Wenatchee Instream Flow Enhancement Project
Trout Unlimited’s Pioneer Pump Exchange Project improves instream flow in the lower Wenatchee River to improve passage and decrease critical temperature barriers at the confluence with the Columbia and Wenatchee Rivers. The Wenatchee River is home to a variety of salmon and trout including Upper Columbia Spring Chinook, steelhead, and bull trout. Instream flow, water temperature and access to off-channel habitat, which all provide refuge for both juvenile and adult salmon, is a threat to the survival of salmon in the Wenatchee River. In 2013, TU and Pioneer Water Users Association (PWUA) embarked on a innovative project to improve instream flow and provide water to agriculturists in the Wenatchee Valley. This project simply changed the gravity fed diversion on the lower Wenatchee River to a sophisticated pumping station that diverts from the flow-abundant Columbia River. This project resulted in improving stream flow by over 35 cfs in the Wenatchee River for fish, while providing high quality, low cost water supply to PWUA users. Construction of the pump station was completed in April 2013.
TU also restored fish access to the historic PWUA side channel via the removal of the dam in the Wenatchee River side-channel. The dam is no longer needed because of the completion of the pump station downstream. Removing the dam will improve fish passage through the side channel and increase water return to the river.
In addition to removing the dam, the project will also restore the stream bank on the highway side of the river where the dam currently exists. Construction for this barrier removal and restoration phase project is scheduled to begin in August or September 2013.
TU installed the most sophisticated irrigation system in the state to supply water in the most efficient way possible to agricultural users. The new pump station allows the flow limited Wenatchee River to see biological benefits for listed fish while maintaining irrigation heritage in the valley. The new pump station is “on demand”, which means that it is controlled by pressure settings and that water is only used when water is needed. This is a huge accomplishment and change from continuous withdrawal that normally occurs with gravity fed irrigation supply.
This project was four years in the making. It required a diverse funding package including 11 different funding agencies, with 17 permits, all while working to insure future water supply with 107 different PWUA users. This project is a model for what can be achieved in water conservation while still meeting human needs. It’s time to utilize 21st century advanced technology to help us better manage water for the future.
Aaron Penvose, project manager, TU Washington Water Project