Seasonal “flip-flop” river operation now in progress in Yakima basin

YAKIMA, Wash. - The Bureau of Reclamation began its annual "flip-flop" to aid in successful spawning and incubation of chinook salmon eggs and to improve winter reservoir storage in the Yakima basin. Changing water conditions should be expected over the coming weeks.

Reclamation will begin diverting water down the Kittitas Reclamation District's spillway 1146 into the Yakima River near Thorp the week after Labor Day weekend. Buoys and warning signs will be in place in the Yakima River by Sept. 8 and remain until mid-October, or after the flow from spillway 1146 has ended. Rimrock Reservoir releases have begun increasing daily and are expected to peak Sept. 15.

"Partnership is essential to managing the Yakima basin-our coordinated work with local districts, communities, and stakeholders helps us meet water, fish, and safety needs across the system," said Chad Stuart, Reclamation Yakima Field Office manager. "This annual operation helps stabilize flows basin-wide and allows Reclamation to meet ecological and irrigation needs heading into the next water year."

Reclamation urges those recreating or working along Yakima basin rivers to exercise caution, especially in the Yakima River near Thorp. Please avoid areas where spillway water flows into the river, portage around buoys, and stay away from dangerously turbulent flows.

"Flip-flop" creates instream flow conditions ideal for chinook salmon spawning in the upper Yakima, Cle Elum, and Bumping rivers. It is a flipping of operations: upper reservoir releases decrease while lower reservoir releases increase during the same period. After mid-September, Reclamation transitions back to normal operations, completing the seasonal cycle.

Real-time streamflow information can be found on Reclamation's website at https://www.usbr.gov/pn/hydromet/yakima/index.html.