Worsening groundwater loss threatens U.S. southwest despite record snowfall

The U.S. southwest faces continuing declines in groundwater supplies, threatening both humans and wildlife in the region, with even record snowfall failing to stop the trend, according to a report by the National Aeronautics and Space Administration (NASA) on Monday.

The new study led by University of Maryland earth scientist Dorothy Hall analyzed 20 years of NASA satellite data, revealing that long-term drought and increasing water demands have strained water reserves in the U.S. Southwest.

Over the past two decades, the region's underground water supply has diminished by 68.7 cubic kilometers. This volume is about two-thirds of California's annual water usage and roughly six times the water left in Lake Mead, the largest reservoir in the United States, at the end of 2023.

The research indicates that while snowmelt offers temporary relief, it is not enough to stop the dramatic water level decline that has been underway in the region, said Hall.

"In years like the 2022-23 winter, I expected that the record amount of snowfall would really help to replenish the groundwater supply," Hall said. "But overall, the decline continued."

One major factor contributing to the decline is upstream water diversion for agriculture and household use. As populations grow, so does water consumption, exacerbating the problem.

Additionally, runoff, increased evaporation and the water needs of plants suffering from hot, dry conditions in the region are intensifying the issue, leaving farmers downstream struggling to meet their needs.

The diminishing water supply in the U.S. Southwest has severe implications for both humans and wildlife, according to the research.

The municipal water supply is at risk, agricultural irrigation is limited, and exposed lake beds harbor toxic minerals from agricultural runoff and waste, posing environmental hazards, Hall said.

(Cover: A sign reminds potential diggers about the underground water pipeline at Fish Springs Ranch near Reno in Nevada, U.S., June 29, 2023. /CFP)