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Fontenelle Dam and Outworks Infrastructure CompleƟon Level II Study

Prepared by:

In associaƟon with:

1600 Specht Point Rd. #209

Fort Collins, CO 80525

Denver, CO Fort Collins, CO Raton, NM Fontenelle Dam and Outworks Infrastructure Completion Level II Study

Prepared for:

Wyoming Water Development Commission 6920 Y ellowtail Road Cheyenne, WY 82002

Prepared by:

~gineering Analytics, Inc.

1600 Specht Point Road, Suite 209 Fort Collins, Colorado 80525 (970) 488-3111 Fax (970) 488-3112

Project No. 110661

December 2018 Fontenelle Dam and Outworks Level II Study Wyoming Water Development Office

TABLE OF CONTENTS

INTRODUCTION AND OVERVIEW ...... 1 Purpose ...... 1 Scope ...... 1 Project Meetings ...... 3 BACKGROUND ...... 5 OUTLET WORKS AND POWERPLANT ...... 7 River Outlet and Hydroelectric Diversion ...... 7

Spillway ...... 9 East Canal ...... 9 West Canal ...... 10 Site Visit...... 10 ALTERNATIVES ANALYSIS ...... 12 Alternatives ...... 12

NEPA CONSIDERATIONS ...... 24 NEPA ...... 24

Agency Coordination ...... 26 December 2018 2 Engineering Analytics, Inc.

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Environmental Considerations ...... 27

Environmental Alternatives Evaluations ...... 32 Permitting, Clearances, and Approvals ...... 32

Summary ...... 34 HYDRAULIC ANALYSIS OF HISTORIC AND FUTURE OPERATIONS ...... 35 Historic Reservoir Operations ...... 35 Reservoir Potential Yield ...... 42 Construction Reservoir Drawdown Scenarios ...... 42

Issues Relative to Interstate Compacts ...... 54 Future Operations...... 55 CONCEPTUAL DESIGNS AND COST ESTIMATES ...... 57 Riprap ...... 57

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Soil Cement ...... 60 Submar Mats ...... 60 Contech Wave Attack Blocks ...... 60 Summary of Costs ...... 60 SCHEDULING ...... 63 Riprap ...... 63 Soil Cement ...... 63 Submar ...... 65 Contech ...... 65 Schedule Variations ...... 65 Power Generation Scheduling...... 69 Summary ...... 70 ECONOMIC ANALYSIS ...... 71 Benefits Associated with the Proposed Project ...... 71 Valuation Methods ...... 72

Direct Water Supply Analysis ...... 75

Drought Mitigation Analysis ...... 80

Drought Avoidance Analysis ...... 105

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Cost Considerations ...... 110

Summary of Benefits ...... 113 CONCLUSIONS AND RECOMMENDATIONS ...... 115 Conclusions ...... 115

Recommendations ...... 116

Extreme Event Alternative ...... 118 REFERENCES ...... 119

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LIST OF TABLES

Table 1-1. Interagency group meetings with their corresponding topics and dates...... 4 Table 4-1. Quantity of riprap for each 20-foot section placed in the dry...... 15 Table 4-2. Quantity of riprap for each 20-foot section for placement in full reservoir. ... 16 Table 4-3. Quantity of soil cement for each 20-foot section...... 19 Table 4-4. Material quantification for placing Submar Mats in full reservoir according to surface area of the dam face requiring armoring...... 20 Table 4-5. Required Material for placing Contech Wave Attack Blocks in the Full Reservoir ...... 21 Table 4-6. Summary of criteria met for each of the alternatives...... 23 Table 5-1. List of endangered and threatened species and details...... 28 Table 5-2. List of facilities and details...... 28 Table 5-3. List of migratory birds and details...... 29 Table 6-1. Fontenelle average monthly inflow and outflows...... 35 Table 6-2. Fontenelle monthly average, maximum, and minimum end-of-month contents...... 40 Table 6-3. Fontenelle Adjusted monthly average, maximum, and minimum end-of-month contents...... 41 Table 6-4. Fontenelle spring drawdown scenario #1...... 44 Table 6-5. Fontenelle reservoir – refilling, scenario #1...... 44 Table 6-6. Fontenelle fall/winter drawdown scenario #2...... 48 Table 6-7. Fontenelle fall/winter drawdown scenario #3...... 50 Table 6-8. Estimated power generation for Scenarios 1-3 over a 36-month simulation. . 53 Table 7-1. Quarries and riprap costs...... 57 Table 7-2. Alternatives cost estimate summary...... 62 Table 8-1. Active Water Lease Contracts in Fontenelle Reservoir ...... 78 Table 8-2: Historical Storage Contents of CRSP Reservoirs...... 81 Table 8-3. Estimates of Consumptive Use (afy) in Green River Basin, Wyoming ...... 83 Table 8-4. Municipal and Industrial Water Uses in the Green River Basin ...... 84 Table 8-5: Municipal Water Pricing in the Green River Basin ...... 94 Table 8-6. Hay Yield Data, 2012 Agriculture Census ...... 95 Table 8-7. Wyoming Statewide Hay Prices ...... 96 Table 8-8. Estimation of Net Agricultural Benefit ...... 96

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Table 8-9: Summary of Benefit Estimates by Scenario ...... 97 Table 8-10: Annual Benefits of Drought Mitigation, Scenario A (1 of 2) ...... 98 Table 8-11: Annual Benefits of Drought Mitigation, Scenario A (2 of 2) ...... 99 Table 8-12: Annual Benefits of Drought Mitigation, Scenario B (1 of 2) ...... 100 Table 8-13: Annual Benefits of Drought Mitigation, Scenario B (2 of 2) ...... 101 Table 8-14: Annual Benefits of Drought Mitigation, Scenario C (1 of 2) ...... 102 Table 8-15: Annual Benefits of Drought Mitigation, Scenario C (2 of 2) ...... 103 Table 8-16: Annual Benefits of Drought Mitigation, Agriculture Only ...... 104 Table 8-17: Annual Benefit of Drought Avoidance ...... 110 Table 8-18: Benefit-Cost Ratio for each Alternative ...... 114

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LIST OF FIGURES

Figure 1. Location map of Fontenelle Dam and Fontenelle Reservoir in Wyoming...... 2 Figure 2. Illustration of Fontenelle Reservoir Storage Pools...... 6 Figure 3. Elevation-discharge curve for the River Outlet works reproduced from the original Fontenelle Dam drawing set (1961) Sheet 154-D-43 which can be found in Appendix B...... 8 Figure 4. Monthly average of Fontenelle power production over the past 4 years...... 8 Figure 5. Spillway elevation-discharge curve...... 10 Figure 6. Potential site layout for construction...... 17 Figure 7. Fontenelle annual inflows...... 36 Figure 8. Fontenelle monthly inflows and outflows...... 36 Figure 9. Fontenelle average monthly inflow and outflows...... 37 Figure 10. Fontenelle historic storage...... 38 Figure 11. Fontenelle average end-of-month contents...... 39 Figure 12. Fontenelle average monthly power releases...... 42 Figure 13. Fontenelle average monthly flows below dam during drawdown scenario #1...... 43 Figure 14. Fontenelle reservoir contents during construction – scenario #1...... 46 Figure 15. Fontenelle reservoir spring inflows (March-July), flow frequency...... 46 Figure 16. Fontenelle reservoir spring inflows (2-yr total, March-July), flow frequency. 47 Figure 17. Fontenelle average monthly flows below dam during drawdown scenario #2...... 47 Figure 18. Fontenelle reservoir contents during construction – scenario #2...... 49 Figure 19. Fontenelle average monthly flows below dam during drawdown scenario #3...... 49 Figure 20. Fontenelle reservoir contents during construction – scenario #3...... 50 Figure 21. Monthly average of Fontenelle power production over the past 4 years...... 51 Figure 22. Monthly average power prices...... 52 Figure 23. Construction drawdown scenario summary...... 54 Figure 24. Typical cross-section of existing and proposed work on embankment face. .. 58 Figure 25. Riprap detail ...... 59 Figure 26. Typical soil cement detail for a 3:1 slope...... 61 Figure 27. Typical soil cement detail for a 2:1 slope...... 61 Figure 28. Riprap construction schedule for dry placement...... 64 December 2018 viii Engineering Analytics, Inc.

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Figure 29. Riprap construction schedule for underwater placement...... 64 Figure 30. Soil cement construction schedule...... 66 Figure 31. Submar Mat construction schedule for underwater placement...... 67 Figure 32. Contech Wave Attack Blocks construction schedule for underwater placement...... 68 Figure 33. Illustration of Fontenelle Reservoir Storage Pools...... 71 Figure 34: Nominal and Real Discount Rates...... 76 Figure 35. Industrial Water Uses in the Green River Basin...... 79 Figure 36. Historical Droughts in the Colorado River Basin...... 82 Figure 37. Probability of Colorado River Basin Shortages...... 86 Figure 38. Percentage of Curtailment Volume by Use Type ...... 89 Figure 39. Distribution of Project Benefit Volume by Use Types ...... 91 Figure 40. Industrial Demand Curve...... 93 Figure 41. Average Lease Rate in SCPP...... 108

LIST OF APPENDICES

Appendix A: Meeting Minutes Appendix B: Fontenelle Dam Drawings Appendix C: Photos Appendix D: NEPA and Environmental Considerations Appendix E: Wave Height and Hydraulic Calculations Appendix F: Alternative Cost Estimates Appendix G: Final Design Process

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INTRODUCTION AND OVERVIEW

Fontenelle Reservoir is a Bureau of Reclamation facility on the Green River near Kemmerer, Wyoming (Figure 1). The Wyoming Water Development Commission (WWDC) funded this study to evaluate the technical and economic feasibility of armoring the dam face, making available the water currently stored below the active pool elevation. The newly available storage would likely be designated as drought mitigation supply or drought avoidance supply rather than an addition to the overall capacity of Fontenelle. This report was prepared by Engineering Analytics, Inc., Trihydro, and WestWater Resources (referred to as the EA Team) under the direction and assistance of the Wyoming Water Development Office (WWDO) for submission to the WWDC. Prepared under our direct supervision, this report presents the results of a Fontenelle Dam and Outworks Infrastructure Completion Level II Study (Level II Study) to investigate the armoring of the unprotected portion of the upstream side of Fontenelle Dam (the Project).

Purpose The proposed project is intended to increase the usable storage capacity in Fontenelle Reservoir. For this analysis, the water supply benefit of the proposed project is considered to be 80,796 acre- feet of new active storage capacity in Fontenelle Reservoir. This is the volume of storage that is currently stored in the reservoir but is not accessible due to a lack of armoring to protect the lower interior dam face. The primary purpose of this Level II Study is to investigate the following:

. The economic benefits of added usable storage . Environmental considerations with armoring the Fontenelle Dam face and/or draining the reservoir . Comparative analysis of four alternatives to armoring the dam

These objectives are discussed in detail within the contents of this report.

Scope Work completed for the Fontenelle Dam and Outworks Level II Study included the following:

. Coordination and documentation of interagency planning meetings. . Scoping and other meetings with Project stakeholders. . Review of existing literature and other background information. . Investigation of the existing outlet works. . Investigation and hydraulic analysis of historic and future operations. . NEPA considerations. . Permitting. . Alternatives analysis for dam armoring. . Cost estimates of dam armoring alternatives. . Reservoir draining, filling, and construction scheduling. . Economic benefits analysis. . Project recommendations.

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Figure 1. Location map of Fontenelle Dam and Fontenelle Reservoir in Wyoming.

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The work that is within the scope is discussed in detail throughout the report. The Level II Study was completed with the understanding of existing literature and background information, personal site visits, and conversations with stakeholders, discussions with engineering and construction professionals, and at interagency meetings. The result of the Level II Study is a recommendation of one of the alternatives, as discussed in the final section of the report.

Project Meetings There were three, formal, documented interagency group meetings and several undocumented coordination efforts to ensure all groups are involved and updated on the Project progress. The EA Team involved the following entities in the coordination efforts:

. WWDO . U.S. Bureau of Reclamation (Reclamation or BOR), Provo Office . Reclamation, Fontenelle Office . Reclamation, Flaming Gorge Office . Wyoming State Engineer’s Office (WSEO) . U.S. Fish and Wildlife Service (USFWS) . Wyoming Game and Fish Department (WGFD) . Trout Unlimited . Seedskadee National Wildlife Refuge (NWR) . Bureau of Land Management (BLM) Rock Springs Field Office (RSFO)

The EA Team documented “Meeting Minutes” for the interagency group meetings. The Meeting Minutes consist of discussion topics, professional opinions, and comments concerning the environmental, economic, and engineering aspects of this Level II Study. Table 1-1 lists the interagency group meetings, the discussion topics, and when they took place. The Meeting Minutes are included in Appendix A.

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Table 1-1. Interagency group meetings with their corresponding topics and dates.

Meeting Topics Discussed Date Represented Agencies Interagency Project overview and scope, 9-26-2016 WWDO, EA, Seedskadee Meeting 1 existing riprap, WY water rights, NWR, Trout Unlimited, discharges during construction, BOR-Provo, BOR- water use, impact to species, Flaming Gorge, BOR- fisheries, power plant, next Fontenelle, WGFD, meeting time. USFWS, USFWS- Cheyenne, BLM-RSFO, WestWater, TriHydro Interagency Project overview and scope, 1-27-2017 WWDO, EA, Seedskadee Meeting 2 seasonal flows and reservoir depth, NWR, BOR-Provo, current snow-pack, dam outlet WGFD, Trout Unlimited, works, fisheries, trumpeter swans, TriHydro terrestrial species concerns, time considerations and scheduling, next steps. Interagency Project overview and scope, 6-30-2017 WWDO, WSEO, EA, Meeting 3 removal of burbot, fishery Seedskadee NWR, BOR- protection, sediment transport Provo, BOR-Flaming downstream, refill rate, power Gorge, BOR-Fontenelle, generation, discussion of four Trout Unlimited, WGFD, construction alternatives, USFWS, WestWater, economic analysis and TriHydro assumptions, next steps.

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BACKGROUND

Fontenelle Reservoir was originally part of the Bureau of Reclamation’s Seedskadee Project and was constructed with the purpose of developing irrigated agriculture in the upper Green River Basin. The dam was designed to have two outlets: East Canal and West Canal. Because the limited growing season and other environmental considerations the project was determined to not produce sufficient agriculture to make the Seedskadee Project economically viable. Since the project was determined to not produce sufficient agriculture the two canals were never used to provide water for agriculture and have remained nonoperational. The discharge of reservoir now feeds the Seedskadee National Wildlife Refuge and the Green River.

The construction of Fontenelle Dam started in 1961 and was completed in 1964. The dam stands 139 feet tall, 5,421 feet long and holds 345,360 acre-feet (AF) of water. As part of the original plan for the dam the upstream slope was armored from the crest of the dam (6,519 feet) down to an elevation of 6,480 feet. [Note: all elevations in this Level II Study are in units of feet, but the units are not included in the remainder of the report.] The armoring was not extended lower than 6,480 for cost savings, and according to the original design, the water level was not proposed to fall below 6,480 due to irrigating restraints. The water level below the armoring and above the low-level outlet (6,408) is referred to in this report as the inactive pool. The inactive pool is water than can physically be released through the dam, but the dam face would not be protected were it released.

During design and construction, there was concern about seepage from the dam’s right abutment, which was a steep, fractured rock face. On September 3, 1965, severe seepage was observed on the downstream face of the dam near the right abutment. Seepage continued and became worse despite the mitigation efforts. The reservoir was then drained to avoid a complete failure and the release of the contents of Fontenelle Reservoir. The main cause of the failure was determined to be mass seepage through the right embankment. This seepage turned into piping and further erosion of the dam embankment.

The dam was then repaired between 1965 and 1966. Repairs consisted of a rehabilitation of the right abutment connection and pressure-grouting down the center of the dam and the right abutment. Several observation wells were drilled and monitored to determine the adequacy of the grout that was placed. It was determined that the grout was not sufficient in decreasing seepage through the dam. Seepage continued to increase and the dam was drained in May 1985 for additional investigation and construction. A thick concrete cut-off wall was poured in the centerline of the dam through the right abutment. This concrete wall seems to have resolved seepage problems the dam was experiencing previously. Also, in 1985, additional riprap was added to the upstream face of the dam, lowering the inactive water surface from 6,480 to 6,457 and setting the current active and inactive capacities (264,000 AF and 80,796 AF respectively).

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The reservoir currently operates under 1962 water rights for 190,250 AF and 1973 water rights for 154,584 AF, and has approximately 563 AF of dead storage, for a total capacity of 345,397 AF. Of the 345,397AF of water available in Fontenelle Reservoir only 264,000 AF is accessible or “Active” due to the limitations of the armoring levels. Of the Active storage, 5,000 AF is allocated to Seedskadee NWR, 46,550 AF are under contract to four industrial water users, and the rest is currently unused (Figure 2). The inaccessible “Inactive” pool of 80,796 AF could be made available if the dam was armored from the current elevation of 6,457 to the bottom of the reservoir at 6,405.

At the present time, the State of Wyoming has the right to market 120,000 acre-feet from the U.S. Bureau of Reclamation (Reclamation or USBR) which owns and operates the storage facility. The Wyoming contract currently provides for a set of “readiness to serve” option contracts for industrial water users in the Green River Basin. The remaining 139,000 acre-feet of unreserved space within the active capacity of the reservoir is currently not contracted and is available for contracting to the State of Wyoming or another individual user. Wyoming has a right of first refusal to the active capacity of uncontracted space. BOR currently operates the reservoir storage for hydropower generation and recreational purposes.

Figure 2. Illustration of Fontenelle Reservoir Storage Pools. The figure shows the 120,000 AF of space currently contracted for use by the State of Wyoming, the 139,000 AF of active capacity which is currently not contracted and is managed by BOR, and the 80,796 AF which is currently inactive and is the subject storage being evaluated under this project. Figure provided by Wyoming Water Development Office. Note that bottom of existing riprap is now estimated to be at elevation 6,457.

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OUTLET WORKS AND POWERPLANT

An investigation of the existing outlet works was included as part of this Level II Study. Based on the historical drawings, Appendix B, The EA team has concluded that Fontenelle Dam has the following outlet works:

. River Outlet and Hydroelectric Diversion . Spillway . East Canal . West Canal The following sections discuss the outlet works in detail. Also discussed is the EA Team site visit on June 6, 2017.

River Outlet and Hydroelectric Diversion The River Outlet is the primary means of releasing water from the reservoir to the Green River. It is made up of three large conduits that are 14-foot wide by 14-foot tall arched culverts. The hydroelectric plant consists of a 10-megawatt (MW) generator with a 16,000 horsepower (hp) hydraulic turbine. Flows for power generation are diverted from the three large River Outlet conduits, with a maximum monthly average flow of 1,350 cfs. When the reservoir is drained, all water is routed through the River Outlet. The inlet elevation is at 6,408 (dead WSEL). The outlet can release up to about 19,000 cubic feet per second (cfs) at the reservoir max WSEL of 6,513. Figure 3 shows the elevation-discharge curve (see

Appendix B for original curve). Figure 4 shows the monthly production in megawatt-hours (MWH) averaged over the past 4 years (June 2013 to May 2017).

Power Generation The power plant operates when the reservoir elevation is high enough to avoid the creation of a vortex. It is our understanding that the pool elevation where a strong vortex begins to form (known as the critical submerged depth) is at the current minimum pool elevation, 6,457. It is possible to decrease the critical submerged depth by using one of the following known solutions: increase submergence, disrupt the angular momentum, force the vortex into a zone in which formation is difficult, increase the air of the intake to reduce velocities, or create a longer flow path to the surface (USBR, 2016b). Of these solutions, the three more practical alternatives for this project include of the installation of 1) an elongated trash rack to suppress the vortex, 2) a submerged raft to disrupt the swirling, or 3) a horizontal wall above the intake (Taghvaei et al, 2012; USBR, 2016b). The use of these alternatives could decrease the critical submerged depth, but they could also increase head loss and subsequently reduce power generation of the turbine. The ideal solution to alter a vortex and reduce critical submerged depth is project specific. If power generation is desired at a lower elevation than 6,457, an in-depth study on the project specific vortex may be warranted.

The modifications to the dam will result in greater availability of water to the power plant only if the allowable water level for outflow is reduced below the critical submerged depth. However,

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Figure 3. Elevation-discharge curve for the River Outlet works reproduced from the original Fontenelle Dam drawing set (1961) Sheet 154-D-43 which can be found in Appendix B.

Figure 4. Monthly average of Fontenelle power production over the past 4 years.

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inflow, outflow and contractual issues would most certainly have a greater impact than making provision for lower reservoir levels. At the existing operation limits, the powerhouse typically generates power year-round. An additional power generation unit could be constructed that is similar to the current powerhouse. The powerhouse would tap into one of the two untapped outlet pipes and generate power in a separate building. The cost of a new powerhouse would be comparable to the cost of the existing powerhouse, but at today’s rates. However, the new powerhouse would only generate additional power during May, June, and July, which is the typical timeframe where flows exceed the current powerhouse capacity. The second powerhouse would only be utilized in those three months and would not be in operation otherwise. The other option to utilized the exceeding flows during May, June, and July is to increase the height of the dam, thus increasing storage for that flow.

The installation of a new powerhouse or raising the dam would be a very significant undertaking and will require congressional approval. Any significant alterations or additions to the power plant would likely not be economical. Modifications and equipment upgrades to the powerhouse should be considered further in the future as the hardware ages. The power generation considerations are discussed more in Section 6.3.4.

Pressurized Pipe Flow Retrofit The downstream community has shown interest in a receiving pressurized flow from the Fontenelle Dam for irrigation, industrial, and municipal uses below the 6,400 contour. The Fontenelle Pipeline Review (WWDO, 2016) concludes that such a system would likely require pump stations, major dam, outlet modifications, and 100+ miles of large diameter pipeline. It has been estimated that this project would cost hundreds of millions of dollars, a cost that cannot be met by the current water users. Retrofitting the exiting outlet works to provide pressurized flow is not feasible unless substantial subsidization is available. In addition, a study would need to show that there is economic feasibility in agriculture in the proposed irrigation areas.

Spillway The Spillway is designed to only be needed for severe flood events. The inlet is a horseshoe- shaped, concrete, ogee weir approximately 300 feet in length. The Spillway channel is a 40-foot wide concrete channel that is at a 46% slope. The weir inlet elevation is at 6,506 and the Spillway can discharge up to 20,000 cfs at a maximum WSEL of 6,513. Figure 5 shows the spillway elevation-discharge curve (see Appendix B for original curve).

East Canal The East Canal has never been used for its original agricultural purposes. During the 1965 dam failure event, the East Canal was used to release water and lower the reservoir more quickly. Its inlet was closed when the concrete cut-off wall was installed in 1985.

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Figure 5. Spillway elevation-discharge curve.

West Canal Like the East Canal, the West Canal was only used once in efforts to rapidly lower the reservoir during the dam failure event in 1965. The West Canal has never been used for its original agricultural purposes. Site Visit On June 6, 2017, the EA Team and WWDO visited Fontenelle Dam and met with BOR to document the existing state of the outlet works, penstocks, and stilling basin to determine if the facilities will meet the release demands during construction. The group also looked at the upstream dam face, existing riprap, outlet works, potential construction routing, and to note other observations that pertain to the Level II Study. At the time of the visit, the reservoir WSEL was 6,479. The total flow being released was 8,400 cubic feet per second (cfs) with about 1,350 cfs being routed through the turbine. The generator was producing about 7 MW of power.

We looked at the East and West Canals, which are no longer operational. We investigated the Spillway from both on top of the dam and at the bottom of the dam. The Spillway looked to be in good condition. The River Outlet was operating when we were there. A proper investigation of the River Outlet would require stopping the flow, adding a coffer dam, and pumping water downstream similar to what has been done previously (see Photograph 15 of USBR, 2013c). The 2013 Annual Exam Report noted some degradation of the stilling basin. During the exam, exposed rebar was visible after draining the stilling basin. Repairs were made to the stilling basin chute blocks and surrounding area in 2013. The EA Team inspected the riprap that was above the current WSEL of 6,479. The riprap appeared to be in acceptable condition at the time of inspection. However, displacement of riprap and bedding were observed from the WSEL to about 10 feet

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above the WSEL (6,479 to 6,489). BOR is aware of this concern and is monitoring the riprap (USBR, 2013c). We recommend there be an evaluation of the riprap closer to the start of construction to determine any riprap maintenance needs. We went inside the buildings that house the turbine and control room. Based on our site visit, the outlet works, penstocks, and stilling basin will meet the release demands during construction based on the water stored in the reservoir. Capacities and outflows are discussed more in Section 6. Photos from the visit are included in Appendix C.

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ALTERNATIVES ANALYSIS

The goal of the alternatives analysis is to develop practical, conceptual alternatives for armoring the upstream face of the dam to access the inactive capacity of the reservoir. Several alternatives have been investigated in detail. Each alternative proposes a different approach to armoring the upstream, unprotected dam face from the bottom of the dam (approximately 6,400) to the bottom of the existing riprap (approximately 6,457) as seen in the drawings in Appendix B. The following criteria were used to evaluate the alternatives:

. Costs – Total project cost, which includes costs associated with design, draining the reservoir, construction, and NEPA. Loss of hydroelectricity generation is determined according to the duration and time of the year the reservoir is drained. . Constructability – Project duration, required specialized expertise, and specialized equipment needed for construction. . Environmental Impact – The construction and project scheduling for each alternative has been optimized to ensure the lowest environmental impacts. This includes the optimization of draining and filling the reservoir (if required) to minimize environmental impacts, as described previously.

In addition, the alternatives must protect the upstream face from wave action from the reservoir. The armoring material longevity is also of considerable importance but is not included in the alternatives analysis because all alternatives are predicted to provide a long (50+ years) service life. Maintenance is a notable criterion but is not included in the above list as it is discussed in the cost estimate section for each alternative.

Alternatives There are several feasible alternatives for armoring the upstream face of Fontenelle Dam. In this study, The EA Team has focused on the following four alternatives:

1. Riprap: Riprap consists of large angular boulders placed for erosion protection. Riprap can be placed all year round in a drained reservoir and can be placed underwater when the reservoir is not frozen. a. Drained Reservoir: If placed in a drained reservoir, the reservoir would be drained down to the dead pool elevation and 52,700 cubic yards (CY) of riprap would be placed on the upstream face of the dam. Riprap would be placed directly on the embankment fill, as was done during the 1985 repair, working along the face in 20- foot-wide strips (or as the contractor determines) running parallel to the dam. As the sections are placed, the reservoir water surface elevation would be raised until the project is completed and the reservoir can operate normally. b. Full Reservoir: If placed in a full reservoir, the riprap would be placed by use of barge and crane or “flexible fall-pipe”. The riprap would be lowered using a box- type container and emptied on the dam face. Another option is to dump the rock through the “flexible fall-pipe” that would act as a large tremie pipe. A team of

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divers would investigate the riprap to ensure adequate placement and coverage of the riprap. The dive team would communicate with the operator regarding locations needing additional riprap.

2. Soil Cement: Soil cement is a mix of sand, Portland cement, and water that is placed and compacted. It can be used as erosion protection on steep slopes (3:1 and 2:1) by using a stair-step placement technique. The reservoir would be drained to the dead pool elevation and 52,100 CY of soil cement would be placed on the upstream face of the dam. Soil cement would be mixed using a mobile twin-shaft mixing plant, placed in 6- to12-inch lifts, and compacted to acceptable conditions. The project is divided into 20-foot sections for analysis purposes. As progress is made, the reservoir water surface elevation would be raised until the project is completed and the reservoir can operate normally. Soil cement cannot be placed underwater or during cold weather.

3. Submar Mats: Submar Mats are a type of articulated concrete block mats (ACBMs) that are installed in large sheets (8 feet wide by 20 feet long by about 1 foot thick). This alternative involves placing the Submar Mats in a full reservoir by use of barge and crane. The mats would either be precast/fabricated on site or at a nearby concrete company and delivered to site. The protection would be lowered in sections (8 foot by 20-foot mats) by cables. A team of divers would be underwater to position the mats and tie them into the adjacent mats as needed. Submar Mats can also be placed in dry conditions, but dry placement was not considered for this project because the cost is much greater than riprap or soil cement.

4. Contech Wave Attack Blocks: Wave Attack Blocks are interlocking concrete blocks that can be used to armor for wave protection. Although they are usually used for marine applications, they can also be used for erosion control on dams. This alternative involves placing the Contech Wave Attack Blocks in a full reservoir by use of barge and crane. The blocks would either be precast/fabricated on site or at a nearby concrete company and delivered to site. The blocks would be lowered in sections (several units in a section) by cable. A team of divers would be underwater to position the sections and tie them into the adjacent blocks as needed. Wave Attack Blocks can also be placed in dry conditions, but dry placement is not considered for this project because the cost is much greater than riprap or soil cement.

The following sections describe each alternative in detail.

Riprap This alternative uses riprap to armor the dam face. Riprap is typically placed on dry surfaces, but it can also be placed in a full reservoir using a barge, crane, and dive team. The following sections describe the procedures and material quantities of the placing riprap in 1) a drained reservoir and 2) a full reservoir.

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4.1.1.1 Riprap Placed in Drained Reservoir This option is the most conventional dam armoring technique of the alternatives in this report. The existing armoring on the upstream side of the dam is also riprap. From elevation 6,480 to 6,519, there is a 5-foot-thick layer of 24 inch or greater (D50) riprap. The riprap is placed directly on the embankment fill, which consists of selected sand, gravel, and cobble compacted by crawler-type tractor to 8-inch layers (see drawings in Appendix B). According to the Appraisal Level evaluation (USBR, 2010), the original riprap was a Quartzitic Sandstone and has shown considerable degradation. In the Appraisal Level evaluation report, this type of rock was suggested to be avoided for use as riprap in the future. From elevation 6,457 to 6,480, a 24-inch (D50) riprap was placed in a 2-foot-thick layer. This section was placed in 1985 when the reservoir was drained to place the concrete cut-off wall in the center of the dam. The rock placed in this section was a dark gray rock and was considered to be more durable than the Quartzitic Sandstone that was previously used. This layer of riprap also was not placed on an additional bedding layer but was placed directly on the embankment fill. At elevation 6,457 there is a 15-foot horizontal bench that is not armored. Below this bench, the embankment has a 2:1 slope until about 6,442 where it changes to a 3:1 slope.

The EA team estimated that the dam face will require a 2.5-foot-thick layer of 24-inch (D50) riprap, similar to what was done in 1985, to protect from wave action, Calculations are provided in Appendix E. The riprap would be placed directly on the embankment fill, as was done with the most recent placement of riprap in 1985 and the original placement of riprap in the 1960s. Final wave runup and riprap sizing calculations should be done in the design phase of this project. A geotechnical investigation will be required to determine if the existing embankment surface will work for riprap bedding. Quality testing should be done on the riprap source to ensure adequate specific gravity, durability, soundness, and other requirements as defined in the specifications developed during the design stage.

The EA Team performed a material quantification to determine the amount of material needed to riprap the rest of the upstream side of Fontenelle Dam. This material quantification assumes the existing riprap starts at an elevation of 6,457 consistent across the width of the dam. The quantification considered the varying length of the dam at different elevations. Table 4-1 shows the quantities of riprap for 20-foot sections starting from the bottom and working up to elevation 6,457. The last section is the armoring of the 15-foot bench. The total quantity of required riprap for dry placement is 52,700 CY.

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Table 4-1. Quantity of riprap for each 20-foot section placed in the dry.

Riprap Section No. Elevation (CY) 1 6,400 to 6,420 6,400 2 6,420 to 6,440 21,900 3 6,440 to 6,457 18,800 4 Bench at 6,457 5,600 Total 52,700

There is a berm/bench that was installed in 1985 from elevation 6,442 to 6,457, just below the newest riprap (see drawings in Appendix B). While the Appraisal Level evaluation (USBR, 2010) suggested removing this bench before the placement of riprap, The EA Team suggests that the bench should remain during the placement of riprap. The bench would be used as a flat, easily drivable surface for haul trucks to dump the riprap from. The riprap would then be spread using a track-hoe excavator and/or dozer.

There are not any quarries around the project site that have 24-inch riprap. The Appraisal Level evaluation (USBR, 2010) listed several riprap locations that vary from 45 miles to 171 miles in haul distance. The EA Team contacted or attempted to contact these locations to confirm if they still have 52,700 CY of 24-inch D50 riprap. All of the locations either no longer had a sufficient amount of large riprap or did not respond. The EA Team contacted Gorge Rock Products to get an aggregate quotation for several of their quarries. Three of their quarry locations met the requirements for 24-inch D50 riprap:

. Atlantic City Gabbro (4-hour haul) . Brown Leucite (4-hour haul) . Big Sandy Granite (2.75-hour haul) – recommended source

4.1.1.2 Riprap Placed in Full Reservoir Armoring the upstream face of Fontenelle Dam without draining the reservoir would eliminate many short-term environmental concerns. The riprap would be placed from a barge crane while a dive team conducts quality control. This alternative is a less conventional method compared to placing riprap in dry conditions.

As with placing the riprap in dry conditions, a geotechnical investigation would be required to determine if the existing embankment surface will meet bedding requirements for the riprap. Also, quality testing should be done on the riprap to ensure its properties meet specifications defined during the design phase of this project.

A sectional barge would be mobilized to Fontenelle Reservoir. The barge and crane would likely be assembled and launched at either the boat ramp or the east side of the dam (photos 18 and 17

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of Appendix C, respectively). If the east side of the dam is used as access, then all materials would need to be hauled across the dam. Any damages to the road on top of the dam, or any roads using for hauling, would need to be repaired at the end of construction. Access road repairs are required for any of the alternatives selected. Figure 6 shows a potential site layout. Once the barge is anchored, riprap would be conveyed onto the barge or transferred by means of typical heavy loading equipment. The riprap would be lowered into the reservoir and placed using a box-shaped container with a releasable gate or similar. Another option is to place the riprap using “flexible fall-pipe” vessels, which act as very large-diameter tremie pipes. Rock falling through the pipe does not segregate, the placement is controlled by the feed rate and ship speed, and deposition of the rock is precisely controlled by telemetered positioning sensors at the discharge end of the pipe (Lagasse, 2006). A dive team would inspect and locate areas where riprap thickness does not meet the minimum design requirement and addition riprap is required. Inspections would need to be done by a professional and technically qualified dive team and may require the use of a dive chamber. This type of quality control could require test dives to determine if visibility is sufficient to confirm riprap coverage. If visibility does not allow for quality control from diving, then alternatives involving sonar locating and measurement should be considered. This process would continue until the entire upstream face of the dam has adequate riprap thickness and coverage.

The riprap size and thickness requirements would be same as placement in the dry: 2.5-foot-thick and a D50 of 24 inches. The quantity of riprap required for this alternative was estimated to be more than placing riprap when the reservoir is drained. A factor of 1.5 was applied to the riprap volume based on the assumption that this alternative would require 50% additional riprap to account for the placement and quality control limitations (Lagasse, 2006). Table 4-2 shows the quantities of riprap for 20-foot sections starting from the bottom and working up to elevation 6,457. For the underwater placement of riprap, is assumed that no excavation will be needed. The total quantity of required riprap for placement in a full reservoir is 79,100 CY. Underwater placement will take longer than placing on a drained reservoir.

Table 4-2. Quantity of riprap for each 20-foot section for placement in full reservoir.

Riprap Section No. Elevation (CY) 1 6,400 to 6,420 9,600 2 6,420 to 6,440 32,900 3 6,440 to 6,457 28,200 4 Bench at 6,457 8,400 Total 79,100

Soil Cement Soil cement is a mix of sand, Portland cement, and water that is placed and compacted and can be used as erosion protection on steep slopes (3:1 and 2:1) by using a stair-step placement technique.

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Figure 6. Potential site layout for construction.

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This alternative uses soil cement to armor the dam face. Soil cement can only be placed on a dry surface. Therefore, underwater placement is not discussed for this alternative. The following section describes the procedures and material quantities of draining the reservoir and placing soil cement on the dam face.

4.1.2.1 Soil Cement Placed in Drained Reservoir This alternative involves draining the reservoir and placing soil cement on the exposed dam face. Reclamation (USBR, 2013b) suggests that soil cement be considered as an alternative when riprap hauling distance exceeds 20 miles. Economically, soil cement becomes an increasingly feasible alternative to riprap as haul distance from the riprap source increases. However, soil cement is only feasible if there is an adequate sand borrow source nearby. It is assumed there is a nearby borrow source containing an adequate amount of sand to mix into the needed amount of soil cement to armor the area from elevation 6,400 to 6,457. During the June 6, 2017 site visit, two borrow sites were located within close proximity to the dam.

Typically, soil cement is placed in 6- to 12-inch lifts. The resulting inner nominal thickness of the soil cement is 2.5 feet at a 3:1 slope and 3.6 feet at a 2:1 slope. This inner nominal thickness is not dependent on lift thickness. Therefore, lift thickness should start at a conservative thickness of about 8 inches and increase toward 12 inches as testing ensures adequate compaction. Thicker lifts could potentially decrease construction time.

The cement ratio is an important component and affects the strength and cost of the material. This ratio typically ranges from 9-12% (cement to dry sand). Silts, clays, or a large percentage of fines in the sand should be avoided to allow for easier/better compaction of the material and so that the cement ratio can be low, which will reduce the price of the material.

The material quantification for soil cement assumes the existing riprap starts at a consistent elevation of 6,457. The quantification considered the varying length of the dam at different elevations. This analysis assumes 8-inch lifts, although increasing lift thickness should not change material quantities. As with riprap, the embankment fill should be sufficient bedding for the direct placement of soil cement. Table 4-3 shows the quantities of soil cement for 20-foot sections starting from the bottom and working up to elevation 6,457. The total quantity of required soil cement is 52,100 CY.

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Table 4-3. Quantity of soil cement for each 20-foot section.

Soil Cement Section No. Elevation (CY) 1 6,400 to 6,420 5,400 2 6,420 to 6,440 22,100 3 6,440 to 6,457 19,000 4 Bench at 6,457 5,600 Total 52,100

It is assumed that a 6-inch layer of embankment fill would need to be removed prior to the placement of bedding and soil cement. The quantity of this excavated material is 10,700 CY.

A mobile mixing plant would be used to mix the sand, cement, water, and additives. The soil cement would be either conveyed or trucked to the dam face for placement and compacted to the specified design density and moisture content (USBR, 2013b). It is important that the lifts be placed on top of each other with as little delay as possible. To further encourage interlayer bondage, a concrete slurry can be added before the placement of the next layer. The soil cement should be swept and a concrete slurry applied before the first layer of soil cement is placed at the start of each work day.

To prevent delay in mixing the soil cement, a material delivery lead time should be considered. Sand should be stockpiled within the proximity of the mixing plant, and the cement should be delivered at a rate sufficient to keep the mixing plant up and running.

Submar Mats Alternative 3 uses Submar Mats to armor the dam face. Submar Mats are a manufactured slope stability product that can be placed in both dry conditions and underwater. However, under drained reservoir conditions, riprap and soil cement are significantly less expensive to place than Submar Mats. Therefore, only placement in a full reservoir is analyzed for this alternative. The following sections describe the procedures and material quantities for placing Submar Mats in a full reservoir.

