‘flat’ projects. The Social Cost of Carbon is an attempt to monetize the consequences of an incremental increase in carbon emissions for a given year. This estimate was developed by the Interagency Working Group on Social Cost of Carbon for the U.S. government with the intent to include this cost in a cost-benefit analysis. Consequences included in this valuation are net agricultural productivity, human health, property damages from increased flood risk, and the value of ecosystem services due to climate change. The Corps used emissions rates to determine the Social Cost of Carbon in the alternatives. This analysis is discussed in detail in Appendix F.

CA1. No Action

Climate change impacts on ESA-listed species Based on predicted increases in summer water temperature, the spawning capacity model predicts a decrease in habitat capacity under CA1. However, results in the Myers et al. 2018 draft may overestimate climate change effects on downstream flow/water temperatures and Chinook salmon, due to reservoir influence on downstream flows and water temperatures. Myers et al. 2018 acknowledges the limitations in dam operation data files used in the analysis, which are based on past hydrology and do not reflect future climate predictions. It cannot be directly assumed that future changes in precipitation and air temperatures would result in similar changes in stream flows and water temperatures below Willamette dams. Reservoir volume significantly affects summer and fall flows and water temperatures below WVS dams. Because spring precipitation plays a much larger role than snowpack in determining spring and summer

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flows, the reduction in snowpack would likely have little effect on the supply of water in the lower basin (Jaeger et al., 2017). The Myers et al. (2018) report, utilized a climate change scenario, which at the time represented an intermediate set of conditions. Climatic models and scenarios have been refined considerably since the results of these forecasts were made (Doppelt et al. 2009, Vynne et al. 2011). While there is uncertainty in the projections, this uncertainty is not uniform. In general, projections suggest more extreme (higher) temperatures than the scenario used in Myers et al. (2018), and many recent projections have used the business as normal scenario, which predict higher CO2 levels (Sheehan et al. 2019).

Green House Gas Emissions Under the CA1, there would be no change to hydropower operations and, therefore, no changes in emissions.

Action Alternatives

Climate change impacts on ESA-listed species Operation of downstream passage and temperature control at Detroit Dam would continue under a wide range of environmental conditions and the Corps would not alter facility maintenance in response to changes in the timing or magnitude of stream flows under climate change. Myers et al. 2018 life cycle modeling also assessed climate change impacts under proposed fish passage scenarios, which could include all action alternatives. The life cycle modeling showed proposed juvenile fish passage at Detroit Dam further increasing spawner abundance, proportionately more so under the historically-based capacity scenarios than the habitat-based capacities. Under the parameters investigated, juvenile passage at Detroit Dam more than compensated for spawner abundance losses due to climate change. The model results also support reestablishing access to higher quality spawning and rearing habitats upstream of the dams under all action alternatives, which would likely be important to UWR Chinook salmon survival and recovery. The use of reservoir releases to mitigate downstream temperature may be compromised if winter precipitation comes in major rain events and must be spilled (Myers et al. 2018). Increased major winter rain events and subsequent spill would also result in higher TDG levels during Chinook salmon incubation. Under this new precipitation regime, it may be more difficult to achieve and hold summer pools, and thus decrease likelihood of having additional cool water in the fall to moderate incubation temperatures. Further, the model utilized by Myers et al. 2018 only applied the predicted annual temperature increase to changes in spawning habitat and prespawning mortality; however, summer temperature increases are predicted to be greater than those in winter, limiting juvenile rearing habitat. Since cold reservoir water 3-315

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is currently limited in some years, there is not be enough to moderate adult migration, holding, and spawning, incubation and rearing temperatures throughout the year. However, a hydrologic and water temperature study of Detroit Lake using General Circulation Models, hydrologic models, and water quality models showed that 2 degrees C increase in air temperature and a 23% decrease to inflows could lead to 1 degree C increase to inflow temperatures and a 1.1 degree C increase to in-lake temperatures on average (Buccola, et.al, 2016). An SWS-like structure was simulated in this study and resulted in some mitigation of future warming (0.6 deg C warmer in summer, 0.6 deg C cooler in autumn compared to existing structures).

Green House Gas Emissions All action alternatives would have the same impact on hydropower production and, thus, the same social cost of carbon (Table 47). For this study we assume a 3% discount rate. Social cost of carbon values are published in 2007 values and were indexed to 2018 values using the gross domestic product (Chained) Price Index for this evaluation. Table 47. Summary of emissions and social cost of carbon (eGRID2016). ∆ ∆ Ozone ∆ Social Annual Season Sulfur Cost of ∆ CO2 ∆ CH4 ∆ N2O ∆ CO2e NOx NOx dioxide Carbon Energy (losses) All Action Alternatives (MWh) kT kT kT kT kT kT kT $

Construction Activities -352,781 -265.3 0.0 0.0 -266.8 -0.2 -0.2 -0.1 -$11,618

Operations 125,740 76.1 0.0 0.0 76.6 0.1 0.1 0.0 $3,335

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SECTION 4 - CUMULATIVE IMPACTS According to the CEQ’s regulations for implementing NEPA, an action may cause cumulative impacts on the environment if its effects overlap in space or time with the effects of other past, present, or reasonably foreseeable future actions, regardless of the agency, company, or person undertaking the action (40 C.F.R. §1508.7). Cumulative effects can result from individually minor but collectively significant actions taking place over a time. Cumulative effects are the incremental impacts upon a resource that result from the interaction of two or more individual actions, including a project action and a non-project action. Each type of cumulative effect must consider past, present, and reasonably foreseeable future actions (temporal component), and actions that may be separated by distance (spatial component) if there is the potential for incremental effects. Cumulative effects can occur when the effects of project related actions interact with non-project actions occurring in the same geographic area. The non-project effects may occur at differing temporal scopes than the project action, such as persisting effects from past actions, or effects that may result from reasonably foreseeable future actions. Non-project actions can include other federal, state, local government or private industry activities, or management and policy decisions relating to social or resource management. Non-project actions that may contribute cumulatively to the effects of the Project are listed in Appendix M. These policies, projects and actions are likely to interact with resources and project actions evaluated in this EIS and could create a cumulative effect upon a resource.

4.1 DEFINE THE GEOGRAPHIC BOUNDARIES AND TIMEFRAME FOR ANALYSIS The Corps has defined the spatial scope of analysis for cumulatively affected resources to be the physical limits or boundaries of: 1. the Project’s effects on the resources; and 2. the contributing effects from other activities within the North Santiam River watershed or the surrounding socioeconomic area. Because an alternative may affect some resources differently, the spatial scope of analysis for each of the resources may vary. The temporal scope of analysis for cumulative effects includes past, present, and future actions and their effects on each resource.

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Past Actions The CEQ issued a memorandum on June 24, 2005 regarding analysis of past actions. This memorandum states, “…agencies can conduct an adequate cumulative effects analysis by focusing on the current aggregate effects of past actions without delving into the historical details of individual past actions.” For the purpose of this analysis, past actions are those which occurred in the past, but which have lasting effects on one or more resources relevant to the proposed action. Thus, this section characterizes the existing conditions of the affected resources and discusses how the direct and indirect effects from implementing the proposed downstream passage project may contribute to lasting impacts from past actions. Those past actions under consideration in this analysis are identified in Appendix M.

Present Actions Present actions are those which are currently occurring and also result in impacts to the same resources as would be affected by the No Action Alternative or the proposed action. Those present actions under consideration in this analysis are identified in Appendix M.

Reasonably Foreseeable Future Actions While present and ongoing activities could continue for many years into the future, and could contribute to cumulative impacts, it is speculative to consider actions beyond what is reasonably foreseeable. The reasonably foreseeable nature of future actions promotes a forward-looking perspective, and the temporal boundary for this analysis has been established for 50 years. This timeframe captures the effects of future actions within the operational timeframe relevant to the downstream passage project and the continued operation and maintenance of the Detroit and Big Cliff dams and the Minto Fish Facility. Those reasonably foreseeable future actions under consideration in this analysis are identified in Appendix M. The consideration of a future action rests upon a level of certainty that it would occur. The certainty of a future project occurring in the project area is based upon a formal project proposal or application to the appropriate jurisdictional agency, approval of such a proposal or application, inclusion of the future action in a formal planning document, or other similar evidence, or through personal communication with an agency proposing work. In addition, a future action must be sufficiently defined in terms of location, scope, and design to allow for meaningful consideration in the cumulative effects analysis.

