NASA study warns Southwest US aquifers are depleting faster than they recharge
A NASA-led analysis using satellite gravity data shows that groundwater in the U.S. Southwest is being drawn down faster than natural replenishment, threatening long-term irrigation and regional food production.
A study published in Proceedings of the National Academy of Sciences, authored by NASA research scientist Mary Michael O’Neill, analyzed terrestrial water storage trends from April 2002 through November 2025 using GRACE and GRACE-FO satellite gravity data. The results reveal that aquifers across the Southwest United States are losing water faster than they can naturally recharge, a pattern linked chiefly to agricultural irrigation and groundwater extraction.
The refined satellite method pinpoints the most severe depletion zones, showing that prior global assessments underestimated the intensity and locality of the losses. O’Neill warns that continued drawdown threatens irrigated agriculture, raises pumping costs, and could force a shift in national food production or increase reliance on imports. Additional experts, including Eric Purnell of BlueServ Technologies and geospatial engineer Mandar Chaudhari, stress the need for better data integration and local monitoring to guide sustainable water management.
Why it matters
Groundwater loss endangers U.S. farm output, rural economies and the nation's food supply.
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