The Zosel Dam in Oroville, WA helps to maintain the level of Osoyoos Lake. (File photo)
Osoyoos Lake water levels are decreasing to winter operational levels, the Washington Department of Ecology announced.
Releases from Zosel Dam to the Okanagan River will increase in volume to bring the lake down about two-and-a-half feet from now until December, a press release from the department states.
Extra water stored in the lake this summer, due to drought declared in the region, provides an opportunity to boost streamflows and protect fish species in the river going into the fall, said Al Josephy, a water resources specialist with the department.
This means the river will be running high this week, and those living downstream are advised to take adequate precautions.
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“The Okanogan River has a tendency to build up sediments on the riverbed, which, over time, clogs gravels on the bottom, making spawning access for fish problematic,” Josephy said.
“Following discussions with local fish biologists, we plan to use the extra available water in the lake to flush those gravels by allowing short intervals of high flows to be released over several days during the middle of September.”
The department plans to ramp up flows to about 1,200 cubic feet per second for one or two days, beginning later this week.
“People living and working along the river below Zosel Dam may experience bursts of high flows and may see conditions like those seen during spring runoff,” the department stated.
Lakeside residents can expect to see the lake drop about six inches by Sept. 25. Following the flush, the drawdown will proceed in its usual course, and the lake levels will continue to decline.
