3.3 Natural Resources This Section Describes the Plants and Animals That Occur, Or Are Likely to Occur Within the CIP Study Area

3.3 Natural Resources This section describes the plants and animals that occur, or are likely to occur within the CIP study area. It also describes critical areas, shorelines, and their current and proposed regulations. Impacts of the alternatives (No Action Alternative, Action Alternative 1, and Action Alternative 2) are analyzed at a programmatic level. All regulations and mitigation requirements pertaining to the management of biota would apply to specific development projects under all alternatives.

Because a large proportion of the CIP study area is either currently developed, or protected through existing regulations, changes in natural resources would be modest under either alternative. However, redevelopment could result in higher building density and greater impervious surface area under either action alternative. Impervious surface area would be highest under Action Alternative 2. However, stormwater management would limit the effects of impervious surface area on stream habitat and water quality. Riparian buffers would be maintained under all alternatives, and the wildlife habitat and migration corridors that they support would continue under all alternatives. 3.3.1 Affected Environment 3.3.1.1 Fish and Wildlife Habitat

Environmental Conditions The CIP study area (Figure 3.3‐1) is largely developed with a high proportion of impervious land cover in the form of buildings, roadways, and parking. Vegetation in the CIP study area includes ornamental landscaping in parks and planting strips, and natural vegetation primarily in remnant wetlands, riparian areas, and on the margins of stormwater ponds. The City has prepared some localized tree canopy information by zone and planning subareas within the City. Localized tree canopy estimates are shown in Table 3.3‐1. Results generally show that the subareas encompassing the Central Issaquah area contain are 30% treed; the possible plantable area is also about 30%. However, on a zone basis, the commercial zones that make up most of the CIP study area range in percentage of trees by 14% to 35% and have much more opportunity for tree plantings at 31% to 46%.

The locations of known wetlands are shown generally on Figure 3.3‐1.1 Wetlands in the CIP study area include forested, emergent, and scrub‐shrub wetlands along Issaquah Creek and Tibbetts Creek. Forested wetlands in the City are typically dominated by willows (Salix sp.), red alder (Alnus rubra), black cottonwood (Populus balsamifera var. trichocarpa), and western red cedar (Thuja plicata) (Parametrix 2003). Scrub‐shrub wetlands are typically dominated by willows, red osier dogwood, salmonberry, and lady fern (Athyrium felixfemina) (Parametrix 2003). Emergent wetlands throughout the City are typically dominated by nonnative species such as reed canarygrass (Phalaris arundinacea) and creeping buttercup (Ranunculus repens) (Parametrix 2003). These wetlands perform important functions in maintaining stream habitat quality, such as detaining

1 This information is based on City geographic information system data and the Hyla Crossing and Rowley Properties Project Environmental Impact Statement. The presence of critical areas would be verified at a project level of review; critical areas are determined on the basis of ordinance definitions and maps are only considered a guide.

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stormwater runoff, filtering pollutants, and providing wildlife cover, foraging and migration corridor habitat.

Table 3.3‐1. Tree Canopy Estimates

Estimated by City Comprehensive Planning Subareas Encompassing Central Issaquah Subarea Total Possible Acres Urban Tree Total Possible Plantable Acres Comprehensive (excluding Canopy Percent Plantable Percent of Total Planning Subareas water) of Total Acres Acres Acres North Issaquah 11,007 39% 3,529 32% Gilman 4,467 31% 1,326 30% Newport 5,960 36% 1,803 30% I‐90 3,044 30% 1,056 35% Estimated by Commercial Zones Found in CIP Study Area Zone (citywide) Subarea Total Urban Tree Total Possible Possible Acres Canopy Percent Plantable Plantable Acres (excluding of Total Acres Acres Percent of Total water) Acres Intensive Commercial 1,218 14% 381 31% Retail 4,107 21% 1,935 47% Professional Office 2,115 35% 979 46% Source: Hanou pers. comm.

As identified on Figure 3.3‐1, streams in the CIP study area include Issaquah Creek, North Fork Issaquah Creek, East Fork Issaquah Creek, Schneider Creek, and Tibbetts Creek. Of these, the mainstem and East Fork Issaquah Creek are designated as a shorelines of the state (Type 1 stream; identified as Class 1 in Issaquah’s critical area regulations), and the others are Type 2 salmon‐bearing streams (called Class 2 in critical area regulations). Table 3.3‐1 lists the salmonid fish species with a documented presence in these streams and their major tributaries in the CIP study area. Two of these species (Puget Sound Chinook salmon and Puget Sound steelhead trout) are listed as Threatened under the federal Endangered Species Act (ESA). In addition to salmonids, these streams likely also support western brook lamprey (Lampetra richardsonii), three‐spine stickleback (Gasterosteus aculeatus), sculpins (Cottus sp.), river lamprey (Lampetra ayersi), peamouth (Mylocheilus caurinus), largescale sucker (Catostomus macrocheilus), and mountain whitefish (Prosopium williamsoni). Issaquah Creek reportedly supports several nonnative fish such as brown bull head (Ameiurus nebulosus), black crappie (Pomoxis nigromaculatus), pumpkinseed sunfish (Lepomis gibbosus), largemouth bass (Micropterus salmoides), and smallmouth bass (Micropterus dolomieu), but likely only below I‐90 in the lower 1 to 2 miles of the stream (Parametrix 2003).