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4.2 RESOURCE-SPECIFIC CUMULATIVE IMPACTS

Resource Areas Dismissed from Cumulative Impact Analysis The cumulative effects analysis provided below evaluates the effects of implementing the No Action Alternative and Project alternatives in association with past, present, and the reasonably foreseeable future actions described in Appendix M, in and near the project area. The effects of past and present actions have resulted in the introduction and spread of non-native, invasive species; physical alterations to rivers, streams, lakes, wetlands, and floodplain habitats supporting fish and wildlife; degradation of water quality throughout the basin from increased pollutants, altered temperature regimes, and the widespread loss of ecosystem processes supporting water quality. Table 48 lists the resources that may experience direct adverse impacts from the Project alternatives but, because these would be short-term construction related impacts, when the impacts are considered alongside the past, present and reasonably foreseeable future actions they are considered cumulatively negligible as they are temporary and not contextually intense. The EIS does not discuss these resources in the cumulative impacts analysis because there would not be cumulative impacts associated with them. The remaining resource may have cumulative effects under one or more alternatives and are discussed in detail below.

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Table 48. Summary of resources included and excluded from cumulative effects analysis Resource Included Excluded*

Air quality x

Noise x

Geology, seismology, and soils x

Hydrology and hydraulics x

Sediment transport and turbidity x

Water quality x

Threatened and endangered species x

Wildlife x

Fish and aquatic species x

Adult fish facilities, hatcheries, and fisheries x

Vegetation x

Water supply x

Hydropower x

Transportation/circulation x

Aesthetic resources x

Cultural, archeological, and historic resources x

Recreation x

Socioeconomics x

Other social effects (OSE) x

Public health and safety x

Climate change x * impacts are considered negligible as they are temporary and not contextually intense when considered alongside the past, present and reasonably foreseeable future actions

Fish, and Aquatic Species including Threatened and Endangered Species A number of ongoing or planned actions would provide a cumulative, long-term improvement to fish, wildlife, and aquatic habitat, especially for ESA-listed salmonid species. These include the implementation of the RPA specified in the 2008 NMFS BiOp, implementation of the several restoration project on the North Santiam River downstream of Detroit and Big Cliff dams, and more stringent non-point source pollution standards such as TMDLs. Implementation of alternatives contained in the Willamette Valley System EIS may also have a cumulative, long-term effect on fish, wildlife, and aquatic habitat, especially for ESA-listed salmonid species. The purpose and need for the Willamette Valley System EIS is the continue operation and maintenance of the Corps’ WVS while meeting ESA obligations for listed species. The operations and maintenance of the existing Minto Fish Facility has had lasting impacts on adult ESA-listed fish populations. Together with other present and 4-320

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reasonably foreseeable future actions, the No Action Alternative would continue to have lasting impacts on these fish populations. The action alternatives would provide a long- term, cumulative improvement to passage efficiency and ESA-listed fish resources throughout the watershed. Any future federal actions would require additional evaluation under the NEPA at the time of their development. Past, present, and future USFS vegetation management projects overlap spatially with the project area, however, USFS buffered all streams and, therefore, these actions will have no cumulative effect on ESA-listed species. Future efforts to reintroduce of Pacific lamprey and ESA listed bull trout would benefit from downstream passage at Detroit Dam by providing connectivity to high quality habitat above Detroit Dam. The FSS will be designed to be lamprey and bull trout friendly. Increase habitat connectivity in the future will aid in population recovery of these species.

Water Quality A number of ongoing or planned actions in the watershed focus on improving water quality. These include operational or structural changes to the WVS under investigation by the Corps, and the implementation of more stringent non-point source pollution standards by the state e.g., the “Three Basin Rule” and TMDLs. These actions and stricter controls on foreseeable future projects would reduce short-term, adverse impacts and the Corps anticipates the actions will provide a long-term, cumulative benefit to water quality in the watershed. Forest management and transmission line activities may affect runoff. However, there are buffers around all streams, limiting stream water quality effect. Future development, construction activities, and other foreseeable future projects, in combination with population growth, would produce changes in the amount of impervious surfaces and associated runoff in the watershed. While future development could have localized negative impacts on these resources, even with the current regulatory regime, these resources are likely to suffer substantial cumulative losses. However, all projects, regardless of sponsor, are required to adhere to local, state, and federal stormwater control regulations and best management practices designed to limit surface water inputs. Future actions would add a negligible amount of impervious surfaces, in addition to other existing and anticipated construction activities, thereby minimizing future adverse effects to water quality. Past and present floodplain restoration projects, as well as future augmentation of sediment and wood, would have a beneficial cumulative effect on streamflow and flood storage processes (namely subsurface or hyporheic flow) which would contribute to improving water quality. Therefore, the combined effects from past, present, and reasonably foreseeable future actions, in combination with the No Action Alternative or the project alternatives described above, would have negligible adverse effects on water quality. Also, by

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improving water temperatures in the North Santiam River below Detroit Dam, the long term operation of the SWS under all action alternatives would have beneficial cumulative effects with other actions in the watershed to improve water quality.

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SECTION 5 - PREFERRED ALTERNATIVE

5.1 INFORMATION USED TO INFORM THE DECISION The screening criteria developed and applied during the alternatives formulation and screening process as documented in the COP and EDR reports (USACE 2015 and USACE 2017a, respectively; incorporated here by reference) was a major driver for the decision (see Sections 2.1 and 2.2 for details on the screening decision making process). The information resulting from the impacts assessment (See Section 3 for details) also drove the decision as the Corps strived to minimize the impacts of the Project to the human environment.

5.2 DESCRIPTION OF THE PREFERRED ALTERNATIVE Under the Corps’ Proposed Action, the Corps would construct the following to meet both the temperature control and the downstream passage elements of the purpose and need: Temperature control element: A SWS (also referred to as a temperature control tower) to control water temperature passing through Detroit Dam. The SWS would be an approximately 300-ft tall tower attached to the face of Detroit Dam. The SWS would have sliding HIWs and LIGs that would allow the Corps to mix warm surface water and at depth cool water so that dam releases meet temperature targets downstream. Downstream passage element: A FSS attached to the SWS to collect downstream migrating fish. The FSS would be a 300 x 100-ft (approximate) barge that screens downstream migrating fish from reservoir outflows, holding them for transport downstream. The Corps would connect the FSS to the SWS high intake wires and outflows would go through the FSS into the SWS and released downstream. The FSS would be able to float up and down the SWS over the full range of reservoir operational elevations prescribed by the Water Control Diagram. Fish collected in the FSS would be transported downstream using the trap-and–haul method with the option to integrate volitional passage in the future if it is determined to be feasible and meets project objectives. The Project would also include the continued operations of the existing Minto Adult Fish Collection Facility (Minto Fish Facility) to provide upstream fish passage. To construct the SWS and FSS, the Corps would not change the Detroit Reservoir elevations outside of the normal Water Control Diagram. This means that the Corps would construct the SWS entirely in the wet (under water with divers or from floating barges, as appropriate). The Corps would stage major construction activities on the Detroit Dam Road and at the Oregon State Parks Maintenance Yard.

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The Corps’ proposed action works within Detroit Dam’s authorized purposes, is a gravity fed system, and meets project objectives. The proposed action would meet the Corps’ purpose and need to provide a temperature control solution that is combinable with a downstream fish passage solution. The proposed temperature control facility would meet temperature targets developed optimized for adult and juvenile salmonids. The proposed downstream fish passage alternative would provide for a volitional swim- up facility, the ability to hold fish, and the capability for water-to-water transfer of fish from the FSS to a point of release in the river downstream of the dam. Once complete, the proposed action would improve the survival rate of juvenile UWR Chinook salmon and steelhead in their downstream migration to reach adulthood, as well as improve the survival of returning adult fish migrating up the North Santiam River and spawning upstream of Detroit Dam. While the project would result in a net benefit to fish in the long-term, there are short-term effects from construction that range from negligible to moderate.

