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In Pend Oreille River Below Box Canyon Dam at USGS Primary Gage No Compilation of Project Hydrologic Data Preparation of Hydrologic Database and Hydrologic Statistics in Support of Relicensing Studies Boundary Hydroelectric Project (FERC No. 2144) Prepared for: Seattle City Light Seattle, Washington Unpublished Work, Copyright 2008 Seattle City Light Prepared by: R2 Resource Consultants, Inc. Redmond, Washington March 2008 Hydrologic Database for Relicensing Studies TABLE OF CONTENTS 1 Introduction.......................................................................................................................... 1-1 2 Development of Hourly Hydrologic Database................................................................... 2-1 2.1. Available Data ........................................................................................................ 2-1 2.2. Standardization of Data .......................................................................................... 2-3 2.3. Missing Data........................................................................................................... 2-3 2.4. Anomalies in Data .................................................................................................. 2-4 2.5. Data Synthesis ...................................................................................................... 2-10 2.6. Description of Hourly Hydrologic Database ........................................................ 2-16 3 Basin Hydrology................................................................................................................... 3-1 3.1. Long-Term Trends.................................................................................................. 3-1 3.2. Impacts of Upstream Projects................................................................................. 3-4 3.3. Tributaries to the Pend Oreille River...................................................................... 3-5 4 Boundary Reservoir............................................................................................................. 4-1 4.1. Inflows to Boundary Reservoir............................................................................... 4-1 4.2. Water Surface Elevations in Boundary Reservoir................................................ 4-12 4.3. Ramping Rates...................................................................................................... 4-27 5 Downstream Reach .............................................................................................................. 5-1 5.1. Inflows to Seven Mile Reservoir ............................................................................ 5-1 5.2. Water Surface Elevations in Seven Mile Reservoir ............................................. 5-15 5.3. Ramping Rates...................................................................................................... 5-23 6 References............................................................................................................................. 6-1 Boundary Hydroelectric Project FERC No. 2144 Seattle City Light 1684.05/Hydrology Report_Boundary_03.08 iii March 2008 Hydrologic Database for Relicensing Studies APPENDIX A: Daily Maximum and Minimum Water Surface Elevations in Pend Oreille River below Box Canyon Dam at USGS Primary Gage No. 12396500 and in Boundary Reservoir Forebay, 1987 through 2005 APPENDIX B: Monthly and Annual Frequency of Exceedance of Hourly Stage in Pend Oreille River in Boundary Forebay and at USGS Primary Gage No. 12396500 below Box Canyon Dam, 1987 to 2005 APPENDIX C: Monthly and Annual Frequency of Exceedance of Daily Stage Fluctuation (daily maximum minus daily minimum) in Pend Oreille River in Boundary Forebay and at USGS Primary Gage No. 12396500 below Box Canyon Dam, 1987 to 2005 APPENDIX D: Monthly and Annual Frequency of Exceedance of Daily Maximum Ramping Rates in Pend Oreille River in Boundary Forebay and at USGS Primary Gage No. 12396500 below Box Canyon Dam, 1987 to 2005 APPENDIX E: Hourly Total Flow Release from Boundary Dam to the Pend Oreille River, 1987 through 2005 APPENDIX F: Monthly and Annual Flow Duration in Pend Oreille River based on Total Hourly Inflow to Boundary Reservoir and Total Hourly Flow Release from Boundary Dam, 1987 to 2005 APPENDIX G: Monthly and Annual Frequency of Exceedance of Daily Flow Fluctuation (daily maximum minus daily minimum) in Pend Oreille River based on Total Inflow to Boundary Reservoir and Total Flow Release from Boundary Dam, 1987 to 2005 APPENDIX H: Monthly and Annual Frequency of Exceedance of Hourly Stage in Pend Oreille River in Boundary Tailwater and in Seven Mile Forebay, 1987 to 2005 APPENDIX I: Monthly and Annual Frequency of Exceedance of Daily Stage Fluctuation (daily maximum minus daily minimum) in Pend Oreille River in Boundary Tailwater and Seven Mile Forebay, 1987 to 2005 APPENDIX J: Monthly and Annual Frequency of Exceedance of Daily Maximum Ramping Rates in Pend Oreille River in Boundary Tailwater and Seven Mile Forebay, 1987 to 2005 APPENDIX K: Boundary Reservoir Storage/Elevation Curves Boundary Hydroelectric Project FERC No. 2144 Seattle City Light 1684.05/Hydrology Report_Boundary_03.08 iv March 2008 Hydrologic Database for Relicensing Studies FIGURES Figure 1-1. Pend Oreille River Basin in Washington, Idaho, Montana, and British Columbia............................................................................................................. 