Central Issaquah Subarea Plan March 2012 3.3‐2 Draft Environmental Impact Statement ICF 00363.11

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In addition to in‐stream habitat, stream riparian corridors also provide narrow migration corridors for a variety of wildlife species. These riparian corridors connect a series of open space areas in City parks that make up a “green necklace” of habitat within the City, and connect this habitat with larger areas of wildlife habitat that surround the City, including Cougar Mountain Regional Wildland Park, Squak Mountain State Park Natural Area, Tiger Mountain State Forest, Lake Sammamish State Park, and privately owned land (see Appendix D for a map of the Issaquah Basin Wildlife Network). Maintaining functional wildlife corridors through protection of stream and wetland buffers, and by appropriate landscaping in parks continues to be an important component of planning efforts in the City.

Table 3.3‐2. Salmonid Fish Species and Type of Habitat in the CIP Study Area

Tributary to East Fork North Fork Common Schneider Tibbetts Tibbetts Issaquah Issaquah Issaquah Name Creek Creek Creek Creek Creek Creek Cutthroat Occurrence Occurrence/ Occurrence Occurrenc Occurrence Occurrence/ trout migration e/ migration migration Steelhead Spawning/ Spawning Occurrence Spawning trout rearing Chinook Spawning Spawning Occurrence/ salmon migration Sockeye Presence Spawning Spawning Spawning salmon Kokanee Occurrence/ Occurrenc Potential salmon migration e/ migration migration and spawning Coho Suspected Spawning Occurrence/ Spawning Spawning Spawning salmon downstrea migration m of I‐90 Sources: U.S. Fish and Wildlife Service 2011; Washington Department of Fish and Wildlife 2011a, 2011b; Watershed Company 2011

An inventory of streams in the City identified habitat conditions in the mainstem of Issaquah Creek that were not properly functioning regarding sediment load, hydrologic disturbance, lack of channel complexity, and riparian vegetation. Peak flows have increased steadily since 1965, and there has been a decreasing trend in annual minimum flows since 1972 (Parametrix 2003). High temperatures during the kokanee and Chinook salmon incubation have been recorded, and large wood recruitment are lacking in the portion of Issaquah Creek that passes through the CIP study area. Pool infilling with fine sediment limit the depth of pools in Issaquah Creek. Streambank modification was found to be fairly frequent along Issaquah Creek in the CIP study area, reducing habitat quality. North Fork Issaquah Creek has also experienced hydrologic disturbance with diminished summer base flow (Parametrix 2003). In 2003, heavy sediment load, loss of channel complexity, and low frequency of large wood limited stream habitat quality in Tibbetts Creek. Since 2003, a restoration project was implemented in Tibbetts Creek to widen the floodplain, install in‐ channel improvements, remove invasive plants, and replant banks with native vegetation (Watershed Company 2011).

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Excessive sediment has been noted as a factor contributing to the decline of salmon in Tibbetts Creek and Issaquah Creek due to fine sediment inputs from landslides on steep forest slopes, bank erosion, logging/gravel roads, and urban development (Kerwin 2001).In Tibbetts Creek, high turbidity and heavy sediment noted during storm events has been attributed to runoff from coal mine tailings and rock quarries (Kerwin 2001). Urban development also has the potential to adversely affect streams through alterations in water quality, hydrology, sediment dynamics, temperature, shading, and nutrient dynamics. Impervious surfaces result in increased stormwater runoff that can increase peak stream flows and cause excessive bank erosion, increased sediment transport, and reduced low flows.

A valuable tool to evaluate the overall biological health of a stream is the use of a benthic index of biotic integrity (BIBI) score. The BIBI score is based on the characteristics of the bottom dwelling (benthic) invertebrate community in the stream. By examining the diversity and tolerance of the invertebrate community, it is possible to get an integrated evaluation of all factors that affect stream biota. The Issaquah StreamTeam, a team of trained volunteers, has sampled stream invertebrates in Issaquah Creek since 1998. The results of this sampling indicate that the BIBI scores upstream and downstream of the CIP study area generally show similar overall BIBI scores and do not show a clear pattern of urbanization effects on stream health (City of Issaquah 2010b). A BIBI sampling station on Tibbetts Creek was sampled by the King County Department of Natural Resource Protection (DNRP) in August of 2010, at the upstream edge of the CIP study area and indicated a fair to poor condition (Puget Sound Stream Benthos 2011). Other samples taken by King County in the CIP study area indicated a good condition at one site (sampled in 2008) and a fair condition at three sites (sampled in 2010) on Issaquah Creek (Puget Sound Stream Benthos 2011).

