Yakima River Basin Study
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Yakima RiverRiver Basin Study Lake Kachess InaInactive ctive Storage Technical MemoraMemorandumndum U.S. Bureau of Reclamation Contract No. 08CA10677A ID/IQID/IQ, Task 4.9 Prepared by HDR Engineering, Inc Anchor QEA U.S. Department of the Interior State of Washington Bureau of Reclamation Department of Ecology Pacific Northwest Region Office of Columbia River March 2011 Columbia-Cascades Area Office MISSION STATEMENTS The mission of the Department of the Interior is to protect and provide access to our Nation’s natural and cultural heritage and honor our trust responsibilities to Indian tribes and our commitments to island communities. The mission of the Bureau of Reclamation is to manage, develop, and protect water and related resources in an environmentally and economically sound manner in the interest of the American public. The Mission of the Washington State Department of Ecology is to protect, preserve and enhance Washington’s environment, and promote the wise management of our air, land and water for the benefit of current and future generations. Yakima River Basin Study Lake Kachess Inactive Storage Technical Memorandum U.S. Bureau of Reclamation Contract No. 08CA10677A ID/IQ, Task 4.9 Prepared by HDR Engineering, Inc Anchor QEA U.S. Department of the Interior State of Washington Bureau of Reclamation Department of Ecology Pacific Northwest Region Office of Columbia River March 2011 Columbia-Cascades Area Office This Page Intentionally Left Blank Contents 1.0 Introduction ......................................................................................................... 1 2.0 Design Criteria .................................................................................................... 2 2.1 Lake Kachess Storage Volume ........................................................................... 2 2.2 Flow Transfer Rate ............................................................................................. 2 2.3 Fish Screens ....................................................................................................... 3 2.4 Minimum Kachess River In-Stream Flow ............................................................ 3 2.5 Operational Rule ................................................................................................. 3 3.0 Geology ............................................................................................................... 3 4.0 Facilities Description ......................................................................................... 4 4.1 Alternative Development ..................................................................................... 4 4.2 Selected Alternatives .......................................................................................... 5 4.3 Lake Tap ............................................................................................................. 6 4.4 Lake Kachess Fish Screen ................................................................................. 7 4.5 Alternative 1 – Gravity Flow Tunnel .................................................................... 7 4.6 Alternative 2 – Lake Kachess Pump Station .......................................................11 5.0 Property and Easements ................................................................................. 13 6.0 Technical Issues for Future Consideration .................................................... 13 6.1 Project Challenges .............................................................................................13 6.2 Next Steps .........................................................................................................14 6.3 Cost Estimates ...................................................................................................14 7.0 References ........................................................................................................ 14 8.0 List of Preparers ............................................................................................... 15 List of Tables Table 1 Lake Kachess Existing and Proposed Storage Depths and Volumes ............................ 2 List of Figures Figure 1. Lake Kachess Inactive Storage project Location (outlined in white) ........................... 1 Figure 2. Alternatives 1 and 2 for Kachess Inactive Storage Project ........................................17 Figure 3. Lake Kachess Contours Bathometric and Aerial Map ................................................18 Figure 4. Lake Kachess Reservoir Area and Capacity Curves .................................................19 Figure 5. Lake Kachess Capacity Curve ..................................................................................20 Figure 6. Published Surface Geology Map ...............................................................................21 Figure 7. Alternatives 1 and 2 for Kachess Inactive Storage Project ........................................22 Figure 8. Lake Tap Tunnel and Fish Screen Plan ....................................................................23 Figure 9. Schematic Lake Tap Tunnel Section .........................................................................24 Yakima River Basin Study i Lake Kachess Inactive Storage Figure 10. Alternative 1 Tunnel Profile .....................................................................................25 Figure 11. Alternative 1 Tunnel & 20 CFS Pump Station Plans ................................................26 Figure 12. Alternative 1 Tunnel & 20 CFS Pump Station Section .............................................27 Figure 13. Alternative 1 Yakima River Portal & Discharge Structure Plans ...............................28 Figure 14. Alternative 1 Yakima River Portal Sections .............................................................29 Figure 15. Alternatives 1 and 2 Transmission Main Profile .......................................................30 Figure 16. Alternative 2 1000 CFS & 20 CFS Pump Station Plans ...........................................31 Figure 17. Alternative 2 1000 CFS & 20 CFS Pump Station Section ........................................32 Figure 18. Alternatives 1 & 2 Kachess River Outlet Structure Plan and Sections .....................33 Yakima River Basin Study ii Lake Kachess Inactive Storage 1.0 IntroductionIntroduction This technical memorandum desc describesribes the design criteria, geology, facilities, prprooperty perty easement needs, challenges and next steps for a project that would withdraw additional wwaaterter from Lake Kachess. The Lake Kachess Inac Inactivetive Storage project site is located in west-centcentrralal Washington just east of Interstate 90 (I-90) ne near ar the small town of Easton. Figure 1 below sshhows ows general project location and Figure 2 showsshoshows ws a more detailed aerial view of the pipeline alignment.aallignment.ignment. The purpose of the project is to betterb etter utilize the storage volume of water availaavailableavailabble le in Lake Kachess by lowering the outlet ofo f the lake, which would allow withdrawal of an additional 200,000 acre-feet of water for be beneficialneficial downstream use when needed. Figure 1. Lake KachessKachesKachess s Inactive Storage project Location (outlined iinn white) white) (Note: Figure 2 shows a more detailedd etailed aerial view of potential alternative projprojectprojeectct facilities thatthat are discussed in this report.) Two alternatives have been identifiedidentidentified ified to withdraw the additional water from LakeLaLakke e Kachess, both starting from a new lake tap outleoutlett in the Lake Kachess Dam about 80 feet belobeloww the existing outlet at the southeast end of the lake: Alternative 1 would use a gravity-flow tutunnnel nel that would discharge approximately 4.6 mile miless southeast of the Lake Kachess Dam into the YakimaY akima River ; Alternative 2 would withdraw wa waterter through a pump station near the lake shorelshoreliinene and discharge to the Kachess River jujust st downstream of the dam. The Lake Kachess Inactive StorageStoraStoragege project is one of several potential structural and and operation changes being studied to improve improve water resources management in the Yakima Basin. Other alternatives include: a flow transfertransftransferer pipeline project between Lake Keechelus andand Lake Kachess, the Wymer dam and reservoir pro projectject, conveyance improvements at the former WapatoxW apatox Power Plant, reducing or eliminating irrigationirrirrigationigation district diversions used for power productionprodproduuctionction at the Roza and Chandler power plants duringdurinduring g outmigration of juvenile anadromous fish, mmodificationsmoodifications difications of Yakima River Basin Study 1 Lake Kachehess s Inactive Storage the Kittitas Reclamation District Main Canal and South Branch, and raising the pool level at Cle Elum Dam. These options are described in other technical memoranda as part of the Yakima River Basin Water Enhancement Project. 2.0 Design Criteria 2.1 Lake Kachess Storage Volume The purpose of the Lake Kachess Inactive Storage project is to provide the capability to withdraw 200,000 acre-feet of water from Lake Kachess and transfer that flow into the Yakima River for beneficial downstream use when needed. This would be in addition to the volume that can currently be discharged through the existing Lake Kachess Dam outlet structure, which has a gate sill (bottom) at elevation 2192.75. Water stored in the lake below that elevation is currently