Researchers have uncovered an enormous underground aquifer beneath the Cascade Mountains in Oregon, a discovery that could dramatically reshape water resource management in the western United States. This hidden reservoir is estimated to hold more than 21 trillion gallons of water—nearly three times the maximum capacity of Lake Mead, the country’s largest reservoir.
The aquifer lies within the volcanic rock formations that form the Cascades’ crest. This natural reservoir is fed primarily by snowmelt, which filters through the porous volcanic rock, storing vast amounts of groundwater. Researchers first identified the aquifer using decades-old geothermal drilling data. These records showed unusual temperature patterns, with cooler readings at depths where warmer temperatures were expected, indicating significant water infiltration. Gordon Grant, a hydrologist with the U.S. Forest Service, said in a statement, “We initially set out to better understand how the Cascade landscape has evolved over time, and how water moves through it. But in conducting this basic research, we discovered important things that people care about: the incredible volume of water in active storage in the Cascades and also how the movement of water and the hazards posed by volcanoes are linked together.”
The discovery has profound implications for the Pacific Northwest, a region increasingly vulnerable to water shortages due to climate change. As droughts intensify and snowpack levels decline, this aquifer could serve as a critical backup water source for communities and ecosystems alike. However, scientists warn that the aquifer’s sustainability is closely tied to the health of the region’s snowpack. Prolonged droughts or shifts in precipitation patterns could disrupt its recharge cycle, jeopardizing its long-term viability.
Beyond its potential as a water source, the aquifer may also interact with the region’s volcanic activity. Large volumes of groundwater can influence eruptions, as water mixing with magma can trigger explosive events.
The discovery of this aquifer gives the Pacific Northwest some hope to alleviate water stress, but researchers from the University of Oregon maintain that it’s important to look into the impacts of drought and climate change on the reservoir before they can properly manage its use.