The City is addressing vegetation, stream and riparian habitat, bank stabilization, and flood issues through an ongoing series of projects covering over 83 acres (Ritland pers. comm.). Projects completed in the CIP study area include several habitat and flood conveyance projects for Tibbetts Creek and Issaquah Creek (Ritland pers. comm.). In 2006, the City commissioned a Stream and Riparian Restoration Plan (Watershed Company 2006). The plan outlined 72 potential restoration projects. Twenty of the proposed projects, including 16 along the mainstem of Issaquah Creek and four along North Fork Issaquah Creek, are located in the CIP study area. Four of the projects on the mainstem of Issaquah Creek are located within the core growth center along the eastern edge of this area. These projects include Pickering Stream Bank Repair upstream of the SE 56th Street bridge, Pickering Cascades located upstream of the mouth of North Fork Issaquah Creek, Pickering Reach located between 56th Street and I‐90, and Pickering Wood Cover to Scour Hole located southwest of SE 60th Street (Watershed Company 2006).

Amphibians and reptile habitat is limited in the CIP study area. However, wetlands, stormwater ponds, and park areas may include pockets of habitat suitable for amphibians and reptiles. Amphibian species that are most likely to occur in the CIP study area include northwestern salamander (Ambystoma gracile), long‐toed salamander (Ambystoma macrodactylum), Ensatina salamander (Ensatina escholtzii), western red‐backed salamander (Plethodon vehiculum), western toad (Bufo boreas), northern red‐legged frog (Rana aurora), Pacific treefrogs (Hyla [Pseudacris] regilla), and the introduced bullfrog (Rana catesbeiana). Reptiles that may occur in the CIP study area include northern alligator lizard (Elgaria coerulea) and garter snakes (Thamnophis sp.).

Over 140 bird species have been observed in the City during the last 3 years (Appendix D). Although some of these species represent unusual sightings, those that have been observed in 2 of the last 3 years may be considered as potentially occurring in, or occasionally flying over, the CIP study area.

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Mammal occurrence data are not available for the CIP study area. In general, few mammals are expected to occur in the developed areas that make up most of the CIP study area. However, a large diversity of mammals inhabit the wildlands that surround the City, and most of these undoubtedly use riparian corridors and could occur within the CIP study area as well. Based on the known distribution and habitat preferences of mammals found in Washington, it is estimated that approximately 30 mammal species may occur in the CIP study area (Appendix D) including opossum, shrews, rodents, rabbits, bats, deer, and carnivores. River otters have been seen several times in Issaquah Creek, and deer, rabbits, raccoons, weasels, mink, and many species of birds are frequently seen in Darst Park (Wall pers. comm.). Beavers are common in Lake Sammamish State Park (Fisher pers. comm.), are found along riparian areas of Tibbetts Creek, and have the potential to be present in the Issaquah Creek riparian zones.

Lights, noise, and human and pet activity can cause avoidance behavior among the wildlife species that potentially inhabit the CIP study area. The timing of activity and the presence of vegetation and structures that block light and line of sight can reduce disturbance to those species. The effects of development are more difficult to predict at a programmatic level, but would be reviewed in association with permit reviews and application of the City critical areas ordinance.

Shoreline Master Program and Fish and Wildlife Regulations The City’s adopted Shoreline Master Program (SMP) (IMC 18.10.940‐1050) govern development within areas designated as shorelands associated with Type 1 streams (Issaquah Creek, East Fork Issaquah Creek), and Lake Sammamish. Regulated shorelands include these waters, a jurisdiction area extending to 200‐foot landward of the ordinary high water mark (OHWM) or associated floodway, plus associated wetlands. Substantial development in these areas requires shoreline permits.

The City’s SMP is under revision and expected to be adopted in 2012. One of the stated purposes of the proposed SMP is, “To ensure, at a minimum, no net loss of shoreline ecological functions and processes and to plan for restoring shorelines that have been impaired or degraded.” The plan includes regulations governing activities in shorelines that support shoreline use and conservation elements that address ecological functions. The goals of these specific elements are:

 Shoreline Use (Goal 3.4.1): Promote a mix and balance of reasonable and appropriate shoreline uses that will be an asset to the community, and will preserve and protect natural systems. Recognize that land use and water management activities on adjacent uplands affect the quality of the City’s shorelines.  Conservation (Goal 3.5.1): Re‐establish, rehabilitate and/or otherwise improve impaired shoreline ecological functions and /or processes through voluntary and incentive‐based public and private programs, consistent with the Shoreline Management Program Restoration Plan. The City’s critical areas regulations include standards intended to protect fish and wildlife habitat including streams and wetlands. Stream buffers for Class 1 and 2 waters are 100 feet from the ordinary high water mark. Wetland buffers range from 40 feet to 225 feet depending on wetland class and habitat features.

