Yakima Project "Flip-Flop" Operation to Begin

Media Contact: David Walsh, (208) 378-5026
Chuck Garner, (509) 575-5848 ext. 205

For Release: August 25, 2010

The Bureau of Reclamation announced that it has begun the annual "flip-flop" operation in the Yakima Basin by gradually reducing flows in the upper arm of the Yakima River and increasing flows in the Tieton and Naches Rivers with increased water releases from Rimrock Reservoir.

"This week we will begin the three week process of gradually increasing the flows out of Rimrock Reservoir and gradually decreasing flows out of Cle Elum Reservoir. The daily change in the flows will be small. A three week transition will provide for a more gradual transition which is better for people, fish, and other critters," said Chuck Garner. "The transition will bring the river flows to the normal mid-September levels but will do it more slowly than in the past."

The purpose of the "flip-flop" operation is to encourage spring Chinook salmon to spawn at relatively low flows in the upper Yakima River and the Bumping River so that less water is required during the winter to keep the egg nests covered. This water operation also reduces impacts on irrigation water supply during the next season.

About midway through this flow transition period, on or about September 7, Reclamation will divert some water down the Kittitas Reclamation District's Spill Way 1146 into the Yakima River near Thorp, Wash. Recreationists should portage around this area. Reclamation will install buoys around where Spill Way 1146 water comes into the Yakima River. The buoys will be in place from about September 7, until about October 20. The buoys serve as a warning to recreationists to stay out of the turbulent flows.

Flows out of Cle Elum Reservoir will gradually decrease from the current flow down to between 200 to 250 cfs by about September 15 or sooner. Flows from Rimrock Reservoir are expected to increase from the current flow to near 2,000 cfs by mid-September and could possibly reach 2,200 to 2,400 cfs, depending upon irrigation demands and weather conditions. Flows could exceed 1,200 cfs by September 1, depending on irrigation demands and weather.

Stream flow changes will occur gradually during the Labor Day holiday weekend. Streamflow information can be obtained by calling (509) 575-5854 or on the internet at: http://www.usbr.gov/pn/hydromet/yakima/index.html.

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Reclamation is the largest wholesale water supplier and the second largest producer of hydroelectric power in the United States, with operations and facilities in the 17 Western States. Its facilities also provide substantial flood control, recreation, and fish and wildlife benefits. Visit our website at www.usbr.gov and follow us on Twitter @USBR.

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