4.1.3.1 Submar Mats Placed in Full Reservoir The placement of Submar Mats is similar to placing riprap in the full reservoir, but the mats would be lowered into place using cables. This alternative has the major benefit, like placing riprap in a full reservoir, of not altering the reservoirs normal operations while construction is underway. Although more expensive than riprap, installing a manufactured product allows for a more consistent placement on the dam face, allows for better quality assurance, and provides a safer environment for the divers.

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According to the significant wave height and wave period, the Submar Mats would need to be 13- to 15-inches thick. Note the maximum manufactured size is 12 inches. Therefore, thicker mats would need to be made specific for this project. The mats would need to be precast either onsite or at a nearby ready-mix plant and then delivered to site. The typical size of Submar Mats is 8 feet wide by 20 feet long by about 1 foot thick. Submar Mats and other similar products have been used, tested, and proven to work on several bank stabilization projects.

The sectional barge and crane would be assembled at the boat ramp or at the east side of the dam. The manufactured erosion protection product would be conveyed or placed by other methods onto the barge. Then the erosion protection would be lowered by cables into the water and placed and anchored by the dive team as needed. This process would continue until the entire upstream face is covered by erosion protection.

It is assumed that the Submar Mats would be placed directly on the embankment, with no need for bedding or excavation of any kind. However, this assumption will need to be confirmed by the manufacturer. Different manufactures may have varying requirements of product thickness according to the significant wave height and wave period and according to their in-house calculations. The material for this alternative was quantified according to surface area (in square feet, SF) of material required to completely armor the upstream face of the dam from elevation 6,400 to 6,457. Table 4-4 shows the surface areas for 20-foot sections starting from the bottom and working up to elevation 6,457. The total surface area of dam face that needs armoring is 568,000 SF.

Table 4-4. Material quantification for placing Submar Mats in full reservoir according to surface area of the dam face requiring armoring.

Surface Area Section No. Elevation (SF) 1 6,400 to 6,420 60,000 2 6,420 to 6,440 203,000 3 6,440 to 6,457 236,000 4 Bench at 6,457 69,000 Total 568,000

Contech Wave Attack Blocks This alternative uses Contech Wave Attack Blocks to armor the dam face. Wave Attack Blocks are a manufactured slope stability product that can be placed in both dry conditions and underwater. However, riprap and soil cement are significantly less expensive to place in a drained reservoir. With its additional costs, dry placement benefits are minimal. Therefore, only placement in a full reservoir is analyzed for this alternative. The following sections describe the procedures and material quantities for placing Contech Wave Attack Blocks in a full reservoir.

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4.1.4.1 Wave Attack Blocks Placed in Full Reservoir This alternative has the major benefit of not altering the reservoir’s normal operations while construction is underway. This alternative is very similar to placing Submar Mats in the full reservoir, only the manufacturer product is different and it requires a bedding layer.

Contech Wave Attack Blocks would need to be 16-to 18-inches thick according to the significant wave height and wave period calculations and according to Contech’s block thickness calculations. Wave Attack Blocks are a new Contech product that is still in development. Unlike the erosion protection mats (Submar and similar), Wave Attack Blocks have not been widely used, tested, or proven to work.

Similar to the construction in the other alternatives involving underwater placement, the sectional barge and crane would be assembled at the boat ramp or at the east side of the dam. The manufactured erosion protection product would be conveyed or placed by other methods onto the barge. Then the Wave Attack Blocks would be lowered by cables into the water and placed and anchored by the dive team as needed. The blocks would be lowered in groups of 8 units tied together. This process would continue until the entire upstream face is covered by erosion protection.

Contech requires a 12-inch thick layer of bedding (3- to 4-inch D50) to be placed before the blocks are placed. The bedding would be placed using a box-shaped container with a releasable gate or similar. The material would be evenly spread out by divers using an I-beam with floats on each end. The material for this alternative was quantified according to surface area (in square feet, SF) for the Wave Attack Blocks and according to volume (in CY) for bedding required to completely armor the upstream face of the dam from elevation 6,400 to 6,457. Table 4-5 shows the surface areas for 20-foot sections starting from the bottom and working up to elevation 6,457. The last section is the armoring of the 15-foot bench. The total surface area of dam face that needs armoring is 568,000 SF.

Table 4-5. Required Material for placing Contech Wave Attack Blocks in the Full Reservoir

Bedding Surface Area Section No. Elevation (CY) (SF) 1 6,400 to 6,420 1,300 60,000 2 6,420 to 6,440 4,400 203,000 3 6,440 to 6,457 3,800 236,000 4 Bench at 6,457 1,200 69,000 Total 10,700 568,000

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Summary of Analysis Riprap is both relatively economical and flexible. However, the down side is that dry placement requires Fontenelle Reservoir to be drained. The biggest driver in cost is travel distance to get the riprap on site. The first riprap used on the dam was a Quartzitic Sandstone and has since shown weathering and degradation. This rock was from a local source and needs to be avoided. If another riprap source becomes available that is closer to Fontenelle Dam, then the price of this alternative could substantially decrease. It would be possible to use a combination of wet and dry placement of riprap. The quantity, cost, and duration would likely be somewhere between the dry placement and the wet placement.

Soil cement is not as flexible as the riprap because it cannot be placed without draining the reservoir and there is a small window in time when the soil cement would have to be placed. However, if a mixing plant is used that has a quick enough production rate, the project can be completed in a single summer. The main disadvantage with using soil cement is that it cannot be installed during freezing conditions. This alternative is relatively inexpensive.

Submar Mats and Contech Wave Attack Blocks are the most expensive alternatives. However, they both allow the upstream face of the dam to be armored while the reservoir is under normal operation. Erosion protection mats have also been used on other projects in the past and have been proven to work. The Wave Attack Blocks have not been tested in similar projects because they are a new Contech product. Table 4-6 shows the summary of criteria met for each of the alternatives.

All of the alternatives would require a Construction Emergency Action Plan with monitoring requirements that will be determined during the design phase of the project. Also, any construction on the dam would require repairs on haul roads, access ramps, and any other structures affected by construction. The contractor will need to discuss with BOR to identify and appropriately protect any monitoring or operating instrumentation that is within the construction zone prior to the start of construction.

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Table 4-6. Summary of criteria met for each of the alternatives.

RIPRAP SOIL CEMENT SUBMAR CONTECH Criteria (Alt 1) (Alt 2) (Alt 3) (Alt 4)

Material Readily Available X X Drain Reservoir and Dry X X X X Placement Under Water Placement X X X

Time of Construction Flexibility X X X

Conventional Design X X X

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NEPA CONSIDERATIONS

Trihydro Corporation (Trihydro), an EA Team member, investigated the potential environmental impacts and/or benefits of the Project. Following the completion of this project, future operations are not expected to change. However, there is potential for the reservoir to be lowered beyond the current inactive pool elevation of 6,457. As a result of a potential change in management of stored water and potential impacts during construction, the project may require environmental review under the National Environmental Policy Act (NEPA), coordinating with affected or interested federal and state agencies, and obtaining appropriate permits. These processes and coordination can be arduous, taking several years or more to complete. Investigations, modeling, and analyses completed under this section are developing information that will be used to support the NEPA environmental review.

NEPA Enacted in 1969, NEPA was one of many legislative and executive responses to the growing concern regarding the condition of the environment and effect of human actions. NEPA is an open, public involvement process that must be undertaken to evaluate projects that are located on federally managed or owned lands, projects funded with federal funds, and/or projects that require federal permits or other federal actions. The purpose of NEPA is to evaluate and avoid (if possible), or minimize and mitigate the environmental impacts resulting from projects that involve federal resources. The process requires analysis and documentation of potential adverse and beneficial effects of a proposed action and alternatives with an open public involvement process.

Following is an abridged discussion of the components of the NEPA process (as summarized in other Wyoming Water Development Office [WWDO] reports).

Purpose and Need Statement An accurate and defensible Purpose and Need statement should be developed early or before commencing the NEPA process. This statement should provide the purpose for the project and provide data or details to support the project need. Developing the Purpose and Need statement should provide enough information to develop and support a “reasonable range” of alternatives including a no-action alternative. More specifically, the Purpose and Need statement guides the alternative development and screening process and considers the agencies involved with the NEPA process (ACE, 2015).

Project Alternatives Appropriate alternatives, including a no-action alternative, are required to be evaluated under the NEPA process. This allows project sponsors, the lead and coordinating agencies, and the public to evaluate a range of impacts and benefits. Impacts typically considered as part of reservoir alternatives include but are not limited to: loss of or impacts to the nature of wetland or riparian areas, impacts to threatened and endangered species, impacts on aquatic species of concern, and impacts on other wildlife (e.g., sage grouse, big game, etc.) (ACE, 2015).

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While several armoring options were screened during the evaluation process or during consultation with agencies, one option may still be considered the preferred alternative. These other options may be evaluated during the NEPA process as alternatives to determine if they have lower environmental impacts (while still providing benefits) as compared to the preferred alternative. For example, the Contech Wave Attack Blocks option results in less environmental impacts during construction compared to draining the reservoir and placing riprap, but costs significantly more. However, the option could still be considered as an alternative under the NEPA process.

NEPA Documentation Path There are essentially three documentation options under NEPA. The first is an Environmental Impact Statement (EIS), which can evaluate multiple alternatives and can take several years to complete. The second option is an Environmental Assessment (EA), which can involve the analysis of one or more alternatives. While still requiring considerable time, an EA can often be completed in less than 18 months. The result of an EA is either a Finding of No Significant Impact (FONSI) or a recommendation to complete an EIS. The third is a Categorical Exclusion (CE), which evaluates the alternatives and determines that there is no significant impact. With a CE neither an EA or EIS is required; however, it is likely that this Project will not fall under a CE. The decision on which documentation approach to pursue will be determined by the lead NEPA agency. If there are no major changes to the long-term operations of the Fontenelle Reservoir, a less intensive process may be acceptable for NEPA documentation.

Public Involvement The NEPA process begins with public and agency outreach and related input focused on alternatives and potential impacts. Public outreach and involvement are critical to, and continuous through, the NEPA process. The level of involvement and input received can greatly affect the alternative development, alternative screening, issues addressed, mitigation measures, the level of NEPA documentation to be prepared (EA or EIS), and the selection of the preferred alternative (ACE, 2015). For these reasons, it is important that the public understands the Purpose and Need for the project and that the benefits and impacts associated with project alternatives are well documented and clearly presented. The process of informing the local public about the Project, its purpose, and the need for the Project has begun with the Interagency and public meetings held during the course of this Level II Study. However, additional public meetings and more rigorous public involvement may be associated with the NEPA process.

Environmental Baseline Data Collecting and analyzing comprehensive environmental data is an important step in the NEPA process. This data allows for analysis of impacts associated with alternatives. Collecting this information early in the project allows for the impacts to be considered and integrated into the development of alternatives, allowing for alternatives that are more likely to avoid or minimize impacts. Early field investigations and collaborating with agencies early in the process can help to focus this effort and streamline subsequent analysis methods, schedule needs, and budget requirements (ACE, 2015).

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Collection of baseline environmental data commenced during the Level II Study and coordination and requests for input from some of the key agencies that will be involved with the NEPA process were also initiated. This information is presented in later subsections.

EA or EIS The draft and final EA or EIS are developed to present an assessment of the project alternatives, and the benefits and impacts associated with each alternative. The document-development stages include: 1. Preparing a preliminary draft for internal review. 2. Preparing a draft that incorporates comments from the preliminary draft and may be circulated for public review (not required if an EA). 3. Preparing a preliminary final that incorporates feedback on the draft and is provided for internal review. 4. Preparing a final that incorporates comments on the preliminary final. This document may also be circulated for public review (not required if an EA). 5. A Record of Decision (ROD) (for an EIS) or Decision Record (for an EA) would then be prepared as the final step of the NEPA process.

Agency Coordination NEPA coordination will include those agencies involved in the NEPA process as well as agencies with other land use or environmental regulatory authority. Federal agencies that are likely to be involved with evaluation, clearance, approval, and permitting of alternatives for this Project include, but may not be limited to: . U.S. Bureau of Reclamation (Reclamation) . Bureau of Land Management (BLM) . Environmental Protection Agency (EPA) . United States Army Corps of Engineers (USACE) . Unites States Fish and Wildlife Service (USFWS) Because Fontenelle Reservoir is a Reclamation owned and operated facility, the lead NEPA agency would likely be Reclamation. Therefore, Reclamation will have discretion regarding what level of environmental review is required for the NEPA process. The level of review will depend on the proposed action and alternatives proposed. If there are significant long-term operational changes recommended as part of the alternatives to Fontenelle proposed, then Reclamation may assume that an EIS would be required for the project to comply with NEPA.

Wyoming state agencies that may be involved with the process include, but may not be limited to: . Wyoming State Engineer’s Office (WSEO) . Wyoming Game and Fish Department (WGFD)

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. Wyoming Department of Environmental Quality (WDEQ) . State Historic Preservation Office (SHPO)

Preliminary Consultations Initial consultations with agencies that are anticipated to be involved with the NEPA process and those responsible for managing potentially impacted resources were undertaken during the Project. Preferred armoring options and future operations were discussed with resource and permitting agencies to gain technical input regarding potential environmental and permitting concerns and approaches. Formal technical input was not submitted, but discussions are captured in the meeting minutes contained in Appendix A. The EA Team and the WWDO met with Reclamation, USFWS, Trout Unlimited, WGFD, and the WSEO on January 27, 2017 and June 30, 2017 to discuss the Project background, environmental and NEPA considerations, top armoring options, economics, and associated concerns/issues. The meetings also provided agency input on the environmental considerations and what level of NEPA would be required. Email responses were received from Reclamation on July 5, 2017 and from the USFWS on July 11, 2017 (Appendix D) regarding the June 30, 2017 presentation and potential issues/additional work needed by the Project. Agencies are anticipated to provide additional comments via a review of this Level II Report.

Environmental concerns and considerations identified through communication with these agencies and review of public documents is discussed in the following sections.

Environmental Considerations Environmental considerations regarding terrestrial resources; aquatic resources; wetlands; and issues, concerns, or considerations specific to the armoring alternatives are presented in the following sections.

Terrestrial Resources 5.3.1.1 Proposed, Threatened, Endangered, and Experimental Species The USFWS developed the Environmental Conservation Online System – Information for Planning and Conservation tool (ECOS-IPaC) (USFWS, 2016) to streamline the USFWS environmental-review process of potential listed species within a proposed project-development area. Proposed, threatened, endangered, and experimental species potentially affected by the proposed alternatives typically require a formal consultation with the USFWS. Formal consultation was not initiated during this Project and should be conducted in the future. Trihydro used the ECOS-IPaC tool to identify listed species within a defined area encompassing the four alternatives. From the ECOS-IPaC analysis, a resource list was reviewed (Appendix D). The species list fulfills requirements of the USFWS under Section 7(c) of the Endangered Species Act of 1973 as amended, (16 U.S.C. 1531 et seq.), the Migratory Bird Treaty Act (MBTA) (16 U.S.C 703), and the Bald and Golden Eagle Protection Act (BGEPA) (16 U.S.C. 668). If other alternatives are evaluated in the future, research on threatened and endangered species in those areas would still need to be conducted.

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Within the project area, impacts to 29 resources managed or regulated by the USFWS were identified by ECOS-IPaC. Of the 29 resources identified, four are listed as endangered species, two are listed as threatened species (Table 5-1), one is a facility (Seedskadee National Wildlife Refuge (NWR)) (Table 5-2), and 22 are migratory birds (Table 5-3); these resources are potentially affected by activities in the area of Fontenelle and downstream.

An Endangered Species Act (ESA) "action area" has not yet been determined, however, the project area likely overlaps with the critical habitat of the Yellow-billed-Cuckoo (Coccyzus americanus). According to USFWS, the Seedskadee NWR has proposed critical habitat for the Yellow-billed- Cuckoo. As indicated earlier, the Yellow-billed-Cuckoo is listed as a threatened species and will require consultation with the USFWS.

Table 5-1. List of endangered and threatened species and details.

Species Name Scientific Name FWS Status Has Critical Habitat Common Name

Birds Yellow-billed Cuckoo Coccyzus americanus Threatened Proposed Fishes Bonytail Chub Gila elegans Endangered Yes (outside project area) Colorado Pikeminnow Ptycholchelilus luscious Endangered Yes (outside project area) Humpback Chub Gila cypha Endangered Yes (outside project area) Razorback Sucker Xyrauchen texanus Endangered Yes (outside project area) Flowering Plants Ute Ladies'-tresses Spiranthes diluvialis Threatened None Note:

Proposed, candidate, threatened, and endangered species are managed by the Endangered Species Program of the U.S. Fish & Wildlife Service.

Table 5-2. List of facilities and details.

Facilities Condition(s) Any activity proposed on the NWR lands must Seedskadee National Wildlife Refuge undergo a "Compatibility Determination" conducted by the Refuge

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Table 5-3. List of migratory birds and details.

Species Name Bird of Conservation Scientific Name Season Common Name Concern (BCC)

Migratory Birds American Bittern Botaurus lentiginosus Breeding Yes Bald Eagle Haliaeetus leucocephalus Year-round Yes Black Rosy-finch Leucosticte atrata Year-round Yes Brewer's Sparrow Spizella breweri Breeding Yes Burrowing Owl Athene cunicularia Breeding Yes Calliope Hummingbird Stellula calliope Migrating Yes Cassin's Finch Carpodacus cassinii Year-round Yes Ferruginous Hawk Buteo regalis Breeding Yes Fox Sparrow Passerella iliaca Breeding Yes Golden Eagle Aquila chrysaetos Year-round Yes Greater Sage-Grouse Centrocercus urophasianus Year-round Yes Loggerhead Shrike Lanius ludovicianus Breeding Yes Long-billed Curlew Numenius americanus Breeding Yes Mountain Plover Charadrius montanus Breeding Yes Olive-sided Flycatcher Contopus cooperi Breeding Yes Peregrine Falcon Falco peregrinus Breeding Yes Rufous Hummingbird Selasphorus rufus Migrating Yes Sage Thrasher Oreoscoptes montanus Breeding Yes Short-eared Owl Asio flammeus Year-round Yes Swainson's Hawk Buteo swainsoni Breeding Yes Western Grebe Aechmophorus occidentalis Breeding Yes Willow Flycatcher Empidonax traillii Breeding Yes Note:

Birds are protected by the Migratory Bird Treaty Act and the Bald and Golden Eagle Protection Act.

5.3.1.2 Colorado River System – Endangered Species In 1988, the Upper Colorado River Endangered Fish Recovery Program was established to help the recovery of four species of endangered fish: the humpback chub, bonytail, Colorado pikeminnow, and razorback sucker. The goal of recovery is to achieve natural, self-sustaining populations of the endangered fish so they no longer require protection under the federal Endangered Species Act. While extremely unlikely, because Fontenelle is located within the Colorado River Basin, changes in future operations may lead to impacts to Upper Colorado River Endangered Fish Recovery Program. However, the program provides the ESA compliance and no additional consultation should be necessary.

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5.3.1.3 Migratory Birds, Bald Eagles Federal agencies have an obligation to protect all species of migratory birds, including eagles and other raptors, that may occur on lands under their jurisdiction. These birds are protected under the MBTA, BGEPA, and Executive Order 13186 (66 FR 3853; January 17, 2001). Under the MBTA it is unlawful to pursue, hunt, take, capture, kill, or sell birds listed as migratory birds (a list of MBTA-protected Migratory Birds can be found on the USFWS website at www.fws.gov). The statute does not discriminate between live and dead birds and grants full protection to any bird parts including feathers, eggs, and nests. The BGEPA prohibits anyone, without a permit issued by the Secretary of the Interior, from pursuing, shooting, shooting at, poisoning, wounding, killing, capturing, trapping, collecting, molesting, or disturbing Bald Eagles or Golden Eagles, including their parts, nests, or eggs. Work that could lead to the taking of a migratory bird or eagle, their young, eggs, or nests should be coordinated with the USFWS before any actions are taken. As discussed in the January 27, 2017 Interagency meeting, potential riparian degradation is possible under significant, long-term, operational changes to the dam, and there might be minor impacts to eagles. Additional analysis may be required in the future.

The Trumpeter Swan (Cygnus buccinator) is not a listed species, however, there is concern that if the reservoir is dropped to install armoring, flows downstream will be reduced enough to result in freezing of the Green River through the Refuge. Trumpeter Swans were not present in the area before transplanting in 1991 but the area now produces 50% of the Trumpeter Swans in Wyoming. As discussed in the January 27, 2017 Interagency meeting, if much of the downstream reach freezes, swans may not have an adequate food resource and could possibly die or leave without returning. Uniform water flows from Fontenelle are to be kept at or above approximately 1,000 cfs to avoid freezing in the Green River as well as to protect the fishery. Additional analysis may be required in the future during the NEPA process.

Aquatic Resources 5.3.2.1 Fisheries and Other Aquatic Resources From the ECOS-IPaC analysis, four fish species were identified as endangered (Table 5-1), but the area of interest was outside the designated critical habitat. Responses received by Reclamation indicated that, to their knowledge, the four species do not occur above Flaming Gorge dam. They also mentioned that these species would come up on the ECOS-IPaC list, but they will be “no effect” species. These species are included on the list because any water depletion from the Upper Colorado River Basin would result in a jeopardy ruling for any specific project (USBR, 2013a). It is not anticipated that the proposed project will deplete water from the basin. Additional consultation with the WGFD and the USFWS needs to be completed to confirm the ranges of these endangered species.

Depending on the alternative selected, the reservoir may or may not need to be drained to install the armoring. If the reservoir is lowered, there is potential that fish could experience colder conditions during the winter. Also, if the reservoir is drained, the lake fishery could be lost and could take an estimated 5 to 8 years to recover.

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As discussed earlier, it is presumed that the Green River downstream of Fontenelle may ice over when water flows are less than approximately 1,000 cfs during the winter months. Uniform winter flows are needed to protect the downstream fishery. If discharge from the dam fluctuates in the winter, a higher fish mortality rate could result. Cold winter conditions could result in much of the river completely freezing (without warm water being released from the reservoir), making for difficult conditions for downstream fish. Lower winter flows could also reduce water levels exposing fish to predators. Similar to winter temperatures, the downstream fishery could be negatively impacted during the summer months if high summer water temperatures were recorded. According to the USFWS, the thermocline that currently develops in the reservoir during the summer keeps the released water temperatures cool enough to support a cold-water trout fishery downstream. Additional water temperature modeling may be required to predict temperatures in the reservoir, and downstream, once the preferred alternative is moved forward.

If the reservoir is drawn down, accumulated sediment within the reservoir could be released and potentially impact the downstream fishery, aquatic resources, and the water delivery system. According to the USFWS, sediment has likely accumulated behind the dam since construction, and mobilization of large amounts of sediment in a short period of time could transfer sediment from Fontenelle Reservoir to the Green River below the dam, including through Seedskadee NWR, the City of Green River, and Jim Bridger Power Plant. It was outside of this Project’s scope, but additional analysis of the potential for sediment to be released if the reservoir is drained may need to be completed.

Wetland Resources Recognizing the potential for continued loss or degradation of the Nation's waters, the United States Congress enacted the Clean Water Act, formerly known as the Federal Water Pollution Control Act (FWPCA) (33 U.S.C. 1344). The objective of the FWPCA is to maintain and restore the chemical, physical, and biological integrity of the waters of the United States, including wetlands. Riparian areas and wetlands are ecologically important as they aid in maintaining stream flows, reducing erosion, and providing wildlife habitat.

Wetland development and management has been the primary focus at Seedskadee NWR since its creation (USFWS, 2014). The Seedskadee NWR supplies water to their wetlands through a gravity fed water delivery system that fills temporarily, seasonally, and semi-permanently flooded wetlands on the Refuge. A majority of the water diverted returns to the river system through return flows. An evaluation of the intakes and potential modifications to the intakes to ensure that water can be diverted to the system during construction was beyond the scope of this Level II Study and was not conducted. A formal analysis of the lowest flows in the Green River during construction relative to the intakes will be required before, or as part of the NEPA process, to determine the level of impacts to wetlands and potential mitigation measures. A wetland investigation will also be required downstream of the dam and through the Seedskadee NWR before or during NEPA in order to determine the area of wetlands that could be temporarily inundated by an increase in flow from the Fontenelle dam. Proposed drawdown releases will be significantly less than historical peak stream flows below the dam, barring the highly unlikely occurrence of historical peak inflows

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at the same time of reservoir drawdown. The wetland species will be evaluated to determine if areas may benefit from periodic submergence and hence will not be impacted by the proposed alternative. A more formal consultation may need to be initiated with the USFWS, Seedskadee NWR, WGFD, and the USACE in the next level to check that the water delivery systems to the Refuge, City of Green River, and Jim Bridger Power plant are not affected and if wetlands will be impacted.

Environmental Alternatives Evaluations It is assumed that each armoring option for construction would generally require the same amount of NEPA process and field analyses, primarily because post-construction impacts (e.g., operational water level changes) would be the same for all alternatives. The construction phase of NEPA will also be approximately the same for all options because agency coordination to address their concerns is required regardless of the type of construction.

Permitting, Clearances, and Approvals Applications for permits and coordination for clearances and approvals should be coordinated with the NEPA process, as much of the information and analyses required will overlap. A summary of anticipated permits and consultations is provided below.

Section 404 Permit Section 404 of the Clean Water Act (CWA) regulates the discharge of dredged or fill material into waters of the United States and a Dredge and Fill permit is required for potentially significant impacts. Individual permits are reviewed by the USACE. Specifically, for this Project, dredge or fill that is placed above the Ordinary High-Water Mark (OHWM) will require a Section 404 permit. Corps regulations define the term “OHWM” (USACE, 2005) as: “…that line on the shore established by the fluctuations of water and indicated by physical characteristics such as a clear, natural line impressed on the bank, shelving, changes in the character of soil, destruction of terrestrial vegetation, the presence of litter and debris, or other appropriate means that consider the characteristics of the surrounding areas.” If disturbances occur below the OHWM, the Project could be covered under a Nationwide Maintenance Permit (NWP) authorized by 33 CFR 330.3. The NWP authorizes the removal of accumulated sediment and debris near existing structures and/or the placement of new or additional riprap to protect the structure. If disturbances are made above the OHWM, then it is likely that this will be an important permit required for the Project and could take several years to obtain. Alternatively, if construction is below the OHWM, then no permit will be required and work can be covered as maintenance. The OWHM was not estimated during the Level II Study, however, because armoring will be placed in the inactive capacity pool of the reservoir, it is assumed that all disturbances will be below the OHWM. Determination of whether this Project would fall under a Section 404 permit or covered as maintenance will need to be initiated by Reclamation and determined by the USACE.

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Endangered Species Action (Section 7 Consultation) A biological assessment will be required as part of the NEPA process; it is typically prepared by the lead NEPA agency or their contractor. The assessment results will be provided to the USFWS and they will issue an opinion on whether or not the action jeopardizes threatened or endangered species or their habitat.

Fish and Wildlife Coordination Act This act requires that agencies take action to protect fish and wildlife resources that may be affected by control or structural stream modification. The act requires consultation with state and federal wildlife agencies to assess impacts and mitigate or compensate for these impacts.

Cultural Resources Coordination and Consultation Assessment of potential impacts to cultural resources will likely be required downstream if water levels are proposed to increase dramatically. Delineation of cultural resources and evaluation of alternative impacts will be coordinated with the SHPO. Impacts must be considered under the following:

. 1966 National Historic Preservation Act (NHPA) (16 U.S.C. § 470 et seq.) . NEPA . 1979 Archaeological Resources Protection Act (ARPA) (16 U.S.C. §470aa et seq.) . Advisory Council on Historic Preservation's Procedures for the Protection of Cultural Properties (36 CFR Part 800) . 1980 Treatment of Archaeological Properties: Determination of Eligibility for Inclusion in the National Register of Historic Places (National Register) (36 CFR 63) . 1983 Secretary of Interior’s Standards and Guidelines for Archaeological Historical Preservation; Reservoir Salvage Act of 1960 . l974 Amendment to the Reservoir Salvage Act of 1960 (ACE, 2015).

Coordination and consultation with pertinent Native American groups may also be required.

Permit to Construct / Dam Safety Review The armoring options will likely require approval by the WSEO. The approval depends on the WSEO’s approval of construction plans and specifications. The design, construction, and operation of these facilities must also comply with the Dam Safety Act regulations.

National Pollution Discharge Elimination System (NPDES) Permit and Section 401 Certification The Wyoming Department of Environmental Quality (WDEQ) Water Quality Division (WQD) administers the Clean Water Act (CWA) in combination with the Wyoming Environmental Quality Act. Under this regulation, detailed in Chapter 2 of the Wyoming Water Quality Rules

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and Regulations, facilities or construction projects that may discharge stormwater are required to obtain a permit through the Wyoming Pollution Discharge Elimination System (WPDES). Depending on the area disturbed, a Small or Large Construction General Permit may be required. To obtain a permit, a Stormwater Pollution Prevention Plan (SWPPP) must be prepared and submitted with a Notice of Intent (NOI) form to the WDEQ WQD at least 30 days before initiation of construction activities.

Mining Permit A mining permit is not required for development of a borrow source that will be used solely for modifying the reservoir. However, material vendors are required to hold appropriate permits.

Special Use Permits / ROWs / Easements Temporary or permanent special-use permits, ROWs, and/or easements may be required for construction features including access roads. The process and requirements for these vary with the agency or the type of land ownership (federal, state, and private).

Others Other temporary permits may be required as part of construction and operation, including permits that would typically be obtained by the general contractor.

Summary Based on the analysis and findings listed above, it is the project team’s opinion that most NEPA considerations are associated with long-term environmental effects that result from changes in future operations of Fontenelle Reservoir and short-term effects due to construction. The various alternatives discussed in this report have the same result: the Fontenelle Dam will be completely armored and the reservoir’s active volume will increase. The alternatives that drain the reservoir will require a more intensive focus on the sort-term effects due to construction. In summary, the NEPA process will be required for any of the selected alternatives. It is likely that the Project will fall under an EA or an EIS. If there are no major changes to the operation of the Fontenelle Reservoir because of the Project, EA may be acceptable for NEPA documentation. However, it is possible the EA will not result in a FONSI and an EIS would be required, which would cause delay. The documentation approach will be determined by the lead NEPA agency on the Project.

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HYDRAULIC ANALYSIS OF HISTORIC AND FUTURE OPERATIONS

This section of the report discusses the hydrologic analysis and potential impacts of the Project. Included is a summary of historic reservoir operations and scenarios for reservoir drawdown during construction on reservoir levels and flows. Also included is a discussion of the Colorado River Compact as related to the Project. Some of the contracting leases and requirements relevant to this project are discussed in Section 9.6.

Historic Reservoir Operations A review of historic reservoir operations was conducted based on historical data provided by Reclamation (USBR, 2017a). Monthly inflow, outflow, and reservoir storage content data are available for the years 1966 – 2016. Additionally, monthly power release data are available for the period 1993-2016. Annual inflows to Fontenelle Reservoir for the period 1966-2016 are illustrated on Figure 7. Over this 51-year period, the average annual inflows were 1,129,000 AF. The maximum annual inflow is 2,246,000 AF (1986) and the minimum is 468,000 AF (1977). Monthly average inflows to and outflows from Fontenelle Reservoir are shown on Figure 8 and the average monthly distribution of inflows and outflows is illustrated on Figure 9 and summarized in Table 6-1. While this table does include the drawdown during the 1980’s, the long-term inflow and outflow averages developed over the 51-year period of record were not significantly affected by this event.

Table 6-1. Fontenelle average monthly inflow and outflows.

Avg. Mo. Avg. Mo. Inflows Outflows (AF) Month (AF) Jan 30,887 54,280 Feb 28,889 51,217 Mar 50,529 59,114 Apr 88,288 81,856 May 175,253 133,121 Jun 317,842 242,274 Jul 188,626 176,680 Aug 77,483 92,534 Sep 47,880 68,633 Oct 48,565 61,205 Nov 41,668 53,908 Dec 32,652 53,567 Total 1,128,561 1,126,992

These data illustrate typical annual reservoir operations involving storing flows in the spring (April – July) and releasing stored flows throughout the remainder of the year for power generation.

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Fontenelle Annual Inflows (AF) 2,500,000

2,000,000

1,500,000

1,000,000 Annual Inflows (AF) Inflows Annual 500,000

0 1960 1970 1980 1990 2000 2010 2020

Figure 7. Fontenelle annual inflows.

Fontenelle Monthly Inflows and Outflows (cfs) 16,000

14,000

12,000

10,000

8,000

6,000 Avg. MonthlyAvg. Flow (cfs) 4,000

2,000

0 December-62 March-71 May-79 August-87 October-95 January-04 April-12 Inflows Outflows

Figure 8. Fontenelle monthly inflows and outflows.

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Fontenelle Avg. Monthly Inflows and Outflows (cfs) 6,000

5,000

4,000

3,000

2,000

Monthly Inflows (cfs) Inflows Monthly 1,000

0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Inflows Outflows

Figure 9. Fontenelle average monthly inflow and outflows.

Historical monthly reservoir storage data for the period 1966-2016 are provided on Figure 10. These data show that the reservoir typically operates between 345,360 and 160,000 AF. These data also illustrate the initial filling of the reservoir in the early-1960s and the evacuation of the reservoir in 1985 when the dam's right abutment developed a leak. A concrete diaphragm wall was built through the core of the dam to stop leakage. The 51-year average end-of-month (EOM) storage volumes are summarized on Figure 11 and in Table 6-2. When the data from the initial filling and the 1980’s emergency drawdown are excluded, adjusted average reservoir contents as shown in Table 6-3 result.

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Fontenelle Historic Storage (AF) 400,000

350,000

300,000

250,000

200,000

150,000 Fontenelle Fontenelle (AF)Storage

100,000

50,000

0 Dec-62 Dec-72 Dec-82 Dec-92 Dec-02 Dec-12

Figure 10. Fontenelle historic storage.

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Fontenelle Avg. EOM Contents 350,000

300,000

250,000

200,000

150,000 Avg. End of Month Storage (AF) 100,000 Adjusted Avg. End of Month

Fontenelle Avg. EOMContents (AF) Storage (AF) 50,000

0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Figure 11. Fontenelle average end-of-month contents.

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Table 6-2. Fontenelle monthly average, maximum, and minimum end-of-month contents.

Avg. End Avg. End Max. End Max. End Min. End Min. End of Month of Month of Month of Month of Month of Month Month Storage Storage Storage Storage Storage Storage (AF) (Elev) (AF) (Elev) (AF) (Elev)

Jan 176,051 6,481.9 279,437 6,499.6 30,795 6,442.6 Feb 150,830 6,476.3 227,600 6,491.8 31,593 6,442.9 Mar 140,020 6,473.8 223,533 6,491.1 34,805 6,444.0 Apr 145,200 6,475.0 222,737 6,491.0 28,274 6,441.8 May 186,296 6,484.1 344,055 6,506.3 30,859 6,442.7 Jun 266,855 6,497.9 365,695 6,507.8 29,606 6,442.3 Jul 284,464 6,500.3 359,339 6,507.4 30,538 6,442.6 Aug 268,781 6,498.2 345,021 6,506.4 29,522 6,442.2 Sep 254,159 6,496.1 343,172 6,506.3 32,465 6,443.2 Oct 239,837 6,493.9 341,809 6,506.1 32,070 6,443.1 Nov 225,602 6,491.5 323,939 6,504.6 31,657 6,442.9 Dec 201,218 6,487.0 314,326 6,503.7 31,570 6,442.9

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Table 6-3. Fontenelle Adjusted monthly average, maximum, and minimum end-of-month contents.

Adjusted Avg. End Max. End Max. End Min. End Min. End Avg. End of Month of Month of Month of Month of Month Month of Month Storage Storage Storage Storage Storage Storage (Elev) (AF) (Elev) (AF) (Elev) (AF) Jan 188,551 6,484.5 279,437 6,499.6 120,994 6,469.0 Feb 160,969 6,478.6 227,600 6,491.8 96,431 6,462.5 Mar 148,474 6,475.8 223,533 6,491.1 98,425 6,463.0 Apr 154,441 6,477.2 222,737 6,491.0 91,896 6,461.2 May 202,378 6,487.3 344,055 6,506.3 106,054 6,465.1 Jun 284,616 6,500.3 365,695 6,507.8 175,999 6,481.9 Jul 306,553 6,502.8 359,339 6,507.4 177,988 6,482.3 Aug 289,403 6,500.9 345,021 6,506.4 178,787 6,482.5 Sep 274,418 6,499.0 343,172 6,506.3 164,576 6,479.4 Oct 259,197 6,496.8 341,809 6,506.1 152,639 6,476.7 Nov 243,760 6,494.5 323,939 6,504.6 152,941 6,476.8 Dec 217,497 6,490.1 314,326 6,503.7 147,380 6,475.5

Fontenelle Power Plant is located adjacent to the toe of the dam, with the power penstock branching from the river outlet works. The power plant consists of one 10,000-kilowatt generator and one 16,000-horsepower hydraulic turbine. Starting in 1993, data on flows for power generation are available (USBR, 2017a). Reclamation also keeps data on discharges through the turbines starting in 1993. Based on an analysis of the 1993 to 2016 data the following comparison with total outflows can be derived; the data show that average monthly power discharge typically varies between 750 cfs and 1,300 cfs, as shown on Figure 12.

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Fontenelle Avg. Power Releases (cfs) 1,600

1,400

1,200

1,000

800

600

400

200

Fontenelle Avg. Avg. (cfs) Mo.Power Releases Fontenelle 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Figure 12. Fontenelle average monthly power releases.

Reservoir Potential Yield To examine the long-term yield potential of Fontenelle Reservoir the StateMod model developed as part of the Green River Basin Plan was used (WWCE, 2010; CDWR, 2015). As the purpose of this analysis was to characterize Fontenelle Reservoir, the existing model was stripped down to just the reservoir itself. Actual historic monthly inflows were substituted for the modeled inflows and reservoir operations were simulated using a set of assumed demands. Reservoir operations were examined over the 49-year period, 1967 to 2015, and it was assumed that the entire active capacity of 344,797 AF was available for use. Uniform monthly demands were assumed in order to quantify reservoir yields and one-fill regulations were assumed to be in effect. On this basis, the Firm Yield of the reservoir was determined to be 300,000 AF per year and the 80% Firm Yield is 312,000 AF per year. These values represent the reservoir yields available for procurement purposes to users like municipal and industrial that typically require higher levels of reliability for water supply than irrigation.

Construction Reservoir Drawdown Scenarios To examine potential reservoir levels from various construction drawdown alternatives, three scenarios were examined:

. Spring drawdown (Mar - Jul) . Fall drawdown (Oct - Mar) . Summer drawdown (May - Oct)

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Each of these scenarios is examined in more detail in the following sections.