Current (2011) updates to the Critical Areas Regulations that address fish and wildlife include changes to wetland and stream buffer averaging (IMC 18.10.650 and IMC 18.10.790) to limit the maximum reductions to 25%, improving conservation of these buffer areas. In addition, changes to regulating wetland mitigation would be revised to ensure no net loss of wetland ecological function (IMC 18.10.490, 18.10.620, and 18.10.720).

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3.3.1.2 Other Critical Areas Critical areas in Issaquah and in the CIP study area include aquifer recharge areas, geologic hazards (coal mines, steep slopes, and areas subject to erosion, landslides, and seismic hazards), flood hazards, wetlands, and fish and wildlife habitat including streams. Wetlands and streams have been described in Section 3.3.1.1, Fish and Wildlife Habitat. Other critical areas are generally described below.

Critical Aquifer Recharge Areas Aquifer protection areas are currently regulated under the City of Issaquah Critical Aquifer Recharge Area Ordinance adopted in 2007 (IMC 13.29) (City of Issaquah 2011a), and critical aquifer recharge areas are regulated under IMC 18.10.796 of the City’s development standards and the Table of Permitted Land Uses in IMC 18.06.130. No changes to the critical areas ordinances regarding aquifer recharge areas are proposed with the shoreline master program update.

Critical aquifer recharge areas in the CIP study area are shown in Figure 3.3‐2. Most of the CIP study area that is east of Issaquah Creek and south of I‐90 is in a wellhead capture zone. Aquifer recharge areas do not overlap with either Planned Action Areas 1 or 2. Aquifer recharge affects fish and wildlife habitat in that it can affect discharge of groundwater to streams, regulating flow and temperature; thus the amount and location of impervious areas can be important. However, current City aquifer regulation is primarily designed to maintain groundwater for water supply wells. City stormwater regulations are intended to promote low impact development techniques which may avoid impacts on recharge areas, where appropriate.

Geologic Hazards Geologic hazards in the City of Issaquah include seismic hazard areas, mine hazard areas, and steep slopes (erosion and landslide hazards) (City of Issaquah 2010c). A large proportion of the CIP study area has been identified as having a high susceptibility to liquefaction during a seismic event (City of Issaquah 2010c). There are no coal mine hazard areas in the CIP study area. Steep slopes (more than 40%) may be susceptible to erosion and landslides, especially during clearing and grading that may be required for construction. There are only a few small areas of steep slopes in the eastern CIP study area (Figure 3.2‐2 in Water Resources). There are no steep slopes in the planned action areas. Critical area regulations vary for each type of geologic hazard but generally include required evaluations by a qualified professional and performance standards. There are buffers required along steep slopes and landslide hazard areas.

The hillside above the commercial complex, east of East Lake Sammamish Parkway, in the Darst Park neighborhood has been graded as part of a former mining reclamation effort, and is not technically considered in a steep slope critical area. Future development on this site or others that may have site specific earth conditions that should be considered would be subject to geotechnical studies in association with building permits, per the City’s uniform building code (as are all developments in the City).

Flood Hazard Areas Flood hazard areas in the CIP study area include floodplains associated with Issaquah Creek, Tibbetts Creek, tributary to Tibbetts Creek north of I‐90, and an area between I‐90 and Gilman Boulevard (Figure 3.2‐2).

Central Issaquah Subarea Plan March 2012 3.3‐8 Draft Environmental Impact Statement ICF 00363.11

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Figure 3.3-2 Aquifer Recharge and Wellhead Protection Areas Central Issaquah Subarea Plan EIS Chapter 3. Affected Environment, Significant Impacts, City of Issaquah and Mitigation Measures

On September 22, 2008 the National Marine Fisheries Service (NMFS) issued a Biological Opinion evaluating the National Flood Insurance Rate Program in the Puget Sound area (National Marine Fisheries Service 2008). The Federal Emergency Management Agency (FEMA) that manages the flood insurance program has provided local communities in the Puget Sound area with options to demonstrate compliance with the NMFS (2008) Biological Opinion. The City has completed a Biological Opinion Checklist (City of Issaquah 2011b) documenting that the existing or proposed IMC and other regulations meet the biological opinion provisions. Until FEMA approves the City’s regulatory approach, it is requiring site by site habitat assessments in association with flood hazard permits.

