Case Study: Assessment of Multipurpose Water Storage Opportunities in WRIA 30

Client: WRIA 30 Planning Unit Location: Klickitat & Yakima Counties, WA Contact for water resource projects: Tim Flynn

Project Background & Challenges

On an annual basis, WRIA 30 likely has adequate water supplies to meet current needs (both instream and out-of-stream) and support some growth. However, water availability varies throughout the year in response to seasonal climate patterns. During the wet winter season, precipitation and streamflows are highest but water demand is lowest. Conversely, precipitation and streamflows are lowest in the summer, when water demands are peaking.

Solution

One approach for addressing this timing problem is to store water during the wet season and deliver it during the summer, when people and fish need it most. Aspect assessed storage opportunities in two priority sub-basins of WRIA 30. This work — part of ongoing watershed planning in WRIA 30 — was a preliminary step in evaluating the feasibility of storage as a resource management tool. The project focused on identifying storage options in the two sub-basins based solely on physical characteristics. After implementing a comprehensive data-collection program, Aspect evaluated options such as enhanced groundwater recharge, aquifer storage and recovery, and storage in on-channel dams and off-channel impoundments. Based on various criteria — potential water sources, storage types and locations, potential obstacles or impacts, general costs, and data gaps — we developed a short list of storage options. Planning Unit members will prioritize these options and implement them as part of the Watershed Management Plan. One of the identified storage options, the City of Goldendale’s use of aquifer storage and recovery, is proceeding into the detailed feasibility study stage.