This irrigation efficiency and groundwater recharge project will improve stream flows for the passage and rearing of summer steelhead, spring Chinook, and bull trout in a flow-impaired segment of the Walla Walla River. The Walla Walla Subbasin Plan’s highest priority project types are those that address imminent threats to ESA listed species, such as dry or low flow stream reaches. This project will address a Subbasin Plan priority restoration area that provides habitat and also passage to primary upstream spawning grounds. Irrigation efficiency projects will utilize the Oregon Conserved Water Program to ensure that conserved water is protected as an instream water right. Shallow aquifer recharge using high winter and spring runoff will benefit spring branches and mainstem cold water refugia.

A three-mile segment of the Walla Walla River near Milton-Freewater, Oregon was dewatered each summer for the last century creating the need for fish rescues. The rescues have not been necessary the last five years after aggressive irrigation efficiency programs and new wells now maintain at least 27 cfs instream throughout the spring and 25 cfs instream throughout the summer.  However, half of these bypass flows are created by an increase in supplemental well use at unsustainable rates. Additional irrigation conservation practices, combined with winter/spring groundwater recharge, will allow irrigators to reduce their demand on the river, reduce negative impacts to groundwater, and protect the conserved water as instream water rights.

Four piping projects, four on-farm efficiency projects, and expansion of an existing groundwater recharge site (see WE 'J') along with the retrofitting of two on-farm storage sites to seasonally function as recharge and the completion of designs for seventeen other recharge sites associated with existing irrigation delivery efficiency piping will be completed by the WWBWC, Walla Walla River Irrigation District, and Hudson Bay District Improvement Company. This project was identified as a priority during the ongoing Bi-State Habitat Conservation Planning with NMFS and USFWS, and in the Draft Bull Trout and Salmon Recovery Plans, and the Walla Walla Temperature TMDL.  In addition, measuring devices and flow management automation will be completed to assist valley irrigators in maintaining more efficiencies.