Every five years, a team convenes to evaluate long-term water supply and demand for the Columbia River Basin. For eastern Washington, the water supply will increase, but not when demand is highest.
“Overall, we’re looking at a large shift of water being available in the winter time when the demand is lower and less available in the summer time, particularly the late summer season,” Washington’s Water Research Center Associate Director Jennifer Adam said.
The study does not account for new irrigation projects or how water users might adapt to more frequent and severe droughts due to climate change.
Meanwhile, groundwater in parts of the Columbia River Basin is declining. Dan Haller, an engineer with consulting firm Aspect, worked with Washington State University on the report.
“We do have a lot of houses, a lot of farms, a lot of industry that are relying on water that for a long time was viewed as secure and now our understanding is getting more mature that that security may not last forever,” Haller said.
The state’s Department of Ecology has been working on a groundwater replacement project in the Yakima Valley town of Odessa for a decade, but Haller said other places facing groundwater declines in Washington aren’t as well-known.
“Within the professional community, there has been an understanding that this is an area that is going to need work,” he said.
Groundwater is just one piece of a long-term Columbia River Basin water forecast that will go to the legislature later this year.
Washington does not have a statewide water forecast. Haller said that requires more funding.
“And then really understanding the specific policies like climate change, water banking and declining groundwater in Eastern Washington that would be important to study statewide,” he said.