After years of dangerous decline in the nation’s groundwater, a series of developments in Western states indicate that state and federal officials may begin tightening protections for the dwindling resource.

In Nevada, Idaho and Montana, a string of court decisions have strengthened states’ ability to restrict overpumping of groundwater. California is considering penalizing local officials for draining their aquifers. And the White House has asked scientists who focus on groundwater to advise how the federal government can help.

“This is truly exciting,” said Upmanu Lall, director of both the Water Institute at Arizona State University and the Columbia Water Center at Columbia University. “There has been stuff like this off and on, but not in such a short period of time across the Western states.”

Groundwater levels have fallen significantly around the country in the past four decades, according to data gathered and analyzed by from tens of thousands of monitoring wells in a New York Times investigation last year.

That water, used to support industrial farms and sprawling cities, could take centuries or millenniums to replenish, if it recovers at all. Climate change is accelerating that depletion, which threatens irreversible harm to American society.

Groundwater supplies 90 percent of the nation’s drinking-water systems, which means draining aquifers could render some communities unlivable. Groundwater loss has also reduced crop yields in some areas and caused the ground to subside in much of the country.