Water Lease and Channel Construction to Effectively Reestablish Summer Steelhead in Salmon Creek, Okanogan, Washington

Salmon Creek, a tributary of the Okanogan River, was regionally-renowned for large returns of anadromous salmonids.  During the early 1900’s two dams were constructed and corresponding reservoirs were dedicated to irrigate 5,000 acres.  An irrigation diversion located at RM 4.3 disconnected Salmon Creek from the Okanogan River, thereby precluding utilization by anadromous salmonids.   

Beginning in 1997 the Colville Confederated Tribes and the Okanogan Irrigation District developed a partnership to maintain current agriculture production while reestablishing anadromous salmonids. Beginning during the spring of 2007 a 12-year water lease was established.  The lease was initially for 700 acre-feet and then increased to 1,200 acre-feet beginning in 2009.  As a result of 100 years of interrupted flow, channel conditions downstream of the diversion were undefined and required a discharge of 25 cfs to provide adequate fish migration conditions.  During 2008, a low flow channel was constructed within the previous channel.  The result would provide suitable fish passage conditions at a flow rate of 10 cfs, thereby increasing the duration of suitable migration conditions from 24 days to 60 days.  Summer steelhead returns to Salmon Creek in 2009 and 2010 were estimated at 71 and 355, respectively.