3.3.1.3 Planned Action Area 1—Hyla Crossing and Rowley Center Planned Action Area 1 supports a very small proportion of vegetated area that includes a mix of native and ornamental landscaping along roads and parking lot edges, drainage swales along SR 900, 18th Avenue NW, and the I‐90 southbound off‐ramp to SR 900; as well as Class 2 riparian wetlands associated with Tibbetts Creek along the western edge of the Hyla Crossing area. Wildlife use in Planned Action Area 1 is likely limited to perching birds and small rodents, except for Tibbetts Creek and associated wetlands, which would also potentially support the fish, reptile, amphibian, and mammal species described above. Small Class 3 wetlands have been delineated in the roadside drainage swales along SR 900 and the southbound I‐90 off‐ramp (EA/Blumen et al. 2011). Critical areas in Planned Action Area 1 include Tibbetts Creek and the wetlands mentioned above. No shorelines of the state are present in this area.

3.3.1.4 Planned Action Area 2—Core Growth Center Remainder Like Planned Action Area 1, Planned Action Area 2 is highly developed. Vegetation includes landscaped native and ornamental species, a deciduous and coniferous forested riparian area along Issaquah Creek, a stormwater pond north of I‐90 and east of 11th Avenue NW, as well as wetland areas northeast of I‐90 and northwest of 17th Avenue NW, and north and south of the intersection of NW Maple Street and Newport Way NW. Forested deciduous parcels are also located north and east of Lake Drive, and west of 11th Avenue W in the northeastern portion of Planned Action Area 2.

Streams in Planned Action Area 2 include short segments of a tributary to Tibbetts Creek located between I‐90 and NW Sammamish Boulevard, and Issaquah Creek at the northeast corner of the area. As described above, both of these streams provide habitat for coho salmon and cutthroat trout. In addition, Issaquah Creek supports Chinook salmon, sockeye salmon, kokanee salmon, and steelhead trout. Issaquah Creek is a shoreline of the state.

Streams and open water pond habitat may support the amphibian species described above, as well as waterfowl species, particularly Canada goose, mallard, and gadwall. Landscaping vegetation may support perching birds and squirrels. And the other mammal species described above are likely present in the forested riparian areas located along the tributary to Tibbetts Creek and along Issaquah Creek.

Critical areas in Planned Action Area 2 include Issaquah Creek, the wetlands mentioned above, and flood hazard areas located in the vicinity of Issaquah Creek, Gilman Boulevard, and the tributary to Tibbetts Creek located in the northwest corner of Planned Action Area 2.

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3.3.1.5 Area Outside Planned Actions In the portion of the CIP study area outside of the planned action areas, landscaping vegetation consists of a mix of ornamental and native plant species that provide limited, fragmented habitat along roadways and parking lots. Other forested areas are found along the riparian zone of Issaquah Creek and North Fork Issaquah Creek in the East Lake, Pickering, Darst Park, and Gilman neighborhoods, as well as in an area located southwest of Newport Way NW and south of SE 60th Street in the southwest corner of the Gilman Neighborhood. These forested areas provide limited areas of wildlife habitat, particularly perching birds and small mammals. The greatest length of Issaquah Creek, and all of North Fork Issaquah Creek in the CIP study area is located outside the planned action areas. As described earlier, Issaquah Creek and North Fork Issaquah Creek provide salmonid fish habitat.

In the areas outside of the planned actions, critical areas include the Issaquah Creek shoreline, flood hazard areas associated with Issaquah Creek and Tibbetts Creek, Tibbetts Creek, North Fork Issaquah Creek, wetlands, and small steep slope areas. Streams and wetlands mapped by the City are shown on Figure 3.3‐1, and flood hazard areas and steep slopes are shown in Figure 3.2‐2. 3.3.2 Impacts 3.3.2.1 Introduction This section addresses potential impacts of the alternatives on plants and animals and critical areas occurring in the CIP study area. Impacts include modification of open spaces that provide habitat, and changes in stormwater quality, quantity, timing or location of delivery to surface waters.

Methodology Potential impacts on plants and animals are evaluated based on the alternatives described in Chapter 2, Description of Alternatives and the existing conditions in the planned action areas. Each alternative assumes the maximum allowable development described in Chapter 2. Potential impacts on aquatic species are primarily dependent on stormwater impacts, which are discussed in detail in the Section 3.2, Water Resources/Stormwater.

Impacts Common to All Alternatives Under all alternatives commercial and residential land uses would continue to operate. Additional development would occur, primarily as redevelopment. Critical area regulations would apply to all alternatives and avoid or minimize impacts on habitats such as streams and wetlands. Stream buffers and water quality standards are designed to protect habitats for fish species.