5.3 SUMMARY OF THE PREFERRED ALTERNATIVES EFFECTS, INCLUDING CUMULATIVE ASSESSMENT The preferred alternative would have the lowest impact of all alternatives. Under the preferred alternative, there would be short-term, localized impacts to air quality, noise, sediment transport, turbidity, fish and wildlife, and vegetation. The Corps expects moderate impacts to resident fish and kokanee near underwater blasting. There would also be impacts to Detroit Dam as a potentially eligible contributing property in the Willamette Valley multiple property nomination and to any cultural resources that may exist within the SWS construction zone. The Corps would be required to perform a cultural resource inventory at the Oregon State Parks Maintenance Yard prior to project implementation. The Corps will consult with SHPO and affected tribes to ensure all construction/staging zones are inventoried. Any newly documented resources would be evaluated for listing in the National Register. Following construction of the SWS, the resulting temperature control operations would provide benefits to downstream fish and aquatic habitats. The Corps would meet temperature targets more frequently, allowing for more historical timing of fish emergence and upstream adult fish migration. More normative run timing of adults could get the pre-spawn fish to ideal holding habitats above the dam prior to them being exposed to the higher concentrations of hatchery fish and pathogens below Minto. This could have positive effects by reducing the frequency and intensity of pre-spawn mortality events. This would especially be the case for hot/dry years with low flow, similar to conditions experienced in 2015, where operational temperature control is limited or impossible due to the reservoir levels precluding the use of the surface spillways. Additionally, for marginal years, the Corps would not have to choose between meeting flow targets and maintaining a higher pool for operational temperature control. 5-324

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This new operational flexibility and ability to provide more idealized temperatures could become increasingly important under current climate trends. Additionally, the reach between Big Cliff and Mehama would be more suitable for the native resident fish and invertebrates, and could result in greater aquatic diversity at all trophic levels. The ability to meet downstream temperature targets would meet the primary purpose and need of the SWS construction. Following construction of the FSS, both upstream and downstream passage for migrating fish would be available. The cumulative benefit should meet the RPA measure 4.12.3 and 5.2 for downstream passage and temperature control for ESA-listed salmonids per the NMFS 2008 BiOp. These along with actions by others including restoration projects upstream and downstream of the dam would make long-term, cumulative improvement to passage efficiency and ESA- listed fish resources throughout the watershed.

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SECTION 6 - REVIEW AND CONSULTATION REQUIREMENTS

6.1 TRIBAL CONSULTATION Tribal consultation for this project began in November 2017. The Corps consulted with the Confederated Tribes of Grand Ronde, the Confederated Tribes of Siletz Indians, and the Confederated Tribes of Warm Springs. The Corps mailed the Tribes a consultation letter on November 17, 2017 that included information about the proposed project location and the purpose and need for the project. Additionally the consultation invited the Tribes to provide any comments or concerns regarding the proposed project or meet with project team members to discuss the project in more detail. The Confederated Tribes of Grand Ronde requested and held a meeting at the Confederated Tribes of Grand Ronde Tribal Governance Building on January 9, 2018. The Corps presented information about the proposed project location, the alternatives, and the purpose and need for the project. The Tribal members and staff present at the meeting expressed support for the project, a willingness to provide assistance and information if needed and emphasized continued communication with them as the project progressed. On February 5, 2018, the Corps hosted a field trip to the project site with representatives from the Confederated Tribes of Grand Ronde. On February 21, 2019, the Corps met with the Confederate Tribes of Warm Springs. The Corps presented information about the proposed project location, the alternatives, and the purpose and need for the project.

6.2 CONSULTATION WITH FEDERAL, STATE, AND LOCAL AGENCIES

National Marine Fisheries Service and U.S. Fish and Wildlife Service The Corps sent a letter to NMFS and USFWS on December 07, 2017 offering them the opportunity to be Cooperating Agencies in preparation of an EIS. The Corps received a letter from the NMFS on June 19, 2018 and from USFWS on January 25, 2018 acknowledging the Corps as the lead agency on the project and accepting the invitation to be a Cooperating Agency in preparation of an EIS. Additionally, the Corps and both agencies along with the BPA and the ODFW are a part of the WATER and the Willamette Fish Facility Design Working Group (WFFDWG). The purpose of WATER and WFFDWG is to provide a forum for coordination and recommendations among the participating members (federal/state/tribal) working to implement strategies for ESA compliance associated with the 2008 BiOp. These groups meet monthly.

Bonneville Power Administration The Corps sent a letter to BPA on December 07, 2017 offering BPA the opportunity to be a Cooperating Agency in preparation of an EIS. The Corps received an email from the BPA on July 09, 2018 declining the invitation for BPA to be a Cooperating Agency.

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Additionally, the Corps and BPA along with the NMFS, USFWS, and ODFW are a part of WATER and WFFDWG. The purpose of WATER and WFFDWG is to provide a forum for coordination and recommendations among the participating members (federal/state/tribal) working to implement strategies for ESA compliance associated with the 2008 BiOp. These groups meet monthly.

U.S. Forest Service The Corps sent a letter to the USFS on December 07, 2017 offering the USFS the opportunity to be a Cooperating Agency in preparation of an EIS. The Corps received a letter from the USFS on April 6, 2018 acknowledging the Corps as the lead agency on the project and declining the invitation for USFS to be a Cooperating Agency in preparation of an EIS. The Corps met with the Detroit District Ranger and staff on November 30, 2017, April 24, 2018, and May 9, 2018 to provide USFS with updates on the EIS development. The District Ranger and staff offered to assist with traffic, wildlife, recreation, and cultural data to assist with the environmental effects analysis for the Project EIS.

Oregon Department of Fish and Wildlife The Corps sent a letter to ODFW on December 07, 2017 offering ODFW the opportunity to be a Cooperating Agency in preparation of an EIS. The Corps received a letter from the ODFW on June 21, 2018 acknowledging the Corps as the lead agency on the project and accepting the invitation for ODFW to be a Cooperating Agency in preparation of an EIS. Additionally, the Corps and ODFW along with the NMFS, USFWS, and BPA are a part of WATER and WFFDWG. The purpose of WATER and WFFDWG is to provide a forum for coordination and recommendations among the participating members (federal/state/tribal) working to implement strategies for ESA compliance associated with the 2008 BiOp. These groups meet monthly.

Oregon Water Resources Department The OWRD representatives attended the water supplier meeting hosted by the City of Salem’s Public Works Departments on February 13, 2018 at which the Corps presented on the current status of the Project and requested information on water supply operations in the basin. On May 11, 2018, the Corps met with OWRD and the City of Salem’s Public Works Department to further discuss the Project’s potential impacts on water supply in the North Santiam basin, how OWRD would regulate water rights under the various alternatives being assessed, and what data OWRD could provide for use in the impacts assessment.

Oregon State Historic Preservation Office Consultation with the Oregon SHPO is underway.

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Oregon Department of Environmental Quality On May 9, 2018, the Corps communicated with representatives from ODEQ, explaining the project purpose, proposed alternatives, and potential impacts. The ODEQ representatives offered to provide input on proposed best management practices to address any water quality impacts.

Oregon Parks and Recreation Department The Corps communicated with OPRD staff on several occasions throughout 2018 to update them on the status of the Project and request data on recreation users in the basin. OPRD staff also provided the Corps with a tour of potential staging sites around Detroit Reservoir, including the State Parks Maintenance Yard.

Santiam Water Control District and Sydney Irrigation Cooperative The SWCD and SIC representatives attended the water supplier meeting hosted by the City of Salem’s Public Works Department on February 13, 2018 at which the Corps presented on the current status of the Project and requested information on water supply operations in the basin. Additionally, the Corps met with both Districts on June 7, 2018 to provide an overview of the project alternatives being assessed at the time and to discuss possible impacts to the Districts’ operations. The Districts’ representatives offered to provide existing data for their water supply and hydropower operations to assist in the impacts analysis.

