The water is saved, for now.
Seven Western states have agreed on a plan to manage the Colorado River amid a 19-year drought, voluntarily cutting their water use to prevent the federal government from imposing a mandatory squeeze on the supply.
State water officials signed the deal on Tuesday after years of negotiations, forestalling what would have been the first federally enforced restrictions on the river’s lower basin. But any victory may be short-lived. Climate change promises to make the American West increasingly hot and dry, putting further pressure on the Colorado and the 40 million people who depend on its water.
“We all recognize we’re looking at a drier future,” said Tom Buschatzke, director of the Arizona Department of Water Resources.
The water in Lake Mead, the vast reservoir formed by the Hoover Dam that supplies the lower basin, has dropped to levels not seen since it began to fill in the 1960s.
Brad Udall, a senior scientist at Colorado State University and an expert on water supplies in the West, told a congressional panel last month that the lower basin uses about 10.2 million acre-feet of water from the river each year, while upstream flows provide just nine million. (An acre-foot is the volume of one foot of water over one acre, about 325,000 gallons.)
Beyond that drain, climate change is bringing on a long-term crisis. “The Colorado River, and the entire Southwest, has shifted to a new hotter and drier climate, and, equally important, will continue to shift to a hotter and drier climate for several decades after we stop emitting greenhouse gases,” he said in his testimony.
In an interview, Mr. Udall said the influence of climate change was already apparent in the West. “Climate change is not some distant process,” he said. “It’s here, it’s now, it’s in our faces. It’s creating messes we have to deal with.”