Wildlife corridors important to large and small mammals would be maintained through riparian and wetland buffer requirements. Redevelopment of non‐conforming structures would not be allowed to further encroach on buffers, although adding height to these buildings could be allowed; the manner in which nonconforming structures could expand could have incremental impacts that should be evaluated for the potential to achieve properly functioning conditions. In certain instances, it is possible that this type of redevelopment could alter the light regime in the adjacent buffer by shading or from artificial lighting from the structure. These changes in lighting could have local impacts on wildlife behavior. However, this type of impact would be site specific, and the level of impact cannot be determined at the programmatic level. The City’s best available science report

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cited research that concluded buffers of 100 to 600 feet were typically required for wildlife habitat functions (City of Issaquah 2004). The 100‐foot buffer required to either side of salmonid streams would provide 200‐foot‐wide corridors, which fall within the range as stated in the literature. Other streams with narrower buffers would not offer the same level of visual screening for wildlife.

Construction Impacts Under all of the alternatives construction could occur that would require ground disturbance and would temporarily increase the potential for sediment erosion and transport to streams and wetlands. However, all construction would be required to meet local building standards and National Pollutant Discharge and Elimination System (NPDES) construction permit requirements.

Construction equipment can cause noise and activity that can disturb wildlife or cause avoidance behavior. Nesting birds especially can be sensitive to increased noise from construction activity. The effect of construction on nesting birds and other wildlife would depend on project‐specific factors including the timing of construction, background noise levels, and the type and duration of construction activities.

New impervious surfaces have the potential to adversely affect fish and aquatic habitat by reducing the infiltration of precipitation into groundwater and increasing the delivery of stormwater to surface waters causing altered stream hydrology and increased pollutant loading. However, because impervious surfaces cover a large proportion of the CIP study area, redevelopment could reduce impervious surface area in some instances.

Operational Impacts Under all alternatives, light from buildings, streetlamps, and vehicles; traffic noise; and other urban activity would continue to cause sensitive wildlife species to avoid the area. Traffic would continue to cause some mortality to wildlife crossing roadways.

Vehicle‐generated pollution would continue to be deposited on roadways and parking areas in the CIP study area, a portion of which would continue to enter surface waters causing, with the potential to affect fish and other aquatic species. Recent research on the causes of pre‐spawn mortality among adult coho salmon in the Puget Sound Basin indicates that the proximity of streams to impervious surfaces, roadway runoff, and commercial properties are all predicative of increased salmon pre‐spawn mortality (Feist et al. 2011). Based on the research by Feist et al. (2011), the relative effect of stormwater runoff from impervious surfaces, roadways, and commercial businesses under each of the alternatives would be dependent on the relative proportion of impervious surface area, traffic volumes, and proportion of commercial land uses. However, stormwater regulations would require that redevelopment include stormwater management facilities. Given the developed condition of the CIP study area, this would likely result in improved stormwater management and reduced pollutant loading compared with existing conditions.

Beavers’ well‐known dam‐ and lodge‐building behaviors, as well as their diet of riparian trees and shrubs, can have dramatic effects on stream habitat conditions. In areas where human development is close to riparian areas, beavers can cause damage to local landscaping and can cause local flooding. Vegetation damage is often managed with the use of protective fencing (Washington Department of Fish and Wildlife 2004). Culverts that are repeatedly plugged by beavers may require protective fencing as well to prevent flooding and road damage (Washington Department of Fish and Wildlife 2004). Some human‐beaver interactions may be expected under all alternatives.

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Chapter 3. Affected Environment, Significant Impacts, City of Issaquah and Mitigation Measures

3.3.2.2 No Action Alternative Impacts from the No Action Alternative would be as described for all alternatives. Because the impervious surface area would be less under the No Action Alternative than under the action alternatives, the potential impacts on fish and other aquatic species would be slightly less (estimated up to 53 acres of added impervious areas, except that there could be a net reduction of about 20 acres of impervious surface under the No Action Alternative if critical area buffers are implemented; zones allow a range of 30% to 65% impervious surface by zone). The current TDR program would remain in effect under the No Action Alternative which would help protect environmentally sensitive areas in the City and rural King County in designated sending areas.

3.3.2.3 Action Alternative 1—Task Force Recommendations Action Alternative 1 would include focused redevelopment, which would occur primarily in areas that are highly developed. There would be an increase in the amount of impervious surface area compared to the No Action Alternative (zoning districts would range from required open space of 10% to 40% which would allow impervious areas of 60% to 90% roughly; estimated at 247 acres, except that there could be a smaller increase in total impervious area at about 69 acres if critical area buffers, proposed parks, and streetscape improvements are implemented).

Although Action Alternative 1 would include development designed to facilitate pedestrian access, the impervious surface area and number of vehicle trips would increase relative to existing conditions and the No Action Alternative. However, with adequate stormwater treatment included with each redevelopment project, pollutant loading could be reduced under Action Alternative 1.