Counties On November 9, 2017, the Corps met with Marion County Commissioners and representatives of Detroit Reservoir recreation stakeholders to discuss Project developments at that time. County representatives met Corps staff on several occasions throughout 2018 to discuss the Project, including several meetings requested by U.S. Congressman Schrader’s staff. At these meetings, the Corps updated the attendees on the status of the Project at the time and listened to attendees concerns.

Cities On February 13, 2018, the City of Salem’s Public Works Departments hosted a meeting for water suppliers in the North Santiam basin at which the Corps presented on the current status of the Project and requested information on water supply operations in the basin. On May 11, 2018, the Corps met with City of Salem’s Public Works Department and OWRD to further discuss the Project’s potential impacts on water supply in the North Santiam basin, how Salem would operate their water supply facilities under the various alternatives being assessed, and what data Salem could provide for use in the impacts assessment. Salem staff provided a tour of their facilities following the meeting. The Corps also attended the City of Salem’s water supply public policy

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meeting on August 7, 2018 and answered questions about the status of the Project at that time. City of Salem staff also attended a boating trip down the North Santiam below Detroit Dam hosted by the Corps to see conditions in the area, including the Salem water supply intake and the Bennett Dam and discuss the potential impacts of the various Project alternatives on habitat and City of Salem water supply operations. On June 18, 2018, the Corps met with staff from the City of Stayton to discuss the Project’s potential impact on water supply in the North Santiam basin, how the City of Stayton would operate their water supply facilities under the various project alternatives, and what data Stayton could provide for use in the impacts assessment. Stayton staff provided a tour of their facilities following the meeting. On June 28, 2018, the Corps similarly met with staff from the City of Turner (by phone) and the City of Gates. Staff from the City of Gates provided a tour of their water supply facilities.

6.3 PUBLIC ENGAGEMENT During the initial phase of alternatives development, to fulfill the requirements of the NEPA, the Corps proceeded with an EA. An EA concludes with one of two decision documents, either a Finding of No Significant Impact or the Notice of Intent to Prepare an EIS. Although it is required to provide the public with the opportunity to review and comment on a Draft EA, public scoping at the start of an EA’s development is not required. However, at the completion of the EDR (USACE 2017) in 2017, it became clear that there would be potentially significant impacts associated with many of the alternatives under consideration. With this understanding, rather than completing the EA with a Notice of Intent to Prepare an EIS, the Corps made the decision to proceed directly with the preparation of an EIS. This triggered the implementation of public scoping. As a result, many alternatives had already been considered and screened out prior to the beginning the EIS, as summarized above. Public scoping for the Project began on November 24, 2017 when the Federal Register published the Corps’ Notice of Intent to prepare an EIS. The Notice of Intent included notice that the Corps would be holding two public scoping meetings and the public scoping included a 45-day comment period. Following the public open house style scoping meeting, the Corps was asked to extend the scoping period. The Corps extended the scoping comment period for an additional fifteen days and held an additional public scoping meeting. The public scoping meetings were well all attended and during the 60-day comment period, a total of 198 comments were received from individuals and groups, including federal and state agencies, city and county governments, and non-governmental organizations. Topics present in the submissions included, but were not limited to, opinions on potential alternatives for meeting the project purpose and concerns over the projects impacts on water supply, the local economy, recreation, agricultural, reservoir fisheries, and environmental justice. ping included three public meetings held in December 2017 and January 2018. 6-329

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In addition to the NEPA Scoping comment period, North Santiam stakeholders had a variety of opportunities to gain awareness of the Corps’ efforts to improve survival of ESA-listed fish species prior to the initiation of public scoping. In 2010, the Corps conducted a series of public informational meetings in the basin to explain the newly released 2008 BiOp and how it could affect Corps dams within the basin. In 2013, the Corps held another series of public informational meetings in Salem and Mill City, to share what had been developed for temperature control and downstream passage for Detroit at that time. Those public informational meetings also included presentations at the North Santiam Watershed Council and the Detroit City Council meeting. Most recently, the Corps has participated in a number of media events, public meetings, and regular briefings with specific stakeholder groups. Following scoping, the Corps attended over 20 meetings with interested stakeholder groups. In August 2018, the Corps hosted three public meetings to brief the public on the alternative formulation and screening process and the alternatives that are assessed in detail in the EIS. As of May24, 2019, the draft EIS is being issued for a 60-day public review period. The Draft EIS is available for review on the Portland District’s website26. The Corps is requesting review comments from federal and state agencies, as well as various interested parties. In anticipation of the release of the Draft EIS for public review, the Corps plans to hold several public meetings to provide an overview of the EIS and inform participants on how they can access the draft EIS for their review and how they can provide their comments. The Corps will consider all received correspondence and comments. The Corps has sent out the Public Notice of Availability for the release of the Draft EIS for public review to interested persons, agencies, and groups, including, but not limited to those parties shown below: National Marine Fisheries Service U.S. Environmental Protection Agency U.S. Fish and Wildlife Service U.S. Forest Service Bonneville Power Administration Bureau of Land Management Confederated Tribes of the Warm Springs Reservation of Oregon Confederated Tribes of Siletz Indians Confederated Tribes of the Grand Ronde Community of Oregon

26 http://www.nwp.usace.army.mil/Willamette/Detroit-fish-passage/ 6-330

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Oregon Department of Environmental Quality Oregon Department of Land Conservation and Development Oregon Department of State Lands Oregon Department of Transportation Oregon Department of Fish and Wildlife Oregon Department of Forestry Oregon State Historic Preservation Office Oregon State Parks Department Oregon State Marine Board Oregon Water Resources Department District 17 State Representative Marion County Linn County City of Salem City of Stayton City of Lyons City of Jefferson City of Turner City of Mill City City of Gates City of Detroit Santiam Water Control District Sydney Irrigation Cooperative The project would be implemented in two phases. The first phase would be to construct the selected alternative for water temperature control at Detroit Dam. The second phase of project implementation would be to construct the selected alternative for downstream passage. A phased approach is being pursued in order to incorporate lessons learned from other downstream passage projects that have been constructed and operated in the region, including the Corps’ Cougar Dam Downstream Fish Passage Project. The Corps would continue to perform public outreach during the development of plans and specifications and during project implementation to keep interested stakeholders updated on project developments. Figure 67 summarizes the project and outreach activities timeline.

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Figure 67. Project Timeline

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Draft EIS Comments To be completed following the Draft EIS public comment period.

Response to Comments To be completed following the Draft EIS public comment period.

List of Commenters To be completed following the Draft EIS public comment period.

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SECTION 7 - COMPLIANCE WITH APPLICABLE FEDERAL ENVIRONMENTAL LAWS AND REGULATIONS This section presents and analyzes the federal statutes, implementing regulations, and Executive Orders that are potentially applicable to the proposed action. The Corps would ensure that the proposed action complies with applicable federal laws, regulations, and Executive Orders. Major environmental compliance regulations and status of compliance are summarized in Table 49 below. Table 49. Other Applicable Laws Law Status of Compliance This EIS has been prepared in compliance with CEQ Regulations for National Environmental Policy Act Implementing the Procedural Provisions of the NEPA (40 C.F.R. §§ (NEPA) of 1969 (42 U.S.C. §§ 4321– 1500–1508), and the Corps’ planning regulations. All agency and public 4347) comments would be considered and evaluated. The proposed action would take place in an attainment or unclassified Clean Air Act, as amended (42 U.S.C. §§ (i.e. in compliance) area for all state and federal air quality standards. 7401–7671q) Air emissions from the proposed action would be localized, temporary and minimal and is, therefore, in compliance with the Clean Air Act. Pursuant to Section 401 of the CWA (33 U.S.C. § 1341), the proposed action requires an individual 401 Certification from the ODEQ to ensure the project meets state water quality standards. The Corps has coordinated with ODEQ and would request a 401 certification for the proposed action during the Plans and Specifications phase of the project.

