The two largest reservoirs in the United States are at “dangerously low levels”, threatening the supply of fresh water and electricity to six states and Mexico, the United Nations Environment Program (UNEP) warned on Tuesday.
Lake Mead and Lake Powell, both human-made reservoirs on the Colorado River, are currently at all-time lows, in part due to ongoing drought exacerbated by climate change.
“The conditions in the American West that we see around the Colorado River basin have been so dry for more than 20 years that we are no longer talking about a drought,” said Lis Mullin Bernhardt, an ecosystem expert at UNEP. “We refer to this as ‘drying’ — a new, very dry normal.”
The river is also struggling thanks to overconsumption due to a growing population and an outdated agreement guaranteeing allocations for its neighboring states. The reservoirs provide water for agricultural and domestic use in Arizona, California, Colorado, Wyoming, Nevada, and New Mexico.
If conditions do not improve, Lake Mead and Lake Powell are at risk of reaching “dead pool” status, in which water is so low that it stops flowing out of a reservoir. That would disable the hydroelectric dams that help provide power for millions of residents in the western US
“We’re talking about a 20-year period of drought conditions, with ever-increasing demand for water,” Bernhardt said. “These conditions are alarming, and especially in the Lake Powell and Lake Mead area, it’s the perfect storm.”
Falling water levels have been a concern of American officials for some time. In June, Bureau of Reclamation Commissioner Camille Calimlim Touton told the Senate Energy and Natural Resources Committee that maintaining “critical levels” in Lake Mead and Lake Powell would require significant reductions in water deliveries.
“What has been a slow-moving train wreck for 20 years is accelerating and the moment of reckoning is near,” John Enzminger, general manager of the Southern Nevada Water Authority, said at the Senate hearing.
Due to the lowering of the water level in Lake Mead, which is located near Las Vegas, three bodies that had long been buried under the water were recently exposed.
Some restrictions on water use are already in place. The Metropolitan Water District of Southern California instituted emergency water cuts in June, typically limiting outdoor watering to one or two days a week.
Drought in the West has had a number of effects in recent years, including unusually bad fire seasons.
Climate scientists say disruptions in the water cycle, especially drought, will become more frequent as a result of rising global temperatures.