Scenario #1 – Spring Drawdown Under this scenario, drawdown of the reservoir would begin in March and continue through the end of July. Note that reclamation’s spring operation typically does not begin major releases from Fontenelle until the treat of ice jamming above Green River, WY is lessened. Ice jamming should be considered if a spring drawdown is carried out. Construction would then take place from August to February. During construction, inflows would essentially be passed through the empty reservoir. High inflows during construction could potentially flood downstream properties and communities. These concerns are increased in the winter after ice forms on the river and ice jamming can cause significant localized flooding. Weather forecasts and river flows should be carefully monitored during construction, and proper measures should be taken to prevent loss of property due to flooding downstream. Re-filling of the reservoir would begin the following March. Table 6-4 and Figure 13 examine discharges below the dam during reservoir initial drawdown period under average flow conditions and for the highest and lowest flows on record for the period.

Fontenelle Reservoir Avg. Mo. Flows below dam during Drawdown Scenario #1 14,000

12,000

10,000

8,000

6,000

4,000

2,000

-

Avg. Mo. Discharge Fontenelle Mo. Bel. Avg. (cfs) Mar Apr May Jun Jul

Highest Year (1986) Highest Year w/Drawdown Average Year Average Year w/Drawdown Lowest Year (1977) Lowest Year w/Drawdown

Figure 13. Fontenelle average monthly flows below dam during drawdown scenario #1.

The starting point for the drawdown analysis is the February average end of month (EOM) reservoir content of 161,000 AF. For this analysis, adjusted EOM values were used that excluded the low reservoir contents during initial filling and emergency repairs in the mid-1980s. During an average year, typical Fontenelle outflows are 2,289 cfs for this four-month period. To drain the average 161,000 AF over the next four-month period average releases would need to be increased

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from 2,289 to 2,821 cfs (23% increase) to accommodate spring runoff as well as simultaneously drawdown reservoir storage levels. Similar data for the highest and lowest years on record are summarized in Table 6-4.

Table 6-4. Fontenelle spring drawdown scenario #1.

Mar-Jul Mar-July Outflows % Increase Due Outflows w/Drawdown to Reservoir (avg. CFS) (avg. CFS) Draining Average Yr. 2,289 2,821 23% Highest Yr. (1986) 5,940 6,472 9% Lowest Yr. (1977) 529 1,059 100%

As discussed, under this scenario, it is assumed that construction is completed on the armoring installation in the August to February period such that re-filling of the reservoir can begin in March of the following spring to take advantage of the naturally rising inflows. Unlike other scenarios, refilling is purposely delayed until the spring months to minimize impacts on winder flows and better take advantage of the springs naturally rising inflows. Subsequent scenarios will model refilling at a rate of 10-foot per month “on the heels of” armor placement as it works its way up the dam face.

Refilling operations were examined by modeling average spring (March to July) inflows as well as the extremes (highest and lowest). A summary of this analysis is provided in Table 6-5.

Table 6-5. Fontenelle reservoir – refilling, scenario #1.

Mar-July Flows bel. Mar-Jul Mar-Jul Mar-July Outflows Dam Inflows Outflows Mar-Jul Outflows w/Refill during (Total (Total Outflows w/Refill (Total Refill as % AF) AF) (Avg. CFS) (Avg. CFS) AF) of Historic Refill Volume = 345,360 AF Average Yr. 820,538 693,045 2,289 1,570 475,178 69% Highest Yr. (1986) 1,915,451 1,797,554 5,940 5,189 1,570,091 87% Lowest Yr. (1977) 279,211 160,442 529 0 0 NA

These data show that the average spring inflows total approximately 820,000 AF. Under normal conditions, flows below the dam during this period are approximately 693,000 AF; however, due to the need to fill the reservoir these flows would be reduced to approximately 475,000 AF (or 69% of normal). Under the Highest Year conditions, the relative impacts on flows below the dam

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are reduced significantly to just 87% of normal. Under extreme low flow conditions (lowest year on record), however, only about 280,000 AF of total reservoir inflows would exist. In this event, storing all inflows and reducing stream flow below the dam to zero would still be insufficient to fill the reservoir. Therefore, under this scenario, it is assumed that filling would be suspended and delayed until the following spring in order to minimize impacts on flows below the dam. These re-fill possibilities are illustrated on Figure 14.

To better define the risk that refill might need to be spread out over two years, flow-frequency figures (Figure 15 and Figure 16) were prepared based on total Fontenelle March to July inflows on a one-year and two-consecutive-year basis. These graphs show that 700,000 AF (roughly double the 345,360 AF re-fill volume) is available about 75% of the time. Furthermore, the two- year spring runoff volume totals are consistently well over 1 million AF, ensuring a statistically high probability in re-filling over a two-year period.

Scenario #2 – Fall/Winter Drawdown Under this second scenario, drawdown of the reservoir would begin in October and continue through the winter to the end of March. The longer drawdown period was selected to minimize impacts on winter flows below the dam. Assuming sufficiently dry conditions, construction would then begin in April. During construction, weather forecasts and flows should be closely monitored. Appropriate measures should be taken to prevent flooding of property downstream of the reservoir. Starting on June 1 it was assumed that the reservoir could begin refilling at the approximate rate of 10-feet per month until reservoir levels reached an elevation of 6,457, which is the bottom of existing riprap. Under this scenario, re-filling would follow “on the heels of” armor placement as it works its way up the dam face. Once the slope armoring is complete, the reservoir can return to normal operations above 6,457.

Table 6-6 and Figure 17 examine discharges below the dam during the reservoir initial drawdown period under average flow conditions and for the highest and lowest flows on record for the period. The starting point for the drawdown analysis is the average end of September reservoir content of 274,000 AF. During an average year, typical Fontenelle outflows average 917 cfs for this six- month period. To drain the average 274,000 AF over the next six-month period while by-passing all inflows, average releases would need to be increased from 917 to 1,680 cfs (83% increase). Similar data for the highest and lowest years on record are summarized in Table 6-6. These results are graphically illustrated on Figure 17 on a monthly basis.

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Fontenelle Reservoir Reservoir Contents during Constuction 400,000 350,000 300,000 250,000 200,000 150,000 100,000

Fontenelle Volume (AF) 50,000 0 Jul Jul Jul Jan Jan Jun Jun Jun Oct Oct Apr Apr Apr Feb Feb Sep Feb Sep Dec Dec Aug Aug Nov Nov Mar Mar Mar May May May Highest Year (1986) Average Year Lowest Year (1977)

Figure 14. Fontenelle reservoir contents during construction – scenario #1.

Fontenelle Inflows Flow Frequency (Mar-Jul Flows, AF) 2,000,000 1,800,000 1,600,000 1,400,000 1,200,000 1,000,000 800,000 Jul Inflows, AF 600,000

Mar - 400,000 200,000 0 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Exceedance Probability

Figure 15. Fontenelle reservoir spring inflows (March-July), flow frequency.

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Figure 16. Fontenelle reservoir spring inflows (2-yr total, March-July), flow frequency.

Figure 17. Fontenelle average monthly flows below dam during drawdown scenario #2.

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Table 6-6. Fontenelle fall/winter drawdown scenario #2.

Oct-Mar % Increase Oct-Mar Outflows Due to Outflows w/Drawdown Reservoir (Avg. CFS) (Avg. CFS) Draining Average Yr. 917 1,680 83% Highest Yr. (1983) 1,462 2,217 52% Lowest Yr. (1935) 359 1,117 211%

As discussed, under this scenario, it is assumed that refilling would begin June 1 at the approximate rate of 10-feet per month until the reservoir levels reach the bottom of existing riprap at elevation 6,457 feet. Refilling operations were examined by modeling average summer (June to October) inflows as well as the extremes (highest and lowest years). A summary of this analysis is provided on Figure 18. As can be seen the limited re-filling rate during the high-runoff months of June and July necessitates a two-year re-fill with an assumed suspension of filling during the low-flow winter months and the balance occurring in the subsequent spring.

Scenario #3 – Summer Drawdown A third construction scenario was developed under which reservoir drawdown of the reservoir would begin in May and continue until the end of October. Construction would then begin in November. Similar to the other scenarios, precautions should be taken to prevent potential for downstream flooding during construction. Starting on January 1 it was assumed that the reservoir could begin refilling at the approximate rate of 10 feet per month until reservoir levels reached 6,457 which is the bottom of existing riprap. Like Scenario 2, re-filling under this scenario would follow “on the heels of” riprap placement as it works its way up the dam face. There are no downstream senior Wyoming water storage rights that would be impaired by this winter filling activity.

Table 6-7 and Figure 19 examine discharges below the dam during the reservoir initial drawdown period under average flow conditions and for the highest and lowest flows on record for the period. The starting point for the drawdown analysis is the average end of April reservoir content of 154,000 AF. During an average year, typical Fontenelle outflows are 2,127 cfs for this six-month period. To drain the average 154,000 AF over the next six-month period and while by-passing inflows, average releases would need to be increased from 2,127 to 2,550 cfs (20% increase). Similar data for the highest and lowest years on record are summarized in Table 6-7 and on Figure 19.

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Fontenelle Reservoir Reservoir Contents during Construction 400,000

350,000

300,000

250,000

200,000

150,000

100,000 Fontenelle Volume (af) 50,000

0 Sep Oct Nov Dec Jan Feb Mar AprMay Jun Jul Aug Sep Oct Nov Dec Jan Feb Mar AprMay Jun Jul

Highest Year (1983) Avg. Year Lowest Year (1935)

Figure 18. Fontenelle reservoir contents during construction – scenario #2.

Fontenelle Reservoir Avg. Mo. Flows below dam during Drawdown Scenario #3 14,000

12,000

10,000

8,000

6,000

4,000

2,000 Avg. Mo. Discharge Fontenelle Mo. Bel. Avg. (cfs)

- May Jun Jul Aug Sep Oct

Highest Year (1986) Highest Year w/Drawdown Average Year Avg. Year w/Drawdown Lowest Year (1934) Lowest Year w/Drawdown

Figure 19. Fontenelle average monthly flows below dam during drawdown scenario #3.

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Table 6-7. Fontenelle fall/winter drawdown scenario #3.

May-Oct % Increase May-Oct Outflows Due to Outflows w/Drawdown Reservoir (Avg. CFS) (Avg. CFS) Draining Average Yr. 2,127 2,550 20% Highest Yr. (1986) 4,938 5,362 9% Lowest Yr. (1934) 868 1,292 49%

As discussed, under this scenario, it is assumed that refilling would begin January 1 at the approximate rate of 10-feet per month until reservoir levels reach the bottom of existing riprap at elevation 6,457 feet.

Refilling operations were examined by modeling average spring inflows as well as the extremes (highest and lowest years). An illustration of this analysis is provided on Figure 20. As can be seen, similar to the first scenario there are typically (under the average and high conditions) sufficient spring runoff flows to allow the re-filling of the reservoir in a single year. Under worst- case conditions a two-year filling period might be required.

Fontenelle Reservoir Reservoir Contents during Constuction 400,000

350,000

300,000

250,000

200,000

150,000

100,000

50,000 Fontenelle Volume (af) 0 Jul Jul Jan Jan Jun Jun Jun Oct Oct Apr Apr Apr Feb Feb Sep Sep Dec Dec Aug Aug Nov Nov Mar Mar May May May

Highest Year (1983) Avg. Year Lowest Year (1935)

Figure 20. Fontenelle reservoir contents during construction – scenario #3.

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Power Generation Considerations Energy production from the Fontenelle power plant is typically greatest in the May to August period, based on the historical data in Figure 21. Energy production can be constrained by available flow and market demand/pricing. Power prices for Fontenelle were analyzed according to monthly averages (MWh) over the past 10 years (2008 to 2017). The maximum and minimum prices were $39.86 and $31.53, respectively. The average was $34.19, and the standard deviation was $2.62. Figure 22 shows the monthly average power prices over the past 10 years. Given the distribution of average monthly prices and for the purposes of this analysis, we assumed that power prices are not variable for Fontenelle’s production (constant price per MWh), and power revenues would not be affected by the time of year. As a base load hydroelectric plant with a maximum capacity of 10MW, Fontenelle should be able to produce and sell its full capacity at any time of the year, in which case allowable flow rates would be the governing constraint.

Figure 21. Monthly average of Fontenelle power production over the past 4 years.

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Figure 22. Monthly average power prices. Power prices were averaged over the past 10 years (2008 to 2017). The value for each month (e.g. January) is a result of averaging that month (e.g. each January) over the last 10 years.

The following criteria are used to analyze the potential impact of each of the proposed construction drawdown scenarios by comparing maximum power output under average flow years (Table 6-8).

a. Power generation can only occur for reservoir levels above 6,457 as presently configured (greater than 81,359 AF [80,796 AF inactive capacity plus 563 AF dead pool capacity]). b. Full output of the plant requires that the drawdown discharge exceed 1350 cfs. c. Any flows below 1350 cfs are not included in estimating power plant production for the construction drawdown periods. d. Full output of the power plant for a typical month will be assumed as: 30 days * 24 hours * 10MW * 95% = 6,840MWh e. The flows predicted for an average year will be used for evaluating each scenario. f. Each scenario will be evaluated over a full 36-month period – January Year 1 through December Year 3. g. Average annual power production over the last four years is 51,924 MWh. h. Normal generation (following completion of re-filling) to fill out the remainder of the 24-month period will be based on the monthly average generation over the last four years (Figure 4).

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Table 6-8. Estimated power generation for Scenarios 1-3 over a 36-month simulation.

Total Generation during Generation Generation during Scenario Normal Generation Generation over Drawdown Unavailable Re-Filling 36 Months Period MWh Period Period MWh Period MWh MWh Feb/Yr1 May/Yr2 Jan/Yr1; Scenario 1 May/Yr1 to to Aug/Yr2 Spring Drawdown 20,520 to 20,520 73,897 114,937 Apr/Yr1 Jul/Yr2 to (Figures 13 and 14) Apr/Yr2 (3 months) (3 months) Dec/Yr3 Jan/Yr1 Oct/Yr1 Apr/Yr3 to Scenario 2 Feb/Yr2 to to Sep/Yr1; Fall/Winter Drawdown 27,360 to 20,520 66,403 114,283 Jan/Yr2 Jun/Yr3 Jul/Yr3 (Figures 17 and 18) Mar/Yr3 (4 months) (3 months) to Dec/Yr3 Jan/Yr1 May/Yr1 Jun/Yr3 to Scenario 3 Sep/Yr2 to to Apr/Yr1; Summer Drawdown 27,360 to 13,680 84,483 125,523 Aug/Yr2 Jul/Yr3 Aug/Yr2 (Figures 19 and 20) May/Yr3 (4 months) (2 months) to Dec/Yr3 Baseline – average production over three 155,772 years

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Based on the simplified analysis above, assuming pricing over the course of the year is constant, Scenario 3 offers the best opportunity for power production provided that the reservoir can be re- filled in Year 2. If not, Scenarios 1 and 2 are essentially equivalent.

Construction Scenario Summary Figure 23 summarizes the construction periods associated with the three presented construction scenarios. Scenario #2 with the wintertime drawdown of the reservoir seems to offer reduced impacts during this environmentally sensitive period and best is able to ensure that flows downstream of the reservoir of 1,000 cfs or more are maintained. Given sufficient flexibility during construction to account for unknown streamflow conditions, all of the examined scenarios could be used while minimizing environmental impacts.

Year 1 Year 2 Scenarios Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Scenario 1 Drawdown Construction Re-filling Scenario 2 Drawdown Construction Re-filling1 Scenario 3 Drawdown Construction Re-filling

= Draining = Construction = Re-Filling Notes: 1. Because of the limited re-filling rate during the high-runoff months of June and July, a two-year re-fill with an assumed suspension of filling during the low-flow winter months and the balance occurring in the subsequent spring is expected.

Figure 23. Construction drawdown scenario summary.

Issues Relative to Interstate Compacts Wyoming is party to two interstate compacts that govern the use of the Colorado River: the Colorado River Compact of 1922 and the Upper Colorado River Basin Compact of 1948 (WSEO 2016). The Colorado River Compact of 1922 (1922 Compact) divides the Colorado River basin into an “Upper Basin” and “Lower Basin” with the dividing line at Lee Ferry. The Upper Division states include Colorado, New Mexico, Utah, and Wyoming. The Lower Division states include Arizona, California, and Nevada. One specific element of the compact that is relevant to Wyoming and the other Upper Division states is Article III, subsection (d). It states: (d) The States of the Upper Division will not cause the flow of the river at Lee Ferry to be depleted below an aggregate of 75,000,000 ac-ft for any period of 10 consecutive years reckoned in continuing progressive series beginning with the first day of October next succeeding the ratification of this compact. When it happens that the Upper Division must curtail water uses to comply with the 10-year non- depletion obligation, the Wyoming State Engineer’s Office (WSEO) has indicated that the priority

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system will inform any regulation in Wyoming and that water rights junior to the Compact (1922) may be regulated off during a curtailment. It should be clear that a curtailment has never happened and efforts are underway to prevent it from occurring. Nevertheless, all post-Compact water rights (with priorities junior to either November 24, 1922 when the Compact was signed, or December 21, 1929, when it was approved by Congress is currently under debate) would be at risk of curtailment under these circumstances (WSEO, 2016). A review of water rights in the State Engineer’s database for the Green River Basin, including the Little Snake River Basin, was therefore undertaken to examine and assess potential risks to Wyoming water users. Findings are summarized below:

In the Green River Basin:

. Approximately 80 significant municipal and industrial direct flow water rights (totaling about 130 cfs). . Notable municipal water right holders include Diamondville, Sweetwater County Joint Powers Water Board, Kemmerer, LaBarge, Lyman, Pinedale, and Bridger Valley Joint Powers Board (Mountain View, Ft. Bridger). . Notable Industrial & Commercial include, Tronox Alkali, Allied Chemical, Mobile Oil, Solvay Minerals, PacificCorp (Jim Bridger Power Plant), and Little America. . Approximately 1,000 post-compact irrigation water rights, covering about 125,000 acres. . Notable reservoir storage rights at risk include those for Fontenelle, Meeks Cabin, Stateline, Boulder Lake, Fremont Lake, Viva Naughton, and Kemmerer No. 1 reservoirs. In the Little Snake River Basin:

. Most notable is the City of Cheyenne State I & II system that diverts between 8,000 and 10,000 AF per year (11 to 14 cfs). . High Savery Reservoir (capacity 22,432.9 AF). . Town of Baggs municipal water rights. . Approximately 100 post-compact irrigation water rights, covering about 9500 acres.

Future Operations Following the completion of this project, future operations are not expected to change. There is potential for the reservoir to be lowered beyond the current inactive pool elevation of 6,457. If such an operation is of interest, then the Bureau of Reclamation would need to work with WWDC through the EIS process and to determine new operations protocol. Also, mitigation efforts would need to be considered. No additional depletions (evaporation or other) are expected upon the completion of this project.

The intent of this project is to provide a long-term drought mitigation plan for the State of Wyoming to mitigate potential impacts of curtailment. This is the only proposed future operation of the additional active volume resulting from the armoring of the lower portion of the dam. This project produces two economic benefits: 1) drought mitigation supply, which is where the project provides a mitigation water supply to allow post-1922 water rights in Wyoming to continue to divert water under conditions of a curtailment in the Colorado River Basin and 2) drought

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avoidance supply, which is where the project provides insurance water supply to the Upper Division as a whole in order to avoid a curtailment in the Upper Colorado River Basin. These two economic benefits are analyzed and discussed further in Section 9, along with Drought Water Supply.

Before drawdown of the reservoir, it is recommended that a rapid drawdown be evaluated to determine if dam safety is a concern during final design. This could result in a limit on the drawdown rate. Also, the presence of the cutoff wall may affect the seepage performance of the dam. The cutoff wall, during drawdown scenario, should be modeled during the design phase of this project, regardless of the alternative selected. If the reservoir is drawn down and refilled, the piezometers, dam face, toe drains, and other monitoring devises should be carefully monitored in a similar manner a as a “First Fill” situation.

If the reservoir is lowered for construction activities, the Wyoming State Historic Preservation Office (SHPO) may request a survey of the reservoir basin and updated documentation of previously identified sites in the inundation zone.

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CONCEPTUAL DESIGNS AND COST ESTIMATES

The EA Team developed conceptual designs and cost estimates for all four alternatives. Conceptual designs are presented to the extent that was reasonable/allowable by the manufacturers. Cost estimates are summarized in this section and details are shown in Appendix F.

The Appraisal Level evaluation (USBR, 2010) evaluated costs associated with draining the reservoir and placing riprap (from a variety of sources) or soil cement on the upstream face. The Reclamation analysis concluded that riprap would cost ($76.04/cubic yard [CY]) and soil cement would cost ($86.06/CY). The total estimated cost of extending the riprap was $5,760,500 (USBR, 2010). The Reclamation (2010) study was used for comparison; however, it did not consider many of the environmental and economic costs that are included in this Level II Study.

For all alternatives, it was assumed that the NEPA process will involve an EIS. This is a conservative assumption because the EIS costs ($1.2 M) are more than the EA ($830,000). However, it is possible that the NEPA process will involve an EA rather than an EIS. The costs for an EA and EIS are in Appendix F.

Power generation costs will be addressed between Wyoming and the Bureau of Reclaiming if an alternative is selected that will result in power losses.

The following sections describe the conceptual designs and cost estimates of the alternatives.

Riprap

Riprap, as mentioned previously, was sized at a D50 of 24 inches and needs to be 2.5-foot thick. The riprap would be placed directly on the existing embankment fill in 20’ sections. Figure 24 shows a typical cross-section of the dam including the proposed riprap section, and Figure 25 shows a detail of the riprap. Table 7-1 has the costs from the three quarry sources provided by Gorge Rock Products. The riprap ranges in cost from $89.51 to $120.45 per CY paid for, delivered to site, and placed. Placement was assumed to add 30% to the cost of purchase and delivery to site. For comparison, the Appraisal Level evaluation (USBR, 2010) estimated riprap delivered and placed at $76.04 per CY.

Table 7-1. Quarries and riprap costs.

Cost per Ton Cost per CY Haul time Description Purchase Haul Install Total Total (hr) Atlantic City Gabbro 4 $38.50 $16.00 $16.35 $70.85 $120.45 Brown Leucite 4 $38.50 $16.00 $16.35 $70.85 $120.45 Big Sandy Granite 2.75 $29.50 $11.00 $12.15 $52.65 $89.51

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Figure 24. Typical cross-section of existing and proposed work on embankment face.

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Figure 25. Riprap detail

The least expensive riprap source ($89.51/CY) was used in the cost estimate. The detailed cost estimate for placing riprap in a drained reservoir is included in Appendix F.

Engineering, survey, and legal are assumed to be 25% of the construction costs (not including mobilization, bonds, or contingency). This includes costs for engineering during construction.

An access road and ramp would be required for this alternative to allow for efficient construction traffic routing. The access road and ramp are estimated to cost $150,000 total. Mobilization, bonds, and contingency were estimated to be 3, 1.5 and 20% of the construction cost, respectively. NEPA is assumed to go through an EIS and costs are the same for all of the alternative cost estimates. The total project cost of placing riprap in a drained reservoir is estimated at approximately $8.5 M. Maintenance on this alternative is estimated to be roughly 5% of the total construction cost, which is about $300,000 annually.

The least expensive riprap source ($89.51/CY) was also used in the cost estimate for placing riprap underwater (Appendix F). As mentioned previously, it was assumed that placing riprap underwater would require 50% more riprap than placing it when the reservoir is drained (Lagasse, 2006). In addition to the extra riprap, there are costs for the dive team and sectional barge that are not required when placing the material in dry conditions. The dive team is estimated to cost a total of $1.62 M for the project. The sectional barge is estimated to cost $1.0 M for mobilization, demobilization, and rental for the duration of the project. We predict that excavation would not be needed for placement of riprap underwater. The total project cost of placing riprap in an un- drained reservoir is estimated at about $15.3 M. Maintenance on this alternative is estimated to be roughly 5% of the total construction cost, which is about $600,000 annually.

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Soil Cement The cost estimate for soil cement considers material and construction costs, and cost of designs. Figure 26 and Figure 27 show a typical soil cement detail for a 3:1 and 2:1 slope, respectively. The detailed cost estimate for soil cement is in Appendix F.

The soil cement cost is estimated at $85 per CY supplied and placed. This was the average cost to supply and place soil cement on a dam located near Green River, WY. For comparison, the Appraisal Level evaluation (USBR, 2010) estimated soil cement delivered and placed at $86.06 per CY.

Engineering, survey, and legal were calculated similar to the placement of riprap in a drained reservoir. An access road and ramp would also be required for this alternative. Other costs, except for soil cement and placement, are estimated similarly to dry placement of riprap. The total estimated cost for this alternative is about $8.2 M. Maintenance on this alternative is estimated to be roughly 5% of the total construction cost, which is about $300,000 annually.

Submar Mats The Submar mats would need to be specially manufactured at a 13-15” thickness for this project. The mats are typically 8’ by 20’ and would be placed with the long side parallel to the embankment slope. Only the placement of Submar mats underwater were considered for the cost estimate. While the option to place the Submar mats in dry conditions exists, it is not as economic or efficient when compared to riprap or soil cement. The detailed cost estimate for placing Submar mats underwater is included in Appendix F.

This cost estimate assumes that engineering, surveying, and legal will cost 25% of the construction costs. According to Submar, the mats are $30/SF, the dive team is $6.48 M in total, and the mats can be installed at a rate of 5 mats/day. The total cost for this alternative is approximately $37.6 M. Maintenance on this alternative is estimated to be roughly 5% of the total construction cost, which is about $1.5 M annually.

Contech Wave Attack Blocks Contech Wave Attack Blocks can be installed in wet or dry conditions. However, because riprap and soil cement are more economic than placing Wave Attack Blocks in dry conditions, only the cost of placing Wave Attack Blocks in the full reservoir were considered. The detailed cost estimate for underwater placement of Wave Attack Blocks is in Appendix F. The construction costs for bedding and placement, Wave Attack Blocks, and Wave Attack Blocks Install by Dive Team are approximate rates from Contech and are subject to change in the future. The total estimated cost of this alternative is about $33.5 M. Maintenance on this alternative is estimated to be roughly 5% of the total construction cost, which is about $1.3 M annually.

Summary of Costs The costs of the alternatives range from about $8.2 M to $37.6 M. Table 7-2 summarizes the construction costs and total costs for each of the alternatives analyzed.

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Figure 26. Typical soil cement detail for a 3:1 slope.

Figure 27. Typical soil cement detail for a 2:1 slope.

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Table 7-2. Alternatives cost estimate summary.

Alternative Reservoir Construction Cost Total Cost Riprap Drained $6,063,000 $8,510,000(1) Riprap Full $12,080,000 $15,331,000(1) Soil Cement Drained $5,844,000 $8,227,000(1) Submar Full $30,283,000 $37,643,000(1) Contech Full $26,752,000 $33,452,000(1) (1) Total Costs includes construction costs, NEPA costs (a fixed $1,230,000 assuming EIS) and engineering costs, which vary for each alternative.

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SCHEDULING

Schedules have been developed for each alternative and are summarized on Figure 28 through Figure 32. The schedules were optimized according to the environmental considerations, historical power production, and physical limitations of the alternative. The following sections describe each alternatives’ schedule.

Riprap Riprap can be placed on the dam embankment any time of the year. Therefore, the riprap construction schedule for dry placement, as shown on Figure 28, was developed to limit environmental and economic impacts that result from draining the reservoir. The quarry that will supply the riprap will need to be notified of the project schedule to ensure adequate lead time. Draining of the reservoir would start in July of the first year and continue to November of the first year. The quarry would start transporting and stockpiling riprap around October of the first year, and continue at a rate that ensures there will be adequate material on site during placement. The timeframe for stockpiling riprap should be adjusted as needed, depending on accessibility to the site during winter conditions. After the reservoir is drained down to the dead water surface at elevation 6,408, the embankment will need time to dry before construction can start. The drying process is estimated to take about 2 months. The Contractor would mobilize in December of the first year and begin construction as soon as conditions allow. The Contractor would establish the ramp and traffic route, then begin riprap placement in January of the second year. The placement of riprap is expected to take between 3 and 4 months. While riprap is being placed, the reservoir would be filled at a rate of 10 feet per month. This puts the end of construction around April of the second year. The filling of the reservoir would ideally start in February of the second year and continue at a rate of about 10 feet per month or as conditions allow, finishing in June or when the reservoir is back at operating conditions.

Riprap can also be placed in the full reservoir. Placement can occur any time of year when Fontenelle Reservoir is not frozen. The start of placement was pushed back 3 months to allow for the ice to melt. It is estimated that placement of riprap underwater would take 50% longer – about 6 months of placement time. Figure 29 shows the construction schedule for placing riprap underwater.

Soil Cement Soil cement must be placed between April and October to prevent the material from freezing. At the beginning of construction, the reservoir will have to be completely drained, which means all incoming flows will be passed through the dam to the Green River. April, May, and June are when the incoming flows are at their highest due to annual snow melt. Flows might be too high to reasonably pass downstream of the dam. Due to these high flows, the placement of soil cement is restricted to July through October. Typically, the pugmill or mixing plant is the limiting factor in production rates. A Rapid twin-shaft mixing plant can produce up to 200 CY of soil cement an hour. Assuming the material can be placed and compacted at the same rate, this rate of production allows soil cement to be placed in about 2 months. Placement would begin sometime in August and be completed in September or October. While soil cement is being placed, the reservoir would

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YEAR 1 YEAR 2 ACTIVITY Jun Jul Aug Sept Oct Nov Dec Jan Feb Mar Apr May Jun Jul Alternative 1: Riprap Draining the reservoir Surface drying Mobilization of construction equipment, etc. Stockpiling of material Establishing traffic route and require ramps Placement of riprap Filling the reservoir (10ft/month) Hydropower inoperable

Figure 28. Riprap construction schedule for dry placement.

YEAR 1 ACTIVITY Jan Feb Mar Apr May Jun Jul Aug Sept Oct Alternative 1: Riprap Mobilization of construction equipment, etc. Stockpiling of material Establishing traffic route and require ramps Placement of riprap

Figure 29. Riprap construction schedule for underwater placement.

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be filled at a rate of 10 feet per month or as conditions allow. The construction schedule for this alternative is shown on Figure 30.

Submar The only seasonal restriction on the placement of the Submar Mats is that they cannot be placed on a frozen reservoir. The manufacturing of the mats would require a 6- to 8-month lead time. The mobilization of the batch plant would start in September and the batch plant would be operational until all Submar Mats have been made. According to Submar, mats can be placed at the rate of 5 mats/day. At that rate, it is estimated that the placement would take about 3 years with periods in the winter months where ice would prevent placement.

The barge, diving team, and construction equipment would mobilize in March, and placement of the mats would begin in April. Figure 31 shows the construction schedule for placing Submar Mats underwater.

Contech The primary time restriction on the placement of the Wave Attack Blocks is that they cannot be placed on a frozen reservoir. This alternative requires a 6- to 8-month lead time for the establishment of a batch plant and the production of the precast wave attack blocks. The mobilization of the batch plant would start in September and the batch plant would be operational until all Wave Attack Blocks have been made.

The barge, diving team, and construction equipment would mobilize in March. The bedding layer would be placed preceding the placement of the Wave Attack Blocks. The bedding and Wave Attack Block placement would overlap and continue until the two are complete. Contech estimates an installation rate of 6,000 SF/day with a dive crew that is working 24/7. This puts the install duration starting in mid-March (or when the ice is thin enough) and continuing until late July. Figure 32 shows the construction schedule for placing Contech Wave Attach Blocks underwater.

Schedule Variations The construction schedule for placing armoring in a drained reservoir (Figure 28 and Figure 30) or in a full reservoir (Figure 29, Figure 31, and Figure 32) are subject to change due to a variety of circumstantial reasons.

The schedule should be adapted according to the forecasted weather patterns and snow runoff as needed. Specifically, for drained reservoir placement, the draining and filling of Fontenelle is dependent on the inflows. For instance, if a situation occurs where inflow significantly greater or less than estimated during the draining of the reservoir, then the timeline might be delayed or expedited, respectively. Similarly, if flows are less than expected during the filling of the reservoir, the filling of the reservoir might be controlled by the inflow rather than construction progress.

Inflows are less of a concern for armor placement in a full reservoir than in a drained reservoir. However, slight delays might occur with the underwater placement of armoring and/or dive team

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YEAR 1 ACTIVITY Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Alternative 2: Soil-Cement Draining the reservoir Surface drying Mobilization of pug mill, construction equipment, etc. Stockpiling of material for pug mill Establishing traffic route and require ramps Placement of bedding layer and soil-cement Filling the reservoir (10ft/month) Hydropower inoperable

Figure 30. Soil cement construction schedule.

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YEAR 1 YEAR 2 ACTIVITY Aug Sept Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Alternative 3: Submar Mats Establishment of batch plant and precasting of wave attack blocks Mobilization of barge Mobilization of diving and construction equipment, etc. Placement of wave attack blocks

YEAR 3 ACTIVITY Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Alternative 3: Submar Mats Establishment of batch plant and precasting of wave attack blocks Mobilization of barge Mobilization of diving and construction equipment, etc. Placement of wave attack blocks

YEAR 4 ACTIVITY Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Alternative 3: Submar Mats Establishment of batch plant and precasting of wave attack blocks Mobilization of barge Mobilization of diving and construction equipment, etc. Placement of wave attack blocks

Figure 31. Submar Mat construction schedule for underwater placement.

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YEAR 1 YEAR 2 ACTIVITY Aug Sept Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Alternative 4: Wave Attack Blocks Establishment of batch plant and precasting of wave attack blocks Mobilization of barge Mobilization of diving and construction equipment, etc. Placement of 12" thick bedding Placement of wave attack blocks

Figure 32. Contech Wave Attack Blocks construction schedule for underwater placement.

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quality control due to unexpected changes in the WSEL. Delays can be minimized if the Contractor is in close communication with the Fontenelle Dam operator concerning the forecasted discharges of the dam and WSEL of the reservoir.

Public access to the reservoir will be limited during the drawdown of the reservoir. It might be necessary to increase the restriction zone by the dam outlet for safety reasons. Recreational access will be further limited once the reservoir is drained. If armoring is placed in a full reservoir, then the public access restrictions will be less extensive. However, it may be necessary to close the boat ramp by the west side of the dam if the ramp is needed for access to the reservoir. Buoys around the construction zone may be necessary to prevent the public from nearing the construction site and barge.

Public access might be limited during construction to ensure the safety of the public and the construction crew. Limitations may include, but are not limited to, the following:

. The boat ramp on the west side of the reservoir by the dam. . The campgrounds immediately downstream of the dam. . The access roads (off of Co. Rd. 52 and/or Co. Rd. 316) to the Green River immediately downstream of the dam.

Final public access restrictions should be determined by the Contractor and Reclamation.

Draining the reservoir to place armoring will affect the facility operations, as discussed in Section 4. The outlet works operations would need to be adjusted from a typical schedule to allow for:

. The draining of the reservoir. . The bypassing of inflow with little or no increase in reservoir WSEL. . The filling of the reservoir.

Aside from affects to the outlet works, it is predicted that the construction would not affect other operations of the facility.

Typical construction delays (weather days, billing delays, poor scheduling by the Contractor, acts of God, etc.) are not included in this discussion because it is assumed that any construction project will be at risk of some delays.

Power Generation Scheduling Power generation scheduling was discussed in Section 4. If the reservoir is drained, production scheduling processes will need to be modified to account for greater outflows during drawdowns until minimum reservoir levels are reached and reduced outflows as the reservoir is refilled. Construction schedule variations may require a change to the power generation schedule. Based on the average year performance statistics, the modifications to the production schedule will be reasonably well-defined and have an impact over two to three years, depending on the Scenario

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implemented. It is suggested that the dam operator and the contractor work closely together to insure both the construction schedule and the power schedule stay updated and work efficiently.

According to the results shown in Table 6-8, the schedule for placing riprap in a drained reservoir (Figure 28) would result in more power generation than the schedule for placing soil cement in a drained reservoir (Figure 30). The other alternatives do not require the reservoir to be drained, which would result in the most power generation, as the power house could essentially maintain current operations.

Summary The construction schedule for dry placement of armoring includes the drawdown and refill time of Fontenelle Reservoir. The alternative schedules were determined primarily according to the physical ability to place material during the time of year and secondarily according to minimizing effects toward environmental considerations and reduced power generation. Overall, the wet placement of riprap and the placement of soil cement have the shortest construction schedule at 9 months. The dry placement of riprap is predicted to take 12 months. The Submar and Contech alternatives are predicted to take 3.5 years (with multiple phases) and 11 months, respectively. Soil cement has a particularly difficult construction schedule because the placement of soil cement must begin around July (a high flow month) to ensure material placement finishes during the warm months of the year. The dry placement of riprap does not have this concern. The alternatives that utilize a barge and crane for wet placement are restricted to months when the reservoir is not frozen.

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ECONOMIC ANALYSIS

This economic analysis evaluates the economic benefits of the additional water storage capacity that would result from the Project. WestWater Research LLC (WestWater), an EA Team member, conducted the economic analysis. WestWater previously communicated with the Wyoming Water Development Office (WWDO) regarding the proposed methodology for estimating the value (or benefit) of the new storage capacity. This report provides WestWater’s benefits valuation approach and results, along with background information supporting the findings.

Benefits Associated with the Proposed Project The proposed project is intended to increase the usable storage capacity in Fontenelle Reservoir. For this analysis, the water supply benefit of the proposed project is considered to be 80,796 acre- feet of new active storage capacity in Fontenelle Reservoir. This is the volume of storage that is currently available under the reservoir water rights but is not accessible due to a lack of armoring to protect the lower interior dam face.

In discussing the proposed approach, it is helpful to keep in mind the existing and accessible storage capacity volume in Fontenelle Reservoir. Figure 33 provides an illustration of the various storage pools in Fontenelle Reservoir for use in understanding the benefits of the proposed project, which would add to the accessible storage capacity. The proposed project intends to activate the bottom 80,796 acre-feet of storage labeled as “Inactive Capacity” in the figure.

Figure 33. Illustration of Fontenelle Reservoir Storage Pools. The figure shows the 120,000 AF of space currently contracted for use by the State of Wyoming, the 139,000 AF of active capacity which is currently not contracted and is managed by BOR, and the 80,796 AF which is currently inactive and is the subject storage being evaluated under this project. Figure provided by Wyoming Water Development Office. Note that bottom of existing riprap is now estimated to be at elevation 6,457.

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At the present time, the State of Wyoming has the right to market 120,000 acre-feet from the U.S. Bureau of Reclamation (Reclamation or BOR) which owns and operates the storage facility. The Wyoming contract currently provides for a set of “readiness to serve” option contracts for industrial water users in the Green River Basin. The remaining 139,000 acre-feet of unreserved space within the active capacity of the reservoir is currently not contracted, and is available for contracting to the State of Wyoming or another individual user. Wyoming has a right of first refusal to the active capacity of uncontracted space. BOR currently operates the reservoir storage for hydropower generation and recreational purposes.