Zoning standards would allow more urban style development with less landscaping; trees may be provided in streetscapes and plazas such as in tree grates. Trees added into urban environments are typically smaller, slower‐growing species and are more likely to be trimmed for safety and visual aesthetics than those growing in open space areas such as parks, and thus, may have less shading value.

Specific development details have been proposed and evaluated in the Hyla Crossing and Rowley Center Project Draft Environmental Impact Statement (EA/Blumen et al. 2011). EA/Blumen et al. (2011) notes that development would occur in previously developed areas. The project would also include habitat improvements along Tibbetts Creek (EA/Blumen et al. 2011).

Under Action Alternative 1, development would be focused on one relatively undeveloped area, the “Western Gateway” area. Herbaceous vegetation and wildlife habitat would be reduced in this area. Additionally, Action Alternative 1 would include six potential new parks (see Section 3.3.3.1, Incorporated Plan Features). Without detailed park designs, it is not possible to determine specifically what effect that would have on the natural environment. Specific impacts would be determined and mitigated if necessary in the design and permitting of specific park projects.

Action Alternative 1 would implement an amended TDR program that could increase use of the program and protect more sending sites in rural King County; this could result in a slightly greater use of development rights transfers resulting in less development outside of the Action Alternative 1 area in the Tibbetts and Issaquah Creek basins.

Central Issaquah Subarea Plan March 2012 3.3‐13 Draft Environmental Impact Statement ICF 00363.11

Chapter 3. Affected Environment, Significant Impacts, City of Issaquah and Mitigation Measures

3.3.2.4 Action Alternative 2—Core Growth Center Under Action Alternative 2, redevelopment would be focused in the core growth center. Impacts would be similar to those that would occur under Action Alternative 1, with slight changes in local development. Under Action Alternative 2, minimum open spaces would be less than Action Alternative 1 and greater impervious areas allowed. Zoning requirements would include open space ranges of 10% to 30% and impervious areas of 70% to 90%; the amount of green space required is less than the total open space required; the resulting additional impervious area is estimated at 351 acres, but this could be reduced to a 173‐acre increase if critical area buffers, proposed parks, and streetscape improvements are implemented. Overall, impervious surface area would be greater under Action Alternative 2 than the other alternatives.

Under Action Alternative 2, development would be focused on one relatively undeveloped area, the “Western Gateway” area. Herbaceous vegetation and wildlife habitat would be reduced in this area. Elsewhere—because Action Alternative 2 would focus most development in the Core Growth Center—less impacts on terrestrial plants and animals would occur than under Action Alternative 1.

Similar to, but to a slightly greater extent, zoning standards under Action Alternative 2 would allow more urban style development with less landscaping; trees may be provided in streetscapes and plazas such as in tree grates. Trees added into urban environments are typically smaller, slower growing species and are more likely to be trimmed for safety and visual aesthetics than those growing in open space areas such as parks, and thus may have less shading value.

Additionally, Action Alternative 2 would include the six potential new parks considered under Action Alternative 1 (see Section 3.3.3.1, Incorporated Plan Features). Without detailed park designs, it is not possible to determine specifically what effect that would have on the City’s natural environment. Specific impacts would be determined and mitigated if necessary in the design and permitting of specific park projects.

As with Action Alternative 1, Action Alternative 2 would implement an amended TDR program that could increase use of the program; this could result in a slightly greater use of TDRs resulting in less development outside of the Action Alternative 2 area in the Tibbetts and Issaquah Creek basins in rural King County. Because Action Alternative 2 would result in the greatest rate of development, use of the TDR program could be more extensive under this alternative.

3.3.2.5 Indirect/Cumulative Impacts Indirect impacts are those impacts that would occur distant from the site of the action, or at a later time. Cumulative impacts are those that would occur as a result of the action and other unrelated actions that are reasonably certain to occur during the lifetime of the plan. Regarding the natural environment, the one type of impact would be both indirect and cumulative. Namely, the potential for urban development to increase pollutant loads and alter stream hydrology in Issaquah Creek and Tibbetts Creek could adversely affect salmon runs in these streams. The effect of urbanization and management of the larger watersheds appear to already be affecting these streams (Kerwin 2001; Puget Sound Stream Benthos 2011; Feist et al. 2011), so it is not clear that the additional development that would occur under any of the alternatives would have a significant additional effect.

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Chapter 3. Affected Environment, Significant Impacts, City of Issaquah and Mitigation Measures

3.3.3 Mitigation Measures 3.3.3.1 Incorporated Plan Features The action alternatives include six proposed parks (shown in Section 3.7, Public Services and Utilities, Figure 3.7‐1):

 Western Gateway Neighborhood Park,

 Tibbetts Creek Greenway Park,

 Gilman Boulevard Creekside Park,

 Overlake Neighborhood Park,

 North Fork Issaquah Creek/High Point Trail Park, and

 Promenade Park.