Section 404 of the CWA (33 U.S.C. § 1344) regulates the discharge of dredge or fill material into Waters of the United States and within the lateral extent of wetlands adjacent to such waters. Pursuant to Section 404, the Corps has determined that the proposed action would result in the discharge of fill dredge or fill material into Waters of the United States and, therefore, a 404(b)(1) analysis would be completed. Clean Water Act, as amended (33 U.S.C.

§§ 12511388) Section 402 of the CWA (33 U.S.C. § 1342) addresses the NPDES permit program. ODEQ administers the NPDES program applicable to federal activities in Oregon. NPDES Construction General Permit No. 1200-C regulates stormwater runoff to surface waters from construction activities that disturb one or more acres in Oregon. Temporary impacts to water quality should be avoided and minimized during the project’s construction and staging. The Corps would obtain any necessary NPDES permits and develop required monitoring plans to reduce construction-related erosion and run off prior to construction. Point source discharges for the facility operation is not expected. If final plans and specifications result in point source discharges, the facility would need to be covered under an NPDES permit issued by the ODEQ. Wild and Scenic Rivers Act (16 U.S.C. § The proposed action would not occur in or near a Wild and Scenic 1271) designated river. This statue is not applicable.

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Law Status of Compliance Under this Executive Order, federal agencies shall take action to minimize the destruction, loss or degradation of wetlands, and to Executive Order 11990, Protection of preserve and enhance the natural and beneficial values of wetlands. Wetlands, (42 Fed. Reg. 26961, 1977) The proposed action would not result in destruction, loss, or degradation of wetlands and is therefore in compliance with Executive Order 11990. The Corps has determined that there would be no impacts to Migratory Bird Treaty Act (16 U.S.C. §§ migratory birds (see Section 3.7.3) from the proposed action and, 703-711) therefore, this proposed actions are in compliance with this act. This Act provides for the protection of bald and golden eagles by prohibiting the taking, possession and commerce of such birds, except under certain specified conditions. Projects involving forestry practices, use of aircraft (or other motorized equipment), blasting and other work may result in loud or intermittent noises if they occur within 1000-ft of an active or alternate nest time during the breeding season (January 1 through August 15) and could disrupt breeding Bald and Golden Eagle Protection Act of activity. 1940, 16 U.S.C. §§ 668 et seq.

USFWS, National Bald Eagle Management Guidelines (May 2007) and the Corps eGIS Information Portal were aids in evaluating project impacts to bald eagles and known nest locations. There are no active nests within 1000 ft of work proposed under the proposed action. For this reason, the proposed action would not disturb bald or golden eagles and therefore complies with this Act. Coastal Zone Management Act of 1972 The proposed action would not occur in or near coastal waters. This (16 U.S.C. § 1451) statue is not applicable. National Marine Sanctuaries Act (16 U.S.C. §§ 1431, et seq.) The proposed action does not fall within a marine protected area or Marine Protection Research and marine sanctuary. These statues are not applicable. Sanctuaries Act of 1972 (33 U.S.C. §§ 1401, et seq.) The Corps has determined that there would be no impacts to marine Marine Mammal Protection Act (16 mammals from the proposed action and, therefore, this proposed U.S.C. §§ 1361–1421h) actions are in compliance with this Act. Relevant fish resources pertinent to the project area, based on Oregon coastal fishery resources, include UWR Chinook salmon. Accordingly, the North Santiam and Santiam rivers are designated as Essential Fish Habitat (EFH) for UWR Chinook salmon and steelhead, as they provide waters and substrate necessary for spawning, breeding, feeding, and Magnuson-Stevens Fishery growth to maturity. Conservation and Management Act - Fishery Conservation Amendments of The NMFS 2008 BiOp provided conservation recommendations to 1996, (16 U.S.C. §§ 1801–1883) – avoid and reduce adverse effects to EFH (blocking habitat, modifying Essential Fish Habitat (EFH) flows, and degrading water quality). Pursuant to the adoption and implementation of the RPA, the adverse effects to EFH would be minimized. The proposed action is proposed as a method to alleviate fish passage and water quality issues and conserve EFH at Detroit Dam and to improve passage. As a result, the proposed action meets the RPA and is, therefore, in compliance with this Act.

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Law Status of Compliance In accordance with Section 7(a)(2) of the ESA of 1973, as amended, federally funded, constructed, permitted, or licensed projects must take into consideration impacts to federally listed or proposed threatened or endangered species. Information on federally listed fish and wildlife species and designated critical habitat is presented in this EIS (see Section 3.8).

The Corp will submit a Biological Assessment to initiate formal ESA Section 7 consultation with NMFS. The Corps has determined that the Project May Affect, is Likely to Adversely Affect UWR Chinook salmon, Endangered Species Act as amended UWR steelhead, and their designated Critical Habitat due to short- (16 U.S.C. §§ 1531–1544) term impacts during implementation, but is not likely to jeopardize the species or adversely modify Critical Habitat in the long-term. The 2008 USFWS BiOp for bull trout and chub addresses effects to these species as a result of the proposed action (USFWS 2008b).

The Corps coordinated early with USFWS regarding potential effects on other listed species under the jurisdiction. A “no effect” determination was made for northern spotted owl and red tree vole and their critical habitat for construction activities associated with the proposed action based on the lack of presence in the project area and timing of specific project elements (See Section 3.8). The proposed action would not impound, divert, channel deepen, or otherwise control or modify a body of water. These statues are not Fish and Wildlife Coordination Act (16 applicable. However, the project team did informally coordinate with U.S.C. § 661 et seq.) the USFWS and NMFS on applicability of FWCA and they concurred with the Corps’ determination. These agencies were provided the opportunity to review and comment on the EIS. This Act requires that federal agencies evaluate the effects of federal undertakings on historical, archeological, and cultural resources, and afford the Advisory Council on Historic Preservation the opportunities to comment on the proposed undertaking. The Corps, in coordination National Historic Preservation Act (54 with the SHPO and Native American tribes, is identifying cultural U.S.C. § 306108): Protection of Historic resources and sites in the project areas for inclusion on the National Properties Register. The Corps intends to meet Section 106 compliance requirements through entering into a programmatic agreement that will include a phased approach to identification, evaluation, and resolution of adverse effects (36 C.F.R 800.4 and 800.6). Executive Order 11593: Protection and Enhancement of the Cultural See previous entry. Environment This Act addresses the recovery, treatment, and repatriation of Native American and Native Hawaiian human remains and cultural items (associated funerary objects, unassociated funerary objects, sacred Native American Graves Protection and objects, and objects of cultural patrimony). The implementation of any Repatriation Act (25 U.S.C. §§ 3001- drawdown measure could result in the exposure of Native American 3013) human remains and cultural items. In the event this should happen, the appropriate tribe(s) and lineal descendants would be notified and the necessary actions taken to protect the burials as prescribed by law.

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Law Status of Compliance This Act provides for the protection of cultural properties located on public and Native American lands; establishes permit requirements for the excavation or removal of cultural properties from public or Native American lands; and establishes civil and criminal penalties for the Archaeological Resources Protection unauthorized appropriation, alteration, exchange, or other handling of Act (16 U.S.C. §§ 470aa-470mm) cultural properties. Reservoir drawdown to elevation 1,450 ft or below could result in new or increased exposure of cultural sites, and potentially lead to vandalism. Appropriate monitoring methods would be developed to prevent or minimize vandalism. Comprehensive Environmental These two acts pertain to hazardous and toxic materials. Pre- Response, Compensation, and Liability construction site investigation indicates HTRW is not expected to be a Act (CERCLA) (42 U.S.C. §§ 9601–9675) problem. Should this situation change during construction, the and the Resource Conservation presence of HTRW would be responded to within the requirements of Recovery Act (RCRA) (42 U.S.C. §§ the law (including notifying the EPA), Corps regulations, and guidance. 6901–6992k). The proposed action would not result in the conversion of any prime, Farmland Protection Policy Act (7 U.S.C. unique state or locally important farmland to non-agricultural uses. §§ 4201-4209) This Act is not applicable. Abandoned Shipwreck Act of 1987, (43 No abandoned shipwrecks as none are known to occur within the U.S.C. §§ 2101-2106) proposed action areas. This Act is not applicable. Submerged Lands Act, (43 U.S.C. §§ No lands covered by the Submerged Lands Act occur within the project 1301, et seq.) area. This Act is not applicable.