This report evaluates three potential benefits of the proposed project to activate the bottom 80,796 acre-feet of storage space in Fontenelle Reservoir:

(1) a direct water supply to meet future water demands within the Green River Basin of Wyoming (2) an insurance water supply to avoid a curtailment being issued in the Colorado River Basin. (3) a mitigation water supply to allow post-1922 water rights in Wyoming to continue to divert water under conditions of a curtailment in the Colorado River Basin

In each of these benefit categories, analyses are presented to first define whether benefits are expected from the proposed project, and then to evaluate the possible water volume quantity of such benefits and the value of the expected benefits.

Valuation Methods Policy Guidance on Estimating Benefits Federal guidance on how benefits of water resources projects should be evaluated and quantified is provided in two documents: the 2013 Principles and Requirements for Federal Investments in Water Resources (CEQ, 2013) and the subsequent 2014 Interagency Guidelines (Chapter 3) (CEQ, 2014), collectively referred to as the Principles, Requirements, and Guidelines (PR&G). In addition, the Department of Interior (DOI) released Agency Specific Procedures for Implementing the CEQ PR&G for Water and Land Related Resources Implementation Studies in November 2015 (DOI, 2015). These recent documents supersede a long-standing Federal guidance document published in 1983 on evaluating the economics of water projects (U.S. Water Resources Council, 1983).

The PR&G makes a clear policy decision to place greater emphasis and importance on non- economic and non-monetary aspects of proposed water resources projects, stating that both quantified and unquantified information will form the basis for evaluating and comparing Federal investments. While Federal policy has indicated a shift toward additional consideration of non- monetized benefits, the DOI Procedures (2015) state that “the approach to quantifying and monetizing benefits in the PR&G and the [1983] P&G are not significantly different.” Therefore,

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in practice, methods that have historically been used to quantify costs and benefits to the National Economic Development (NED) account should remain applicable under the new PR&G policies.

The PR&G were designed to evaluate and compare alternatives, similar to an environmental impacts analysis under the National Environmental Policy Act (NEPA). For this report, basic planning elements such as the Purpose & Need are not defined. Instead, the intent of this benefits valuation is to evaluate a with-project and without-project set of scenarios. Further, the scope of our analysis is intended to focus on “estimates of potential values for the activated pool volume based on the future use and operations scenarios” as stated in the Request for Proposal (WWDC, 2016) and is not intended to represent a full-scale evaluation as described under the PR&G.

Focusing on the methods to quantify economic benefits, there are relatively clear and consistent policy recommendations in the PR&G, DOI Procedures, and other Federal references to utilize an economic principle of “willingness to pay” defined as “the maximum amount an individual would be willing to give up in order to secure a change in the provision of a good or service.” Various methods are available to apply this principle, as described in the following section.

Common Methods of Estimating Economic Benefits Economic valuation methods generally fall into one of two categories: market valuation or non- market valuation. Market values refer to conditions for which a price can be observed, such as for human consumptive uses. Non-market valuation methods usually apply to a resource for which there is no established market to observe values, such as ecosystem restoration or wildlife conservation. Economic benefits are often determined by one of following five valuation approaches:

• Willingness to pay (demand curve) • Actual or simulated market prices • Change in net income • Cost of the most likely alternative • Administratively established values

9.2.2.1 Willingness to Pay Method The user-value, or willingness to pay, method refers to the value of the resource to the consumer. Willingness to pay refers to the value that a “seller” would obtain if able to charge each individual user a price that captures the full value to the user. Implementing this approach requires estimation of a demand curve. Three methods are commonly used to estimate a demand curve: (1) revealed preferences, which relies on market-based data; (2) contingent valuation, which uses surveys to directly elicit consumer benefits; and (3) benefits transfer, which uses estimates from previously completed studies. In recognition that conducting surveys is often prohibitively expensive, values from previous economic studies may be used to build a demand curve and to estimate willingness to pay provided they are relevant to the study area and output being valued.

9.2.2.2 Actual or Simulated Market Prices Method

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Market prices may be used to estimate society’s willingness to pay for a good or service. The 1983 P&G provide some limited guidance on the use of market prices when the output of the project is expected to have a significant effect on market price. Prices should be expressed in real terms (inflation adjusted). Real prices should be adjusted throughout the planning period to account for expected changes in demand and supply conditions.

9.2.2.3 Change in Net Income Method Benefits can be estimated by the change in net income to producers associated with a project. This method is most frequently applied to circumstances when water supply from a project will be used as an input in a production process such as irrigated agriculture.

9.2.2.4 Cost of the Most Likely Alternative Method In situations where water supply alternatives to a proposed project exist, the cost of the most likely alternative to obtain the same level of output can be used as a proxy measure of benefits. When applying this method, it is important to consider alternatives that would realistically be implemented in the absence of the proposed project. This method is generally considered for benefit categories that cannot be estimated through the market-based methods described above. This method identifies the cost of obtaining or developing the next unit of a resource to meet a particular objective. The net benefit is estimated by subtracting the cost of developing the project under consideration from the cost of the alternative unit. For water supply reliability benefits, for example, the cost of the most likely alternative represents the next unit of water supply the water user would purchase or develop if the project under consideration were not in place. If the proposed project provides the same output as the most likely alternative at a lower cost, the net benefit of the project is equal to the difference in the project costs.

9.2.2.5 Administratively Established Values Methods Administratively established values are representative values for specific goods and services that are cooperatively established by the water resources agencies. This method is the least preferred approach to estimating economic benefits and is only implemented when other options cannot be completed.

Discount Rate Assumptions Economic analysis requires the calculation of a net present value of future benefits. For water projects, current Federal policy is to apply a specific discount rate based on the interest rate of U.S. treasury bonds as defined more specifically in CFR Section 704.39: The interest rate to be used in plan formulation and evaluation for discounting future benefits and computing costs, or otherwise converting benefits and costs to a common time basis, shall be based upon the average yield during the preceding fiscal year on interest-bearing marketable securities of the United States which, at the time the computation is made, have terms of 15 years or more remaining to maturity: Provided, however, that in no event shall the rate be raised or lowered more than one-quarter of 1 percent for any year. The average yield shall be computed as the average during the fiscal year of the daily bid prices. Where

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the average rate so computed is not a multiple of one-eighth of 1 percent, the rate of interest shall be the multiple of one-eighth of 1 percent nearest to such average rate. This Federal water project discount rate is currently set at 2.875% (NRCS, 2017). This represents a nominal discount rate, calculated without removing inflationary effects. For economic analyses, the PR&G recommends using constant-dollar (real) values, which is how analyses are conducted for this study. The use of a nominal discount rate with real dollar values has fundamental flaws (CRS, 2016). Therefore, a revised Federal water project discount rate was calculated based on real (inflation-adjusted) discount rates using 30-year Treasury bond yields, as reported by the Office of Management and Budget (OMB) in Circular A94, Appendix C. Figure 34 shows the difference between nominal and real Federal water project discount rates. The real discount rate of 1.0% was applied for this analysis.

Direct Water Supply Analysis Current Conditions The first type of benefit evaluated for the proposed project is to provide a direct supply to present and future water demands in the Green River Basin of Wyoming. Similar to the existing option contracts, individual water users would contract with Wyoming for Fontenelle Reservoir water supplies, and Wyoming would contract additional storage space from BOR to fulfill those individual contracts.

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14%

12% Discount Rates: Federal Water Project (Reported) Nominal 30-Year Treasury Interest Rates Nominal Federal Water Project (Calculated) Real 30-Year Treasury Interest Rates 10% Real Federal Water project (Calculated)

8% Discount Rate Discount

6%

4%

2%

0% 1980 1985 1990 1995 2000 2005 2010 2015

Figure 34: Nominal and Real Discount Rates. Figure shows calculated discount rates using nominal and real interest rates for 30-year U.S. Treasury securities. The thin lines of each color (red/green) show the annual interest rates on securities, and the thick lines of each color (red/green) show the calculated Federal water project discount rate, which is based on the average annual interest rate but limited to change by no more than 0.25% from the preceding year. The figure also shows (in blue) the reported Federal water project discount rate.

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The need for the project water supply can be evaluated by considering the present and future needs for new water supplies in the Green River Basin, and the rate at which existing and established water supply sources in the Green River Basin will be utilized. This section describes the existing water supply contracts in Fontenelle Reservoir and estimates of future water demand growth from basin-wide planning efforts.

9.3.1.1 Authorized Uses of the Project The Seedskadee Project authorized construction of Fontenelle Dam and Reservoir. The Project was originally authorized and constructed for irrigation purposes, but the poor results from agricultural use resulted in project purposes evolving to be for municipal and industrial uses, hydropower production, and fish, wildlife and recreational benefits. The purposes of use listed in the Wyoming water use permits (Permit Nos. 6629R and 9502R) held by BOR for Fontenelle Reservoir include: irrigation, domestic, industrial, municipal, stock watering, fish propagation, wildlife, recreation, and hydropower.

9.3.1.2 Wyoming Water Use Contracts The 1958 Congressional authorization for the Seedskadee Project provided the ability to store water in Fontenelle Reservoir for municipal and industrial purposes. In 1962, the State of Wyoming, acting through the Natural Resources Board (precursor to the Wyoming Water Development Office), contracted with BOR for 60,000 acre-feet of storage capacity at a cost of $900,000 paid in 50 equal annual installments. In 1974, the State, acting through the Department of Economic Planning and Development, contracted with BOR for an additional 60,000 acre-feet of active storage capacity at a cost of $11,410,000 paid in 40 annual installments. Currently, Wyoming is able to market water storage contracts for up to 120,000 acre-feet, and holds a right of first refusal to any uncontracted storage space within the active capacity of Fontenelle Reservoir.

9.3.1.3 Existing Water Lease Agreements The State of Wyoming holds several active water lease contracts with local industrial water users. These leases are structured as “readiness to serve” or option contracts in which Fontenelle Reservoir provides backup and/or supplemental water supplies to the industrial operations. Table 8-1 summarizes these lease agreements.

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Table 8-1. Active Water Lease Contracts in Fontenelle Reservoir

Annual Option Purchase Contract Term Lessee Volume Price Rate Date (yrs) Name (afy) ($/afy) ($/afy) Purchase Rate Inflation Purpose of Use 5-year intervals based 75% 1/1/2009 35 PacifiCorp 35,000 $10 $61 of increase in CPI-Urban for Jim Bridger Power Plant U.S. over 2009 value 5-year intervals based 75% Church & Green River baking 1/1/2008 30 1,250 $5 $61 of increase in CPI-Urban for Dwight Co. soda production U.S. over 2008 value 5-year intervals based 75% Shute Creek Plant 1/1/2013 30 Exxon Mobil 300 $5 $65 of increase in CPI-Urban for domestic uses and U.S. over 2013 value natural gas production 5-year intervals based 75% SF of increase in Implicit Price Rock Springs chemical 1/1/2000 30 Phosphates 10,000 $5 $42 Deflator for construction fertilizer production (Simplot) over 2000 value Note: All four leases also require the lessee to pay a pro-rata OM&R rate for any purchased water and to make pro- rata contributions to major dam capital projects and repairs.

To date, these option contracts have never been called upon and no water supplies have been delivered from Fontenelle Reservoir. This is an important consideration, as it illustrates a current condition in which a new water supply source (in the form of new storage capacity in Fontenelle Reservoir) effectively has no benefit in terms of direct use in Wyoming. Future growth in water demands is expected to modify this current condition (WWDO, 2011).

Future Conditions 9.3.2.1 Green River Basin Plan Projections Water uses in the Green River Basin fall into three main categories: (1) municipal, (2) industrial, and (3) agricultural. Municipal water uses were reported as approximately 7,500 acre-feet per year (afy) in the 2010 Green River Basin Water Plan, and were projected to increase by 24% to 9,300 acre-feet per year in 2055, under a conservative low growth scenario. In general, municipal water demands are likely to continue to be relatively small volumes that are served by local water resources. The largest potential municipal user of Fontenelle Reservoir as a direct supply source is likely to be the Green River – Rock Springs – Sweetwater County Joint Power Board (JPB). The JPB is currently and will likely continue to be served from the Green River with a treatment plant located in the town of Green River. The JPB has been exploring reservoir storage options in close proximity to the treatment plant and Fontenelle Reservoir would not fit the criteria needs of the JPB as of 2010 (Nelson Engineering, 2010).

The industrial water use sector is considered to be the most likely user of Fontenelle Reservoir water supplies (WWDO, 2011). Past records and future projections of industrial water uses in the Green River Basin are shown on Figure 35. For this analysis, the low growth rate projections from the 2001 and 2010 Green River Basin Plans (SWWRC, 2001; WWCE, 2010) are applied in the analysis. Industrial demand growth in the Basin Plans is characterized by: no significant increase

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140,000 1970 Plan 2001 Plan 120,000 2010 Plan Actual 100,000 Assumed

80,000

60,000 Water Use Water Use (afy)

40,000

20,000

0 1960 1980 2000 2020 2040 2060 2080

Figure 35. Industrial Water Uses in the Green River Basin. Figure shows actual industrial water use estimates as black dots and projections at different historical points as dashed lines under moderate growth assumptions. Recent uses have been consistent from 2000 to 2016. Assumed future industrial demands used in the analysis track the low growth scenario from the 2010 Basin Plan.

in power plant water needs; growth in soda ash production requiring an additional 14,400 afy; and an increase in Simplot fertilizer production and associated water demand increase of 1,800 afy to a total demand of 2,400 afy.

The 2010 Basin Plan estimated basin-wide industrial water uses (depletions) as 56,800 acre-feet per year, which is similar to recent (2011-2015) estimates provided in the 2016 SEO Annual Report. The total long-range increase in industrial water demands is estimated as 18,600 acre-feet in 2055. The State of Wyoming retains approximately 73,450 acre-feet of available storage capacity in Fontenelle Reservoir out of the 120,000 acre-feet of contracted space, after removing existing water lease contracts. Therefore, the existing available contract space in Fontenelle Reservoir is considered to be adequate to meet the growth in water demands in the industrial water use sector over a 40-year timeline. It is also likely that some portion of these future industrial water demands can be met by local direct flow diversions near the location of the industry. Wyoming could also contract additional space from the active capacity pool in Fontenelle Reservoir to meet new industrial water uses in the Basin, without utilizing the project water supply (currently inactive space).

New irrigation water uses are considered unlikely in the geographic areas that could be served by Fontenelle Reservoir. A series of maps were created to evaluate the soil resources and slopes for lands located below the dam outlet, which could be served by gravity diversions. The satellite

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photo mapping shows limited current irrigation below the Fontenelle Dam outlet elevation, mostly comprised of single farm center pivots and plots in the Green River valley. NRCS soil survey data show erosion and limited rooting depth concerns across much of the serviceable area, and no capable soils for irrigated agriculture. The 2010 Green River Basin Plan provides the possibility that additional water storage for irrigation could develop in the Blacks Fork Basin and upper northwest tributary creeks of the Green River, but not in areas that would be served by Fontenelle Reservoir (WWC Engineering, 2011). In addition, the original failure of the irrigation test plots associated with the Seedskadee Project supports the idea that large-scale irrigation development is unlikely to occur.

Summary Opinion of Benefit The 80,796 acre-feet of additional storage capacity is considered not likely to be required to meet new consumptive use demands in the Green River Basin of Wyoming. Existing active storage capacity in Fontenelle Reservoir is considered adequate to meet future water demands associated with growth in the municipal and industrial sectors.

Drought Mitigation Analysis Overview of Benefit The project storage could provide a drought mitigation supply for use by the State of Wyoming in meeting its commitments under the 1922 Colorado River Compact, the 1948 Upper Colorado River Basin Compact, and other laws pertaining to the Colorado River Basin. Under the 1922 Compact, the Upper Division states are prohibited from depleting the flow at Lees Ferry below 75M acre-feet over a running 10-year period (or an average of 7.5M acre-feet per year) through the exercise of post-1922 water rights and uses. Under the 2007 Interim Guidelines for Lower Basin Shortages and Coordinated Operations for Lake Powell and Lake Mead, which provides drought management guidelines until 2026, the annual releases from the Upper Division at Lee Ferry vary from 7.00M to 9.5M acre-feet per year (or more if equalization is required), and have typically been 9.0M acre-feet year. Since 2007, the Upper Division release has had a mean average of approximately 9.0M acre-feet per year. In concept, the 80,796 acre-feet of additional storage capacity could be used to provide a one-time release of water during a severe drought to allow a portion, or all the rights where water is available, of the post-1922 water rights in Wyoming to continue to operate under an Upper Colorado River Basin curtailment situation. Fontenelle Reservoir would not be able to accrue storage during a Colorado

Defining Curtailment Conditions In evaluating this potential benefit of the project, the first step is to define the conditions of a curtailment in the Colorado River Basin, and to quantify how Wyoming would respond to such a curtailment. The following sections describe the assumptions made in this analysis for defining curtailment conditions.

9.4.2.1 Drought Duration and Water Supply Deficit A significant body of research continues to develop on the hydrology of the Colorado River Basin. The likely duration of any curtailment has not been directly addressed in available research, but

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conceptually it is tied to the severity and duration of droughts and assumptions about reservoir storage levels and consumptive demands throughout the Upper Division. For a given drought period, storage reserves in Lake Powell and the other Colorado River Storage Project (CRSP) reservoirs would have to be drawn down before any curtailment would occur. Table 8-2 summarizes the storage capacity and historical contents of the CRSP reservoirs.

Table 8-2: Historical Storage Contents of CRSP Reservoirs

Storage Peak Annual Peak Annual Year Capacity Storage (AF) Storage (AF) Unit Reservoir Built (AF) 1970-2016 Average 2007-2016 Average Blue Mesa 1966 940,800 712,161 717,990 Aspinall Crystal 1977 26,000 17,343 17,300 Morrow Point 1970 117,190 115,034 113,578 Flaming Gorge Flaming Gorge 1962 3,788,799 3,277,547 3,317,361 Navajo Navajo 1962 1,708,600 1,432,886 1,412,352 Glen Canyon Powell 1963 26,215,000 18,471,691 14,600,228 Total Colorado River Storage Project 32,796,389 24,026,661 20,178,809 Fontenelle 1965 345,397 295,430 307,808

These assumptions of drought duration and magnitude are based upon historical drought data summarized in the 2012 USBR Colorado River Basin Study, as shown on Figure 36. A drought duration of 9 years and total magnitude of 28M acre-feet (of supply deficit) represents the 2000-2008 drought period. For this analysis, a curtailment is defined by the following assumptions: • A 9-year drought was assumed, based on the 2000-2008 drought period (USBR, 2012). • The first 6 years of the drought would reduce system storage by 25M acre-feet (USBR, 2012) and fully deplete the storage reserves of the CRSP reservoirs. The average peak annual system storage for the CRSP for the last 46 years (1970-2016) is approximately 24M acre-feet (USBR). • The subsequent 3 years of the drought would be administered under a Basin curtailment.

9.4.2.2 Wyoming Curtailment Obligation For mitigating issues of curtailment, it is first necessary to inventory which Wyoming water rights might be impacted by a curtailment under the Colorado River Basin compacts. The exact threshold priority date to apply remains uncertain, with both 1922 and 1929 representing possible thresholds for curtailment (WSEO, 2016). Current water uses (depletions) in the Green River Basin of Wyoming are provided in Table 8-3.

The State of Wyoming publishes a listing of adjudicated water rights by priority date (and other attributes) in the Division 4 tab book. This listing does not provide a direct inventory of consumptive use by water right priority date. The SEO has stated that “The bulk of the irrigation water rights in the Green River Basin in Wyoming have a pre-1922 priority date” (WSEO, 2016)

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Figure 36. Historical Droughts in the Colorado River Basin. Figure shows the duration and cumulative magnitude of historical droughts, measured as the deficit below mean streamflow for 3 historical drought periods. A drought duration of 8 years and a magnitude of 20M AF was assumed for this analysis.

and has developed a preliminary estimate of 333,600 acre-feet of pre-1922 water use. Other research efforts show that the vast majority of municipal and industrial uses in the Green River Basin have a post-1922 priority date (Carrico, 2014). For this analysis, it is assumed that average Green River Basin consumptive use is 574,869 acre-feet, resulting in approximately 209,169 acre- feet of post-1922 water rights. This estimate of water right priority dates does not represent any legal analysis relative to Compact issues and state water rights, but represents an estimate developed for analyzing a hypothetical curtailment scenario.

As noted above, the post-1922 water uses in Wyoming that would be subject to a curtailment include both irrigation and municipal and industrial (M&I) uses. The 2010 Green River Basin Plan (WWCE, 2010) provides more specific details on the exact M&I users that would be at risk, and this is summarized in Table 8-4. It should be noted that four industrial entities included in Table 8-4 already have “readiness to serve” lease contracts from Fontenelle Reservoir totaling 46,550 acre-feet per year. These lease agreements are summarized in Table 8-1. The current annual water use of these four entities with lease contracts totals approximately 29,341 acre-feet per year.

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Table 8-3. Estimates of Consumptive Use (afy) in Green River Basin, Wyoming

Sector Type 2011 2012 2013 2014 2015 2016 Average Irrigation 548,950 458,521 410,858 429,727 456,743 488,815 465,602 Agriculture Stock 1,755 1,755 1,755 1,755 1,755 1,755 1,755 SW 6,578 6,578 6,578 6,578 6,578 6,578 6,578 Municipal GW 817 817 817 817 817 817 817 SW 0 0 0 0 0 0 0 Domestic GW 3,042 3,042 3,042 3,042 3,042 3,042 3,042 SW 56,100 56,618 57,592 56,927 56,100 40,569 53,984 Industrial GW 1,954 1,954 1,954 1,954 1,954 7,982 2,959 Cheyenne 5,262 5,754 12,784 8,063 5,262 7,553 7,446 Exports Broadbent 367 377 508 830 367 1,060 585 Main Stem ------Evaporation In-State 32,100 32,100 32,100 32,100 32,100 32,100 32,100 TOTAL 656,925 567,516 527,988 541,793 564,718 590,271 574,869 Note: Dashed values are generally small and considered negligible.

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Table 8-4. Municipal and Industrial Water Uses in the Green River Basin

Annual Water Use Sector Entity Source of Supply (afy) Town of Baggs Little Snake River 28 Bridger Valley Joint Power Smith's Fork, Black's Fork 418 Dixon Little Snake River 25 Town of Granger Green River 20 Kemmerer - Diamondville Joint Powers Board Hams Fork River 301 Town of LaBarge Green River 148 Pinedale Fremont Lake Dam 581 Municipal Green River - Rock Springs - Sweetwater County Joint Green River 5,057 Town of Bairoil Groundwater - Battle Springs 38 Town of Big Piney Groundwater - Wasatch Formation 46 Town of Marbleton Groundwater - Wasatch Formation 715 Town of Opal Groundwater - Green River Formation 17 Town of Superior Groundwater - Erickson Sandstone 39 Town of Wamsutter Groundwater - Wasatch Formation 30 Sub-Total 7,463 Jim Bridger Power Plant ** Green River 28,560 Naughton Power Plant Hams Fork River 11,114 FMC Wyoming Green River 7,362 General Chemical Green River 3,788 OCI Wyoming Green River 2,994 Industrial Solvay Green River 2,234 Church & Dwight ** Green River 160 Exxon Shute Creek ** Green River 16 Simplot Phosphates ** Green River 605 Sub-Total 56,833 Trans- City of Cheyenne Little Snake River 15,281 Basin Export Sub-Total 15,281 Notes: ** indicates that the entity currently holds a water lease contract in Fontenelle Reservoir. The M&I water uses listed in the table were obtained from the 2010 Green River Basin Plan.

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If a curtailment becomes necessary, the obligations of each Upper Division state are defined in Article 4 of the 1948 Compact as pro-rata curtailment based on the fraction of total Upper Division consumptive use in the prior year: “the extent of curtailment by each State of the Upper Basin of the consumptive use of water apportioned to it by Article III of this Compact shall be such as to result in the delivery at Lee Ferry of a quantity of water which bears the same relation to the total required curtailment of use by the States of the Upper Basin as the consumptive use of Upper Colorado River System water which was made by each such State during the water year immediately preceding the year in which the curtailment becomes necessary bears to the total consumptive use of such water in the States of the Upper Basin during the same water year; provided, that in determining such relation the uses of water under rights perfected prior to November 24, 1922, shall be excluded.” To accurately define Wyoming’s curtailment obligation volume, an expansive inventory of pre- and post-1922 water rights and uses would need to be compiled for each Upper Division state, in order to understand each state’s fraction of total Upper Division usage under post-1922 water rights. In place of such an inventory, the Wyoming SEO has made preliminary estimates that Wyoming’s maximum obligation under a curtailment would be approximately 70,000 to 80,000 acre-feet. This analysis assumes that Wyoming would be obligated to produce 75,000 acre-feet of reduced consumptive use under a curtailment.

9.4.2.3 Probability of Curtailment In addition to the volume of potential curtailment in the Colorado River Basin, the probability of a curtailment is also of interest but highly uncertain. The most recent efforts to quantify such probabilities are reported by BOR in the 2012 Colorado River Basin Study (USBR, 2012b) and by the Colorado River District in the 2016 Risk Study (Colorado River District, 2016). The modeling output from these efforts are summarized on Figure 37.

For this analysis, the 2012 Basin Study modeling results on the probability of a Lee Ferry deficit are applied, as they are the most direct measure of a curtailment condition. Under historical hydrology, the probability of a curtailment is minimal, near 0%. Under paleo-hydrology and climate change hydrology conditions, the probability increases as shown on Figure 37. For this analysis, the probability of curtailment is assumed to be represented by the paleo-hydrology conditions line on Figure 37, increasing from 0% currently up to about 8% in 2055.

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50%

45% CO River District Risk Study Probability of Lake Powell 40% falling below Elev. 3525'

35%

30% USBR Basin Study Probability of a Lee 25% Ferry deficit

Probability 20% Reduced Demands 15% 10%

5%

0% 2010 2015 2020 2025 2030 2035 2040 2045 2050 2055 2060

Model Year

Figure 37. Probability of Colorado River Basin Shortages. Two different probability calculations are shown in the figure, under various hydrology and water demand assumptions. The data were interpreted from output graphs from each modeling effort.

Additional Considerations There are a number of factors that would need to be addressed in order for Wyoming to utilize dedicated storage releases from Fontenelle Reservoir as a method of mitigating its need to reduce post-1922 consumptive uses under a curtailment. A curtailment has never been issued, and therefore there are inherent uncertainties in how it would be conducted and how Upper Division states could manage to fulfill their obligation to the Lower Division. Some of the prominent factors to consider for this type of project benefit are outlined below.

9.4.3.1 Mitigation to Offset Consumptive Use Reductions A curtailment is intended to ensure that the Lower Division states receive a water supply of 75M acre-feet over a 10-year period, by reducing certain consumptive uses which are currently occurring in the Upper Division states. The benefit being evaluated for the project water supply in Fontenelle Reservoir is for Wyoming to make a dedicated release of storage water downstream in the Green River and to Lee Ferry instead of reducing consumptive uses. In concept, the Lower Division states would receive the same benefit from the dedicated release as from a reduction in consumptive use. This analysis assumes that mitigation water represents a benefit to the State of Wyoming.

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9.4.3.2 Operations of Flaming Gorge Reservoir The potential use of Fontenelle Reservoir storage space as a drought mitigation supply is contingent upon any releases from Fontenelle Reservoir being passed through Flaming Gorge Reservoir and flowing in the Green River into Utah and eventually into Lake Powell. The current operations of Flaming Gorge Reservoir are an important consideration in evaluating this potential benefit. Reservoir operations, including flow releases, are largely governed by a set of policy documents to target specific flow and temperature recommendations for endangered fish species (USBR 2005 and 2006; USFWS 2005).

Demand for Project Water Supplies Under a curtailment scenario, as described above, the demand for project water supplies depends on the extent to which Wyoming would need to utilize the bottom 80,796 acre-feet of storage space in Fontenelle Reservoir to meet its curtailment obligation of 75,000 acre-feet per year through mitigation. A simple water balance of Fontenelle Reservoir storage was developed for a future 50- year period to quantify the need for project water supplies under a curtailment scenario, and to quantify the volume of benefit to different use types in Wyoming. Several baseline assumptions were incorporated into the water balance:

• The State of Wyoming currently has rights to market a storage volume of 120,000 acre- feet (this includes the 46,550 AF of current ready to serve contracts with four industrial water users). The remaining storage capacity in Fontenelle Reservoir is utilized by BOR for hydropower production. The 80,796 acre-feet of additional storage capacity being considered is in addition to the volume currently reserved under existing lease contracts and is in excess of the current active capacity (see Figure 33). In order to utilize the additional inactive storage capacity, Wyoming would need to exercise its right of first refusal to contract for the remaining storage capacity in Fontenelle Reservoir for dedication to Wyoming uses, such as mitigation of curtailments. This contracting is necessary to ensure that Wyoming is able to carry storage reserves from one year to the next during a drought period, without BOR making hydropower releases. The costs to acquire the remaining storage capacity need to be included in the analysis, and are outlined in the 1962 and 1974 contracts.

• The volume of storage in Fontenelle Reservoir at the start of a drought period leading to a curtailment has an important influence on the extent to which the additional storage capacity of 80,796 acre-feet is needed to offset post-1922 water uses in the Green River Basin, and which types of uses would be offset. In concept, greater storage volumes in Fontenelle Reservoir at the start of a curtailment would reduce the reliance upon the project water supply. For this analysis, Fontenelle Reservoir was assumed to have a starting storage volume of 276,600 acre-feet at the start of a curtailment period, which is the average of peak annual storage for the drought period 2000-2005 (USBR, 2017a). The useable storage capacity in Fontenelle Reservoir was not reduced by 5,000 acre- feet of dedicated pool that benefits the Seedskadee Wildlife Refuge, because this environmental pool was assumed to not be active during a curtailment.

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• There exists a significant volume of currently unutilized storage capacity in Fontenelle Reservoir, and it is assumed that any use of the 80,796 acre-foot storage pool under consideration would only take place after the currently accessible storage capacity in Fontenelle Reservoir, totaling approximately 195,800 acre-feet, is applied to offset curtailments. The 46,600 acre-feet (rounded from the four lease contracts described in Table 8-1) of currently active contracts is included in this total. As discussed above, it is assumed that Wyoming will retain control and carryover of any unused storage during a curtailment period.

• Each year was modeled as a 3-year curtailment, as described previously. In the first two years, the currently accessible storage volume (195,800 acre-feet) is able to satisfy the full curtailment obligation of 75,000 acre-feet per year. The proposed project is not estimated to provide any benefit in the first two years of a curtailment. In the third year of curtailment, the reduced storage volume in Fontenelle Reservoir requires use of approximately 29,200 acre-feet of additional storage capacity provided by the proposed project, calculated as follows: Starting Storage – 2 years Curtailment = Year 3 Storage 195,800 – (2 x 75,000) = 45,800 Year 3 Curtailment – Year 3 Storage = Additional Storage Need 75,000 – 45,800 = 29,200

In the third year of curtailment, the available storage water supplies in Fontenelle Reservoir are applied to offset curtailment obligations for specific categories of water uses. The beneficiaries of the proposed project are those specific water rights which would be curtailed in priority in order for Wyoming to generate its 75,000 acre-feet of curtailment water. The water right priority dates provided in the Division 4 tab book were analyzed to define which water use categories would be subjected to curtailment under priority administration. Figure 38 shows the results of this analysis. Under current water rights, the vast majority (70%) of curtailed water use would be from irrigation.

In future years, the proportion of water use types benefitting from the additional storage volume provided by the proposed project might change, depending on whether those new consumptive uses are developed within existing water right portfolios or require new junior-priority water right

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100%

90% 80% 70%

60% Irrigation 50%

Industrial Curtailment Annual 40% Municipal Stockwater 30% Project Benefit 20%

Percent of Curtailment Volume Curtailment of Percent 10% 0% 10,000 20,000 30,000 40,000 50,000 60,000 70,000 80,000 Curtailment Volume

Figure 38. Percentage of Curtailment Volume by Use Type The lines represent the percentage of the curtailment volume for each water use type. These data were calculated by calculating the cumulative volume of water rights (consumptive use estimate) starting with the most junior-priority rights in Division 4 tab book

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filings. All future water demand growth is expected to be in the municipal and industrial (M&I) use sectors. Three scenarios were developed to represent possible future conditions:

• Scenario A, No New Water Rights: The current distribution of water use beneficiaries would extend each year into the future, which represents a condition in which all new water uses are developed within existing water right portfolios and no new (junior-priority) water rights are required for the M&I water use sectors.

• Scenario B, Some New Water Rights: Demand growth in the M&I use sectors would initially take place within existing water right portfolios, but would extend beyond those portfolios and require new water right filings at some future point in time. Current industrial water use is estimated to be approximately 75% of the volume associated with industrial water rights from the Division 4 tab book. Future industrial uses were estimated to reach 75,500 acre-feet per year in 2066, which compares to an estimated existing industrial water right volume of 75,000 acre-feet. No new industrial water rights were assumed for the 50-year analysis period. For the municipal sector, assuming existing uses represent 75% of the available water rights, new water right filings would be required starting 20 years into the future (2036) and continuing for the remainder of the 50-year analysis period. New water right filings would total approximately 4,800 acre-feet out of a total 50-year demand growth of 9,300 acre-feet. Under this scenario, the water right priority list from the Division 4 tab book was adjusted to account for new water rights and curtailment volumes by use sector were calculated in each year.

• Scenario C, All New Water Rights: This scenario assumes that the existing water right portfolios in the M&I demand sectors are being fully-utilized, and any new demand growth would have to come from new (junior-priority) water rights. The result is that a greater portion of curtailment volumes fall on the M&I use sectors in future years because they hold increasingly greater volumes of junior-priority water rights.

Figure 39 illustrates the benefit distribution by water use sector under these three future scenarios. The total volume benefit of the proposed project is 29,200 acre-feet per year in the third year of curtailment, and the figure illustrates which water use sectors are benefitting from this volume of additional supply.

Benefit Valuation by Sector The proposed approach to valuing the annual benefit of a mitigation supply to offset a curtailment is summarized in the following equation:

= , $ , + , $ , + , $ , Where: 𝑌𝑌 𝑀𝑀 𝑌𝑌 𝑀𝑀 𝑌𝑌 𝐼𝐼 𝑌𝑌 𝐼𝐼 𝑌𝑌 𝐴𝐴 𝑌𝑌 𝐴𝐴 𝑌𝑌 𝑌𝑌 B𝐵𝐵Y is the� �annual𝑉𝑉 benefit� in �year𝑉𝑉 Y � �𝑉𝑉 �� 𝑃𝑃 VX,Y is the annual volume of mitigation supply for Municipal, Industrial, and Agricultural uses in year Y $X,Y is the unit value of mitigation supply for Municipal, Industrial, and Agricultural uses in year Y, expressed in constant (inflation adjusted) dollars. PY is the Probability of a curtailment occurring in year Y

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Scenario A: No New Water Rights 35,000 30,000 Municipal 25,000 Industrial 20,000 15,000 10,000 Agriculture Annual Benefit (AF) Benefit Annual 5,000 0

2017 2022 2027 2032 2037 2042 2047 2052 2057 2062

Scenario B: Some New Water Rights 35,000

30,000

25,000 Municipal Industrial 20,000

15,000

10,000 Agriculture Annual Benefit (AF) Benefit Annual 5,000

0

2017 2022 2027 2032 2037 2042 2047 2052 2057 2062

Scenario C: All New Water Rights 35,000

30,000

25,000 Municipal

20,000 Industrial 15,000

10,000

Annual Benefit (AF) Benefit Annual Agriculture 5,000

0

2017 2022 2027 2032 2037 2042 2047 2052 2057 2062

Figure 39. Distribution of Project Benefit Volume by Use Types

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The overall project benefits are calculated as the net present value of discounted future annual benefits. The following sections describe the estimation of unit values by water use sector that were applied to the annual volumes described above.

9.4.5.1 Industrial Uses The industrial benefit is that an existing industrial water supply can continue to operate without restriction during a curtailment. Therefore, the benefit represents having an industrial water supply during an emergency condition. The value of such a benefit can be determined by constructing an industrial demand curve. The demand function to be applied can be written as: = ^( ( )/ + ) Where: 𝑃𝑃 is the𝑒𝑒 observed𝑙𝑙𝑙𝑙 𝑄𝑄 𝜂𝜂 price𝐶𝐶 ($/AF) of water for industrial water supply is a mathematical constant approximately equal to 2.71828 𝑃𝑃 is the estimated volume (AF) of industrial water use 𝑒𝑒 is the short-run price elasticity of demand 𝑄𝑄 is the integration constant. 𝜂𝜂 An industrial𝐶𝐶 demand curve was constructed using the current price and volume data reflected by the four option contracts in Table 8-1. These option contracts have an average wet-water lease rate of $57 per acre-foot and a contracted volume of 46,550 acre-feet. A short-run price elasticity of demand for the industrial sector is inherently difficult to identify, and was selected as a default value of -0.5 without more specific information (Clements, 2008). The integration constant was calculated using the current observed price (P2017) and level of water use (Q2017) data from the four option contracts. Figure 40 provides a graphical representation of the industrial demand curve for current (2017) conditions.

For future years, the integration constant was scaled according to the ratio of industrial water demand in each year to water demand in 2017 (DYear / D2017) as shown in the following equations: = ( ) { ( )/ } = + { (( / ))/ } 2017 2017 2017 𝐶𝐶 𝑙𝑙𝑙𝑙 𝑃𝑃 − 𝑙𝑙𝑙𝑙 𝑄𝑄 𝜂𝜂 2066 2017 Year 2017 The economic𝐶𝐶 benefit𝐶𝐶 of𝑙𝑙𝑙𝑙 an 𝐷𝐷emergency𝐷𝐷 water𝜂𝜂 supply in the industrial sector was calculated according to the following equation:

Annual Benefit = 1 1 𝐶𝐶Y 𝑒𝑒 �1+�𝜂𝜂�� �1+�𝜂𝜂�� 1 Y 𝑆𝑆 Where, ��1+�𝜂𝜂�� � ∗ �𝑄𝑄 − 𝑄𝑄 � is the volume (AF) of industrial water demand in year Y with the proposed project mitigation water supply in place 𝑌𝑌 𝑄𝑄 is the volume (AF) of industrial water demand in year Y without the proposed project mitigation water supply in place 𝑆𝑆 𝑄𝑄 The cost of water treatment was not factored into the above equation because the price and volume data from the current option contracts represent raw water supplies. The annual benefit calculated

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$1,000 $900 $800 $700 $600 $500 $400 Price ($/AF) $300 $200 $100 $0 5,000 10,000 15,000 20,000 25,000 30,000 35,000 40,000 45,000 50,000 Demand Volume (AF)

Figure 40. Industrial Demand Curve. This graph shows the relationship between price and demand volume for the industrial sector, using an integration constant calculated based on price and volume data reflected in the current option contracts in Fontenelle Reservoir.

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using the above equation was then be multiplied by the annual probability of occurrence in each future year (see Figure 37) and discounted to a net present value. A common benefit valuation method was applied for all industrial uses, both those currently holding option contracts in Fontenelle Reservoir and those which currently do not have contracts.

