Wenatchee Water Resource Management Strategy
The Wenatchee Watershed has been listed by the State Department of Ecology as one of 16 basins in the state with critical and inadequate streamflows for fish. Critical basins are also referred to as “over-appropriated,” meaning that more water has been allocated to out-of-stream uses than is naturally available in some years. Snowmelt is a primary source of late summer and fall streamflows in the Wenatchee Watershed. Variability in winter precipitation results in highly variable streamflow, especially in late summer and earl fall (July-October). Water demand is highest during the period when streamflows are lowest. Water is needed during this critical time of year for aquatic habitat, fruit production, fire protection, increased tourism needs, domestic irrigation and household needs, and municipal use.
The Wenatchee Watershed Planning Unit has developed a Water Resource Management Strategy to address concerns about protecting and enhancing flows for fish, while at the same time, providing a water reservation to accommodate future growth in the watershed. The Water Resource Management Strategy includes proposed new management (in-stream) flows on the mainstem Wenatchee River and a number of tributaries; a water reservation to provide a year-round supply for future domestic and municipal use and stock water; and a seasonal supply of water (Maximum allocation) for seasonal use and storage. The quantity of the water reserve has been determined based on both the protection of in-stream uses and the projected out-of-stream needs in the watershed.
The Instream flow rule recommends that a four (4) cfs water reservation from the mainstem Wenatchee River and its tributaries be made available to supply future municipal, domestic and stock water to the watershed. Currently, withdrawals for municipal and domestic use in the watershed total approximately 7.5 cfs. The reserve will be allocated between the upper and lower portions of the WRIA, and among sub-watersheds to ensure that the water available for servicing growth is distributed equitably and based on projected growth and future water needs. Additional limitations and sub-watershed allocations are based on protecting and sustaining local aquatic habitat needs.
The strategy also includes specific actions to be implemented at the local, or “sub-watershed” scale, as necessary. A number of actions are recommended to address water shortages in the Mission and Chumstick sub-watersheds. The proposed water resource management strategy will not affect existing water rights and applies only to new water rights for new uses to be established in the future. Although the instream flows proposed as part of this strategy will not put water into streams, they will protect aquatic resources from degradation, and existing senior water rights from impairment.