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Law Status of Compliance This EO requires a Federal agency, when taking an action, to avoid short and long term adverse effects associated with the occupancy and the modification of a floodplain. The agency must avoid direct and indirect support of floodplain development whenever floodplain siting is involved. In addition, the agency must minimize potential harm to or in the floodplain and explain why the action is proposed. Additional floodplain management guidelines for EO 11988 were also provided in 1978 by the Water Resources Council. Corps implementation guidance in Engineering Regulation (ER) 1165-2-26 (March 30, 1984), states the following in Paragraph 6:

“EO 11988 has as an objective the avoidance, to the extent possible, of long-and short-term adverse impacts associated with the occupancy and modification of the base floodplain and the avoidance of direct and indirect support of development in the base flood plain wherever there is a practicable alternative. Under the Order, the Corps is required to provide leadership and take action to: • Avoid development in the base flood plain unless it is the only practicable alternative; • Reduce the hazard and risk associated with floods; • Minimize the impact of floods on human safety, health and welfare; and • Restore and preserve the natural and beneficial values of the base floodplain.”

Executive Order 11988: Floodplain General procedures to implement Executive Order 11988 include eight Management steps as outlined and evaluated for this Study. 1. Determine if the proposed action is in the base floodplain (1% ACE): the proposed action is within the base floodplain. 2. If the action is in the floodplain, identify and evaluate practicable alternatives to locating in the base floodplain: the project is assessing alternatives for to provide downstream passage and temperature control for ESA listed UWR spring Chinook and steelhead. There are no practicable alternatives to locating fish collection and temperature control activities outside the base floodplain. 3. Provide public review: the public has been advised of the proposed action and the Corps has requested their comments on the recommended plan. 4. Identify the impacts of the proposed action and any expected losses of natural and beneficial floodplain values: The proposed alternative would not change the base floodplain elevation and would not result in losses of natural and beneficial floodplain values. 5. Minimize threats to life and property and to natural and beneficial floodplain values. Restore and preserve natural and beneficial floodplain values: the proposed action is not likely to induce development in the floodplain. 6. Reevaluate alternatives: no alternatives considered are likely to induce development in the floodplain .

Issue findings and a public explanation: to be completed after public review

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Law Status of Compliance This EO requires a Federal agency, when taking an action, to provide for the meaningful public involvement by minority and low-income populations. All construction, operation and maintenance activities for the proposed action and alternatives would be on Federal lands. All activities and any potential release of contaminants or regulated substances which could adversely affect the environment would remain on Federal lands or would be contained within the navigable waters of the U.S. A review of the demographics within the bounds of the areas potentially affected (Detroit Reservoir downstream to the confluence of the Santiam and Willamette rivers) by future activities does not reveal any potential demographic who may be unduly affected by a potential negative environmental consequence as a Executive Order 12898: “Environmental result of Corps operations or policies. Justice for Low Income & Minority

Populations” After a thorough review of the area potentially affected by the proposed action, no group of people appears to bear a disproportionate share of the potential negative environmental consequences resulting from actions or negligence of a Federal employee, its contractor(s), or agent(s). Public involvement would be provided by a public review of the EIS, through the 60 day public review period. Should a particular demographic be identified to potentially be adversely effected by future Government actions, the review period would immediately stop and renewed planning efforts would commence until an appropriate alternative is in place to avoid or completely ameliorate any environmental consequence that disproportionally affects any one demographic group. Under this Executive Order, federal agencies shall make it a high priority to identify and assess environmental health risks and safety risks that may disproportionately affect children; and shall ensure that Executive Order 13045: Protection of its policies, programs, activities, and standards address Children from Environmental Health disproportionate risks to children that result from environmental Risks and Safety Risks health risks or safety risks. The project would not result in environmental health risks and safety risks that may disproportionately affect children and is therefore in compliance with this Executive Order.

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SECTION 8 - LIST OF PRINCIPLE PREPARERS Name and Title Contributing Sections Kelly Janes, Environmental Resource Specialist Primary Author Kristina Fortuny, Structural Engineer and Design Section 2 Technical Lead Jeff Sedey, Cost Engineer Section 2 Nathan Stormzand, Civil Engineer Section 2 David Scofield, Geotechnical Engineer Sub-section 3.12 Norman Buccola, Hydraulic Engineer Sub-sections 3.14 & 3.20 Jennifer Gervais, Hydraulic Engineer Sub-sections 3.13 & 3.22 Ricardo Walker, Fish Biologist Sub-sections 3.17, 3.18, 3.19, & 3.20 Jon Rerecich, Fish Biologist Sub-sections 3.17, 3.18, 3.19, & 3.20 Andrew Traylor, Fish Biologist Sub-sections 3.19 Garrett Dorsey, Wildlife Biologist Sub-sections 3.15 & 3.16 Kathryn Warner, Environmental Engineer Sub-sections 3.21 Russell Davidson, Civil Engineer Hydropower Sub-sections 3.22 Specialist Molly Casperson, Archeologist Sub-sections 3.25 Louis Landre, Economist Sub-sections 3.26 & 3.27 Jessie Mizic, Social Scientist Sub-sections 3.26 & 3.27

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SECTION 9 - REFERENCES CITED AMEC Geomatrix and Quest Structures. (2009). Regional Seismic Hazard Assessment: Willamette Valley in the Pacific Northwest Region: Report prepared for U.S. Army Corps of Engineers, Headquarters, 24 February 2009. Anderson, H.W., Suspended-sediment discharge as related to stream-flow, topography, soil and land use; America Geophysical Union Transactions, v.35, no. 2 p. 268-281 Andersen, E. (2009). Santiam basin fish passage barriers. Map file downloaded 1/9/2019 from http://www.sswc.org/what-we-do/monitoring/santiam-basin-fish-passage- barrier-inventory/. Bangs, B.L. and M. H. Meeuwig. (2018). 2017 Oregon Chub Investigations. Salem, Oregon. Banks, J.W. (1969). A review of the literature on the upstream migration of adult salmonids. Journal of Fish Biology 1:85-136. Beeman, J.W., and Adams, N.S., eds. (2015). In-reservoir behavior, dam passage, and downstream migration of juvenile Chinook salmon and juvenile steelhead from Detroit Reservoir and Dam to Portland, Oregon, February 2013–February 2014: U.S. Geological Survey Open-File Report 2015-1090, 92 p., http://dx.doi.org/10.3133/ofr20151090. Bell, M. C. (1990). Fisheries handbook of engineering requirements and biological criteria. U.S. Army Corps of Engineers. Portland, Oregon. Benton Soil and Water Conservation District. (2017). 2016 Water Quality and Ludwigia Monitoring Report for Stewart Slough, Collins Bay, and Scatter Bar Pond. Corvallis, OR: Mosaic Ecology, LLC BLMS (Bureau of Land Management, Salem District). (1998). Little North Santiam River watershed analysis. Bureau of Land Management, Salem District, Oregon. Bragg, Heather M., S. Sobieszczyk, M.A. Uhrich, and D.R. Piatt. (2007). Suspended- Sediment Loads and Yields in the North Santiam River Basin, Oregon, Water Years 1999–2004, Scientific Investigation Report 2007-5187, U.S. Department of the Interior, U.S. Geological Survey, Reston, Virginia. Buccola, N. L., Rounds, S. A., Sullivan, A. B., & Risley, J. C. (2012). Simulating potential structural and operational changes for Detroit Dam on the North Santiam River, Oregon, for downstream temperature management. U.S. Department of the Interior, U.S. Geological Survey. 68 p. Buccola, N. L., Risley, J. C., & Rounds, S. A. (2016). Simulating future water temperatures in the North Santiam River, Oregon. Journal of Hydrology, 535, 318- 330. ISSN 0022-1694, https://doi.org/10.1016/j.jhydrol.2016.01.062. 9-341

