Yakima Project “Flip-Flop” Operations Underway

Media Contact: Annette Ross, (208) 378-5322, aross@usbr.gov

For Release: August 22, 2017

YAKIMA, Wash. – The Bureau of Reclamation has begun its annual “flip-flop” operation in the Yakima Basin by gradually reducing flows out of Keechelus and Cle Elum reservoirs in the upper Yakima River basin and increasing flows from Rimrock Reservoir. This operation will affect flows in the Tieton and Naches rivers, and Kachess Reservoir flows into Lake Easton in the upper basin.

The purpose of the “flip-flop” operation is to achieve and maintain relatively low flows in the upper Yakima, Cle Elum, and Bumping rivers where the spring Chinook salmon spawn. These lower flows are closer to natural flow conditions and aid in successful spawning and incubation of the salmon eggs. It also reduces impacts on irrigation water supply by allowing for lower flow releases throughout the winter to improve reservoir storage for the coming season.

As part of the process, on or about Sept. 5, Reclamation will begin to divert water down the Kittitas Reclamation District’s Spillway 1146 into the Yakima River near Thorp. Crews will install buoys that will be in place from Sept. 5 until about Oct. 22. For their safety and well-being, recreationists are strongly advised to portage around the buoys and to stay out of the dangerously turbulent flows.

“Those who are enjoying the river should avoid the area where the spillway water pours into the river,” said Chuck Garner, Yakima Project River Operations supervisor.

Flows out of Cle Elum Reservoir have been gradually decreasing since Aug. 6 from a high of 3,650 cubic feet per second (cfs) and will continue to decline to a low of about 220 cfs in mid-September. Flows from Rimrock Reservoir are expected to be in the 1,000-to-1,500 cfs range by Sept. 1 and increase to between 1,800 and 2,400 cfs by mid-to-late September, depending on irrigation demands and weather conditions.

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

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