9.4.5.2 Municipal Uses The municipal benefit is that an existing municipal water supply can continue to operate without restriction during a curtailment. Therefore, the benefit represents having a municipal water supply during an emergency condition. Therefore, the benefit valuation methods follow those describe above for the industrial sector, but with different inputs and calibration points.

A total of 14 municipal water providers in the Green River Basin were contacted for water rate information. Municipal water system pricing data were compiled, and those with variable cost components in their rate structure were selected. These rates and the resulting observed price of approximately $708 per acre-foot for municipal water supplies are shown in Table 8-5. A municipal demand curve was constructed following the methods described above for industrial benefits. A short-run price elasticity of demand for the municipal sector was selected as -0.4 based on a review of various studies on price elasticity of residential water demands (Espey et al., 1997). The integration constant was calculated using the current observed price (P2017) and level of water use (Q2017) data.

Table 8-5: Municipal Water Pricing in the Green River Basin

Variable Cost Avg House Avg House Use Avg Annual Avg Unit Municipal Water User ($/1,000gals) Use (AF/yr) (gal/month) Variable Cost Cost ($/AF) Town of Baggs $2.25 0.15 4,147 $112 $733 Kemmerer-Diamondville Joint Powers Board $2.35 0.21 5,661 $160 $766 Town of LaBarge $4.25 0.63 17,213 $878 $1,385 Green River-Rock Springs- Sweetwater County Joint Powers Board $1.52 0.37 10,043 $183 $495 Town of Wamsutter $0.50 0.16 4,317 $26 $163 Average 0.30 8,276 $272 $708

For this analysis, the cost of water treatment and distribution were subtracted from the calculated benefit, because the project only provides raw water supplies. Water treatment and distribution costs were estimated as $1.90 per 1,000 gallons (USBR, 2001), which is equivalent to approximately $620 per acre-foot. The annual benefit calculated using the above equation was then be multiplied by the annual probability of occurrence in each future year (see Figure 37) and discounted to a net present value.

9.4.5.3 Agricultural Uses Agricultural water use in the Green River Basin is dominated by the irrigation of forage crops, primarily mountain hay and pasture ground (WSEO, 2017). The practice of irrigation is considered

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to primarily support livestock operations, as either a source of winter feed or increasing productivity of the grass pasture. The benefit of irrigation in the Green River Basin is to increase the yield of the forage crop relative to dryland conditions. A curtailment of irrigation water supplies would necessitate that ranchers purchase additional supplemental feed to maintain livestock herds. Therefore, the benefit of the proposed project to the agricultural sector is estimated based on the foregone costs of having to purchase supplemental feed during a curtailment.

The 2012 USDA Census of Agriculture provides county-level yield data, as summarized in Table 8-6 for the four counties in the Green River Basin of Wyoming. The average yield for both irrigated and non-irrigated hay farms is reported as 1.55 tons/acre. Based on the percent of irrigated acres, the irrigated yield was estimated to average approximately 1.95 tons/acre. Dryland yields were estimated to be approximately 0.5 tons/acre based on average effective precipitation data across the basin districts (WSEO, 2017) and an assumed yield relationship of 0.11 tons/acre per inch of crop ET (Pochop and Burman, 1987). The difference, or 1.45 tons/acre, is estimated as the average yield benefit of maintaining irrigation water supplies on the ranch.

Table 8-6. Hay Yield Data, 2012 Agriculture Census

Estimated Irrigated Quantity Yield Irrigated % Yield County Acres (tons) (tons/acre) Acres Irrigated (tons/acre) Sublette 93,340 114,379 1.23 86,214 92% 1.33 Lincoln 74,928 133,113 1.78 54,988 73% 2.42 Sweetwater 27,915 55,715 2.00 21,129 76% 2.64 Uinta 44,166 53,815 1.22 38,015 86% 1.42 Average 1.55 1.95

Wyoming state-wide hay prices are summarized in Table 8-7. An average hay price over the last 10 years is reported as $130 per ton. In addition, the cost of hauling supplemental hay to the ranch is estimated as $20 per ton. Reduced irrigation and yields also reduce farm costs related to harvest, which were estimated as $52 per acre (CSU, 2017) based on one cutting per season. The net cost of acquiring supplemental forage feed is estimated as $166 per acre. The average irrigation water requirement in 2016 across the various districts was estimated at 1.53 acre-feet per acre (WSEO, 2017). Therefore, the net benefit of avoiding the purchase of supplemental forage is calculated as $108 per acre-foot of consumptive use, as shown in Table 8-8.

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Table 8-7. Wyoming Statewide Hay Prices

All Alfalfa Other Hay Hay Hay Year ($/ton) ($/ton) ($/ton) 2006 $101 $101 $103 2007 $109 $109 $109 2008 $114 $115 $109 2009 $98 $99 $94 2010 $92 $93 $85 2011 $139 $142 $122 2012 $208 $210 $193 2013 $184 $187 $168 2014 $141 $145 $128 2015 $114 $118 $101 Average $130 $132 $121

Table 8-8. Estimation of Net Agricultural Benefit

Item Description Quantity Units A Irrigation Grass Hay Yield 1.95 tons/acre B Dryland Grass Hay Yield 0.50 tons/acre C (A-B) Yield Reduction without Irrigation 1.45 tons/acre D Hay Price $130 $/ton E Hauling Cost $20 $/ton F (C x (D+E)) Cost of Purchasing Supplemental $218 $/acre G Reduced Harvest Cost $52 $/acre H (F-G) Net Cost of Supplemental Feed $166 $/acre I Net Irrigation Requirement 1.53 AF/acre J (H/I) Unit Benefit of Irrigation $108 $/AF

Discussion of Benefit The annual combined benefits of the proposed project for drought mitigation are summarized in Table 8-10 to Table 8-11. A more detailed list of annual benefits over the 50-year analysis period is shown in Table 8-10 to Table 8-14 for the three scenarios described previously. The net present value of future benefits is estimated to range from approximately $6.2M under Scenario A (no new water rights) to $18.4M under Scenario C (all new water rights). Within this range, Scenario B (some new water right) has an estimated net present value of benefits equal to approximately $9.0M. Based on available information, Scenario B is considered to be the most likely scenario in terms of how future M&I demands would grow into existing water rights and require new junior- priority rights.

The three tables show that the majority of future benefit value is tied to mitigating for municipal shortages in the Green River Basin. To provide perspective, a similar net present value calculation assuming that the full 29,200 acre-feet of benefit accrues only to the agricultural sector results in a value of approximately $4.6M (see Table 8-16). This agricultural benefit of the proposed project

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considers the possibility that municipalities would temporarily lease water supplies from the agricultural sector in the event of a curtailment, rather than experience shortages; and therefore, the agricultural sector would be the primary beneficiary of the proposed project providing a water supply to mitigate curtailment. The possibility of municipal curtailment being mitigated by water leases from the agricultural sector was not analyzed on a site-specific basis for this report, and there are many factors which would influence whether such leasing activity could provide relief from curtailment shortages.

Table 8-9: Summary of Benefit Estimates by Scenario

Net Present Value Scenario Description of Benefits No New Water Rights. All new water uses are developed A within existing water right portfolios. $6,182,365 Some New Water Rights. About 50% of new municipal use is B sourced from new (junior-priority) water rights. $9,035,784 All New Water rights. All new M&I uses are sourced from C new (junior-priority) water rights. $18,445,246 Assumes that M&I uses would lease water from agricultural Ag Only sector in response to curtailment. $4,627,820

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Table 8-10: Annual Benefits of Drought Mitigation, Scenario A (1 of 2)

Industrial Municipal Agriculture Unit Unit Unit Total Count Year Volume Benefit Benefit Volume Benefit Benefit Volume Benefit Benefit Benefit 1 2017 3,670 $66 $241,272 3,141 $919 $2,885,2 22,389 $108 $2,421,8 $5,548,3

2 2018 3,670 $65 $238,183 3,141 $875 $2,748,8 22,389 $108 $2,421,8 $5,408,8

3 2019 3,670 $64 $235,727 3,141 $837 $2,627,8 22,389 $108 $2,421,8 $5,285,3

4 2020 3,670 $64 $233,578 3,141 $802 $2,519,7 22,389 $108 $2,421,8 $5,175,1

5 2021 3,670 $63 $231,817 3,141 $771 $2,422,6 22,389 $108 $2,421,8 $5,076,2

6 2022 3,670 $63 $230,235 3,141 $743 $2,334,9 22,389 $108 $2,421,8 $4,987,0

7 2023 3,670 $62 $228,911 3,141 $718 $2,255,4 22,389 $108 $2,421,8 $4,906,1

8 2024 3,670 $62 $227,698 3,141 $695 $2,182,8 22,389 $108 $2,421,8 $4,832,3

9 2025 3,670 $62 $226,626 3,141 $674 $2,116,4 22,389 $108 $2,421,8 $4,764,9

10 2026 3,670 $62 $226,315 3,141 $654 $2,055,4 22,389 $108 $2,421,8 $4,703,6

11 2027 3,670 $62 $226,201 3,141 $637 $1,999,2 22,389 $108 $2,421,8 $4,647,2

12 2028 3,670 $62 $225,982 3,141 $620 $1,947,2 22,389 $108 $2,421,8 $4,595,0

13 2029 3,670 $61 $225,130 3,141 $605 $1,899,0 22,389 $108 $2,421,8 $4,546,0

14 2030 3,670 $61 $224,360 3,141 $590 $1,854,2 22,389 $108 $2,421,8 $4,500,4

15 2031 3,670 $61 $223,688 3,141 $577 $1,812,4 22,389 $108 $2,421,8 $4,457,9

16 2032 3,670 $61 $223,049 3,141 $565 $1,773,4 22,389 $108 $2,421,8 $4,418,2

17 2033 3,670 $61 $222,486 3,141 $553 $1,736,8 22,389 $108 $2,421,8 $4,381,1

18 2034 3,670 $60 $221,946 3,141 $542 $1,702,5 22,389 $108 $2,421,8 $4,346,3

19 2035 3,670 $60 $221,468 3,141 $532 $1,670,2 22,389 $108 $2,421,8 $4,313,5

20 2036 3,670 $60 $221,339 3,141 $526 $1,651,2 22,389 $108 $2,421,8 $4,294,3

21 2037 3,670 $60 $221,212 3,141 $520 $1,632,8 22,389 $108 $2,421,8 $4,275,8

22 2038 3,670 $60 $221,107 3,141 $514 $1,615,1 22,389 $108 $2,421,8 $4,258,0

23 2039 3,670 $60 $220,985 3,141 $509 $1,598,0 22,389 $108 $2,421,8 $4,240,8

24 2040 3,670 $60 $220,883 3,141 $504 $1,581,5 22,389 $108 $2,421,8 $4,224,2

25 2041 3,670 $60 $220,766 3,141 $498 $1,565,5 22,389 $108 $2,421,8 $4,208,1

26 2042 3,670 $60 $220,651 3,141 $493 $1,550,0 22,389 $108 $2,421,8 $4,192,5

27 2043 3,670 $60 $220,539 3,141 $489 $1,535,1 22,389 $108 $2,421,8 $4,177,4

28 2044 3,670 $60 $220,428 3,141 $484 $1,520,6 22,389 $108 $2,421,8 $4,162,8

29 2045 3,670 $60 $220,320 3,141 $480 $1,506,6 22,389 $108 $2,421,8 $4,148,7

30 2046 3,670 $60 $220,213 3,141 $475 $1,493,0 22,389 $108 $2,421,8 $4,135,0

31 2047 3,670 $60 $220,109 3,141 $471 $1,479,8 22,389 $108 $2,421,8 $4,121,7

32 2048 3,670 $60 $220,007 3,141 $467 $1,467,0 22,389 $108 $2,421,8 $4,108,8

33 2049 3,670 $60 $219,906 3,141 $463 $1,454,6 22,389 $108 $2,421,8 $4,096,3

34 2050 3,670 $60 $219,808 3,141 $459 $1,442,6 22,389 $108 $2,421,8 $4,084,2

35 2051 3,670 $60 $219,711 3,141 $456 $1,430,9 22,389 $108 $2,421,8 $4,072,4

36 2052 3,670 $60 $219,616 3,141 $452 $1,419,5 22,389 $108 $2,421,8 $4,060,9

37 2053 3,670 $60 $219,523 3,141 $448 $1,408,4 22,389 $108 $2,421,8 $4,049,8

38 2054 3,670 $60 $219,431 3,141 $445 $1,397,7 22,389 $108 $2,421,8 $4,038,9

39 2055 3,670 $60 $219,341 3,141 $442 $1,387,2 22,389 $108 $2,421,8 $4,028,4

40 2056 3,670 $60 $219,253 3,141 $438 $1,377,1 22,389 $108 $2,421,8 $4,018,1

41 2057 3,670 $60 $219,168 3,141 $435 $1,367,1 22,389 $108 $2,421,8 $4,008,1

42 2058 3,670 $60 $219,085 3,141 $432 $1,357,5 22,389 $108 $2,421,8 $3,998,4

43 2059 3,670 $60 $219,004 3,141 $429 $1,348,0 22,389 $108 $2,421,8 $3,988,9

44 2060 3,670 $60 $218,926 3,141 $426 $1,338,9 22,389 $108 $2,421,8 $3,979,6

45 2061 3,670 $60 $218,849 3,141 $423 $1,329,9 22,389 $108 $2,421,8 $3,970,6

46 2062 3,670 $60 $218,775 3,141 $423 $1,329,9 22,389 $108 $2,421,8 $3,970,5

47 2063 3,670 $60 $218,703 3,141 $423 $1,329,9 22,389 $108 $2,421,8 $3,970,4

48 2064 3,670 $60 $218,632 3,141 $423 $1,329,9 22,389 $108 $2,421,8 $3,970,4

49 2065 3,670 $60 $218,564 3,141 $423 $1,329,9 22,389 $108 $2,421,8 $3,970,3

50 2066 3,670 $60 $218,498 3,141 $423 $1,329,9 22,389 $108 $2,421,8 $3,970,2

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Fontenelle Dam and Outworks Level II Study Wyoming Water Development Office

Table 8-11: Annual Benefits of Drought Mitigation, Scenario A (2 of 2)

Probability of Revised Net Present Count Year Total Benefit Curtailment Benefit Value 1 2017 $5,548,311 0% $0 $0 2 2018 $5,408,827 0% $0 $0 3 2019 $5,285,364 0% $0 $0 4 2020 $5,175,145 0% $0 $0 5 2021 $5,076,299 0% $0 $0 6 2022 $4,987,032 1% $49,870 $47,450 7 2023 $4,906,128 1% $49,061 $46,218 8 2024 $4,832,374 2% $96,647 $90,145 9 2025 $4,764,909 3% $142,947 $132,009 10 2026 $4,703,608 3% $141,108 $129,021 11 2027 $4,647,277 4% $185,891 $168,285 12 2028 $4,595,076 4% $183,803 $164,747 13 2029 $4,546,018 4% $181,841 $161,374 14 2030 $4,500,424 3% $135,013 $118,631 15 2031 $4,457,968 3% $133,739 $116,348 16 2032 $4,418,284 4% $176,731 $152,227 17 2033 $4,381,159 5% $219,058 $186,817 18 2034 $4,346,308 5% $217,315 $183,496 19 2035 $4,313,571 4% $172,543 $144,249 20 2036 $4,294,393 4% $171,776 $142,186 21 2037 $4,275,898 5% $213,795 $175,214 22 2038 $4,258,070 5% $212,904 $172,756 23 2039 $4,240,838 5% $212,042 $170,354 24 2040 $4,224,208 4% $168,968 $134,404 25 2041 $4,208,113 3% $126,243 $99,425 26 2042 $4,192,546 3% $125,776 $98,076 27 2043 $4,177,480 4% $167,099 $129,009 28 2044 $4,162,893 5% $208,145 $159,107 29 2045 $4,148,761 5% $207,438 $156,997 30 2046 $4,135,064 4% $165,403 $123,943 31 2047 $4,121,782 5% $206,089 $152,902 32 2048 $4,108,896 4% $164,356 $120,732 33 2049 $4,096,389 6% $245,783 $178,759 34 2050 $4,084,244 6% $245,055 $176,465 35 2051 $4,072,446 6% $244,347 $174,213 36 2052 $4,060,981 7% $284,269 $200,669 37 2053 $4,049,834 7% $283,488 $198,137 38 2054 $4,038,993 8% $323,119 $223,600 39 2055 $4,028,445 8% $322,276 $220,808 40 2056 $4,018,171 6% $241,090 $163,548 41 2057 $4,008,163 4% $160,327 $107,684 42 2058 $3,998,412 3% $119,952 $79,769 43 2059 $3,988,912 3% $119,667 $78,791 44 2060 $3,979,653 4% $159,186 $103,773 45 2061 $3,970,629 4% $158,825 $102,513 46 2062 $3,970,555 4% $158,822 $101,496 47 2063 $3,970,482 4% $158,819 $100,489 48 2064 $3,970,412 4% $158,816 $99,493 49 2065 $3,970,344 4% $158,814 $98,506 50 2066 $3,970,277 4% $158,811 $97,529 TOTAL $6,182,365

December 2018 99 Engineering Analytics, Inc.

Fontenelle Dam and Outworks Level II Study Wyoming Water Development Office

Table 8-12: Annual Benefits of Drought Mitigation, Scenario B (1 of 2)

Industrial Municipal Agriculture Unit Unit Unit Total Count Year Volume Benefit Benefit Volume Benefit Benefit Volume Benefit Benefit Benefit 1 2017 4,894 $62 $305,198 3,141 $918 $2,884,3 21,166 $108 $2,289,4 $5,479,0

2 2018 4,894 $62 $305,015 3,141 $875 $2,748,0 21,166 $108 $2,289,4 $5,342,5

3 2019 4,894 $62 $304,835 3,141 $836 $2,627,1 21,166 $108 $2,289,4 $5,221,4

4 2020 4,894 $62 $304,657 3,141 $802 $2,519,0 21,166 $108 $2,289,4 $5,113,2

5 2021 4,894 $62 $304,482 3,141 $771 $2,422,0 21,166 $108 $2,289,4 $5,015,9

6 2022 4,894 $62 $304,309 3,141 $743 $2,334,3 21,166 $108 $2,289,4 $4,928,1

7 2023 4,894 $62 $304,138 3,141 $718 $2,254,8 21,166 $108 $2,289,4 $4,848,4

8 2024 4,894 $62 $303,970 3,141 $695 $2,182,3 21,166 $108 $2,289,4 $4,775,7

9 2025 4,894 $62 $303,804 3,141 $674 $2,115,9 21,166 $108 $2,289,4 $4,709,2

10 2026 4,894 $62 $303,640 3,141 $654 $2,054,9 21,166 $108 $2,289,4 $4,648,0

11 2027 4,894 $62 $303,478 3,141 $636 $1,998,7 21,166 $108 $2,289,4 $4,591,7

12 2028 4,894 $62 $303,318 3,141 $620 $1,946,8 21,166 $108 $2,289,4 $4,539,6

13 2029 4,894 $62 $303,161 3,141 $605 $1,898,6 21,166 $108 $2,289,4 $4,491,2

14 2030 4,894 $62 $303,005 3,141 $590 $1,853,8 21,166 $108 $2,289,4 $4,446,3

15 2031 4,894 $62 $302,852 3,141 $577 $1,812,0 21,166 $108 $2,289,4 $4,404,3

16 2032 4,894 $62 $302,700 3,141 $565 $1,773,0 21,166 $108 $2,289,4 $4,365,1

17 2033 4,894 $62 $302,550 3,141 $553 $1,736,4 21,166 $108 $2,289,4 $4,328,4

18 2034 4,894 $62 $302,402 3,141 $542 $1,702,1 21,166 $108 $2,289,4 $4,294,0

19 2035 4,894 $62 $302,256 3,141 $532 $1,669,9 21,166 $108 $2,289,4 $4,261,6

20 2036 4,894 $62 $302,112 3,292 $548 $1,805,0 21,015 $108 $2,273,1 $4,380,2

21 2037 4,894 $62 $301,970 3,447 $566 $1,949,7 20,860 $108 $2,256,3 $4,508,1

22 2038 4,894 $62 $301,829 3,602 $583 $2,100,1 20,705 $108 $2,239,6 $4,641,6

23 2039 4,894 $62 $301,690 3,757 $601 $2,256,2 20,550 $108 $2,222,8 $4,780,8

24 2040 4,894 $62 $301,552 3,912 $618 $2,418,1 20,395 $108 $2,206,0 $4,925,7

25 2041 4,894 $62 $301,417 4,067 $636 $2,585,7 20,240 $108 $2,189,3 $5,076,4

26 2042 4,894 $62 $301,283 4,222 $654 $2,759,1 20,085 $108 $2,172,5 $5,232,9

27 2043 4,894 $62 $301,150 4,377 $671 $2,938,4 19,930 $108 $2,155,7 $5,395,3

28 2044 4,894 $62 $301,019 4,532 $689 $3,123,5 19,775 $108 $2,139,0 $5,563,5

29 2045 4,894 $61 $300,890 4,687 $707 $3,314,5 19,620 $108 $2,122,2 $5,737,7

30 2046 4,894 $61 $300,762 4,842 $725 $3,511,5 19,465 $108 $2,105,4 $5,917,7

31 2047 4,894 $61 $300,636 4,997 $743 $3,714,5 19,310 $108 $2,088,7 $6,103,8

32 2048 4,894 $61 $300,511 5,152 $762 $3,923,4 19,155 $108 $2,071,9 $6,295,9

33 2049 4,894 $61 $300,387 5,307 $780 $4,138,5 19,000 $108 $2,055,1 $6,494,0

34 2050 4,894 $61 $300,265 5,462 $798 $4,359,6 18,845 $108 $2,038,4 $6,698,2

35 2051 4,894 $61 $300,145 5,617 $817 $4,586,8 18,690 $108 $2,021,6 $6,908,6

36 2052 4,894 $61 $300,025 5,772 $835 $4,820,1 18,535 $108 $2,004,8 $7,125,0

37 2053 4,894 $61 $299,907 5,927 $854 $5,059,7 18,380 $108 $1,988,1 $7,347,7

38 2054 4,894 $61 $299,790 6,082 $872 $5,305,4 18,225 $108 $1,971,3 $7,576,5

39 2055 4,894 $61 $299,675 6,237 $891 $5,557,4 18,070 $108 $1,954,5 $7,811,7

40 2056 4,894 $61 $299,561 6,392 $910 $5,815,9 17,914 $108 $1,937,8 $8,053,2

41 2057 4,894 $61 $299,448 6,547 $929 $6,080,8 17,759 $108 $1,921,0 $8,301,3

42 2058 4,894 $61 $299,336 6,702 $948 $6,352,2 17,604 $108 $1,904,2 $8,555,8

43 2059 4,894 $61 $299,226 6,748 $943 $6,365,3 17,558 $108 $1,899,2 $8,563,7

44 2060 4,863 $61 $297,126 6,779 $936 $6,341,8 17,558 $108 $1,899,2 $8,538,1

45 2061 4,708 $61 $286,884 6,934 $954 $6,615,3 17,558 $108 $1,899,2 $8,801,5

46 2062 4,553 $61 $276,706 7,089 $954 $6,763,4 17,558 $108 $1,899,2 $8,939,3

47 2063 4,398 $61 $266,595 7,244 $954 $6,911,4 17,558 $108 $1,899,2 $9,077,2

48 2064 4,243 $60 $256,550 7,399 $954 $7,059,2 17,558 $108 $1,899,2 $9,215,0

49 2065 4,088 $60 $246,572 7,554 $954 $7,206,9 17,558 $108 $1,899,2 $9,352,7

50 2066 3,934 $60 $236,535 7,709 $954 $7,354,4 17,558 $108 $1,899,2 $9,490,2

December 2018 100 Engineering Analytics, Inc.

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Table 8-13: Annual Benefits of Drought Mitigation, Scenario B (2 of 2)

Total Probability of Revised Net Present Count Year Benefit Curtailment Benefit Value 1 2017 $5,479,069 0% $0 $0 2 2018 $5,342,550 0% $0 $0 3 2019 $5,221,412 0% $0 $0 4 2020 $5,113,209 0% $0 $0 5 2021 $5,015,986 0% $0 $0 6 2022 $4,928,162 1% $49,282 $46,890 7 2023 $4,848,442 1% $48,484 $45,675 8 2024 $4,775,759 2% $95,515 $89,089 9 2025 $4,709,225 3% $141,277 $130,467 10 2026 $4,648,093 3% $139,443 $127,498 11 2027 $4,591,734 4% $183,669 $166,273 12 2028 $4,539,611 4% $181,584 $162,758 13 2029 $4,491,265 4% $179,651 $159,431 14 2030 $4,446,301 3% $133,389 $117,204 15 2031 $4,404,377 3% $132,131 $114,949 16 2032 $4,365,194 4% $174,608 $150,398 17 2033 $4,328,494 5% $216,425 $184,572 18 2034 $4,294,047 5% $214,702 $181,290 19 2035 $4,261,653 4% $170,466 $142,513 20 2036 $4,380,273 4% $175,211 $145,029 21 2037 $4,508,108 5% $225,405 $184,730 22 2038 $4,641,609 5% $232,080 $188,317 23 2039 $4,780,810 5% $239,041 $192,044 24 2040 $4,925,747 4% $197,030 $156,726 25 2041 $5,076,456 3% $152,294 $119,941 26 2042 $5,232,972 3% $156,989 $122,415 27 2043 $5,395,329 4% $215,813 $166,618 28 2044 $5,563,563 5% $278,178 $212,640 29 2045 $5,737,707 5% $286,885 $217,125 30 2046 $5,917,797 4% $236,712 $177,378 31 2047 $6,103,865 5% $305,193 $226,430 32 2048 $6,295,948 4% $251,838 $184,994 33 2049 $6,494,077 6% $389,645 $283,390 34 2050 $6,698,286 6% $401,897 $289,407 35 2051 $6,908,610 6% $414,517 $295,539 36 2052 $7,125,081 7% $498,756 $352,079 37 2053 $7,347,731 7% $514,341 $359,486 38 2054 $7,576,595 8% $606,128 $419,443 39 2055 $7,811,704 8% $624,936 $428,177 40 2056 $8,053,279 6% $483,197 $327,786 41 2057 $8,301,317 4% $332,053 $223,024 42 2058 $8,555,811 3% $256,674 $170,689 43 2059 $8,563,774 3% $256,913 $169,157 44 2060 $8,538,170 4% $341,527 $222,641 45 2061 $8,801,504 4% $352,060 $227,236 46 2062 $8,939,389 4% $357,576 $228,510 47 2063 $9,077,247 4% $363,090 $229,737 48 2064 $9,215,049 4% $368,602 $230,915 49 2065 $9,352,765 4% $374,111 $232,046 50 2066 $9,490,236 4% $379,609 $233,125 TOTAL $9,035,784

December 2018 101 Engineering Analytics, Inc.

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Table 8-14: Annual Benefits of Drought Mitigation, Scenario C (1 of 2)

Industrial Municipal Agriculture Unit Unit Unit Count Year Volume Benefit Benefit Volume Benefit Benefit Volume Benefit Benefit Total Benefit 1 2017 3,670 $61 $223,613 3,141 $919 $2,885,222 22,389 $108 $2,421,817 $5,530,652 2 2018 3,962 $61 $242,589 3,329 $954 $3,175,514 21,909 $108 $2,369,936 $5,788,039 3 2019 4,253 $62 $261,740 3,517 $988 $3,476,432 21,430 $108 $2,318,055 $6,056,226 4 2020 4,545 $62 $281,065 3,705 $1,022 $3,787,623 20,950 $108 $2,266,174 $6,334,862 5 2021 4,836 $62 $300,564 3,893 $1,055 $4,108,750 20,471 $108 $2,214,293 $6,623,607 6 2022 5,128 $62 $320,236 4,082 $1,088 $4,439,486 19,991 $108 $2,162,412 $6,922,134 7 2023 5,419 $63 $340,080 4,270 $1,119 $4,779,519 19,511 $108 $2,110,531 $7,230,131 8 2024 5,711 $63 $360,096 4,458 $1,150 $5,128,549 19,032 $108 $2,058,650 $7,547,295 9 2025 6,002 $63 $380,282 4,646 $1,181 $5,486,287 18,552 $108 $2,006,769 $7,873,338 10 2026 6,294 $64 $400,639 4,834 $1,211 $5,852,454 18,072 $108 $1,954,888 $8,207,981 11 2027 6,585 $64 $421,164 5,022 $1,240 $6,226,786 17,593 $108 $1,903,007 $8,550,957 12 2028 6,877 $64 $441,859 5,210 $1,268 $6,609,024 17,113 $108 $1,851,127 $8,902,009 13 2029 7,168 $65 $462,721 5,398 $1,297 $6,998,923 16,634 $108 $1,799,246 $9,260,890 14 2030 7,460 $65 $483,751 5,586 $1,324 $7,396,245 16,154 $108 $1,747,365 $9,627,361 15 2031 7,751 $65 $504,948 5,774 $1,351 $7,800,764 15,674 $108 $1,695,484 $10,001,196 16 2032 8,043 $65 $526,310 5,963 $1,377 $8,212,259 15,195 $108 $1,643,603 $10,382,172 17 2033 8,334 $66 $547,838 6,151 $1,403 $8,630,520 14,715 $108 $1,591,722 $10,770,080 18 2034 8,626 $66 $569,531 6,339 $1,429 $9,055,345 14,235 $108 $1,539,841 $11,164,716 19 2035 8,917 $66 $591,387 6,527 $1,453 $9,486,537 13,756 $108 $1,487,960 $11,565,884 20 2036 9,209 $67 $613,407 6,620 $1,457 $9,647,464 13,371 $108 $1,446,355 $11,707,226 21 2037 9,500 $67 $635,590 6,713 $1,461 $9,808,541 12,987 $108 $1,404,750 $11,848,881 22 2038 9,792 $67 $657,934 6,806 $1,465 $9,969,763 12,602 $108 $1,363,146 $11,990,843 23 2039 10,083 $67 $680,440 6,899 $1,468 $10,131,127 12,217 $108 $1,321,541 $12,133,108 24 2040 10,375 $68 $703,107 6,992 $1,472 $10,292,626 11,833 $108 $1,279,936 $12,275,669 25 2041 10,667 $68 $725,934 7,085 $1,475 $10,454,258 11,448 $108 $1,238,331 $12,418,523 26 2042 10,958 $68 $748,920 7,179 $1,479 $10,616,018 11,063 $108 $1,196,727 $12,561,664 27 2043 11,250 $69 $772,065 7,272 $1,482 $10,777,901 10,679 $108 $1,155,122 $12,705,088 28 2044 11,541 $69 $795,368 7,365 $1,485 $10,939,904 10,294 $108 $1,113,517 $12,848,789 29 2045 11,833 $69 $818,829 7,458 $1,489 $11,102,024 9,910 $108 $1,071,912 $12,992,765 30 2046 12,124 $69 $842,447 7,551 $1,492 $11,264,257 9,525 $108 $1,030,307 $13,137,011 31 2047 12,416 $70 $866,221 7,644 $1,495 $11,426,599 9,140 $108 $988,703 $13,281,523 32 2048 12,707 $70 $890,150 7,737 $1,498 $11,589,048 8,756 $108 $947,098 $13,426,296 33 2049 12,999 $70 $914,235 7,830 $1,501 $11,751,600 8,371 $108 $905,493 $13,571,328 34 2050 13,290 $71 $938,474 7,923 $1,504 $11,914,252 7,986 $108 $863,888 $13,716,614 35 2051 13,582 $71 $962,868 8,016 $1,507 $12,077,001 7,602 $108 $822,284 $13,862,152 36 2052 13,873 $71 $987,414 8,110 $1,509 $12,239,845 7,217 $108 $780,679 $14,007,938 37 2053 14,165 $71 $1,012,113 8,203 $1,512 $12,402,781 6,833 $108 $739,074 $14,153,968 38 2054 14,456 $72 $1,036,964 8,296 $1,515 $12,565,806 6,448 $108 $697,469 $14,300,240 39 2055 14,748 $72 $1,061,967 8,389 $1,517 $12,728,919 6,063 $108 $655,864 $14,446,750 40 2056 15,039 $72 $1,087,120 8,482 $1,520 $12,892,474 5,679 $108 $614,247 $14,593,840 41 2057 15,331 $73 $1,112,424 8,575 $1,523 $13,056,381 5,294 $108 $572,620 $14,741,424 42 2058 15,622 $73 $1,137,877 8,669 $1,525 $13,220,548 4,909 $108 $530,986 $14,889,411 43 2059 15,914 $73 $1,163,479 8,762 $1,528 $13,384,881 4,524 $108 $489,350 $15,037,710 44 2060 16,205 $73 $1,189,230 8,856 $1,530 $13,549,285 4,139 $108 $447,713 $15,186,229 45 2061 16,497 $74 $1,215,129 8,949 $1,532 $13,713,663 3,754 $108 $406,081 $15,334,873 46 2062 16,788 $74 $1,241,175 9,042 $1,535 $13,877,915 3,369 $108 $364,455 $15,483,546 47 2063 17,080 $74 $1,267,368 9,135 $1,537 $14,041,942 2,985 $108 $322,840 $15,632,151 48 2064 17,372 $74 $1,293,708 9,228 $1,539 $14,205,643 2,600 $108 $281,239 $15,780,590 49 2065 17,663 $75 $1,320,193 9,321 $1,541 $14,368,915 2,216 $108 $239,656 $15,928,763 50 2066 18,684 $76 $1,415,210 9,414 $1,544 $14,531,653 1,102 $108 $119,192 $16,066,056

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Table 8-15: Annual Benefits of Drought Mitigation, Scenario C (2 of 2)

Total Probability of Revised Net Present Count Year Benefit Curtailment Benefit Value 1 2017 $5,530,652 0% $0 $0 2 2018 $5,788,039 0% $0 $0 3 2019 $6,056,226 0% $0 $0 4 2020 $6,334,862 0% $0 $0 5 2021 $6,623,607 0% $0 $0 6 2022 $6,922,134 1% $69,221 $65,862 7 2023 $7,230,131 1% $72,301 $68,111 8 2024 $7,547,295 2% $150,946 $140,790 9 2025 $7,873,338 3% $236,200 $218,127 10 2026 $8,207,981 3% $246,239 $225,147 11 2027 $8,550,957 4% $342,038 $309,643 12 2028 $8,902,009 4% $356,080 $319,163 13 2029 $9,260,890 4% $370,436 $328,743 14 2030 $9,627,361 3% $288,821 $253,776 15 2031 $10,001,196 3% $300,036 $261,020 16 2032 $10,382,172 4% $415,287 $357,707 17 2033 $10,770,080 5% $538,504 $459,248 18 2034 $11,164,716 5% $558,236 $471,362 19 2035 $11,565,884 4% $462,635 $386,771 20 2036 $11,707,226 4% $468,289 $387,622 21 2037 $11,848,881 5% $592,444 $485,534 22 2038 $11,990,843 5% $599,542 $486,487 23 2039 $12,133,108 5% $606,655 $487,385 24 2040 $12,275,669 4% $491,027 $390,583 25 2041 $12,418,523 3% $372,556 $293,412 26 2042 $12,561,664 3% $376,850 $293,856 27 2043 $12,705,088 4% $508,204 $392,357 28 2044 $12,848,789 5% $642,439 $491,083 29 2045 $12,992,765 5% $649,638 $491,669 30 2046 $13,137,011 4% $525,480 $393,765 31 2047 $13,281,523 5% $664,076 $492,693 32 2048 $13,426,296 4% $537,052 $394,506 33 2049 $13,571,328 6% $814,280 $592,229 34 2050 $13,716,614 6% $822,997 $592,643 35 2051 $13,862,152 6% $831,729 $593,001 36 2052 $14,007,938 7% $980,556 $692,188 37 2053 $14,153,968 7% $990,778 $692,479 38 2054 $14,300,240 8% $1,144,019 $791,667 39 2055 $14,446,750 8% $1,155,740 $791,859 40 2056 $14,593,840 6% $875,630 $594,001 41 2057 $14,741,424 4% $589,657 $396,045 42 2058 $14,889,411 3% $446,682 $297,045 43 2059 $15,037,710 3% $451,131 $297,033 44 2060 $15,186,229 4% $607,449 $395,996 45 2061 $15,334,873 4% $613,395 $395,913 46 2062 $15,483,546 4% $619,342 $395,793 47 2063 $15,632,151 4% $625,286 $395,636 48 2064 $15,780,590 4% $631,224 $395,438 49 2065 $15,928,763 4% $637,151 $395,199 50 2066 $16,066,056 4% $642,642 $394,659 TOTAL $18,445,246

December 2018 103 Engineering Analytics, Inc.