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Bury, R.B. 1975. Population ecology of freshwater turtles. In: Harless M, Murdock H, editors. Turtles: Perspectives and research. New York, NY: John Wiley and Sons. p 571-602. Church, D.R., L.L. Bailey, H.M. Wilbur, W.L. Kendall, and J.E. Hines. (2007). Iteroparity in the variable environment of the salamander Ambystoma tigrinum. Ecology 88(4): 891-903. Climate Impacts Group. 2010. Final Report for the Columbia Basin Climate Change Scenarios Project. University of Washington. Online at: http://warm.atmos.washington.edu/2860/report/ CRITFC (Columbia River Inter-Tribal Fish Commission). (2011). Tribal Pacific Lamprey Restoration Plan for the Columbia River Basin. Portland, Oregon. 195 pp Dahl, J., J. Dannewitz, L. Karlsson, E. Petersson, A. Löf, and B. Ragnarsson. (2004). The timing of spawning migration: implications of environmental variation, life history, and sex. Canadian Journal of Zoology 82:1864-1870. Dalton, M.M, K.D. Dello, L. Hawkins, and P.W. Mote (2017) The Third Oregon Climate Assessment Report, Oregon Climate Change Research Institute, College of Earth, Ocean and Atmospheric Sciences, Oregon State University, Corvallis, OR. Delaney, D.K., T.G. Grubb, P. Beier, L.L. Pater, and M.H. Reiser. (1999). Effects of helicopter noise on Mexican spotted owls. Journal of Wildlife Management 63(1): 60- 76. Delaney, D.K., and T.G. Grubb. (2003). Effects of off-highway vehicles on northern spotted owls: 2002 Results. A report to the State of California Department of Parks and Recreation, Off-Highway Motor Vehicle Recreation Division under Contract No. 439129-0-0055. USDA Rocky Mountain Research Station, May 2003. 38 pp. Dewey, James W., Reagor, B. Glen, Johnson, Dennis, Choy, George L., and Baldwin, Frank. (1994). The Scotts Mills, Oregon, Earthquake of March 25, 1993: Intensities, Strong Motion Data, and Teleseismic Data. U.S. Geological Survey Open-File Report 94-163 Duncan, J.P. and T.J. Carlson. 2011. Characterization of Fish Passage Conditions through a Francis Turbine, Spillway, and Regulating Outlet at Detroit Dam, Oregon, Using Sensor Fish, 2009. PNNL- 20365, Pacific Northwest National Laboratory, Richland, WA. Environmental Protection Agency (EPA). (1989). Federal Manual for Identifying and Delineating Jurisdictional Wetlands: An Interagency Cooperative Publication

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Falcy M. (2017). Population viability of Willamette River winter steelhead: an assessment of the effect of sea lions at Willamette Falls. Oregon Department of Fish and Wildlife Ford, M.J. (Ed.), T. Cooney, P. McElhany, N. Sands, L. Weitkamp, J. Hard, M. McClure, R. Kope, J. Myers, A. Albaugh, K. Barnas, D. Teel, P. Moran and J. Cowen. (2011). Status Review Update for Pacific Salmon and Steelhead Listed Under the Endangered Species Act: Pacific Northwest. U.S. Department of Commerce, NOAA Technical Memorandum NOAA-TM-NWFSC-113. November 2011. Forsman, E.D., E.C. Meslow, and H.M. Wight. (1984). Distribution and biology of the spotted owl in Oregon. Wildlife Monographs 87: 1-64. Fox A. and W. Haller. (2000). Influence of water depth on the rate of expansion of giant cutgrass populations and management implications. Journal of Plant Management. 38:17-25. Gagner, M. R., C. Huang, T. J. Sullivan, D. W. Reiser, and T. L. Nightengale. (2014). Evaluation of Habitat-Flow Relationships for Spring Chinook and Winter Steelhead in the North and South Santiam Rivers, Oregon. R2 Resource Consultant, Inc. Redmond, Washington 98052. Goldfinger, et al. (2012). Turbidite Event History – Methods and Implications of Holocene Paleoseismicity of the Cascadia Subduction Zone: U.S. Geological Survey Professional Paper 1661-F. GSI Water Solutions Inc. (GIS). (2014). Water Management Conservation Plan. Prepared for City of Salem, OR. GIS. (2019). Water Management Conservation Plan. Prepared for City of Salem, OR. Hannum, Michelle, Jonathan Damp, Mary Keith, and Mary Sutherland. (2017). Detroit Reservoir Archaeological Inventory, Linn and Marion Counties, Oregon. Report by Harris Environmental for Army Corps, Northwest Portland District. Oregon SHPO Report #28514. Hansen, A.C., T. J. Kock, and G. S. Hansen. (2017). Synthesis of downstream fish passage information at projects owned by the U.S. Army Corps of Engineers in the Willamette River Basin, Oregon: U.S. Geological Survey Open File Report 2017- 1101, 118 p., https://doi.org/10.3333/ofr20171101. Herron, C. L., Kent, M.L. and Schreck, C.B. (2017 accepted). Swimming endurance in juvenile Chinook Salmon (Oncorhynchus tshwaytscha) infected with Salmincola californiensis. J Aquat Anim Health. Accepted Author Manuscript. doi:10.1002/aah.10010.

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Hudson, M. J. (2017). Willamette river management: bull trout recovery action implementation, monitoring and evaluation, and Pacific lamprey passage assessment FY 16 progress report. U. S. Fish and Wildlife Service Vancouver, Washington, 98683. Jaeger, W., A.J. Plantinga, C. Langpap, D. Bigelow, and K. Moore. 2017. Water, Economics, and Climate Change in the Willamette Basin, Oregon. EM 9157. Oregon State University Extension Service. Kaylor, M.J., VerWey, B.J., Cortes, A., and Warren, D.R. (2019). Drought impacts to trout and salamanders in cool, forested headwater ecosystems in the western Cascade Mountains, OR. Hydrobiologia 833: 65-80 Keefer, M.L., C.A. Peery, and C.C. Caudill. (2008). Migration Timing of Columbia River Spring Chinook Salmon: Effects of Temperature, River Discharge, and Ocean Environment. Transactions of the American Fisheries Society 137:1120-1133. Keevin, T.M and Hempen, G.L. (1997). The environmental effects of underwater explosions with methods to mitigate impacts. St. Louis, Missouri. U.S. Army Corps of Engineers, St. Louis District. Khan F., I.M. Royer, G.E. Johnson, and K.D. Ham. (2012). Hydroacoustic Evaluation of Juvenile Salmonid Passage and Distribution at Detroit Dam, 2011. PNNL-21577. Pacific Northwest National Laboratory Richland, Washington 99352. Prepared for U.S. Army Corps of Engineers, Portland District Under an Interagency Agreement with the U.S. Department of Energy Contract DE-AC05-76RL01830. Kock, T.J., Beeman, J.W., Hansen, A.C., Hansel, H.C., Hansen, G.S., Hatton, T.W., Kofoot, E.E., Sholtis, M.D., and Sprando, J.M. (2015). Behavior, passage, and downstream migration of juvenile Chinook salmon from Detroit Reservoir to Portland, Oregon, 2014-15: U.S. Geological Survey Open-File Report 2015-1220, 30 p. Lan Y., Cui B., Li X., Han Z., and W. Dong. (2010). The determinants and control measures of the expansion of aquatic macrophytes in wetlands. Procedia Environmental Sciences. 2: 1643-1651. Larson, D.W. (2000). Willamette Reservoirs Oregon: Detroit, Big Cliff, Green Peter, Foster, Blue River, Cougar Limnological and Water Quality Studies 1950-2000: Final Report, Portland State University, September, 2000. Lewis, J. A. (1996). Effects of underwater explosions on life in the sea. DSTO-GD-0080. Australian Department of Defence. Melbourne, Australia. 38 pp. Luzier, C. W., H. A. Schaller, J. K. Brostrom, C. Cook-Tabor, D.H. Goodman, R.D. Nelle, K. Ostrand and B. Streif. (2011). Pacific lamprey (Entosphenus tridentatus)

