The Middle Lake Roosevelt Watershed, also known as Water Resource Inventory Area (WRIA) 58, is defined as the area that drains to that portion of Lake Roosevelt that lies upstream of the mouth of the Spokane River and downstream from the mouth of the Colville River. Lake Roosevelt itself is a reservoir on the Columbia River created by Grand Coulee Dam, located in Northeastern Washington and covering portions of Ferry and Stevens counties.
Most of the watershed lies within tribal reservation land of the Colville Confederated Tribes and the Spokane Tribe.
The Middle Lake Roosevelt’s major tributaries are Hall, Nez Pierce, and Ninemile creeks. The watershed includes various other tributary streams which are mostly seasonal.
Existing water rights
In addition to long-standing tribal water rights, state water rights have been issued in the Middle Lake Roosevelt Watershed for over 100 years, and the U.S. Bureau of Reclamation has reserved rights from Lake Roosevelt for the Columbia Basin Project. As a result most water in the watershed is already legally spoken for or “appropriated.”
Find more information about water availability in WRIA 58 in our Water Availability Focus Sheet linked below: