Appendix I. Alternative operations at Grand Coulee

Operate Grand Coulee Dam from July through December consistent with the following considerations:

  • Subject to in-season management, draft Lake Roosevelt to the target elevations of 1,278 or 1,280 feet by the end of August. As specified in Washington’s Columbia River Basin Water Management Program, by the end of August Lake Roosevelt may be drafted an additional 1.0 foot in non-drought years and by about 1.8 feet in drought years. As much as possible within current operating constraints, manage the reservoir and dam discharges to minimize fluctuations and ramping rates and produce steady flows across each season and each day
  • From September through December, attempt to maximize water retention times and protect kokanee access and spawning. Federal action agencies, fish and wildlife agencies and tribes, and others should consult within the in-season management process to determine how to provide the biological benefits above while meeting biological opinion requirements, including chum flows, and operating to protect flows for the Hanford Reach.
  • Two high priorities for Grand Coulee through the year should be to contribute to the establishment and protection of the necessary spawning and rearing conditions in the Hanford Reach described above and to refill by the end of June, subject to in-season management. Summer and fall operations should be consistent with these priorities.
Period Minimum Mean Minimum Elevation Water Retention Time
January 1,270 ft above sea level 45 days
February 1,260 40 days
March-April 15 1,250 30 days
April 16 1,255 30 days
May 1,265 35 days
June Fill to 1,290 40-60 days or maximum historically achievable for each month

← Appendix H. Fish Passage Center

Appendix J. Wildlife crediting forum →

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