Thursday, January 25, 2024

Majority of America’s underground water stores are drying up, study finds

 Many of America’s critical sources of underground water are in a state of rapid and accelerating decline, a new study has found.

More than half of the aquifers in the United States (53 percent) are losing water, according to research published Wednesday in Nature.And in about 1 in 8 American aquifers — roughly 12 percent — the collapse of underground water levels has sped up during the 21st century, the researchers found. 

“Groundwater levels are declining rapidly in many areas,” co-author Scott Jasechko of the University of California, Santa Barbara told The Hill. 

“And what’s worse, the rate of groundwater decline is accelerating in a large portion of areas,” Jasechko said.

The impacted aquifers support much of the U.S. food system, as well as providing water used by many Americans. And the country is not alone in its losses: The study found rapid loss of water in aquifers that supply hundreds of millions of people worldwide. 

But the researchers added that these grim findings came with a bright spot: Many once-declining regions have bucked the trend.

“Long term groundwater losses,” they wrote, “are neither universal nor inevitable.” 

Hydrologists talk about aquifers in terms of “shallowing” and “deepening” — that is, is whether groundwater is getting closer to or further from the surface. 

When it came to the global trend of shallowing, the prime culprit the researchers identified was agriculture; 70 percent of global withdrawals of underground water went toward irrigation.  

This helps explain declines in aquifers that support large amounts of U.S. agriculture and cities — particularly the breadbaskets of California’s Central Valley and the dairies and alfalfa farms of Arizona’s Gila Bend...more  

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