These parks are located in some of the remaining open space areas in the CIP study area. If conservation of biological resources are incorporated into the design of these parks, plants and habitat for wildlife could be maintained or enhanced. The Green Necklace plan would connect to the Issaquah Alps and associated habitat network.

3.3.3.2 Regulations and Commitments All development would be subject to all local, state, and federal regulations governing biological resources. These include, but are not limited to those shown in Table 3.3‐3.

Table 3.3‐3. Natural Resources Regulations and Commitments

Regulation\Permit Administering Agency IMC 16.26 Building and Construction – Clearing and Grading City of Issaquah IMC 16.30 Buildings and Construction – Erosion and Sediment Control City of Issaquah IMC 16.36 Buildings and Construction ‐ Areas of Special Flood Hazard City of Issaquah IMC 18.10.010‐330 Environmental Protection – Environmental Policy City of Issaquah (for non‐planned action and non‐exempt projects) IMC 18.10.340‐515 Environmental Protection – Critical Areas City of Issaquah IMC 18.10.940‐1050 Shoreline Regulations City of Issaquah Stream and Riparian Areas Restoration Plan City of Issaquah Washington Hydraulic Code Rules (WAC 220‐110) WDFW Water Pollution Control Act (Chapter 90.48 RCW) Ecology NPDES Construction Permit Ecology NPDES Municipal Stormwater Permit Ecology Water Quality Certification Ecology Federal Endangered Species Act (ESA) NMFS, USFWS Federal Migratory Bird Treaty Act (MBTA) USFWS Federal Bald and Golden Eagle Protection Act USFWS IMC = Issaquah Municipal Code; WAC = Washington Administrative Code; RCW = Revised Code of Washington; ESA = Endangered Species Act; MBTA = Migratory Bird Treaty Act; WDFW = Washington Department of Fish and Wildlife; Ecology = Washington State Department of Ecology; NMFS = National

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Chapter 3. Affected Environment, Significant Impacts, City of Issaquah and Mitigation Measures

Regulation\Permit Administering Agency Marine Fisheries Service; USFWS = U.S. Fish and Wildlife Service.

As part of the 2011 shoreline master program update, proposed changes to the IMC that regulate the area of wetland and stream buffers that can be removed in the buffer averaging process from the current ratio of 2:1 to a ratio of 1:1. Buffer removal would only be allowed where impervious surface area are removed and planted with native vegetation. This change would increase conservation of wetland and stream buffer areas.

In addition, the Stream and Riparian Areas Restoration Plan (Watershed Company 2006) projects are being implemented to improve stream habitat conditions in the City including the CIP study area.

3.3.3.3 Other Potential Mitigation Measures There are existing uses and structures inside the standard buffers for critical areas (streams and wetlands). It is assumed that new development including substantial redevelopment will be subject to full compliance with standard buffers. Prior to new development or substantial redevelopment, some property owners may want to expand their uses or structures on an interim basis. To ensure impacts on critical areas are avoided, the City could add a policy and regulations that specify how minor building expansion could occur in already degraded areas. For example, building expansion could be allowed on existing impervious areas or by expanding upper floors to avoid increasing a building footprint. In addition, the City could require enhancement of the remaining buffer area and critical area such as by planting native vegetation or adding in‐stream habitat. The enhancement required could be proportional to the location and amount of the proposed building expansion. 3.3.4 Significant Unavoidable Adverse Impacts All alternatives would result in additional impervious surface area and vehicle traffic in the CIP study area with the potential to increase pollutant loading to Tibbetts Creek, Issaquah Creek, and Lake Sammamish. However all alternatives would allow for critical area buffers to be established as redevelopment occurs. In addition, the action alternatives propose parks and streetscape improvements. All of these enhancements to buffers, parks, and tree canopy would offset some of the increased impervious surfaces.

Increased pollutant loading in turn has the potential to adversely impact aquatic species, especially salmonid fish species. However, assuming new construction will result in improvements to existing stormwater treatment, the overall effect could be an improvement in conditions for fish and other aquatic species.

Some loss of landscaping vegetation would occur during redevelopment. However, redevelopment would be in compliance with City building, land use, and critical areas ordinances. Therefore, no significant adverse impacts on critical areas are expected. In addition, replacement of low value vegetation such as English ivy (Hedera helix) with native vegetation that includes wildlife benefits could improve the habitat value for some species.

Last, while there would be an increase in urban development and human use of the subarea, the action alternatives support the Green Necklace concept of added parks, recreation, open space, and natural features, which could connect to the broader wildlife network of the Issaquah Alps.

Central Issaquah Subarea Plan March 2012 3.3‐16 Draft Environmental Impact Statement ICF 00363.11