U.S., Canadian and Washington state officials have approved an updated plan for the state Department of Ecology to continue to operate Zosel Dam on Lake Osoyoos.

The 10-mile long lake crosses the border, and lies in both Okanogan County and British Columbia.

A 1987 pact over managing its water was set to expire in late February. Washington State owns and operates the Zosel Dam.

During years of high runoff, the lake sometimes rises to an elevation of 913 feet, a news release from the state Department of Ecology said.

Under the new agreement, the lake can be used to store water up to 912.5 elevation in a drought year, a half foot lower than drought storage allowed in the 1987 agreement.

In a normal year, the lake is kept between 911.5 feet and 909 feet.

The lower level will ensure there’s enough water in the river below the dam to accommodate fish, including some endangered species, said Ecology spokeswoman Joye Redfield-Wilder.

Gov. Chris Gregoire signed the agreement before leaving office this week.

Seven years of study and public input led to the agreement.

— K.C. Mehaffey, World staff