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Table 8-16: Annual Benefits of Drought Mitigation, Agriculture Only

Agriculture Probability Unit Total of Revised Net Present Count Year Volume Benefit Benefit Benefit Curtailment Benefit Value 1 2017 29,200 $108 $3,158,562 $3,158,562 0% $0 $0 2 2018 29,200 $108 $3,158,562 $3,158,562 0% $0 $0 3 2019 29,200 $108 $3,158,562 $3,158,562 0% $0 $0 4 2020 29,200 $108 $3,158,562 $3,158,562 0% $0 $0 5 2021 29,200 $108 $3,158,562 $3,158,562 0% $0 $0 6 2022 29,200 $108 $3,158,562 $3,158,562 1% $31,586 $30,053 7 2023 29,200 $108 $3,158,562 $3,158,562 1% $31,586 $29,755 8 2024 29,200 $108 $3,158,562 $3,158,562 2% $63,171 $58,921 9 2025 29,200 $108 $3,158,562 $3,158,562 3% $94,757 $87,506 10 2026 29,200 $108 $3,158,562 $3,158,562 3% $94,757 $86,640 11 2027 29,200 $108 $3,158,562 $3,158,562 4% $126,342 $114,376 12 2028 29,200 $108 $3,158,562 $3,158,562 4% $126,342 $113,244 13 2029 29,200 $108 $3,158,562 $3,158,562 4% $126,342 $112,123 14 2030 29,200 $108 $3,158,562 $3,158,562 3% $94,757 $83,259 15 2031 29,200 $108 $3,158,562 $3,158,562 3% $94,757 $82,435 16 2032 29,200 $108 $3,158,562 $3,158,562 4% $126,342 $108,825 17 2033 29,200 $108 $3,158,562 $3,158,562 5% $157,928 $134,684 18 2034 29,200 $108 $3,158,562 $3,158,562 5% $157,928 $133,351 19 2035 29,200 $108 $3,158,562 $3,158,562 4% $126,342 $105,625 20 2036 29,200 $108 $3,158,562 $3,158,562 4% $126,342 $104,579 21 2037 29,200 $108 $3,158,562 $3,158,562 5% $157,928 $129,429 22 2038 29,200 $108 $3,158,562 $3,158,562 5% $157,928 $128,148 23 2039 29,200 $108 $3,158,562 $3,158,562 5% $157,928 $126,879 24 2040 29,200 $108 $3,158,562 $3,158,562 4% $126,342 $100,498 25 2041 29,200 $108 $3,158,562 $3,158,562 3% $94,757 $74,627 26 2042 29,200 $108 $3,158,562 $3,158,562 3% $94,757 $73,888 27 2043 29,200 $108 $3,158,562 $3,158,562 4% $126,342 $97,542 28 2044 29,200 $108 $3,158,562 $3,158,562 5% $157,928 $120,721 29 2045 29,200 $108 $3,158,562 $3,158,562 5% $157,928 $119,526 30 2046 29,200 $108 $3,158,562 $3,158,562 4% $126,342 $94,674 31 2047 29,200 $108 $3,158,562 $3,158,562 5% $157,928 $117,170 32 2048 29,200 $108 $3,158,562 $3,158,562 4% $126,342 $92,808 33 2049 29,200 $108 $3,158,562 $3,158,562 6% $189,514 $137,834 34 2050 29,200 $108 $3,158,562 $3,158,562 6% $189,514 $136,469 35 2051 29,200 $108 $3,158,562 $3,158,562 6% $189,514 $135,118 36 2052 29,200 $108 $3,158,562 $3,158,562 7% $221,099 $156,077 37 2053 29,200 $108 $3,158,562 $3,158,562 7% $221,099 $154,532 38 2054 29,200 $108 $3,158,562 $3,158,562 8% $252,685 $174,859 39 2055 29,200 $108 $3,158,562 $3,158,562 8% $252,685 $173,128 40 2056 29,200 $108 $3,158,562 $3,158,562 6% $189,514 $128,560 41 2057 29,200 $108 $3,158,562 $3,158,562 4% $126,342 $84,858 42 2058 29,200 $108 $3,158,562 $3,158,562 3% $94,757 $63,014 43 2059 29,200 $108 $3,158,562 $3,158,562 3% $94,757 $62,390 44 2060 29,200 $108 $3,158,562 $3,158,562 4% $126,342 $82,363 45 2061 29,200 $108 $3,158,562 $3,158,562 4% $126,342 $81,547 46 2062 29,200 $108 $3,158,562 $3,158,562 4% $126,342 $80,740 47 2063 29,200 $108 $3,158,562 $3,158,562 4% $126,342 $79,940 48 2064 29,200 $108 $3,158,562 $3,158,562 4% $126,342 $79,149 49 2065 29,200 $108 $3,158,562 $3,158,562 4% $126,342 $78,365 50 2066 29,200 $108 $3,158,562 $3,158,562 4% $126,342 $77,589 TOTAL $4,627,820

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Drought Avoidance Analysis Overview of Benefit The drought mitigation benefit described above is framed as a response to a Colorado River Basin curtailment. Upper Division stakeholders have been evaluating concepts to provide insurance against a curtailment ever occurring. The storage elevation in Lake Powell remains the simplest indicator of how much insurance the Upper Division has against a curtailment. Current concepts being explored seek ways to provide dedicated flows from each of the Upper Division states, likely through demand reduction and the fallowing of irrigated agriculture, to Lake Powell with the intent of bolstering the storage pool elevation. Such concepts have been and continue to be evaluated technically and have been the subject of a basin-wide pilot program. The term “system conservation” has been used to describe the concept of providing dedicated flows to the Colorado River system.

The additional 80,796 acre-feet of storage capacity in Fontenelle Reservoir could be provided as a one-time release to the Colorado River system (as a whole) under a program like the system conservation pilot program. The details of this drought avoidance benefit remain uncertain, but it may represent the most likely benefit framework for the proposed project as the Upper Division states continue to collaborate on drought planning. For this analysis, it is assumed that the State of Wyoming would fund the capital costs of the project and contract for the 80,796 acre-feet of storage space from BOR, and would therefore seek compensation if the project storage were utilized for system conservation purposes. Alternative contracts and agreements could be developed while maintaining this overall concept.

System Conservation Pilot Program In 2014, four of the largest municipal water providers in the Colorado River Basin (Central Arizona Water Conservancy District, Metropolitan Water District of Southern California, Southern Nevada Water Authority, and Denver Water) signed an agreement with BOR to help fund a System Conservation Pilot Program (SCPP) (USBR, 2016a). The original SCPP provided $11M (with $2.75M in the Upper Division) to test a wide range of water conservation concepts that reduce consumptive water use in the Colorado Basin. An additional $1.8M was secured for Upper Division projects in 2017. The conserved water is for the sole purpose of increasing storage levels in Lake Powell, without any water supply benefit accruing to an individual water user. The SCPP has conducted three rounds of funding in the Upper Division from 2015 to 2017. In addition, a Congressional bill was introduced in May 2016 to significantly increase Federal funding for the SCPP to $50M but no action has been taken on the proposal (114th Congress, 2016).

The SCPP indicates a willingness for high-value water uses in the Colorado River Basin to pay for system conservation measures that provide insurance against future water supply shortages and a basin curtailment. Currently, the SCPP is simply a pilot program and interest in continuing to fund such efforts may erode based on annual hydrologic conditions (Buschatzke, 2017). The SCPP is important however, because it provides a possible view into what future water management activities may take place in the Colorado River Basin during a severe drought.

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Under the three rounds of SCPP funding in the Upper Division, accepted projects were primarily full-season and partial-season fallowing activities that provided reductions in consumptive use as a system conservation benefit. Preliminary estimates of consumptive use savings in the Upper Division are 21,383 acre-feet over the three years of funding (UCRC, 2015). Currently, project participants are evaluating difficult questions and concerns regarding shepherding the conserved water to Lake Powell to provide the system-wide benefits desired under the program. The additional storage capacity in Fontenelle Reservoir could provide a volume of conserved water to help bolster elevations in Lake Powell, which is large relative to past SCPP efforts. This represents a benefit to the entire Upper Division system, similar to the SCPP.

Regulatory Considerations 9.5.3.1 Interstate Water Uses Article IX of the 1948 Upper Division Compact provides the ability for the interstate use of water between the Upper Division states, but each state allocation under the 1948 Compact accounts for where water is used, and not necessarily where water is diverted. In effect, water leasing between Upper Division states would not occur.

Marketing of Upper Division water supplies to the Lower Division is fraught with legal and political obstacles. Several historical projects have tried to accomplish such market transfers from the Upper to Lower Division, but all such proposed projects have failed. Under the current laws and policies that define Colorado Basin administration, market transfers from Fontenelle Reservoir to any of the Lower Division states or individual water users within the Lower Division states is considered unrealistic and infeasible.

Under the proposed benefit, the State of Wyoming could make a voluntary release from Fontenelle Reservoir to provide insurance against a Compact curtailment for the benefit of all water uses in the Upper Division. This is considered distinct from interstate water use and transfer concepts described above.

9.5.3.2 Wyoming Policy on Exporting Water The State of Wyoming has statutory restrictions on exporting water outside of the state. Wyoming statute 41-3-115 provides that the Wyoming Legislature must approve, based on a State Engineer opinion and recommendation, any project which exports 1,000 acre-feet or more of water to a neighboring state (State of Wyoming, 2017). The factors to be considered when evaluating an export application include:

(1) The amount of water proposed to be appropriated and the proposed uses; (2) The amount of water available for appropriation from the proposed source, and the natural characteristics of the source; (3) The economic, social, environmental and other benefits to be derived by the state from the proposed appropriation;

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(4) The benefits to the state by the use of the water within the state that will be foregone by the proposed appropriation; (5) The benefits presently and prospectively derived from the return flow of water in intrastate use which will be eliminated by the proposed out-of-state use; (6) The injury to existing water rights of other appropriators that may result from the proposed use; (7) Whether the use formulated and carried out promotes or enhances the purposes and policies of the state's water development plans and water resources policy, and that the use will not unreasonably interfere with other planned uses or developments for which a permit has been or may be issued; (8) Whether the proposed use will significantly impair the state's interest and ability to preserve and conserve sufficient quantities of water for reasonably foreseeable consumptive uses and other beneficial uses recognized by law to include but not limited to domestic, livestock, agricultural, municipal and industrial purposes; (9) Whether the proposed use will adversely affect the quantity or quality of water available for domestic or municipal use; (10) Whether, to the greatest extent possible, the correlation between surface water and groundwater has been determined, to avoid possible harmful effects of the proposed use on the supply of either.

To date, the only water export project that has been approved by Wyoming is environmental water leases out of Pathfinder Reservoir in the Platte River Basin. This export project was approved in 2009 and provides for the annual export of approximately 34,600 acre-feet from the Pathfinder Modification Project for the purpose of fulfilling Wyoming’s environmental instream flow obligations under the Platte River Recovery Implementation Program (WSEO, 2009). This project represents a direct release of water to a use outside of Wyoming.

Similar to the Pathfinder project, a dedicated release of water from Fontenelle Reservoir would likely be considered an export of water, even though the physical water may not be used in the downstream receiving state. Therefore, any water leasing out of Fontenelle Reservoir for system conservation purposes will likely require approval from the Wyoming Legislature and a specific permit from the Wyoming State Engineer. In terms of the consideration factors for export projects, the potential new storage in Fontenelle Reservoir is considered to be a beneficial project for the State of Wyoming. There may be some conflict if the water is released from Fontenelle Reservoir for the benefit of all Upper Division states instead of being held for use in mitigating a curtailment of Wyoming water uses.

9.5.3.3 Shepherding Water Another issue to consider is the potential need to shepherd a dedicated storage release to its intended place of use, which would be Lake Powell. Shepherding water basically means conveying a dedicated water supply past points of diversion that would otherwise have the right and desire to divert the supply. As described previously, any releases from Fontenelle Reservoir that are intended to benefit the Upper Colorado River Basin will immediately flow into Flaming

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Gorge Reservoir, and the operations of Flaming Gorge Reservoir are currently closely tied to the recovery of the four endangered fish species. Downstream from Flaming Gorge Reservoir, water rights in Utah would need to be managed such that the dedicated releases from Fontenelle Reservoir accrue in Lake Powell.

Benefit Valuation The 80,796 acre-feet of additional storage capacity could be used to provide inflows into Lake Powell in order to avoid a curtailment in the Upper Division. The Upper Division states are currently conducting Drought Contingency Planning in cooperation with BOR. This effort consists of: (1) weather modification, (2) drought reservoir operations, and (3) demand management (WSEO, 2016). There is acknowledged uncertainty regarding how BOR would operate Fontenelle Reservoir under Drought Contingency Planning if the entire storage capacity were contracted to Wyoming. This is a critical question to answer in order for the project to have drought avoidance benefits. This topic was discussed with a number of representatives from State of Wyoming and BOR and currently there is no firm position on how Fontenelle Reservoir would be managed for system conservation or drought contingency planning. All parties acknowledge the benefit, but the specific mechanism of reservoir operations remains uncertain.

For this analysis, it is assumed that Wyoming could realize the value of system conservation supplies by making dedicated releases from Fontenelle Reservoir. The buyer or source of payment is not specifically identified. The current SCPP is funded by a mix of interested stakeholders in the Colorado River Basin. The value of system conservation water is estimated from prices paid for Upper Division demand management projects under the SCPP from 2015 through 2017 (UCRC, 2017). There were approximately 45 projects conserving 21,383 acre-feet, with an average price of $211 per acre-foot of conserved water. Figure 41 shows that there has been a price reduction over the three funding cycles, as more applications have been received.

2015 2016 2017

Figure 41. Average Lease Rate in SCPP.

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The average lease rate for the three years of the System Conservation Pilot Program has shown a decrease as more participants apply and a greater diversity of projects and areas are included. It is expected that the market rate for system conservation leases will continue to decline as the agricultural sector becomes more familiar and comfortable with the program and process. Into the future, the market rate for system conservation practices is expected to be close to the net return over operating costs for forage crops, which dominate the Upper Division crop mix. Current grass hay crop enterprise budgets in Western Colorado indicate a lease rate of approximately $115 per acre-foot (CSU, 2017). Previous work completed for the Colorado Water Bank Working Group on net returns to water for Colorado West Slope forage crops indicated a similar average value of $112 per acre-foot (WestWater Research, 2015). The large volume of project water supply relative to past system conservation volumes might also lead to a discount in unit price. For this analysis, a future market value for system conservation water supplies is estimated to be $100 per acre-foot of consumptive use.

The probability of payment for a system conservation release from Fontenelle Reservoir was assumed to be equal to the probability of Lake Powell reaching an elevation of 3575 feet, as shown on Figure 37 based on the reduced demand scenario in the Colorado River District Risk Study. The available modeling extends to the year 2036, and beyond that year until the year 2066 the probability is assumed to be 13%, which is the average probability over the model period. The annual benefit is calculated using a unit value of $100 per acre-foot, multiplied by the full project water storage volume of 80,796 acre-feet. The annual benefit is then be multiplied by the annual probability of occurrence in each future year and discounted to a net present value.

Summary Opinion of Benefit The annual benefit of the proposed project for drought avoidance are shown for the 50-year analysis period in Table 8-17. The net present value of future benefits is estimated to be $41.8M.

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Table 8-17: Annual Benefit of Drought Avoidance System Conservation Probability of Revised Net Present Count Year Volume Unit Benefit Benefit Elevation 3575 Benefit Value 1 2017 80,796 $100 $8,079,600 0% $0 $0 2 2018 80,796 $100 $8,079,600 3% $242,388 $239,988 3 2019 80,796 $100 $8,079,600 11% $888,756 $871,244 4 2020 80,796 $100 $8,079,600 17% $1,373,532 $1,333,137 5 2021 80,796 $100 $8,079,600 17% $1,373,532 $1,319,937 6 2022 80,796 $100 $8,079,600 17% $1,373,532 $1,306,869 7 2023 80,796 $100 $8,079,600 20% $1,615,920 $1,522,270 8 2024 80,796 $100 $8,079,600 17% $1,373,532 $1,281,118 9 2025 80,796 $100 $8,079,600 11% $888,756 $820,751 10 2026 80,796 $100 $8,079,600 16% $1,292,736 $1,182,000 11 2027 80,796 $100 $8,079,600 11% $888,756 $804,579 12 2028 80,796 $100 $8,079,600 9% $727,164 $651,774 13 2029 80,796 $100 $8,079,600 9% $727,164 $645,321 14 2030 80,796 $100 $8,079,600 16% $1,292,736 $1,135,879 15 2031 80,796 $100 $8,079,600 16% $1,292,736 $1,124,632 16 2032 80,796 $100 $8,079,600 16% $1,292,736 $1,113,497 17 2033 80,796 $100 $8,079,600 11% $888,756 $757,950 18 2034 80,796 $100 $8,079,600 22% $1,777,512 $1,500,891 19 2035 80,796 $100 $8,079,600 13% $1,050,348 $878,109 20 2036 80,796 $100 $8,079,600 13% $1,050,348 $869,415 21 2037 80,796 $100 $8,079,600 13% $1,050,348 $860,807 22 2038 80,796 $100 $8,079,600 13% $1,050,348 $852,284 23 2039 80,796 $100 $8,079,600 13% $1,050,348 $843,846 24 2040 80,796 $100 $8,079,600 13% $1,050,348 $835,491 25 2041 80,796 $100 $8,079,600 13% $1,050,348 $827,219 26 2042 80,796 $100 $8,079,600 13% $1,050,348 $819,028 27 2043 80,796 $100 $8,079,600 13% $1,050,348 $810,919 28 2044 80,796 $100 $8,079,600 13% $1,050,348 $802,890 29 2045 80,796 $100 $8,079,600 13% $1,050,348 $794,941 30 2046 80,796 $100 $8,079,600 13% $1,050,348 $787,070 31 2047 80,796 $100 $8,079,600 13% $1,050,348 $779,277 32 2048 80,796 $100 $8,079,600 13% $1,050,348 $771,562 33 2049 80,796 $100 $8,079,600 13% $1,050,348 $763,922 34 2050 80,796 $100 $8,079,600 13% $1,050,348 $756,359 35 2051 80,796 $100 $8,079,600 13% $1,050,348 $748,870 36 2052 80,796 $100 $8,079,600 13% $1,050,348 $741,456 37 2053 80,796 $100 $8,079,600 13% $1,050,348 $734,114 38 2054 80,796 $100 $8,079,600 13% $1,050,348 $726,846 39 2055 80,796 $100 $8,079,600 13% $1,050,348 $719,649 40 2056 80,796 $100 $8,079,600 13% $1,050,348 $712,524 41 2057 80,796 $100 $8,079,600 13% $1,050,348 $705,470 42 2058 80,796 $100 $8,079,600 13% $1,050,348 $698,485 43 2059 80,796 $100 $8,079,600 13% $1,050,348 $691,569 44 2060 80,796 $100 $8,079,600 13% $1,050,348 $684,722 45 2061 80,796 $100 $8,079,600 13% $1,050,348 $677,942 46 2062 80,796 $100 $8,079,600 13% $1,050,348 $671,230 47 2063 80,796 $100 $8,079,600 13% $1,050,348 $664,584 48 2064 80,796 $100 $8,079,600 13% $1,050,348 $658,004 49 2065 80,796 $100 $8,079,600 13% $1,050,348 $651,489 50 2066 80,796 $100 $8,079,600 13% $1,050,348 $645,039 TOTAL $41,796,970

Cost Considerations There are a number of project costs to consider alongside the benefits defined herein. These costs must be subtracted from the net present value of benefits in order to understand the net benefits of the proposed project. This economic analysis was not intended to quantify all of these costs. Provided below is a narrative description of various cost considerations for the proposed project.

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Capital and Annual Operating Costs Capital and annual operation and maintenance (O&M) costs of the proposed project are calculated as part of this Level II study. Costs were developed for various alternative technologies and construction methods to armor the existing dam embankment. These costs are described in other sections of this report.

Storage Contracting Costs The State of Wyoming has entered into two contracts with BOR for a total use of 120,000 acre- feet of storage space in Fontenelle Reservoir. The terms of these two existing contracts are described below:

• June 14, 1962. The Wyoming Natural Resource Board contracted for 60,000 acre-feet of storage capacity from BOR at a cost not to exceed $900,000. The actual cost was to be based on the actual project costs, and the pro-rata allocation of costs to the 60,000 acre-feet of municipal and industrial uses contracted by Wyoming. This lump sum payment was to be paid in 50 equal, annual installments, and was exclusive of annual operation, maintenance, and rehabilitation (OM&R) costs obligations of Wyoming. Any of the contract water not used by the State of Wyoming shall be used by BOR for the benefit of the project as a whole. The State of Wyoming is also obligated to pay its pro- rata share of the OM&R costs, paid in advance each year based on BOR estimates.

• December 27, 1974. The Wyoming Department of Economic Planning and Development contracted 60,000 acre-feet of storage capacity from BOR at a cost of $11,410,000. The contract specifies that the active storage space (written as 190,250 acre-feet) is to be managed in the following priority pools: (1) 5,250 acre-feet reserved by U.S. for Seedskadee National Wildlife Refuge and recreational uses, (2) a common pool consisting of 60,000 acre-feet contracted by Wyoming in the contract, 60,000 acre- feet previously contracted by Wyoming, 65,000 acre-feet reserved to the U.S. for other uses. Any contracts executed between Wyoming and a third party are subject to a benefit sharing clause, in which Wyoming agrees to provide to the U.S. 50% of net revenues in excess of Wyoming’s payment obligations to the U.S., with these funds being applied to the unpaid balance of the Wyoming repayment obligation. The repayment obligation of $11.41M was calculated based on the allocated construction cost of the project and funded interest through 1977 at an annual rate of 2.632%. This repayment obligation was to be paid in 40 annual installments, with a scheduled interest rate of 2.632%. The repayment obligation does not include annual OM&R payments, and Wyoming is obligated to pay its pro-rata portion of OM&R on Fontenelle Dam and Reservoir, but not on the hydropower plant and related facilities. BOR agreed to not charge Wyoming for loss of power revenue due to water withdrawals which bypass the hydropower plant. The contract also provides Wyoming with a first right of refusal to purchase any additional water available in Fontenelle Reservoir. In order to maintain the fishery resource below Fontenelle Dam, Wyoming agreed that at least 50% of the contracted storage water would be leased to diversions occurring at or downstream of the Interstate 80 crossing of

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the Green River. The U.S. similarly agrees to limit diversions from its reserved storage to not more than 25% above this crossing point, and to maintain 50 cfs of streamflow in Green River at the Town of Green River gaging station.

Based on the timing of these two contracts, Wyoming should have completed, or be close to completing, its repayment obligations. The two contracts had a unit contract cost of $15 (1962) and $190 (1974) per acre-foot of storage capacity. Under the benefits evaluated in this report, Wyoming would need to contract for the 80,796 acre-feet of project storage capacity. The unit price for such a contract is uncertain, and would need to be negotiated but could be similar to 1974 costs at a minimum. At the 1974 price level, the contract cost for the 80,796 acre-feet of storage space is approximately $15.4M. In addition, Wyoming would have to pay annual OM&R cost associated with the 80,796 acre-feet of contracted space. Current OM&R payments by Wyoming for the existing 120,000 acre-feet of contract space were roughly estimated at $160,000 (USBR, 2017b), or a unit cost of $1.33 per acre-foot, per year. Over a 50-year analysis period, the net present value of these annual OM&R payments is approximately $2.9M.

Wyoming is currently considering a variety of options and alternatives for negotiating a repayment contract with BOR for the 80,796 acre-feet of project storage capacity. No agreement framework has currently been identified, and therefore the actual costs of contracting the project storage space remain uncertain and subject to negotiation.

Hydropower and Recreation Costs The proposed project has the potential to negatively impact two current benefits of the existing Fontenelle Dam and Reservoir facility during the construction phase. Hydropower generation might be reduced during construction if the reservoir pool is drawn down to provide dry access to the dam embankment, as discussed in Section 4. Hydropower generation after project completion should not be significantly impacted.

Recreational uses of the reservoir are also likely to be impacted during construction if the reservoir is drawn down. In addition, complete evacuation of the reservoir above dead pool, as envisioned to provide benefits under the proposed project, would impact the incremental recreational use of the reservoir pool below the existing active capacity. Negative economic impacts to recreations include the displacement of anglers, hunters, and recreational guides that use the reservoir, Green River, and surrounding area. There is also potential for lost revenue to the surrounding communities that depend on the business of the lost recreation. These costs are not quantified for this report.

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Summary of Benefits Three benefits were evaluated for the proposed project. The following points summarize the net present value of each benefit:

• Direct Water Supply. This benefit looked at the project providing a direct water supply to meet future water demands within the Green River Basin of Wyoming. After reviewing existing Basin planning documents, it is concluded that Fontenelle Reservoir storage water, and particularly the project storage water, is unlikely to be utilized as a direct supply source over a 50-year time frame. No value was assigned to this benefit.

• Drought Mitigation Supply. This benefit looked at the project providing a mitigation water supply to allow post-1922 water rights in Wyoming to continue to divert water under conditions of a curtailment in the Colorado River Basin. Such a benefit is characterized as high-value and low-probability. Based on a defined set of drought and curtailment conditions, the project could benefit existing uses in the municipal, industrial, and agricultural sectors. A demand curve approach was applied to municipal and industrial uses and a replacement cost approach was applied to agricultural uses. The probability of realizing this benefit was estimated based on model results from the Colorado River Basin Study. The net present value of this benefit was estimated to be $9,035,784

• Drought Avoidance Supply. This benefit looked at the project providing an insurance water supply to the entire Upper Division in order to avoid a curtailment occurring in the Upper Colorado River Basin. The value of such a benefit considered the three years of market lease transactions under the System Conservation Pilot Program but ultimately utilized estimates of net returns to irrigated forage crops. The probability of realizing this benefit was estimated based on current hydrologic risk modeling. The net present value of this benefit was estimated to be $41,796,970.

There is a value disparity between the drought mitigation and drought avoidance benefit frameworks described above. The unit values of benefit are similar for the agricultural sector in each framework. The drought avoidance benefit is considerably higher because it assumes that the full 80,796 acre-feet of project water supply is utilized and that there is a higher probability in future years that the benefit will be realized. While both the drought mitigation and drought avoidance benefits have uncertainty, the drought avoidance benefit is considered to be more uncertain and less conservative because it relies upon an unknown source of payment among Upper Division stakeholders. The present value of future project benefits is estimated to be $9,035,784 from the drought mitigation approach. This value represents the gross benefit and is not a net benefit, as it does not consider a number of cost considerations. Unconsidered costs associated with the proposed project include: (1) capital and annual operating costs, (2) storage contracting costs, and (3) temporary losses in benefits from current hydropower generation and recreational use. Without these additional costs being defined, a benefit-cost ratio cannot be accurately calculated. However, it is important to note that the drought mitigation supply benefit- cost ratio, excluding the unknown costs, ranges from 0.24 to 1.10, depending on the alternative chosen. The actual ratio would be lower if the unknown costs were included, which would result

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in a benefit-cost ratios less than 1.00. Table 8-18 shows the cost-benefit ratio for each alternative. The table includes drought mitigation supply (the concluded estimate of present value of future project benefits) and drought avoidance supply (for comparison).

Table 8-18: Benefit-Cost Ratio for each Alternative

Drought Mitigation Supply Drought Avoidance Supply Alternative Reservoir Benefit-Cost Ratio2 Benefit-Cost Ratio3 Riprap Drained 1.06 4.91 Riprap Full 0.59 2.73 Soil Cement Drained 1.10 5.08 Submar Full 0.24 1.11 Contech Full 0.27 1.25 Notes: 1) The benefit-cost ratios in this table lack the costs associated with capital and annual operating costs, storage contracting costs, and temporary losses in benefits from current hydropower generation and recreational use. 2) This analysis uses the drought mitigation supply benefit of $9,035,784 as the benefit for each alternative. It has been concluded that the drought mitigation supply is the estimated present value of future project benefits and is considered the most likely scenario. 3) This analysis uses the drought avoidance supply benefit of $41,796,970 as the benefit for each alternative. Note that the drought avoidance benefit is considered to be more uncertain and less conservative.

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CONCLUSIONS AND RECOMMENDATIONS

This Level II Study was conducted to evaluate the technical and economic feasibility of expanding the active storage in Fontenelle Reservoir by adding armoring to the unprotected portion of the upstream dam face. Our Level II Study conclusions and recommendations are as follows.

Conclusions Drawdown Analysis Three drawdown scenarios were considered. The fall/winter drawdown scenario is predicted to have the least effect on short-term environmental considerations. The spring and summer drawdown scenarios are also feasible, but the construction operations might need to take special precautions to account for unknown stream flow conditions. Power generation was estimated for each scenario and is summarized in Table 6-8. Results show that Scenario 3 offers the best opportunity for power production provided that the reservoir can be re-filled in Year 2. If not, Scenarios 1 and 2 are essentially equivalent.

NEPA Considerations It is likely that the Project will require an Environmental Assessment (EA) or an Environmental Impact Statement (EIS). If there are no major changes to the long-term future operations of the Fontenelle Reservoir due to the Project, an EA may be acceptable for NEPA documentation. However, if an EA did not result in a Finding of No Significant Impact (FONSI), an EIS would be required, which would cause delay. The documentation approach will be determined by the lead NEPA agency on the Project.

Alternatives Analysis The remote location of the Project increases material cost of riprap because of the long haul distance. As a result, soil cement becomes a potentially feasible alternative relative to riprap. In the alternatives analysis, it was determined that the dry placement of riprap and soil cement have very similar costs ($8.5 M and $8.2 M, respectively). Wet placement of riprap ($15.3 M) is more expensive than dry placement of riprap or soil cement, and the most expensive alternatives are the Submar mats and Contech wave attack blocks ($37.6 M and $33.5 M, respectively). It is predicted that the alternatives presented are of similar product quality.

Scheduling The construction schedule for dry placement of embankment protection include the drawdown time and refill time of Fontenelle Reservoir. Overall, the wet placement of riprap and the dry placement of soil cement have the shortest construction schedules at 9 months. The dry placement of riprap is predicted to take 12 months. The Submar and Contech alternatives are predicted to take 3.5 years (with multiple phases) and 11 months, respectively. Soil cement has a particularly difficult construction schedule because the placement of soil cement must begin around July (a high flow month) to ensure material placement finishes during the warm months of the year. The dry placement of riprap does not have this concern. The alternatives that utilize a barge and crane for wet placement are restricted to months when the reservoir is not frozen.

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Economic Analysis The following three benefits were evaluated: direct water supply, drought mitigation supply, and drought avoidance supply. Of these benefits, only drought mitigation supply (net present value of $9,035,784) and drought avoidance supply (net present value of $41,796,970) were considered likely to be utilized. Since the drought avoidance supply has considerable uncertainty, the Project net present value is considered to be represented by the drought mitigation supply benefit. Therefore, the Project’s present value of future project benefits is estimated to be $9,035,784. For the alternative analyzed, the benefit-cost ratio ranges from 0.24 to 1.10. This range of ratios do not include all costs, and the actual ratio would likely be lower, and likely less than 1.00.

Required Authorizations As required for all Reclamation projects of this nature, Congressional authorization would be required for the modification of Fontenelle Reservoir for additional armoring. Wyoming State Delegation in Washington in currently working on the congressional approval of Bill S. 2902 that aims “to provide for long-term water supplies, optimal use of existing water supply infrastructure, and protection of existing water rights.” Within this bill, Section 102 is the “Authority to make entire active capacity of Fontenelle Reservoir available for use.”

Long-Term Operations Several challenges are associated with changes to long-term operations at Fontenelle, including the following:

. A longer and more intensive NEPA process would be required. . The Fontenelle operations would have to be evaluated and possibly rewritten. . Power generation might be affected if the WSEL decreases below about 6,457. The intent of armoring the un-armored face of Fontenelle Dam is to make the inactive water available. The current inactive WSEL is at 6,457 and consists of 80,796 AF. The intent is that this water would become available for drought mitigation supply and/or drought avoidance supply. This use of the water would not affect the long-term operations of Fontenelle.

The modifications to the dam will result in greater availability of water to the power plant only if the allowable water level for outflow is reduced below 6,457. In that case, power could be produced for greater periods until the level reaches the new minimum. However, inflow, outflow and contractual issues would most certainly have a greater impact than making provision for lower reservoir levels.

Recommendations The EA Team recommends riprap be placed on the unprotected portion of the upstream dam face using underwater placement methods. Key benefits of underwater placement of riprap include the following:

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. Underwater placement of riprap does not require the reservoir to be drained. Draining the reservoir is a primary concern for many of the short-term environmental considerations. Because this alternative does not require the reservoir to be drained, it nearly eliminates the short-term environmental considerations, including flood mitigation issues that could result from drawdown and environmental effects of unregulated stream flow. Also, interruption to power generation is minimized or completely excluded. . Underwater placement of riprap is more flexible than the dry armor placement alternatives (dry placement of riprap and soil cement). Riprap can be placed underwater during most of the year; the only restriction is a frozen reservoir. Inflows have little to no effect on underwater placement of riprap, but could have a significant effect on dry placement of riprap or soil cement. . Underwater placement of riprap is relatively low cost compared to the other underwater armoring alternatives (Submar and Contech). The total project present day cost is estimated to cost $15.3 M. The benefit-cost ratio for this alternative is 0.59. The cost for the project for construction starting in 2020, with an inflation factor of 3.0%, is $16,554,000, as seen in Appendix F.

Roadmap to Implementation A detailed Final Design Process flow chart is included in Appendix G. It summarizes the activities may be required, starting with the design prework process and continuing through project completion. Though we tried to capture all of the next steps in the flow chart, there may be some we are unable to anticipate at this time due to project specifics. It is estimated that the NEPA process will begin at the completion of 60% design and continue until 100% design. Following 100% design, the funding and paperwork will be finalized, and then the project will be issued for bid. The design team will be involved throughout construction and until the completion of the project.

In addition to the roadmap outlined above, the following items should be investigated: • A geotechnical investigation to look at filter compatibility between the riprap and the use of the embankment as riprap bedding. • A rapid drawdown analysis of the embankment to assess the safety of drawing down the reservoir in a drought situation. • Testing of the proposed riprap sources to determine if the sources will meet the durability requirements.

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Extreme Event Alternative Toward the end of this project Reclamation suggested the following as a potential alternative. If access to the bottom portion of Fontenelle Reservoir is only required during an extreme drought event, it may be possible that this water can be released without additional armoring of the dam face. The lowering of the reservoir during an extreme event would be a temporary drawdown that is of short duration with minimal damage to the dam. This extreme event alternative would require a complete risk analysis by BOR and would need prior approval by Reclamation.

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114th Congress. 2016. Senate Bill S.2907. A bill to amend the Energy and Water Development and Related Agencies Appropriations Act, 2015, to strike the termination date for funding for pilot projects to increase Colorado River System water in Lake Mead, and for other purposes. https://www.congress.gov/bill/114th-congress/senate-bill/2907/text

66 FR 3853. 2001. Executive Order 13186 of January 10, 2001: Responsibilities of Federal Agencies To Protect Migratory Birds. January 17.

Anderson Consulting Engineers, Inc. (ACE). 2015. Blacks Fork River Watershed Study, Level I, Phase II, Upper Blacks Fork, prepared for Wyoming Water Development Commission, January 2015.

Buschatzke, T. 2017. Central Arizona Water District plan is a risky gambit. Arizona Capital Times. http://azcapitoltimes.com/news/2017/04/27/central-arizona-water-conservation- district-plan-is-a-risky-gambit/

Carrico, K. 2014. You Never Step in the Same River Twice – The Effects of Changes in Supply and Demand in the Colorado River Basin on Wyoming Water Users. Wyoming Law Review.

Clements, K.W. 2008. Price elasticities of demand are minus one-half. Economics Letters. 99(3), 490-493.

Colorado Division of Water Resources (CDWR). 2015. StateMod User's Manual, Version 15.

Colorado State University (CSU) Extension. 2017. Crop Enterprise Budgets – 2016 Western Colorado Grass Hay Budget. http://www.wr.colostate.edu/ABM/cropbudgets.shtml

Colorado River District. 2016. West Slope Basin Roundtable Risk Study. July.

Congressional Research Service (CRS). 2016. Discount Rates in the Economic Evaluation of U.S. Army Corps of Engineers Projects. August 15, 2016.

Council on Environmental Quality (CEQ). 2013. Principles and Requirements for Federal Investments in Water Resources. https://obamawhitehouse.archives.gov/administration/eop/ceq/initiatives/PandG.

Council on Environmental Quality (CEQ). 2014. Chapter III: Interagency Guidelines. https://obamawhitehouse.archives.gov/administration/eop/ceq/initiatives/PandG.

Department of the Interior (DOI). 2015. Agency Specific Procedures for Implementing the Council on Environmental Quality’s Principles, Requirements, and Guidelines for Water and land Related Resources Implementation Studies. https://elips.doi.gov/elips/0/doc/4244/Page1.aspx

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M. Espey et al. Price elasticity of residential demand for water: A meta-analysis. Water Resources Research. June 1997

Kuhn, E. 2016. Colorado River District Memorandum Re: Joint West Slope Roundtables Risk Study Results Summary and Thoughts on the Next Steps. September 13.

Lagasse, P. F. et al. 2006. NCHRP Report 568: Riprap Design Criteria, Recommended Specifications, and Quality Control.

MWH Americas, Inc. (MWH). 2012. Colorado River Water Bank Feasibility Study, Phase 1. Prepared for Colorado River Water Conservation District. June.

Natural Resources Conservation Service (NRCS). 2017. Rate for Federal Water Projects/NRCS Economics. https://www.nrcs.usda.gov/wps/portal/nrcs/detail/?cid=nrcs143_009685

Nelson Engineering. 2010. Water Supply, Level II Study. Prepared for WWDC and Joint Power Water Board. July.

Pochop and Burman Development of Evapotranspiration Crop Coefficients, Climatological Data, and Evapotranspiration Models for the Upper Green River. March 1987

State of Wyoming. 2017. Wyoming Statute 41-3-115. http://legisweb.state.wy.us/NXT/gateway.dll?f=templates&fn=default.htm

States West Water Resources Corporation (SWWRC). 2001. Green River Basin water planning process. Final Report. Prepared for: Wyoming Water Development Commission Basin Planning Program. Wyoming Water Development Office. Cheyenne, WY. http://waterplan.state.wy.us/plan/green/.

Taghvaei, S. M. et al. 2012. Anti-vortex structures at hydropower dams. International Journal of the Physical Sciences. Vol. 7(28), pp. 5069-5077. 19 July, 2012.

Upper Colorado River Commision (UCRC). 2015. Upper Colorado River Commission. http://www.ucrcommission.com/RepDoc/SCPPDocuments/SCPP_15_18.pdf

U.S. Army Corps of Engineers (USACE). 2005. Regulatory Guidance Letter No. 05-05, Subject Ordinary High Water Mark Identification, December 2005.

U.S. Bureau of Reclamation (USBR). 2001. Water Treatment Primer for Communities in Need

U.S. Bureau of Reclamation (USBR). 2005. 2005 Operation of Flaming Gorge Dam Final Environmental Impact Statement. September.

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U.S. Bureau of Reclamation (USBR). 2006. Record of Decision, Operation of Flaming Gorge Dam, Final Environmental Impact Statement. https://www.usbr.gov/uc/envdocs/rod/fgFEIS/final-ROD-15feb06.pdf

U.S. Bureau of Reclamation (USBR). 2010. Fontenelle Dam Repair and Improvement, Appraisal Level Estimate. February.

U.S. Bureau of Reclamation (USBR). .2011. Drought In the Upper Colorado River Basin. August. https://www.usbr.gov/uc/feature/drought.html.

U.S. Bureau of Reclamation (USBR). 2012a. Water Supply Assessment – USBR Colorado River Basin Supply and Demand Assessment. December. Figure B-18 of Technical Report B. https://www.usbr.gov/lc/region/programs/crbstudy/finalreport/index.html

U.S. Bureau of Reclamation (USBR). 2012b. Colorado River Basin Water Supply and Demand Study – Technical Report G – System Reliability Analysis and Evaluation of Options and Strategies. December.

U.S. Bureau of Reclamation (USBR). 2013a. Environmental Assessment Seedskadee Revocation Project Wyoming, PRO-EA-012-003, Seedskadee Project, Wyoming Upper Colorado Region, May 2013.

U.S. Bureau of Reclamation (USBR). 2013b. Design Standards No. 13: Embankment Dams – Chapter 17: Soil-Cement Slope Protection, Final: Phase 4. August.

U.S. Bureau of Reclamation (USBR). 2013c. Fontenelle Dam Annual dam Safety Site Inspection. December 6, 2013.

U.S. Bureau of Reclamation (USBR). 2016a. Colorado River Basin, Pilot System Conservation Program. https://www.usbr.gov/lc/region/programs/PilotSysConsProg/pilotsystem.html

U.S. Bureau of Reclamation (USBR). 2016b. Intake Vortex Formation and Suppression at Hydropower Facilities. Research and Development Office. September.

U.S. Bureau of Reclamation (USBR). 2017a. Reclamation / Upper Colorado Region / Water Operations / Fontenelle.. https://www.usbr.gov/uc/water/crsp/cs/ftd.html (Last Updated August 24, 2017) and https://www.usbr.gov/rsvrWater/HistoricalApp.html

U.S. Bureau of Reclamation (USBR). 2017b. Phone conversation with USBR representative. O&M cost was stated as being approximate for 2016.

