City to Begin Underground Water Storage Pilot

The city of Kennewick has entered into an agreement to receive up to $1 million from the Washington Department of Ecology (Ecology) to study how to store millions of gallons of Columbia River water in basalt formations under Southridge in Benton County.

The project is being funded by the state’s Columbia River water management program that was authorized in 2006 and makes $200 million available to explore new water resources from the Columbia River through storage, conservation and voluntary regional agreements, according to a Jan. 7 press release.

The city plans to take water from the Columbia River in the winter and store it underground in natural aquifers, thereby reducing withdrawals from the river in the summer. The pilot will help the state and municipalities learn more about aquifer storage and recovery projects and establish protocols for implementing projects in the future.

“Underground storage is appealing because there’s no dam construction and the stored water will remain cool and clean and can be released at the times of year we need it most,” said Dan Haller,  Columbia River unit supervisor.

The city will have another source of water from which to draw during times of peak capacity, and water can be available in-stream during the critical months of July and August.

The first phase of the study will analyze whether the current site is viable for an underground reservoir, and how much water might be stored at the site and how the water stored might benefit stream flows and be allocated for out-of-stream uses. The first phase is estimated to cost about $200,000.

Actual withdrawal and injection of water into the aquifer through test wells is planned in the second phase of the project, based on results of the initial study.