1-3 Figure 1-2. Pend Oreille River upstream from Boundary Dam (not including portions of the basin in Canada) (USGS 2007). ............................................................... 1-4 Figure 1-3. Pend Oreille River from Albeni Falls Dam to the confluence with the Columbia River and location of major dams...................................................... 1-5 Figure 1-4. Monthly average daily maximum and minimum temperatures, and monthly average daily precipitation in Newport, Washington........................... 1-6 Figure 1-5. Locations of major dams within Pend Oreille River Basin. ............................... 1-8 Figure 1-6. Tributaries to Boundary Reservoir between Box Canyon Dam and Boundary Dam.................................................................................................... 1-9 Figure 2-1. Hourly flows in the Pend Oreille River below Box Canyon Dam (USGS Gage No. 12396500), and hourly water levels in Boundary Forebay, and the USGS primary and auxiliary gages in the Pend Oreille River below Box Canyon Dam, September 8 to 21, 1989. ..................................................... 2-6 Figure 2-2. Hourly water surface elevations and hourly change in water surface elevation in Pend Oreille River in Seven Mile Forebay, and hourly flow releases from Boundary Dam and from Seven Mile Dam to the Pend Oreille River, November 4 to 7, 1991. ............................................................... 2-8 Figure 2-3. Hourly water surface elevations in Boundary Tailwater, raw and adjusted data, May 18 to June 17, 1991............................................................................ 2-9 Figure 2-4. Hourly water surface elevations in Boundary Tailwater, raw and adjusted data, May 4 to June 29, 1997.............................................................................. 2-9 Figure 2-5. Seasonal adjustment factor used to synthesize flows in Sullivan Creek above Outlet Creek (USGS Gage No. 12396900) based on flows in Boundary Creek Idaho (USGS Gage No. 12321500) and flows in Salmo River, British Columbia (Water Survey of Canada Gage No. 08NE074)........ 2-12 Figure 2-6. Approximate water surface elevation in Pend Oreille River below Box Canyon Dam, estimated from flow release from Box Canyon Dam, and water surface elevation in Boundary Forebay. Water surface elevations estimated from this figure would be most accurate under steady-state conditions.......................................................................................................... 2-13 Figure 2-7. Observed and approximate synthesized hourly stage hydrographs, Pend Oreille River below Box Canyon Dam, USGS Primary Gage No. 12396500, September 21 to 27, 1990. .............................................................. 2-14 Boundary Hydroelectric Project FERC No. 2144 Seattle City Light 1684.05/Hydrology Report_Boundary_03.08 v March 2008 Hydrologic Database for Relicensing Studies Figure 2-8. Approximate water surface elevation in Boundary Tailwater, estimated from flow release from Boundary Dam, and water surface elevation in Seven Mile Forebay. Water surface elevations estimated from this figure would be most accurate under steady-state conditions..................................... 2-15 Figure 2-9. Observed and approximate synthesized hourly stage hydrographs, Boundary Tailwater March 15 to 20, 1988....................................................... 2-16 Figure 3-1. Historical trends in long-term basin hydrology for the Pend Oreille River in the vicinity of Boundary Dam, as determined from the cumulative departure from long-term average flow.............................................................. 3-2 Figure 3-2. Flow duration for Pend Oreille River in the vicinity of Boundary Dam, derived from average annual flows from Calendar Year 1913 through 2006. Percent exceedance of average annual flows from 1987 through 2005 are shown, based on their ranking within the 94-year period extending from 1913 through 2006. ................................................................... 3-2 Figure 3-3. Maximum and minimum average monthly flows
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