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assessment and template for conservation measures. U.S. Fish and Wildlife Service, Portland, Oregon. 282 pp. Major, R.L. and J.L. Mighell. (1967). Influence of Rocky Reach Dam and the Temperature of the Okanogan River on the Upstream Migration of Sockeye Salmon. U.S. Fisheries Bulletin 66; 131-147. Mapes R. L., C. A. Sharpe, T. A. Friesen. (2017). Evaluation of the trap and transport of adult steelhead above USACE project dams in the upper Willamette Basin. Oregon Department of Fish and Wildlife Corvallis, Oregon 97333. Marshall, D.B., M.G. Hunter, A. Contreras (eds.). (2003). Birds of Oregon: A General Reference. Oregon State University Press, Corvallis, Oregon. Mayfield, M. P., L. D. Schultz, L. A. Wyss, B. J. Clemens, and C. B. Schreck. (2014). Spawning patterns of Pacific lamprey in tributaries to the Willamette River, Oregon. Transactions of the American Fisheries Society, 143(6), 1544-1554. McCulley Kelley, Cara. (2001). Cultural Resource Inventory Report for the Detroit Lake State Park Master Plan. Report by Willamette National Forest, Detroit Ranger District, Detroit, OR. Oregon SHPO Report #17785. McElhany, P., M.H. Ruckelshaus, M.J. Ford, T.C. Wainwright. (2000). Viable salmonid populations and the recovery of evolutionarily significant units. U.S. Dept. of Commerce, NOAA Tech. Memo., NMFS-NWFSC-42, 156p. McElhany, P., M. Chilcote, J. Myers, and R. Beamesderfer. (2007). Viability status of Oregon salmon and steelhead populations in the Willamette and Lower Columbia Basins. Prepared for Oregon Department of Fish and Wildlife and National Marine Fisheries Service. National Marine Fisheries Service, Northwest Fisheries Science Center, Seattle, Washington. McLaughlin, L., K. Schroeder, and K. Kenaston. (2008). Interim activities for monitoring impacts associated with hatchery programs in the Willamette Basin, USACE funding: 2007. Oregon Department of Fish and Wildlife. Monzyk, F. R., Friesen, T. A., & Romer, J. D. (2015). Infection of juvenile salmonids by Salmincola californiensis (Copepoda: Lernaeopodidae) in reservoirs and streams of the Willamette River basin, Oregon. Transactions of the American Fisheries Society, 144(5), 891-902. Mote, P.W., J. Abatzoglou, K.D. Dello, K. Hegewisch, and D.E. Rupp. (2019): Fourth Oregon Climate Assessment Report. Oregon Climate Change Research Institute. occri.net/ocar4.

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Myers, J., Jorgensen, J., Sorel, M., Bond, M., Nordine, T., and Zabel, R. (2018). Upper Willamette River Life Cycle Modeling and the Potential Effects of Climate Change. Submitted to the U.S. Army Corps of Engineers, Portland District. DRAFT (under review) n.d.b. Section II. National Register Criteria for Evaluation: Guidelines for Evaluating and Documenting Historic Aids to Navigation to the National Register of Historic Places. National Register Bulletin. No. 15. Accessed online 1/27/2019 at https://www.nps.gov/nr/publications/bulletins/nrb15/nrb15_2.htm NMFS (National marine Fisheries Service). (2003). Preliminary conclusions regarding the updated status of listed ESUs of West Coast salmon and steelhead. Report of the West Coast Salmon Biological Review Team dated February 19, 2003. NMFS (National Marine Fisheries Service). 2002. Effects of elevated turbidity from water temperature control construction at Cougar Dam on Upper Willamette River Chinook salmon. Letter to G. Miller, U.S. Army Corps of Engineers, from B. J. Brown, NMFS, Portland. NMFS. (2005). Final Assessment of NOAA Fisheries’ Critical Habitat Analytical Review Teams for 12 Evolutionarily Significant Units of West Coast Salmon and Steelhead. August 2005. NMFS. (2008). Endangered Species Act section 9(a)(s) consultation biological opinion and Magnuson–Stevens Fishery Conservation and Management Act essential fish habitat consultation: consultation on the “Willamette River Basin Flood Control Project.” National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Northwest Region, F/NWR/20000/02117. NMFS. (2011). Anadromous Salmonid Passage Facility Design. NMFS, Northwest Region, Portland, Oregon. NMFS. (2015). Status Review Update for Pacific Salmon and Steelhead Listed Under the Endangered Species Act: Pacific Northwest. Northwest Fisheries Science Center. December 2015. NMFS. (2016). Endangered and threatened species; 5-year reviews for 28 listed species of Pacific salmon, steelhead, and Eulachon. Federal Register 81:102(May 26,2016):33468–33469. Normandeau Associates, Inc. (2011). Estimates of direct survival and injury of rainbow trout (Oncorhynchus mykiss) passing spillway, turbine, and regulating outlet at Detroit Dam, Oregon: Report of Normandeau Associates, Inc., Drumore, Pennsylvania, prepared for U.S. Army Corps of Engineers, Portland, Oregon, contract W912EF-08-D-0005-DT01, 182 p.

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Oetting, A. C. (2017). Archaeological survey of selected parcels at Detroit and Big Cliff reservoirs, Linn and Marion Counties, Oregon: Report of Heritage Research Associates, Inc., Eugene, Oregon, prepared for U.S. Army Corps of Engineers, Portland, Oregon, contract W9127N-16-P-0151, 81 p. Olsen, E., P. Pierce, M. McLean, and K. Hatch. (1992). Stock summary reports for Columbia River anadromous salmonids, volume I: Oregon. Bonneville Power Administration, Portland, Oregon. O’Malley, K. G., M. L. Evans, M. A. Johnson, D. P. Jacobson, and M. Hogansen. (2015). An evaluation of spring Chinook salmon reintroductions above Detroit Dam, North Santiam River, using genetic pedigree analysis. Pp. 25. Portland, OR. Oregon Biodiversity Information Center. (2016). Rare, Threatened and Endangered Species of Oregon. Institute for Natural Resources, Portland State University, Portland, Oregon. 130 pp. Oregon Climate Change Research Institute (OCCRI). (2015). Historical Trends and Future Projections of Climate and Streamflow in the Willamette Valley and Rogue River Basins, June 2015. Oregon Department of Agriculture. (2012). A Comprehensive Valuation of Agriculture Lands: A Perpetual Investment in Oregon’s Economy and Environment with Marion County Case Study ODEQ. (Oregon Department of Environmental Quality). (2006). Willamette Basin TMDL: Temperature Chapter 4: Temperature-Mainstem TMDL and Subbasin Summary, Oregon Department of Environmental Quality, September, 2006. ODEQ. (2018). emailed excel spreadsheet communication, “Copy of All NPDES and WPCF in Will Basin DEQ.xlsx”, August 13, 2018. ODFW (Oregon Department of Fish and Wildlife). (2005). Oregon native fish status report. Salem, Oregon. ODFW. (2011). Upper Willamette River conservation and recovery plan for Chinook salmon and steelhead. Oregon Department of Fish and Wildlife, Salem, and NOAA Fisheries, Northwest Region, Seattle WA. Oregon Heath Administration (OHA). (2017). Recreational Use Public Health Advisory Guidelines Cyanobacterial Blooms in Freshwater Bodies, Oregon Harmful Algae Bloom Surveillance (HABS) Program, Public Health Division Center for Health Protection Environmental Public Health Section, September 2018. Accessed on February 3, 2019 at https://www.oregon.gov/oha/PH/HEALTHYENVIRONMENTS/RECREATION/HARMFULAL GAEBLOOMS/Pages/resources_for_samplers.aspx.

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