The two largest reservoirs in the United States are at “dangerously low levels,” threatening the supply of fresh water and electricity in six states and Mexico, the United Nations Environment Programme (UNEP) warned on Tuesday.
Lake Mead and Lake Powell, which are both man-made reservoirs on the Colorado River, are currently at their lowest levels ever, in part because of an ongoing drought exacerbated by climate change.
“The conditions in the American West which we're seeing around the Colorado River basin have been so dry for more than 20 years that we're no longer speaking of a drought,” said Lis Mullin Bernhardt, an ecosystems expert at UNEP. “We refer to it as ‘aridification’ — a new, very dry normal.”
The river is also struggling thanks to overconsumption due to a growing population and an outdated agreement that guarantees allotments for its neighboring states. The reservoirs provide water for agricultural and residential use in Arizona, California, Colorado, Wyoming, Nevada and New Mexico.
If conditions don’t improve, Lake Mead and Lake Powell are at risk of reaching “dead pool” status, in which the water is so low it stops flowing out of a reservoir. That would disable the hydroelectric dams that help provide power for millions of residents of the western U.S.
“We are talking about a 20-year period of droughtlike conditions, with an ever-increasing demand on water,” Bernhardt said. “These conditions are alarming, and particularly in the Lake Powell and Lake Mead region, it is the perfect storm.”
The falling water levels have been a concern for U.S. 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” at Lake Mead and Lake Powell would require significant reductions in water deliveries.
“What has been a slow-motion train wreck for 20 years is accelerating, and the moment of reckoning is near,” John Entsminger, general manager of the Southern Nevada Water Authority, said at the Senate hearing.
Due to the declining water levels in Lake Mead, which is near Las Vegas, three dead bodies long buried under the water have recently been exposed.
Some water use restrictions have already been put in place. The Metropolitan Water District of Southern California instituted emergency water curtailments in June, typically limiting outdoor watering to one or two days per week.
The drought in the West has had a number of effects in recent years, including unusually bad wildfire seasons.
Climate scientists say disruptions to the water cycle, especially drought, will become more common as a result of rising global temperatures.