U.S. Fish and Wildlife Service (USFWS). 2005. Operation of Flaming Gorge Dam Final Environmental Impact Statement, Final Biological Opinion Technical Appendix. September.

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U.S. Fish and Wildlife Service (USFWS). 2014. Seedskadee National Wildlife Refuge, Wyoming – Habitat. https://www.fws.gov/refuge/Seedskadee/wildlife_and_habitat/habitat.html.

U.S. Fish and Wildlife Service (USFWS). 2016. Environmental Conservation Online System- Information for Planning and Conservation tool (ECOS-IPaC. https://ecos.fws.gov/ipac/.

WestWater Research. 2015. Memorandum Re: Compact Water Bank Pricing. May.

WWC Engineering (WWCE). 2010. Green River Basin Plan. Prepared for: Wyoming Water Development Commission Basin Planning Program. Wyoming Water Development Office. Cheyenne, WY. December. http://waterplan.state.wy.us/plan/green/2010/finalrept/gw-finalrept.html.

Wyoming State Engineer’s Office (WSEO). 2009. State Engineer’s Final Opinion and Recommendations on the Application to Export Storage Water from the Pathfinder Modification Project. January 14.

Wyoming State Engineer’s Office (WSEO). 2016. Wyoming and Colorado River: A Report. November.

Wyoming State Engineer’s Office (WSEO). 2017. Green River Basin Annual Consumptive Use Report, 2016. July.

Wyoming Water Development Commission (WWDC). 2016. Request for Proposal No. 16-18 Fontenelle Dam and Outworks Infrastructure Completion Level II Study, Task 6 – Economics (p. 13). March 7.

Wyoming Water Development Office (WWDO). 2011. Technical Memorandum Re: Use of Wyoming’s Contract Storage Water in Fontenelle Reservoir. February. http://waterplan.state.wy.us/plan/green/2010/finalrept/fontenelle.pdf

Wyoming Water Development Office (WWDO). 2016. Fontenelle Pipeline Review.

.

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Appendix A: Meeting Minutes

Fontenelle Dam and Outworks Infrastructure Completion Project Interagency Meeting No. 1- Minutes

MEETING TIME: 1:00PM DATE: September 26, 2016 LOCATION: BLM Rock Springs/Go-To-Meeting/Phone PROJECT NO: 110661 ATTENDEES: Tony Rutherford (WWDO) Clint Brown (EA) Rich Tocher (EA)) Tom Koener( Seedskadee NWR) Cody Parker ( Seekskadee NWR) Cory Toye ( Trout Unlimited) Nick Walrath ( Trout Unlimited) Wes James (BOR-Provo)) Steve Hulet ( BOR-Flaming Gorge) Kirk Jensen ( BOR-Fontenelle) Troy Laughlin ( WGFD) Robert Keith (WGFD) Lisa Solberg-Schwab ( USFWS) Kimberlee Foster (BLM-RSFO) Steve Wolfe (WWDO) phone Tom Annear( WGFD) phone Todd Hanlin( TriHydro) phone Tim and Jana ( USFW) phone Brett Bovee ( WestWater) phone Steve Mower (BOR) phone Nate Snyder ( BOR) phone Brian Hart ( BOR-Provo) phone Nathan ( USFW-Cheyenne) phone

1.0 NEW BUSINESS

The following is a summary of the items that were discussed

Item Action 1. Attendees were introduced and an overview of the No Action project provided by (TR)

2. Detailed scope of project provided (CB) No Action

3. The existing riprap should be evaluated (WJ) EA to include in first phase of study

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Meeting Minutes 9.26.2016 Interagency FONTENELLE DAM AND OUTWORKS INFRASTRUCTURE COMPLETION PROJECT PROJECT NO: 110661 | SEPTEMBER 26, 2016 | INTERAGENCY MEETING

4. An inventory of existing water rights in WY that could EA to develop a list of the be at risk of curtailment should be made. affected rights

5. How will minimum discharge be maintained during EA to develop general construction? Wil a cofferdam be used? construction sequence 6. A high level evaluation of a pressurized system to EA to evaluate downstream irrigators will be included (TR)

7. What will the long term changes to river discharges be EA to discuss with BOR from the use of the additional active pool?

8. Will there be annual reservoir drawdown and what will EA to evaluate the impacts be?

9. What is the long term use of the water; single purpose or EA to evaluate. multi purpose?

10. What are the potential impacts to the following species; EA evaluate trout, bald eagles, trumpeter swans and yellow bill cuckoos (TR))

11. Fontenelle Reservoir is shallow enough that a No Action thermocline doesn’t develop. (SH)

12. Locations of downstream diversions need to be EA to contact WY SEO and identified (TR) WGFD to identify locations 13. Green River freezes at 1000 cfs. Need to keep uniform No Action winter flows to protect fishery.

14. Reservoir typically fills to within 1-foot of spillway in No Action Spring and then released through outlet works and power plant penstock. BOR-SLC (Heather Pano) sets operation plan for discharges (SH)

15. Power plant typically runs 24/7/365 (SH) No Action

16. What are the risks to dam stability due to lowering EA will review Reclamation reservoir on a regular basis. (WJ) PFMAs and revise as necessary

17. Next Interagency meeting will be late January or early T Rutherford and C Brown to February schedule meeting

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2

Meeting Minutes 9.26.2016 Interagency

Fontenelle Dam and Outworks Infrastructure Completion Project Interagency Meeting No. 2- Minutes

MEETING TIME: 8:30AM DATE: January 27, 2017 LOCATION: Go-To-Meeting/Phone PROJECT NO: 110661 ATTENDEES: Tony Rutherford (WWDO) Clint Brown (EA) Dylan Hoehn (EA) Tom Koener (Seedskadee NWR) Nick Walrath (Trout Unlimited) Wes James (BOR-Provo) Tom Annear (WGFD) Todd Hanlin (TriHydro)

1.0 NEW BUSINESS

The following is a summary of the items that were discussed

Item Action 1. Attendees were introduced and an overall goal of the No Action project provided: Planning, permitting, and potential of Fontenelle Dam Project.

2. The low water timeframe is predicted to be sometime EA and WWDO will check with in April. Scheduling needs to occur soon to allow for Heather Patno the BOR to be able to attend.

3. Current snow-pack is similar to 2011 hydrology See above reports, which should be referenced when considering the hydrology predictions of this project.

4. A higher-resolution inflow and discharge plot should EA team will produce this be investigated (daily rather than monthly).

5. Can we pass all the river through the outlets? During the 1980 construction the outlets were able to pass the inflows, EA team will investigate further 6. The existing riprap and outlet works should be EA team will investigate further evaluated at low reservoir elevations for outflow capacity.

7. Lake Fishery concerns: During winter, the fish will Noted experience colder conditions if reservoir is lowered.

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8. Lake Fishery will be lost if reservoir drained and will Noted require 5-8 years to recover.

9. Downstream fishery concerns: Fish would be more Noted exposed to predators. The discharge from the dam might fluctuate in the winter, resulting in higher fish mortality rate. Cold winter conditions could result in much of the river completely freezing (without warm water from being released from the reservoir), making for difficult conditions for downstream fish.

10. Trumpeter Swan concerns: If much of downstream Noted freezes, swans will not have adequate food and will likely die or leave without returning.

11. Trumpeter Swans were not present in the area before Noted transplanting in 1991, the area now produces 50% of Trumpeter Swans in Wyoming.

12. Terrestrial concerns: Possible riparian degradation. Noted Eagles and otters might have minor impacts.

13. Potential concern with sediment at the bottom of the EA Team will explore further reservoir: 1) does it affect depth-volume assumptions and 2) will it be released downstream and how will it affect downstream?

14. Additional modeling may be required to predict EA team will discuss with temperatures in reservoir and streams, consider using WWDO USACE models.

15. Time considerations: EA team will address and use for recommendations Dec.-Mar. – low reservoir could result in stream freezing and swan population declining. Jan.-Feb. – Good time to lower reservoir while fish are spawning July-Sept. – Water needs to be below 72°F to avoid stressful environment for downstream fishery. Sept.-Dec. – lowering reservoir in this timeframe might result in inadequate storage for water rights users during following months.

16. Long-term impacts should be investigated and EA team will explore further described in probability terms.

17. It was suggested to address problems that might occur EA team will explore further during or after construction.

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18. Any Riprap placement options that would not require EA team will explore further lowering the reservoir?

19. Could timing of material placement be scheduled to EA team will explore further adjust for staging the placement to reduce environmental impacts?

20. Water users need to be considered. In particular, the EA team with WWDO will City of Green River needs its water, and will the discuss items with other entities. wetlands suffer from water limitations.

21. Next steps: Look at project and future risk in terms of probability vs absolute. Start modeling with consideration of the environmental concerns. Talk to municipalities and energy producers. Understand downstream water user needs, patterns, requests. Talk to State Engineer’s Office to discuss the effect of the project on the Colorado River Compact

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Fontenelle Dam and Outworks Infrastructure Completion Project Interagency Meeting No. 3- Minutes

MEETING TIME: 9:00AM DATE: June 30, 2017 LOCATION: Go-To-Meeting/Phone PROJECT NO: 110661 ATTENDEES AND Tony Rutherford (WWDO) INTERESTED Jason Mead (WWDO) PARTIES: Harry LaBonde (WWDO) Steve Wolff (WY SEO) Clint Brown (EA) Dylan Hoehn (EA) Rich Tocher (EA) Tom Koener (Seedskadee NWR) Cody Parker (Seedskadee NWR) Wes James (BOR-Provo) Jared Baxter (BOR-Provo) Peter Crankston (BOR-Provo) J Parker (BOR-Provo) Brian Hart (BOR-Provo) Steve Mower (BOR-Provo) Heather Patno (BOR-Provo) Steve Hulet (BOR Flaming Gorge) Kirk Jensen (BOR Fontenelle) Brad Rogers (USFWS) Don Anderson (USFWS) Lisa Solberg Schwab (USFWS) Nathan Darnall (USFWS) Tom Korner (USFWS) Tom Chart (USFWS) Jana Mohrman (USFWS) Tom Annear (WGFD) Robert Keith (WGFD) Troy Laughlin (WGFD) Corey Toye (Trout Unlimited) Nick Walwrath (Trout Unlimited) Scott Neff (Trout Unlimited) Todd Hanlin (TriHydro) Derrick Thompson (TriHydro) Brett Bovee ( WestWater)

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1.0 NEW BUSINESS

The following is a summary of the items that were discussed

Item Action 1. Attendees were introduced and meeting agenda No Action discussed.

2. The low reservoir during construction would allow for Noted removal of invasive (burbot). It may not be a long term solution though

3. How will fishery be protected downstream while the EA team will investigate further reservoir is lowered for construction. Fishery could experience dangerously high temperatures.

4. Will sediment be transported downstream during EA team will investigate further lowering of reservoir and passing flows during construction?

5. What level of environmental permitting will be EA team will investigate further required for the project? Will there be a change in historic operation which will determine permitting requirements?

6. Avoidance is preferred over mitigation. Noted

7. Rules should be clearly outline as to when the Noted additional 80,000 AF can be accessed.

8. A refill rate of 10 feet per month was discussed. This Noted rate is acceptable to BOR

9. Can the outlet works pass the normal winter flow rates? Noted T. Hanlin discussed historic operations and concluded the outlet can pass the winter flows.

10. Trumpeter Swan concerns: If much of downstream Noted freezes, swans might not have adequate food.

11. Power generation history discussed and pointed out Noted that peak power production is in May through August

12. Four construction alternatives presented for both EA Team will explore further drained and undrained reservoir. Costs ranged from and present a preferred $6-24 million alternative 13. Economic analysis assumptions presented for three EA team to conduct analyses based on input from meeting

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scenarios.

14. Next steps: EA team will develop Prepare Draft of Feasibility Report Select a Preferred Alternative

15. Comments on the meeting presentation should be sent All to Clint Brown (EA) by July 12

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Appendix B: Fontenelle Dam Drawings l Exlstfng rlprap-----.._ )~ Existing access road !--- £ Crest oi' dam embankment ... I 5. O'., ~·~------<.1' Ef. 6480 I 1 LIJaxlmum w.s. El. 6516 L..,,..-<::===::::t:::- ---/-- .Q El. 65/9 El. 6516 fH 15.0' Min. -- EI. New 24" r Jprop

El.6480 2-- 15' Mfn.

E f • -----Construction berm to be left In pface

Zone 2 NEW RJPRAP PLACEMENT DETAIL Zone I NOT TO SCALE ------~._t

Approximate top oi' bedrock EMBANKMENT ZONING EXPLANATION £ Cuto ft' trench 1 and existing orout -1 Zone I Selectea clay, sl rt, sand ard graver compactea by tamping curtain----- ro r lers to 6- Inch foyers. rExlst Tng embankment J Zone 2 Selectea sand, gravel, and cobbles compactea by crawler­ type tractor to 8-fnch layers. (Existing embankmentJ SECTION 8-8(6891 Zone 3 Mlscel/aooous material compac+ed by tamping railers to 40 0 40 80 120 12-lnch layers. rExlstlng embankmenr> Zone IA Selected CL, SC and GC compacted to 6-lnch rayers by SCALE OF FEET pneumatlc-tfre rolfer. Pl greater or equar to 12. 30.0' 18• Maxfmum camber 5• gravel surfacing Slope varlable dependlng on El. 6520.5~ camber, Max. 2.71•1 Cr&sf without comber Cable guard fence, reused EI. 6519.0-~ 2.0 2X ------=~L;:~]I:~~~~=£~~~=::!=:~ Dam embankment to be restored to or lg Ina I cross sect Ion after wa 11 construct !on. Approx/mote exfstlng surface i-.__,~-----+-1z:_o_ne__ 2A_-...- __::..._:~ ...--Typical work platform El. 6516. Depth of excavation may vary to of dam embankment ...., ' ~.L~acl I !fate cutoff wal I construction. Replace Zone 2 and 24° rlprap--- / I I ~-- --~/?:---~7 -- 22. O' Remove Intermixed existing ___- ""·------==----_..... '~ ', Slope variable depending upan camber r I prap and embankment mater I a I / __.--- / ol' I • 81 • f max f1rum _..-- / i+--1'--'5-'.-'-0'---i ~ EI. 6505, Slope fntersect Ion 3• I ~-- ,,. at max /mum camber. NOTE _...- ___ __ -----~=- ,,. ,, ',~''',,. Zone 2 -696 to 700. // ~------Zone 2 /;one 1 24" Min. ~ /,,./~~~-- _:5---;• /f Cutoi't' waf r ;one ',~ ', ::;.:.,..-- ..------r f Crest dam embankment

---- 30 10 0 10 20 REFERENCE DRAWINGS CREST DETAIL I I I I I I I I I I I SCALE OF FEET E. Sta. 17+37 to E. Sta. 28+~5 and *GENERAL PLAN A/ID SECT JONS------154-lrB CUTOFF fA~L. GENERAL PL.ti/ E. Sta. 31+51 to E. Sta. 58+20 Af'ID PROFlLE------,,,4-J-689 * DrCJlf/rt;JS of exist 're facrfures. Referere«/ to prov rde I ntormat I on

5-2r-9B AS lulLT B~ 437, ~TR. U-14 • 97. 0- ff4-

AS BIJJLT BY 4280 LTR. 2-6-!12

E. Sta. 62+50.00 12 - 23 - 87 G£HCRAL REV 15 !0NS. 0 - J.M.C. E. Sta. 17+00. 00 --·-- ~l...--~~£. Sta. 59+50.00 ~ AL'lllAYS THI~lK SAF£TY I - EJ. 6520.5 El. 6519.0 IJNIT£0 STAT£S D£PAR1MENT OF THE INTERIOR BUREAU OF RECLMIA T ION SEEDSKADEE PROJECT - WYONING FONTENELLE OAAI S.=0.0075 --~ PHASE I J MODJF !CAT JONS S.= 0.0050 CAMBER ON CREST OF DAM EMBANKMENT CUTOFF WALL SECTION AND DETAILS OESlGN£1J_ iJKIP. ~,_ ~.!FJl_ ---- TEClftlCAL N'PROV AL !!Qf!Jl!.5_ l/..! - JjQCf!!Jl DRMN- ______D.D. Orou !lord_ sua..rJTED _John______At. Cygan -- l ew___ ! CZ -- 200 0 200 400 60C:. CHE.CJCED_fl!!GP!. .f:•_ ~- __ - _APl'F/tNED- ~f??_m_~- ~:. _"!._G_D_G_!1_1~_!- __

SCALE OF FEET ODii £R, COLORAJJO 'EC. Z4, 1916 CON#'UTCR DRAF'1/IG ~TtM. MIO MOit rn:rtJU.I. •.A 0£.SIBN ~T scr-, lON Q&.I • ~ 111,, lllti!IOM. :JG1ii1t. I l2 1--11~• tOl >2~tl ------3 \ \ \0.}~ '- .

Oom Sta. JOt22 91 ~ Outlet Sta. JOHJ0.00 >- N. 10,86J. 57 , --, E. 14, 345. 19 ; \,

------oo -- --.- u ..... -E/. 641!-- . -~--.=12 ' roe droi~ _,,_;t q ___ JI"_ -

--- ·---crest El.6519 ..:::.::CL_,-.,..k-.;r.;r.-.-,xzi-.t: ::t.::c::r.:-r..;r32....,.-X'f.Cf.(torJ,!'.!.nc'!.:.J...::c*"":::...-=.rs-~ -- _ ·; ·.:;~- erm fl.6480 --~ - ,.-..-

-.--·--·Disposal area- .. - · · ···>- G£N£RAL PLAN ...... EMBANKMENT EXPLANATION SC ALE OF F E E T P. I.outlet Sta. 23•96.0J ~ (i) Selected cloy, silt, sond ond grovel compacted by tamping N: 11,46173 ~---- rollers to 5-inch layers. E. 14,183. 91 J ® Selected sand, gravel and cobbles compacted by crawler­ type trocf()r to S-inch layers. ,---Maximum W S. El. 6512.9 Miscellaneous material compacted by 'lamping rollers to - - ,,,------Conservation W S. 11 * 60•00' 0 0 12- inch foyers. --- El. 6506 R 200' , ( P.I. outlet Sto.16+4 0.00 ,------1nf,'~~i//· S. ~: 7t~~:,4,~ --~ N. 1/,663.41 ' E. /J,453.64

,-Dead WS. :.' ~ . 6408

'·-5' ---12• Toe drain. in -. G~ou,t cop-_-_-_". __ _, 50 · --~~ -~--£~~~vate to firm foundation abutments only Grout holes ot opprox.10 crs. - ;J f-<-·-£ Crest of dam 00 I £Cutoff trench------

OF FEET MA X IM UM SECTION

CAMBER ON CREST OF DAM

U N I TEO $TAT£$ ••oo~~~--~,------{-f_o_s_t_C_o~no_l_o_u_ff_et_w_or_k_s-----~-~-~-----,~~-~-~,-,-~C~r-es_t_E_l_. 6_5_1_9~-~----~~.-----~------~---.-_ -__-_ E::-:R~iv_e_r_o_u~ff~e~t -w~a~rk~s=------~---~-,r--~-~{;;:-;S~p~n~l:w:o:y:--____- -__-_--~~-~~-_-_-_-, . _~_-_-,-_~_-_-_-_-_-_-_-_-_-_-_-_-_-,= OEPAl'tTMt!'NT OF THE INTERIOR 1 au"CAU o~ ftECL.AMATION SEEDSICADEE PROJEcr-WYOMING ~-- ______r,:::_Oriqinol!.roundsurfoce _,;:-Assumed firm !oundotion j ~---- ,,z~ __;"' .. 150'-->: y·51--- ~~:::: ~ Y •• 00 f--~~_:__~_::~~~===~""'""'.;.,;;,;:;;,;;;;;,;;;;;;,;;,;;;;:;;;;,,;;:;,;:;~=~. ~.. , ~~ '""';;,;;;;,;~;;;;;,;:;,;;,;;;;~;;;;;,;;;~;;;;;;...,,g~'"'i'iiiiiil''l~'i';;;;,;:;,=.;;;..;;.;;.;;;.;::f.;;;,;;J:;,;;;;,::;.;:;,;;;.;:;;;;;;:;;;,;;:;;;.=.::;;:;.;:;,::.,;;;;;:;;i..~ "~' ~~-~~!~;,;;;;;;.:::.;;;~"~=:=~;;;;:;;;;;;~~;;:F;::;i;..::;:=;::;;:=:=;:j;;;;;;;;m;;:r;;;if!Fii:::::::::;;~--'~£~~V.e~sttCC~on~o;il:--!:;._~--t------~--~ FONTENELLE DAM , ' I I 1 "'·--Grout cop I 'l'!'1' ;•1•;o GENERAL PLAN AND SECTIONS I I ~-· 1-

OENVC/lf, co1.0"ADO. FC•. PROFILE DIV £ OF CREST OF DAM $t

Def)ress armor rock locally to provide oullel for surface drainage:, ,~·-•o -

1'',

/ ,. / -- ~}_~..,. ,' El 6390.0 - -

d' 00 ••• /"/ 6520

Omit bedding where armor rock 1s 6~ 1 0 placed aga inst pervious backfill or,, P L A N river sands and grovels.------6500 .. •OO SCALE OF FEET"' 6490

C480 z Mox. W.S. El. 6512.9 ---- -, 0 o;schorgtJ • .. 6470 Top of conservation pool E~l..;.6.;,50;.6_ .;.o"'-I'-' ....,=,,,..­ ..., > Top of inactive pool El. 6484.9-, "'-' 6460 1--+- -+---+--t _ _;__,_ __ '--~.+-"'~-_, 6400 ~ "' ;: , T. W. El 6404.4. 38,700 cfs "'0 ,-Sta. 3lt29.00 0• > 6450 - ~--+--1 6398 ~ ' /Combined spillway and "' "'-' "' outlet works dischorge ) "' "' 8440 1-- -1--+-7""+---lf--+--+---t- '-j .... "' .,.."' ••:io f--- -!,.;'---+---+~-.-::-:-:---':---:~~---i--,639 4~

6420 .....

+-·-+ --I 6390

•• 00 0~--'--!:---.._-~,o!:----':---,~.-~--;:20 SECTION A-A DISCHARGE IN TMOUSANOS OF CFS DISCHARGE- TAILWATER CURVES Original ground

NOTES 3' Riprap over , M~qa;pj~~!;f1~~ff:/ For general concrete outline notes see Dwg. 40·0-5530. 12· bedding-,' CONCRETE FINISHES Electrical conduit, control piping and apparatus, Surfaces covered by f i ll : Fl , Ut. miscellaneous metal work and re1nforr:ement not shown. SECTION B-8 Outs ide exposed surfaces of ga te structure : F3 SECTION D-D • - . ~~-.1 : Surfaces of bell mouths and transitions from Sta. 26 •48.00 to Sta. 1z:J~ - r..:~, 1 1l . f..!.- ---~ ' 26•88.00 and surfaces Df transitions and water passages below El. 6412.00 from Sta. 29•37.83 to Sta. J0• 19.oo : F4, U3 . 20-0 ' ':/ '-~';•Armor rock over 18 • Surfaces of conduit from Sta. 30+19.00 to Sta. 32•29.00 " 10 Anchor bars' bedding above r;: . F2. below 'i . F4 UJ. Surfaces of hoist room of El. 6530.25 and control room of El. SECTION F-F 6519.n . UJ All other surfaces. F2,U2 UNlrEo SrArEs OEPARrMENr OF' rHc 1Nr£R10R

REFERENCE DRAWINGS IJUR~AU OF RECLAMATION PRO.JECT-WYOMINQ {'"'i" Brass carriage~-•. _ . g • . DAM- GENERAL PLAN ANO SECTIONS. ------• ------J54·0 - 8 a 9 SEEOSKADE~ bolts placed along : : . _ ... bock fill ~ -. RIVER OUTLET WORKS- conduit and walls. For -. ~ : ._. - :'. :_: · JNTAl

Appendix C: Photos DATE PHOTO NO. DESCRIPTION 6/7/2017 1 Riprap on upstream dam face 6/7/2017 2 Riprap on upstream dam face; vortex created by inlet to auxiliary spillway 6/7/2017 3 Flow from auxiliary spillway (7,000 cfs) - from above 6/7/2017 4 Top of dam looking west 6/7/2017 5 West Canal inlet 6/7/2017 6 West Canal channel downstream of dam 6/7/2017 7 West Canal and Emergency Spillway inlets 6/7/2017 8 Emergency spillway and stilling basin 6/7/2017 9 Riprap on upstream dam face 6/7/2017 10 Riprap on upstream dam face 6/7/2017 11 Riprap on upstream dam face 6/7/2017 12 Emergency Spillway, stilling basin, and right abutment 6/7/2017 13 Flow from auxiliary spillway (7,000 cfs) - from above 6/7/2017 14 Riprap on upstream dam face taken from bench at EL 6480 6/7/2017 15 Riprap on upstream dam face taken from bench at EL 6480 6/7/2017 16 East Canal downstream of dam 6/7/2017 17 East side of dam upstream of dam 6/7/2017 18 Boat ramp on west side of reservoir 6/7/2017 19 Boat ramp on west side of reservoir 6/7/2017 20 Emergency spillway taken from downstream of dam 6/7/2017 21 Seepage on west side of dam 6/7/2017 22 Seepage on west side of dam 6/7/2017 23 Stilling basin taken from west downstream edge of dam 6/7/2017 24 Stilling basin taken from west downstream edge of dam 6/7/2017 25 Stilling basin taken from west downstream edge of dam 6/7/2017 26 Emergency Spillway taken from bottom 6/7/2017 27 Fishermen 6/7/2017 28 Fontenelle Reservoir taken from top of dam 6/7/2017 29 Fontenelle Reservoir taken from top of dam 6/7/2017 30 Emergency Spillway inlet weir 6/7/2017 31 Downstream face of dam 6/7/2017 32 Emergency Spillway inlet weir 6/7/2017 33 Emergency Spillway taken from top of dam 6/7/2017 34 Right shale abutment 6/7/2017 35 Riprap on upstream dam face 6/7/2017 36 Riprap on upstream dam face 6/7/2017 37 east side of dam 6/7/2017 38 east side of dam 6/7/2017 39 east side of dam 001.JPG

002.JPG 003.JPG

004.JPG 005.JPG

006.JPG 007.JPG

008.JPG 009.JPG

010.JPG 011.JPG

012.JPG 013.JPG

014.JPG 015.JPG

016.JPG 017.JPG

018.JPG 019.JPG

020.JPG 021.JPG

022.JPG 023.JPG

024.JPG 025.JPG

026.JPG 027.JPG

028.JPG 029.JPG

030.JPG 031.JPG

032.JPG 033.JPG

034.JPG 035.JPG

036.JPG 037.JPG

038.JPG 039.JPG

Appendix D: NEPA and Environmental Considerations Derrick Thompson

From: Todd Hanlin Sent: Wednesday, July 12, 2017 10:29 AM To: Derrick Thompson Subject: FW: Fontenelle Interagency Meeting 6-30-2017 Attachments: Comments on 2017-06-30 Presentation.xlsx

From: Clint Brown [mailto:[email protected]] Sent: Wednesday, July 12, 2017 10:27 AM To: [email protected]; [email protected]; Todd Hanlin ; Dylan Hoehn Subject: FW: Fontenelle Interagency Meeting 6-30-2017

From: Baxter, Jared [mailto:[email protected]] Sent: Wednesday, July 05, 2017 8:29 AM To: Clint Brown Subject: Re: Fontenelle Interagency Meeting 6-30-2017

Clint, Attached are comments on the presentation and conference call on the Fontenelle Riprap project from 6/30/17. I provided comments in an excel spreadsheet, and Peter Crookston reviewed them. If you need anything else, let me know. Thanks, Jared

On Fri, Jun 30, 2017 at 12:09 PM, Clint Brown wrote:

All,

Thank you for your time this morning and for the discussion we had for the Fontenelle Dam Outworks and Infrastructure project. I have attached a copy of the presentation that we used for our discussion this morning and we look forward to your comments and questions. Please note that we want to have all comments regarding this presentation by July 12, 2017, this is to ensure that they are implanted in our draft report. Also, please note that this work is still in the development phase and has not be distributed to the public for public comment as such please do not distribute this without written permission from Tony Rutherford with the Wyoming Water Development office.

L. Clint Brown, P.E. Vice President, Project Dam/Reservoir Engineer

1

Engineering Analytics, Inc.

1600 Specht Point Road, Suite 209

Fort Collins, CO 80525 www.enganalytics.com

Main 970-488-3111 | Fax 970-488-3112 | Cell 970-672-6092 [email protected]

NOTICE OF CONFIDENTIALITY The information contained in this e-mail is confidential to Engineering Analytics, Inc. It is intended for a specific individual and purpose, and is protected by law. Any disclosure, copying, or unauthorized action based on it, is strictly prohibited. If you have received this information in error, please immediately notify us by telephone or e-mail

-- Jared Baxter Fish & Wildlife Biologist Bureau of Reclamation Provo Area Office Provo, Utah 84606 (801) 379-1081

2 Slide Number Content Comment Commentor N/A I don't know how far downstream we go with our ESA "action Environmental Yellow-billed Cuckoo area" but Seedskadee WR has proposed critical habitat for the JB Considerations YBC. Probably need at least some form of informal consultation?

This may have been talked about in previous conference calls that Pictures of the 4 endangered I didn't attend, but to our knowledge the 4 endangered CR fish do 4 JB Colorado River fish not occur above Flaming Gorge Dam. Local WGFD can correct me. They'll come up on the USFWS IPaC list but it will be a "no effect".

This is correct -- BOR will have discretion as far as level of NEPA. 6 Agency Discretion Any of the alternatives (as described in the call and in the JB presentation) will be at least an EA.

Not deviating from historical operations is a key issue - deviating 6/8-10 Historic Operations could push us into an EIS. From the basic information presented, it JB doesn't seem like this should be an issue.

It seems like this would need to be at least part of an economics 14 Power Generation JB section, if not it's own section in the EA/EIS.

Need to use alternate terminology. "Re-operation" really denotes 31 "Re-operation of FG Reservoir" changing operations of FG Dam which are largely based on the JB 2006 ROD. This terminology would push this project into an EIS.

This would probably push the project into an EIS. If this is truly listed as one of the benefits of the project, then it would have to 35 New Water Uses JB be analyzed, including the development of water projects and new land being brought into production. Derrick Thompson

From: Todd Hanlin Sent: Wednesday, July 12, 2017 10:28 AM To: Derrick Thompson Subject: FW: Fontenelle Interagency Meeting 6-30-2017

From: Clint Brown [mailto:[email protected]] Sent: Wednesday, July 12, 2017 10:26 AM To: Koerner, Tom Cc: [email protected]; [email protected]; Todd Hanlin Subject: RE: Fontenelle Interagency Meeting 6-30-2017

Tom, Thanks for your comments. These will help us as we put together this draft report.

L. Clint Brown, P.E. Vice President, Project Dam/Reservoir Engineer

Engineering Analytics, Inc. 1600 Specht Point Road, Suite 209 Fort Collins, CO 80525 www.enganalytics.com

Main 970-488-3111 | Fax 970-488-3112 | Cell 970-672-6092 [email protected]

NOTICE OF CONFIDENTIALITY The information contained in this e-mail is confidential to Engineering Analytics, Inc. It is intended for a specific individual and purpose, and is protected by law. Any disclosure, copying, or unauthorized action based on it, is strictly prohibited. If you have received this information in error, please immediately notify us by telephone or e-mail

From: Koerner, Tom [mailto:[email protected]] Sent: Tuesday, July 11, 2017 8:50 AM To: Clint Brown Subject: Re: Fontenelle Interagency Meeting 6-30-2017

Hello Clint,

Thank you for the opportunity to comment. I thought comments might make the most sense if I made them according to slide numbers from the attachment.

1 1) Slide #2 Was the capacity of Fontenelle Reservoir determined from As Built survey or some later one? If the As Built was used, are there any estimates of how much of the dead pool and inactive capacity has silted in since construction was completed?

2) Slide #4 The downstream fishery section does not mention that potentially the cold water fishery could be negatively impacted if summer water temperatures were to approach the high 70s and/or reach into the 80s. The thermocline that currently develops in the reservoir during the summer keeps the released water temperatures cool enough to support a tremendous cold water fishery for trout.

3) I did not see discussion of potential impacts to the ability to gravity flow into water delivery system on Seedskadee National Wildlife Refuge, the City of Green River, or Jim Bridger Power Plant. An evaluation of what the lowest flows in the Green River will be during construction would help to evaluate what that will mean for water elevation for these intakes and if any modifications may be needed if gravity flow no longer supplies the water.

4) I did not see any discussion of the possibility of sediment transfer from Fontenelle Reservoir to the Green River below, including through Seedskadee NWR, the City of Green River, and Jim Bridger Power Plant. Sediments have likely accumulated behind the Dam since construction, and mobilization of large amounts of sediment in a short period of time could potentially have negative impacts to aquatic resources and water delivery systems.

I appreciate that you have reached out several times to identify any potential impacts to consider.

Tom Koerner

Project Leader Seedskadee and Cokeville Meadows National Wildlife Refuge Complex [email protected] 307-875-2187 Ext 16 307-413-6149 cell 307-875-4425 fax P.O. Box 700 Green River, WY 82935

http://www.fws.gov/refuge/Seedskadee/ https://www.facebook.com/Seedskadee

On Fri, Jun 30, 2017 at 12:09 PM, Clint Brown wrote:

All,

Thank you for your time this morning and for the discussion we had for the Fontenelle Dam Outworks and Infrastructure project. I have attached a copy of the presentation that we used for our discussion this morning and we look forward to your comments and questions. Please note that we want to have all comments regarding this presentation by July 12, 2017, this is to ensure that they are implanted in our draft report. Also, please note that this work is still in the development phase and has not be distributed to the public for public comment as

2 such please do not distribute this without written permission from Tony Rutherford with the Wyoming Water Development office.

L. Clint Brown, P.E. Vice President, Project Dam/Reservoir Engineer

Engineering Analytics, Inc.

1600 Specht Point Road, Suite 209

Fort Collins, CO 80525 www.enganalytics.com

Main 970-488-3111 | Fax 970-488-3112 | Cell 970-672-6092 [email protected]

NOTICE OF CONFIDENTIALITY The information contained in this e-mail is confidential to Engineering Analytics, Inc. It is intended for a specific individual and purpose, and is protected by law. Any disclosure, copying, or unauthorized action based on it, is strictly prohibited. If you have received this information in error, please immediately notify us by telephone or e-mail

3 7/5/2017 IPaC: Explore Location

IPaC U.S. Fish & Wildlife Service

IPaC resource list

This report is an automatically generated list of species and other resources such as critical habitat (collectively referred to as trust resources) under the U.S. Fish and Wildlife Service's (USFWS) jurisdiction that are known or expected to be on or near the project area referenced below. The list may also include trust resources that occur outside of the project area, but that could potentially be directly or indirectly affected by activities in the project area. However, determining the likelihood and extent of effects a project may have on trust resources typically requires gathering additional site-specific (e.g., vegetation/species surveys) and project-specific (e.g., magnitude and timing of proposed activities) information.

Below is a summary of the project information you provided and contact information for the USFWS office(s) with jurisdiction in the defined project area. Please read the introduction to each section that follows (Endangered Species, Migratory Birds, USFWS Facilities, and NWI Wetlands) for additional information applicable to the trust resources addressed in that section.

Location Lincoln and Sweetwater counties, Wyoming

'--~·-~·-, -

Local office

\.. (307) 772-237 Ii (307) 772-2358 5353 Yellowstone Road, Suite 308a Cheyenne, WY 82009-4178 http://www.fws.govtwominges/

Endangered species

This resource list is for informational purposes only and does not constitute an analysis of project level impacts. The primary information used to generate this list is the known or expected range of each species. Additional areas of influence (AOI) for species are also considered. An AOI includes areas outside of the species range if the species could be indirect ly affected by activities in that area (e.g., placing a dam upstream of a fish population, even if that fish does not occur at the dam site, may indirectly impact the species by reducing or eliminating water flow downstream). Because species ca n move, and site conditions ca n change, the species on this list are not guaranteed to be found on or near the project area. To fully determine any potential effects to species, additional site-specific and project­ specific information is often required. Section 7 of t he Endangered Species Act requires Federal agencies to "request of the Secretary information whether any species which is listed or proposed to be listed may be present in the area of such proposed action" for any project that is conducted, permitted, funded, or licensed by any Federal agency. A letter from the local office and a species list which fulfills this requirement can only be obtained by requesting an official species list from either the Regulatory Review section in IPaC (see directions below) or from the local field office directly.

For project evaluations that require USFWS concurrence/review, please return to the IPaC website and request an official species list by doing the following: 1. Draw the project location and click CONTINUE. 2. Click DEFINE PROJECT. 3. Log in (if directed to do so). 4. Provide a name and description for your project. https://ecos.fws.gov/ipac/location/BVB6G6TTDZCQRIRH UPIZCSGSSl/resources 1/6 7/512017 IPaC: Explore Location 5. Click REQUEST SPECIES LIST. Listed species! are managed by the Ecolai:ical Serykes Prni:ram of the U.S. Fish and Wildlife Service.

1. Species listed under the Endangered Species Act are threatened or endangered; IPa C also shows species that are candidates, or proposed, for listing. See the listinr: statys par:e for more information. The following species are potentially affected by activities in this location: Birds NAME STATUS Yellow-billed Cuckoo Coccyzus americanus Threatened There is a proptJSed critical habitat for this species. Your location overlaps the proposed critic11I habitat. https://ecos.fws.gov/ecp/species/3911

Fishes NAME STATUS Bonytail Chub Gila elegans Endangered There is a fin;il critkal habitat designated for this species. Your location is outside the designated critical habitat. https://ecos.fws.gov/eq;itspecies/1377

Colorado Pikeminnow (=squawfish) Ptychocheilus lucius Endangered There is a final critkal habitat designated for this species. Your location is outside the designated critical habitat. https://ecos.fws.gov/ecp/species/3531

Humpback Chub Gila cypha Endangered There Is a fln;il crJtlcal habitat designated for this species. Your location Is outside the designated critical habitat. https·//ecos fws gov/e<;plspecjes/3930

Razorback Sucker Xyrauchen texanus Endangered There Is a flnal crJtlcal habitat designated for this species. Your location Is outside the designated critical habitat. https:/(ecos.fws.gov/e<;p/specles/530

Flowering Plants NAME STATUS Ute Ladies'-tresses Spiranthes diluvialis Threatened No critical habitat has been designated for this species. https;//ecos.fws.gov/ec;p/species/2159

Critical habitats Potential effects to critical habitat(s) in this loc.ation must be analyzed along with the endangered species themselves. This location overlaps the critical habitat for the following species: NAME TYPE Yellow-billed Cuckoo Coccyzus americanus Proposed https·lfecos fws govte<;ptspecjesJ3911 #cr1thab

Migratory birds

Certain birds are protected under the Migratory Bird Treaty Actl and the Bald and Golden Eagle Protection Act• .

