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- NASA satellites detected rapid and accelerating groundwater losses in the Colorado River Basin from 2002 to 2024, with 68% of losses in the lower basin (mostly Arizona).
- The basin lost about 27.8 million acre-feet of groundwater, roughly equal to the storage capacity of Lake Mead.
- Groundwater loss rate more than doubled from 5 mm/year (2002-2014) to 12 mm/year (2015-2024), driven by La Niña conditions and increased agricultural water use.
- Irrigated agriculture consumes 72% of Arizona's water supply, with flood irrigation for crops like alfalfa and cotton causing significant water loss.
- Active management areas established by Arizona's Groundwater Management Act of 1980 have helped reduce losses in some areas, but overall depletion remains severe.