Groundwater levels are declining across Eastern Washington’s aquifer system and threaten its sustainability, according to a new study by a Washington State University (WSU) researcher.
The study from WSU highlights significant declines in groundwater levels in certain areas.
Two areas noted in the study are the Odessa region and the Yakima Basin, where levels have been dropping three to four inches per year.
Research published in the journal Groundwater for Sustainable Development highlights the Columbia Plateau Regional Aquifer System, which spans Washington, Idaho, and Oregon.
The aquifer system provides irrigation water in the region.
The study introduces a new metric, available drawdown (ADD), to measure water accessibility with current wells, emphasizing the urgency of the issue.
“With these numbers we can say, ‘Hey, this is a problem now,’” said Sasha McLarty, an assistant professor in the Department of Civil and Environmental Engineering at WSU and the corresponding author of the new study.
The study focused on the variability of the aquifer system in terms of geographic location and depth, which is comprised of four main geological layers.
The Grand Ronde layer, the thickest basalt layer, shows the steepest declines in groundwater, averaging 1.86 feet per year.
Not all aquifers are losing water.
The Spokane aquifer has seen its water levels increase.
This increase is believed to have been tied to management and monitoring efforts.
Some areas, like the Rock Glade Water Resources Inventory Area, show the complexity of data gathered in these studies.
They have seen some layers declining and some increasing, even in the same area.
McLarty hopes that her study will help people understand the importance of improving groundwater stability.
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