Any activity that results in the t.ak~(to.har.ass ... tiarm •. p.ur:s.u.e.hunt..shQQt...ltllaund,. .kill,J.r.aµ, ..captur.e..ar..i:o.llect....ar..tc ..atte.mµt.ta ..engage.in ..anx S!.Kh..~a.d.u.i:tl of migratory birds or eagles is prohibited unless authorized by the U.S. Fish and Wildlife Service~. There are no provisions for allowing the take of migratory birds that are unintentionally killed or injured. https://ecos.fws.gov/ipac/location/BVB6G6TTDZCQRIRHUPIZCSGS51/resources 216 7/512017 IPaC: Explore Location Any person or organization who plans or conducts activities that may result in the take of migratory birds is responsible for complying with the appropriate regulations and implementing appropriate conservation measures.

1. The Migratory Bjrds Treaty Act of 1918. 2. The Bald and Golden Eagle Protection Act of 1940. 3. 50 C.F.R. Sec. 10.12 and 16 U.S.C. Sec. 668(a)

Additional information can be found using the following links:

• Birds of Conservation Concern http://ww1N.fws.goytbjrdstmanagemenumanaged-specjest bjrds-of-conservatjon-concern php • Conservation measures for birds http://www.fws.1:ov/bjrds/mana1:ement/prqject-assessment-tools-and-gujdance/ conservation-measures.php • Year-round bird occurrence data http:/fwww.bjrdscanada.or:gfbjrdmon/defaylUc!atasymmarjesJsp

The migratory birds species listed below are species of particular conservation concern (e.g. Birds of Conservation Concern) that may be potentially affected by activities in this location. It is not a list of every bird species you may find in this location, nor a guarantee that all of the bird species on this list will be found on or near this location. Although it is important to try to avoid and minimize impacts to all birds, special attention should be made to avoid and minimize impacts to birds of priority concern. To view available data on other bird species that may occur in your project area, please visit the AKN Histogram Tools and Other Bird Data Resources. To fully determine any potential effects to species, additional site-specific: and project-specific information is often required.

NAME SEASON(SJ

American Bittern Botaurus lentiginosus Breeding https·//ecos fws me<;p/species/6582

Bald Eagle Haliaeetus leucocephalus Year-round https·llecos fws me<;p/specles/1626

Black Rosy-finch Leuc:osticte atrata Year-round https://ecos.fws.mecp/spedes/9460

Brewer's Sparrow Spizella breweri Breeding https:{(ecos,fws.goyte<;p/spec1es/9291

Burrowing Owl Athene cunicularia Breeding https://ecos,fws.goy/e<;p/species/9737

Calliope Hummingbird Stellula calliope Migrating https://ecos.fws.mv/ecp/spedes/9526

Cassia's Finch Carpodacus cassinii Year-round https://ecos.fws.gov/ecp/species/9462

Ferruginous Hawk Buteo regalis Breeding bttps·/fecos fws me<;p/species/6038

Fox Sparrow Passerella iliaca Breeding

Golden Eagle Aquila chrysaetos Year-round https;//ecos.fws.gov/es;p/species/1680

Greater Sage-grouse Centrocercus urophasianus Year-round https://ecos.fws.gov/ecp/species/8159

Loggerhead Shrike Lanius ludovicianus Breeding bttps://ecos.fws.gov/ecp/spedes/8833

Long-billed Curlew Numenius americanus Breeding https://ecos.fws.gov/ecp/species/5511

Mountain Plover Charadrius montanus Breeding https'llecos fws gov/eCD/specles/3638 https://ecos.fws.gov/ipac/location/BVB6G6TTDZCQRIRHUPIZCSGS51/resources 316 7/512017 IPaC: Explore Location

Olive-sided Flycatcher Contopus cooperi Breeding https:t{ecos.fws.goytes;pl spedesJ391 4

Peregrine Falcon Falco peregrinus Breeding https:llecos.fws.gov/ec;p/species/8831

Rufous Hummingbird selasphorus rufus Migrating https:llecos.fws.gov/ecp/species/8002

Sage Thrasher Oreoscoptes montanus Breeding https:llecos.fws.gov/ ec;p/sped es/9433

Short-eared Owl Asio flammeus Year-round https:llecos.fws.gov/ecp/species/9295

Swainson's Hawk Buteo swainsoni Breeding https·necos fws "1"'e<;ptspecjes£1098

Western Grebe aechmophorus occidentalis Breeding https·ttecos fws "1"'e<;p/specjes/6743

Willow Flycatcher Empidonax traillii Breeding https·t(e<;os fws goyte<;plspeclesJ3482

What does IPaC use to generate the list of migratory bird species potentially occurring in my specified location?

Landbirds:

Migratory birds that are displayed on the IPaC species list are based on ranges in the latest edition of the National Geographic Guide, Birds of North America (6th Edition, 2011 by Jon L. Dunn, and Jonathan Alderfer}. Although these ranges are coarse in nature, a number of U.S. Fish and Wild I ife Service migratory bird biologists agree that these maps are some of the best range maps to date. These ranges were clipped to a specific Bird Conservation Region (BCRJ or USFWS Region/Regions, if it was indicated In the 2008 llst of Birds of Conservation Concern (BCQ that a species was a BCC species only In a particular ReglontRegions. Additional modifications have been made to some ranges based on more local or refined range information andtor information provided by U.S. Fish and Wildlife Service biologists with species expertise. All migratory birds that show in areas on land in I Pac are those that appear In the 2008 Birds of Conservation Concern report.

Athmtic Seabirds:

Ranges in IPaC for birds off the Atlantic coast are derived from species distribution models developed by the National Oceanic and Atmospheric Association (NOAA) National Centers for Coastal Ocean Science (NCCOS} using the best available seabird survey data for the offshore Atlantic Coastal region to date. NOAANCCOS assisted USFWS in developing seasonal species ranges from their models for specific use in IPaC. Some of these birds are not BCC species but were of interest for inclusion because they may occur in high abundance off the coast at different times throughout the year, which potentially makes them more susceptible to certain types of development and activities taking place In that area. For more refined details about the abundance and richness of bird species within your project area off the Atlantic Coast. see the Northeast Ocean Data Portal. The Portal also offers data and information about other types of taxa that may be helpful in your project review.

About the NOAANCCOS models: the models were developed as part of the NOAANCCOS project: Integrative Statistic;al Modeling and Predictive Mapping of Marine Bjrd Djstrjbytjons and Abundance on the Atlantic Oyter eontjnental Shelf. The models resulting from this project are being used in a number of decision­ support/mapping products In order to help gu Ide declslon-maklng on activities off the Atlantic Coast with the goal of red ucl ng Impacts to migratory birds. One such product is the Ngrtheast Ocean pata pgrtal which can be used to explore details about the relative occurrence and abundance of bird species in a particular area off the Atlantic Coast.

All migratory bird range maps within IPaC are continuously being updated as new and better information becomes available.

Can I get additional information Cl bout the levels of occurrence in my project Clrea of specific birds or groups of birds listed in I Pae?

Landblrds:

The Avian Knowledge Netwgrk !AKNl provides a tool currently called the "Histogram Tool", which draws from the data within the AKN (latest.survey, point count, citizen science datasets) to create a view of relative abundance of species within a particular location over the course of the year. The results of the tool depict the frequency of detection of a species in survey events, averaged between multiple datasets within AKN in a particular week of the year. You may access the histogram tools through the Mjgratgry Bjrd Programs AKN HjstQgram Tools webpage.

The tool is currently available for 4 regions (California, Northeast U.S., Southeast U.S. and Midwest), which encompasses the following 32 states: Alabama. Arkansas. California, Connecticut, Delaware, Florida, Georgia, Illinois, Indiana, Iowa, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, New Hampshire, New Jersey, New York. North, Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee, Vermont. Virginia, West Virginia, and Wisconsin.

In the near future, there are plans to expand this tool nationwide within the AKN, and allow the graphs produced to appear with the list of trust resources generated by IPaC, providing you with an additional level of detail about the level of occurrence of the species of particular concern potentially occurring in your project area throughout the course of the year.

Atlantic Seabirds:

https://ecos.fws.gov/ipac/location/BVB6G6TTDZCQRIRHUPIZCSGS51/resources 4/6 7/512017 IPaC: Explore Location

For additional details about the relative occurrence and abundance of both individual bird species and groups of bird species within your project area off the Adantic Coast, please visit the Northeast Ocean Data portal. The Portal also offers data and information about other taxa besides birds that may be helpful to you in your project review. Alternately, you may download the bird model results files underlying the portal maps through the NOAANCCOS lntearative Statjstjcal Modelin& and Predictive Mapoing of Marine Bird Distributions and Abundance on the Atlantic Outer Continental Shelf project web page.

Facilities

Wildlife refuges Any activity proposed on Nat jonal Wildlife RefuiE! lands must undergo a 'Compatibility Determination' conducted by the Refuge. Please contact the individual Refuges to discuss any questions or concerns. This location overlaps the following National Wildlife Refuges:

REFUGE ACRES

Seedskadee National Wildlife Refuge 51,939.82 acres

\. (307) 875-2187 Ii (307) 875-4425

MAILING ADDRESS P.O. Box700 Green River, WY 82935-0700

PHYSICAL ADD RESS 37 Miles North Of Green River, Wy On Highwy 372 Green River, WY 82935 https:ljwww,fws,i:oyt refui:es/profilestjndex.cfrn?jd=65580

Fish hatcheries

THERE ARE NO FISH HATCHERIES AT THIS LOCATION.

Wetlands in the National Wetlands Inventory

Impacts to NWI wetlands and other aquatic: habitats may be subject to regulation under Section 404 of the Clean Water Act. or other State/Federal statutes. For more information please contact the Regulatory Program of the local U.S. Army Corps of Engineers District.

WETLAND INFORMATION IS NOT AVAILABLE AT THIS TIME This can happen when the National Wetlands Inventory (NWI) map service is unavailable, or for very large projects that intersect many wetland areas. Try again, or visit the NWI map to view wetlands at this location.

Data !imitations

The Service's objective of mapping wetlands and deepwater habitats is to produce reconnaissance level information on the location, type and size of these resources. The maps are prepared from the analysis of high altitude Imagery. Wetlands are Identified based on vegetation, visible hydrology and geography. A margin of error is inherent in the use of imagery; thus, detailed on-the-ground inspection of any particular site may result in revision of the wetland boundaries or classification established through image analysis.

The accuracy of Image Interpretation depends on the quality ofthe Imagery, the experience of the Image analysts, the amount and quality ofthe collateral data and the amount of ground truth verification work conducted. Metadata should be consulted to determine the date of the source imagery used and any mapping problems.

Wetlands or other mapped features may have changed since the date of the imagery or field work. There may be occasional differences in polygon boundaries or classlflcatlons between the Information depicted on the map and the actual conditions on site.

Data excluslons

Certain wetland habitats are excluded from the National mapping program because of the limitations of aerial imagery as the primary data source used to detect wetlands. These habitats Include seagrasses or submerged aquatic vegetation that are found In the Intertidal and subtldal zones of estuaries and nearshore coastal https://ecos.fws.gov/ipac/location/BVB6G6TTDZCQRIRHUPIZCSGS51/resources 5/6 7/512017 IPaC: Explore Location waters. Some deepwater reef communities (coral or tuberficid worm reefs) have also been exduded from the inventory. These habitats, because of their depth, go undetected by aerial imagery.

Data precautions Federal, state, and local regulatory agencies with jurisdiction over wetlands may define and describe wetlands in a different manner than that used in this inventory. There is no attempt, in either the design or products of this inventory, to define the limits of proprietary jurisdiction of any Federal, state, or local government or to establish the geographical scope of the regulatory programs of government agencies. Persons intending to engage in activities involving modifications within or adjacent to wetland areas should seek the advice of appropriate federal, state, or local agencies concerning specified agency regulatory programs and proprietary Jurisdictions that may affect such activities.

https://ecos.fws.gov/ipacllocation/BVB6G6TIDZCQRIRHUPIZCSGS51/resources 616

Appendix E: Wave Height and Hydraulic Calculations FREEBOARD DESIGN DATE 3/31/17

PROJECT Fontenelle Dam Analysis Type Minimum Freeboard

a. EFFECTIVE FETCH

Fe = Σ Xcosα Σ cosα

α r cos α X X*cos(α) 40 30 20 10 0 29040 1.000 29040.00 29040.00 From Google Earth 10 20 30 40

Σ = 1.00 Σ = 29040.00

Fe = 29040.00 feet = 5.50 miles

b. WIND RELATIONSHIP - Water to Land (Table 2)

Effective Fetch, Fe (miles) 0 0.5 1 2 3 4 Over Water Wind Velocity Ratio Over Land 1 1.08 1.13 1.21 1.26 1.28

Selected Ratio = 1.30 Page 2 Fontenelle Dam 3/31/17

SITE WIND VELOCITIES (Figures 1 thru 8)

Table 1 Max. Over Land:Water Max. Over Fastest Mile MPH Land Vel. Ratio Water Vel. Winter 64 Spring 70 70 1.30 91.00 Summer 56 Fall 66 Max 1-hr Winter 49 Spring 48 49 1.30 63.70 Summer 35 Fall 40 c. WIND VELOCITY AND DURATION (Figure 9)

Fetch Duration Site Wind Vel. Wind Vel Figure 9 Table 1 (mph) (min) (mph) 1 91.00 60 63.70 120 61.15 80 48 70 50 60 55 50 59 40 65 30 78 d. PLOT GRAPH AND CHOOSE DESIGN WIND SPEED

Design Wind Velocity = 68 mph Design Wind Duration = 51 min e. SELECT SIGNIFICANT WAVE HEIGHT AND WAVE PERIOD

Hs = 7 ft T = 5 sec EQUIVALENT STONE DIAMETER (;LEAR SQUARE OPENINGS US STANDARD SI EVE NUMBERS 361zd'241JS11 12'' Bu 611 4u3"2.t:2' 1 1}2'1 11 1 11 4 8 10 16 30405070100 2.00 ( 1 ~ ~·3~ .... JOO I I\ I I ~ I I i'\ EXAMPLE OF ~ '-,I ~ I RIPRAP DESIGN \ \ .\ \ FOR EXPECTED \ \ MAXIMUM WAVE 60 \ \ HEIGHT= 6 FT f- \ \ \ :i: \ I I I I I \2 I I ' w \ DEMBANKMENT RIP RAP .\FILTER iAFILTER LAYE~~ :s: 60 \ \ / so111 >- \LAYER IT w ' \ 0: \ \ \ w l ;;;. \ \ Ii. \ \ f-40 z ,\ \ " \ w \ I\ \ I\ 0 \ 0:w 11. \ .\ ,\. '\ \ \ ' 20 '\ I\ ' \ " ' ;'-. I\. ~"'...... I\ I'-- !"- ' ~ 0 ""- .... " 1000 8 6 4 3 2. 100 8 6' 4 3 2. 108 6 43 "2 I 8 6 4 3 2. I 8 6 4 3 2. .01 GRAIN SIZE MILLIMETERS

I I FINE I CO!.RSE JIED(Uli I F'INE I sn:.r m rur I BOULDERS I Ct;BSt..ES ::.ANu I ' ' GENERAL REQUIREMENTS: MAXIMUM AVERAGE MAXIMUM LAYER 1. FOR EMBANKMENT SLOPES WA'VE HEIGHT ROCK SIZE ROCK SIZE THICKNESS BETWE:EN 1:2. AND:l:4 FT Df!(~IN. POUNDS IN. DUMPED RlPRAP SHALL 0 TO l 8 100 lZ c MEET THE FOLLOWING l TO 2. 10 zoo 15 CilITERIA: I z.Ti'.54 l~ 500 Iii' 4TO 6 15 1500 Z4 6 TO 8 18 2.500 30 8 TO 10 Z4 4000 36 2. RIPRAP SHALL BE WELL GRADED FROM A MAXIMUM SIZE AT LEAST 1.5 TIMES AVERAGE ROCK SIZE,'l'O l IN. SPALLS SUITABLE TO FILL VOIDS BETWEEN ROCKS. 3. RIPRAP BLANKET SHALL :EXTEND TO AT LEAST 8 FT BELOW LOWEST LOW WATER. 4. UNDER THE MOST EXTREME ICING AND TEMPERATURE CHANGES, ROCK SHOULD MEET SOUNDNESS AND DENSITY REQUIREMENTS FOR CONCRETE AGGB.EOATE. OTHERWISE, ANY UNWEATHER:ED ROCK WITH G> 2.. 60, OTHE:R THAN ARGlLLACEOUS TYPES, ARE SUITABL:E. 5. FILTER SHALL BE PROVIDED BETWEEN MAXIMUM WAVE FILTER Das RIPB..AP AND EMBANKMENT SOILS TO HEIGHT, FT SIZE AT LEAST. MEET THE FOLLOWING CRITERIA: 0 TO 4 l TO lfIN. 4 TO 10 l!TO 2. llf. NO FILTER IS NEEDED IF EMBANKMENT MEETS THE ABOVE REQUIREMENTS FOR Das SIZE. FI.LTER MAY NO'I: ..UE REQUIRED lF EM.BANKMEli_T CONSIST.$ OF CH OE. CL WITH LL) 30. RESISTANT TO SURFACE EROSION •. IF A FILTER IS USED lli" THIS CASE IT ORDINARILY MEETS FILTER CRITERIA AGAINST RIPRAP ONLY. IF EMBANKMENT CONSISTS OF NONPLASTIC SOILS WHERE SEEPAGE WILL MOVE FROM EMBANKMENT AT LOW WATER, 2. FILTER .T...AYE;RS MAY BE REQUIRED WlilCH SHALL MEET FILTER CRITERIA AGAINST BOTH EMBANKMENT AND RIPRAP. (EXAMPLE IS SHOWN ABOVE). 6. MlNIMUM THICKNESS OF Sll'lGLE LAYER MAXIMUM WAVE FILTER FILTERS ARE AS FOLLOWS: HEIGHT. FT THICKNESS, IN. I 0 TO 4 b i DOUBLE FILTER LAYERS SHOULD BE AT 4 TO 8 9 LEAST 6 IN. 'I'HICK. 8 TO 12 lZ

FIGURE 9· l ( Design Criteria !or Riprap on Earth Embankments

7.9.13

. 578-0iB 0 • 75 - L2

Appendix F: Alternative Cost Estimates

NEPA COSTS ITEMS AMOUNT UNIT COST/UNIT ITEM COST ENVIRONMENTAL AND OTHER COSTS - EIS NEPA Liaison* 1 LS $230,000 $230,000 NEPA* 1 LS $1,000,000.00 $1,000,000 SUBTOTAL $1,230,000 ENVIRONMENTAL AND OTHER COSTS - EA NEPA Liaison* 1 LS $180,000 $180,000 NEPA* 1 LS $650,000 $650,000 SUBTOTAL $830,000 * These planning level cost estimates include fish, water quality, downstream wetlands, threatened and endangered species, and sensitive species' (e.g., Trumpeter Swan) analyses RIPRAP PLACEMENT IN DRAINED RESERVOIR Engineer's Opinion of Construction Cost ITEMS AMOUNT UNIT COST/UNIT ITEM COST DESIGN Engineering, Surveying and Legal (25%) 1 LS $1,217,000 $1,217,000 SUBTOTAL $1,217,000 CONSTRUCTION Access - road and ramp 1 LS $150,000 $150,000 Riprap and placement 52700 CY $89.51 $4,718,000 Mobilization/Demobilization (3%) 1 LS $147,000 $147,000 Performance/Payment/Warranty Bond (1.5%) 1 LS $74,000 $74,000 Contingency (20%) 1 LS $974,000 $974,000 SUBTOTAL $6,063,000 EIS NEPA Liaison* 1 LS $230,000 $230,000 NEPA* 1 LS $1,000,000 $1,000,000 SUBTOTAL $1,230,000 Total Cost $8,510,000 * These planning level cost estimates include fish, water quality, downstream wetlands, threatened and endangered species, and sensitive species' (e.g., Trumpeter Swan) analyses RIPRAP PLACEMENT IN FULL RESERVOIR Engineer's Opinion of Construction Cost ITEMS AMOUNT UNIT COST/UNIT ITEM COST DESIGN Engineering, Surveying and Legal (25%) 1 LS $2,021,000 $2,021,000 SUBTOTAL $2,021,000 CONSTRUCTION Sectional Barge and Crane 1 LS $1,000,000 $1,000,000 (Mobilization/Demobilization and Rental) Riprap and placement 79100 CY $89.51 $7,081,000 Dive Team 540 Diver/Day $3,000 $1,620,000 Mobilization/Demobilization (3%) 1 LS $292,000 $292,000 Performance/Payment/Warranty Bond (1.5%) 1 LS $146,000 $146,000 Contingency (20%) 1 LS $1,941,000 $1,941,000 SUBTOTAL $12,080,000 EIS NEPA Liaison* 1 LS $230,000 $230,000 NEPA* 1 LS $1,000,000 $1,000,000 SUBTOTAL $1,230,000 Total Cost $15,331,000 * These planning level cost estimates include fish, water quality, downstream wetlands, threatened and endangered species, and sensitive species' (e.g., Trumpeter Swan) analyses SOIL CEMENT PLACEMENT IN DRAINED RESERVOIR Engineer's Opinion of Construction Cost ITEMS AMOUNT UNIT COST/UNIT ITEM COST DESIGN Engineering, Surveying and Legal (25%) 1 LS $1,153,000 $1,153,000 SUBTOTAL $1,153,000 CONSTRUCTION Access - road and ramp 1 LS $150,000 $150,000 Excavation 10700 CY $3.00 $33,000 Soil-cement and placement 52100 CY $85.00 $4,429,000 Sampling and Quality Insurance 1 LS $100,000 $100,000 Mobilization/Demobilization (3%) 1 LS $139,000 $139,000 Performance/Payment/Warranty Bond (1.5%) 1 LS $70,000 $70,000 Contingency (20%) 1 LS $923,000 $923,000 SUBTOTAL $5,844,000 EIS NEPA Liaison* 1 LS $230,000 $230,000 NEPA* 1 LS $1,000,000 $1,000,000 SUBTOTAL $1,230,000 Total Cost $8,227,000 * These planning level cost estimates include fish, water quality, downstream wetlands, threatened and endangered species, and sensitive species' (e.g., Trumpeter Swan) analyses SUBMAR MATS PLACEMENT IN FULL RESERVOIR Engineer's Opinion of Construction Cost ITEMS AMOUNT UNIT COST/UNIT ITEM COST DESIGN Engineering, Surveying and Legal (25%) 1 LS $6,130,000 $6,130,000 SUBTOTAL $6,130,000 CONSTRUCTION Submar Mats Delivered 568,000 SF $30.00 $17,040,000 Submar Mats Install by Dive Team 2,160 Diver/Day $3,000 $6,480,000 Sectional Barge and Crane 1 LS $1,000,000 $1,000,000 (Mobilization/Demobilization and Rental) Mobilization/Demobilization (3%) 1 LS $706,000 $706,000 Performance/Payment/Warranty Bond (1.5%) 1 LS $353,000 $353,000 Contingency (20%) 1 LS $4,704,000 $4,704,000 SUBTOTAL $30,283,000 EIS NEPA Liaison* 1 LS $230,000 $230,000 NEPA* 1 LS $1,000,000 $1,000,000 SUBTOTAL $1,230,000 Total Cost $37,643,000 * These planning level cost estimates include fish, water quality, downstream wetlands, threatened and endangered species, and sensitive species' (e.g., Trumpeter Swan) analyses CONTECH WAVE ATTACK BLOCKS PLACEMENT IN FULL RESERVOIR Engineer's Opinion of Construction Cost ITEMS AMOUNT UNIT COST/UNIT ITEM COST DESIGN Engineering, Surveying and Legal (25%) 1 LS $5,470,000 $5,470,000 SUBTOTAL $5,470,000 CONSTRUCTION Bedding and placement 568,000 SF $5.00 $2,840,000 Wave Attack Blocks 568,000 SF $20.00 $11,360,000 Wave Attack Blocks Install by Dive Team 568,000 SF $10.00 $5,680,000 Sectional Barge and Crane 1 LS $2,000,000 $2,000,000 (Mobilization/Demobilization and Rental) Mobilization/Demobilization (3%) 1 LS $597,000 $597,000 Performance/Payment/Warranty Bond (1.5%) 1 LS $299,000 $299,000 Contingency (20%) 1 LS $3,976,000 $3,976,000 SUBTOTAL $26,752,000 EIS NEPA Liaison* 1 LS $230,000 $230,000 NEPA* 1 LS $1,000,000 $1,000,000 SUBTOTAL $1,230,000 Total Cost $33,452,000 * These planning level cost estimates include fish, water quality, downstream wetlands, threatened and endangered species, and sensitive species' (e.g., Trumpeter Swan) analyses RIPRAP PLACEMENT IN FULL RESERVOIR Engineer's Opinion of Construction Cost for Construction Starting in 2020 ITEMS AMOUNT UNIT COST/UNIT ITEM COST DESIGN Engineering, Surveying and Legal (25%) 1 LS $2,275,000 $2,275,000 SUBTOTAL $2,275,000 CONSTRUCTION Sectional Barge and Crane 1 LS $1,061,000 (Mobilization/Demobilization and Rental) $1,061,000 Riprap and placement 79100 CY $95 $7,515,000 Dive Team 540 Diver/Day $3,183 $1,719,000 Mobilization/Demobilization (3%) 1 LS $328,000 $328,000 Performance/Payment/Warranty Bond (1.5%) 1 LS $165,000 $165,000 Contingency (20%) 1 LS $2,185,000 $2,185,000 SUBTOTAL $12,973,000 EIS NEPA Liaison* 1 LS $245,000 $245,000 NEPA* 1 LS $1,061,000 $1,061,000 SUBTOTAL $1,306,000 Total Cost $16,554,000 * These planning level cost estimates include fish, water quality, downstream wetlands, threatened and endangered species, and sensitive species' (e.g., Trumpeter Swan) analyses Appendix G: Final Design Process December 2017 FINAL DESIGN PROCESS GENERAL FLOW CHART COORDINATION ACTIVITIES

Dams, Pumping Plants, Powerplants: 10-30 Months; Pipelines: 12-24 Months; Canals and Tunnels: 10-20 Months 14-28 Weeks Varies 6-12 Months NEPA PROCESS 12-36 Months 6-8 Weeks-IFB 4 Weeks-IFB 1-3 Months 2-12 Months 4-10 Months 2-6 Months _i4-6I Weeks, 4 Weeks 4-6 Weeks 4-6 Weeks 16 Weeks-RFP 6 Weeks-RFP

� TA SPEC � � � � � � � � � � � � � 60% DRAFT I FINAL SCHED 30% DESIGN FINAL SPEC 90% 100% BOOKPRE BID AWARD CONSTR CONSTR COMP PREWORK CONCEPT I REVIEW I I SPEC 1 BID SUB­ - DESIGNI FINAL - DESIGN FlNAL FINAL AWARD iCONSTRCI START I � I � -..JRE VIEWC � I � I ISSUE I � I I � I I � I COMP I � � I COMP PMP DESIGN (DESIGNC) D5ffiN D5ffiN V V V (CONCEPTC) V V (SPECD) V V (SPECB) V V V V V V PM ASSIGNED BY DESIGN TEAM FORMED DEVELOP/REFINE INITIAL ALL OUTSTANDING DESIGN SPEC COORDINATOR INVOLVED PARTIES REVIEW CHANGES DISCUSSED FINALIZE VE IFB IFB CO ISSUES NOTICE TO REVIEW ALL RSNs FOR ANALYSIS OF CLAIMS ORIGINATING OFFICE CONCEPT DATA IS RECEIVED AND RECEIVES DRAFT DRAFT SPEC PACKAGE AND AND AGREED TO AT ACCOUNTABILITY SPECIAL INSPECTION ADDRESS PROTESTS PROCEED COMPLETION SCHEDULING ACTIVITIES INCORPORATED INTO DRAWINGS FROM THOSE DOCUMENT COMMENTS REVIEWC ARE MADE TO REPORT (>$1,000,000) REQUIREMENTS PROVIDE EXPERT PMT MAY BE INITIATED REQUEST DESIGN DATA DESIGNS DISCIPLINES THAT THE SPEC AND RESOURCED BIDS EVALUATED CONTRACTOR PERFORMS ENSURE AS-BUILTS ARE TESTIMONY ESTABLISHED (DDR) REQUIRE PARAGRAPH DESIGN TEAM REVIEWS DRAWINGS BY FUNDING CONSTRUCTION COMPLETE PMP APPROVED: COMPLETE LABORATORY PREPARATION DRAFT SPEC TO ENSURE APPROPRIATE DESIGN REQUIREMENTS PRE-BID INFORMATION CO DETERMINES ACTIVITIES ASSISTANCE IN STARTUP PROJECT FEATURES AND • SCOPE OF WORK REQUEST GEOLOGIC TESTING (HYDRAULIC THAT CHANGES/REVISIONS TEAM MEMBER - (PREVAL ESTIMATE) MEETING CONDUCTED BY CONTRACTOR ASSIST IN PREPARATION AND INITIAL O&M SCHEDULES MAY OR • SCHEDULE DATA (FER) MODELS INCLUDED) COMPLETE ALL DRAWINGS DISCUSSED AT TASPEC ADDITIONAL INFO OR FURNISHED TO CO BY CONTRACTING OFFICE RESPONSIBILITY DESIGN TEAM: OF PUNCH LIST FOR MAY NOT BE FIRMLY • STAFF RESOURCES THROUGH TECHNICAL REVIEW HAVE BEEN MADE DATA, IF REQUIRED, IS ESTIMATOR • PARTICIPATES IN COMPLETION CO ACCEPTS RELEASE OF ESTABLISHED DEFINED REQUEST LAB TESTING PREPARE DRAFT GEOLOGIC APPROVAL REVIEW PROVIDED TO THE AMENDMENTS PREPARED CONTRACT AWARDED READINESS REVIEW, CLAIMS • BUDGET DESIGN REPORT REVIEW MEETING IS HELD DESIGN TEAM CONTRACTING OFFICE AND SENT TO PRECONSTRUCTION, ASSIST IN EQUIPMENT DESIGN WORK IS EVALUATE DESIGN, LAB, COMPLETE DRAFT WITH INVOLVED PARTIES PREPARES FOR CONTRACTING OFFICE DRAFT DESIGN AND CONCRETE CHECKOUT AND STARTUP FINAL REPORT OF FUNDED DESIGN TEAM: GEOLOGIC DATA FOR COMPLETE ANALYSIS OF SPECIFICATIONS - AND THE DESIGN TEAM FINAL DRAWINGS ISSUING THE FINAL SUMMARY PREPLACEMENT CONSTRUCTION • DETERMINE NEED FOR: COMPLETENESS - STRUCTURES, FOUNDATIONS, ALL DESIGN GROUPS (2-5 DAYS) SIGNED THRU PEER SOLICITATION/SPEC AMENDMENTS ARE ISSUED DISTRIBUTED MEETINGS PERFORM WARRANTY PREPARED DESIGN TEAM LEADER - GEOLOGIC FIELD REQUEST MORE AS EQUIPMENT AND SYSTEMS REVIEW ARE SENT TO BY CONTRACTING OFFICE • PREPARES REVISIONS INSPECTIONS ASSIGNED EXPLORATION NEEDED SUBMIT DRAFT PREPARE FINAL REVIEW SPEC COORDINATOR, CONTRACTING OFFICE RFP AND CORRESPONDING COMPLETE CONTRACT - MATERIAL TESTING DESIGN FEATURES AND SPECIFICATIONS AND MEETING NOTES THAT LIST WHO REVIEWS THE ENTERS PURCHASE IGCE PREPARED AND COST ESTIMATES TO ASSIST WITH FINAL CLOSE OUT PLANNING STUDIES - HYDRAULIC MODEL DEVELOP ALTERNATIVE IDENTIFY BORROW AND TECHNICALLY APPROVED AREAS OF DISCUSSION, DRAWING LIST WITH REQUEST IN FBMS CO PREPARES MODIFY THE CONTRACT INSPECTION TRANSMITTED TO CO PRENEGOTIATION COMPLETED - PILOT STUDY CONCEPTS DISPOSAL AREAS DRAWINGS TO SCHEDULES, AND THE TITLE BLOCKS, (REQUIRED) (IF REQUIRED) FINALIZE DESIGN • IDENTIFY SPECIAL (IF REQUIRED) SPECIFICATIONS INDIVIDUALS AND PROVIDES PAGE CO SUBMITS MEMORANDUM • REVIEWS CONTRACTOR'S ACCEPTANCE OF ALL SUMMARY AND DOC DSO CORRECTIVE STUDIES: IDENTIFY AND COORDINATE COORDINATOR (TASPEC) RESPONSIBLE FOR OR SHEET NUMBERS SOCIO-ECONOMIC RSNs AND RF!s WORK AS COMPLETE BIDS OPENED BY CO DETERMINES ACTION STUDY - SEISMOTECTONIC PREPARE 30% FINAL DESIGN DETAILS ACROSS FOLLOW-UP ACTIONS SCREENING FORM CONTRACTING OFFICE • INSPECTS AND APPROVES HOLD LESSONS LEARNED COMPLETED - HYDROLOGIC DESIGN COST TECHNICAL DISCIPLINES COMPLETE AND APPROVE SPECIFICATIONS CONTRACTOR FOUNDATIONS MEETING RESPONSIBILITY • IDENTIFY CLIENT ESTIMATES FINAL TMs HOLD REVIEWC CLOSEOUT SIGNATURE SHEET CO SUBMITS DRAFT RFP • PROVIDES TECHNICAL VALUE PLANNING AND GOALS AND (RECOMMENDED) DEVELOP DRAFT BRIEFING AND SIGN SIGNED THROUGH SOLICITATION FOR ASSISTANCE DEC REVIEW REQUIREMENTS SPECIFICATIONS DRAWINGS FINALIZE BASIS OF DECISION DOCUMENT TECHNICAL APPROVAL REVIEW SPECIAL INSPECTION CONTRACT AWARDED • PROVIDES TECHNICAL COMPLETED IDENTIFY PREFERRED DESIGN DOCUMENT REQUIREMENTS ANALYSIS OF CLAIMS (IF REQUIRED) DESIGN CONCEPT COST, COMPLETE VE STUDY FINAL SPEC AND PRESOLICITATION RESOURCED DEBRIEF OFFERORS • PREPARES FOUNDATION ADDITIONAL DATA (>$1,000,000) COMPLETE TASPEC DRAWINGS IN PDF NOTICE ISSUED BY ACCEPTANCE SUMMARY REQUIREMENTS, AND REVIEW OF FORMAT SENT TO CONTRACTING OFFICE PRE-PROPOSAL ADDRESS PROTESTS MEMORANDUMS REVISED PREPARE DRAFT VE SPECIFICATIONS CONTRACTING OFFICE AT LEAST 15 DAYS CONFERENCE CONDUCTED (IF REQUIRED) SCHEDULE/RESOURCES ACCOUNTABILITY REPORT PACKAGE BEFORE ISSUE BY CONTRACTING OFFICE CE: FOR RFP: DESIGN TEAM DRAFT DESIGN • PERFORMS FIELD AND IDENTIFY ACQUISITION PREPARE DRAFT REVISE SPECIFICATIONS AND CE DEVELOPS CO POSTS SOLICITATION AMENDMENTS PREPARED SUMMARY FACTORY INSPECTIONS LEGEND AND SENT TO DISTRIBUTED TYPE CONSTRUCTION SCHEDULE EVALUATION CRITERJA ON FBO WEBSITE • ASSISTS IN DEVELOPING CE: CONSTRUCTION ENGINEER CONTRACTING OFFICE PREPARE 90% FINAL AND DELIVERS TO CO AND IMPLEMENTING CO: CONTRACTING OFFICER PERFORM SECURITY PERFORM CONSTRUCTABILITY DESIGN COST ESTIMATE ACCEPTANCE TEST DDR: DESIGN DATA REQUEST AMENDMENTS ARE ISSUED REVIEWS (IF REQUIRED) REVIEW (OPTIONAL) FINAL QUANTITIES PROCEDURES DEC: DESIGN, ESTIMATING, AND FURNISHED TO THE BY CONTRACTING OFFICE • TECHNICAL ACCEPTANCE CONSTRUCTION IDENTIFY TMs TO BE PREPARE DRAFT AT 90% FINAL DESIGN: ESTIMATOR OF FIELD DOC: DESIGNER'S OPERATING CRITERJA IGCE PREPARED AND PREPARED SPECIFICATIONS TABLE OF • DRAFT MODIFICATIONS DSO: DAM SAFETY OFFICE CONTENTS, BID SCHEDULE, SPECIFICATIONS PREPARE 100% FINAL TRANSMITTED TO CO • MONITORS PROGRESS OF FBMS: FINANCIAL AND BUSINESS PREPARE DRAFT BASIS DIVISION I PARAGRAPHS, PACKAGE SUBMITTED DESIGN COST WORK MANAGEMENT SYSTEM TECHNICAL PROPOSAL OF DESIGN DOCUMENT AND DRAWING LIST TO CONTRACTING ESTIMATE (OPTIONAL) • LISTS ALL OUTSTANDING FBO: FEDERAL BUSINESS OPPORTUNITIES OFFICE EVALUATION COMMITTEE PROJECT REQUIREMENTS FER: FIELD EXPLORATION REQUEST HOLD MILESTONE PREPARE DRAFT TMs AND • MEMO SENT TO ALL START PREVAL COST (TPEC) EVALUATE WHICH HAVE NOT BEEN IFB: INVITATION FOR BID CONCURRENCE IDENTIFY ADDITIONAL TMs INVOLVED PARTIES ESTIMATE (REQUIRED) PROPOSALS COMPLETED IGCE: INDEPENDENT GOVERNMENT COST BRIEFING AND SIGN TO BE PREPARED THAT DRAFT SPEC • ACCEPTS THE WORK AS ESTIMATE DECISION DOCUMENT AND DRAWINGS WERE AMEND DPR TPEC SENDS EVALUATION SUBSTANTIALLY PM: PROJECT MANAGER UPDATE BASIS OF DESIGN SENT, INFO ON OF TECHNICAL PROPOSALS COMPLETE PMP: PROJECT MANAGEMENT PLAN RISK ANALYSIS DOCUMENT REVIEWC MEETING, MEMORANDUM TO CO PMT: PROJECT MANAGEMENT TEAM (TSC) AND INSTRUCTIONS PREVAL: PREVALIDATION COORDINATE WITH PM ON ON COORDINATING RF!: REQUEST FOR INFORMATION REQUIRED PERMITS AND COMMENTS RFP: REQUEST FOR PROPOSAL ENVIRONMENTAL REVIEWS RSN: REQUIRED SUBMITTAL NUMBER NEPA PROCESS TM: TECHNICAL MEMORANDUM PREPARE 60% FINAL DESIGN VE: VALUE ENGINEERING COST ESTIMATE (OPTIONAL)

HOLD MILESTONE CONCURRENCE BRIEFING AND SIGN DECISION DOCUMENT FIGURE 1