YAKIMA – Methow watershed irrigators with interruptible water rights continue to have their water curtailed because of low flows.
The state Department of Ecology shut off their water June 17 because stream flows were below pre-set limits. As of July 5, their withdrawals remained curtailed, said Joye Redfield-Wilder of the state Department of Ecology in Yakima.
Stream flow restriction letters were sent to Okanogan, Similkameen and Methow watershed junior water users in April. Their water use is based on stream flow levels, regardless of whether there is a declared drought.
Gov. Jay Inslee has declared drought conditions in Okanogan County and several others statewide.
“When orders are issued based on projections that stream flows won’t be met, these water users are required to call our hotline before they are allowed to irrigate to be sure there’s enough water in the rivers,” said Redfield-Wilder.
Stream flow thresholds vary, depending on the time of year.
Water users with interruptible rights in the Okanogan and Similkameen watersheds had their water curtailed June 10 but were allowed to start diverting water again June 30.
“We believe recent thunderstorms and our raising water levels in Lake Osoyoos earlier in June has helped with water supplies,” said Redfield-Wilder.
In early June, extreme low flows forecast in the Okanogan and Similkameen rivers threatened the ability of local irrigators to use water from the rivers later in the summer, so water was allowed to flow into the lake.
Lake levels are managed at Zosel Dam in Oroville under orders of control mandated by the International Joint Commission. The dam is being operated through Sept. 15 according to drought condition rules included in the orders of control.
Under drought operation authorization, the department can fill the lake a half-foot higher than usual, from 912 feet to 912.5 feet, and draw it down to 910.5 later in the summer. That’s below the usual operating summer minimum of 911 feet.
The higher level is expected to provide an extra 3,000 acre-feet of water, said Al Josephy of the department’s water resources program.