As the Colorado River’s giant reservoirs have declined during the last two decades, even larger amounts of water have been pumped and drained from underground, according to new research based on data from NASA satellites. Scientists at Arizona State University examined more than two decades of satellite measurements and found that since 2003 the quantity of groundwater depleted in the Colorado River Basin is comparable to the total capacity of Lake Mead, the nation’s largest reservoir. The researchers estimated that pumping from wells has drained about 34 cubic kilometers, or 28 million acre-feet, of groundwater in the watershed since 2003 — more than twice the amount of water that has been depleted from the river’s reservoirs during that time.

Other Colorado River Basin news:

• Eric Kuhn and John Fleck at Inkstain: Blog: The May USBR Colorado River 24-month study confirms what we feared
• Arizona Daily Star (Tucson): Ariz. water chief upbeat about Colorado River negotiations
• KJZZ (Phoenix, Ariz.): Instead of cuts, federal officials are extending agreements to conserve Colorado River water
• Colorado Public Radio: Drought conditions likely to get worse in Colorado as Western water supplies shrink
• The Desert Review (Brawley, Calif.): IID approves 2025 Deficit Irrigation Program to bolster Colorado River conservation efforts