In the Southwest this past summer, the outlook was equally sobering. A catastrophic reduction in the flow of the Colorado River — which mostly consists of snowmelt from the Rocky Mountains — has always served as a kind of thought experiment for water engineers, a risk situation from the outer edge of their practical imaginations. Some 30 million people depend on that water. A greatly reduced river would wreak chaos in seven states: Colorado, Utah, Wyoming, New Mexico, Arizona, Nevada and California. An almost unfathomable legal morass might well result, with farmers suing the federal government; cities suing cities; states suing states; Indian nations suing state officials; and foreign nations (by treaty, Mexico has a small claim on the river) bringing international law to bear on the United States government. In addition, a lesser Colorado River would almost certainly lead to a considerable amount of economic havoc, as the future water supplies for the West’s industries, agriculture and growing municipalities are threatened. As one prominent Western water official described the possible future to me, if some of the Southwest’s largest reservoirs empty out, the region would experience an apocalypse, “an Armageddon.”
One day last June, an environmental engineer named Bradley Udall appeared before a Senate subcommittee that was seeking to understand how severe the country’s fresh-water problems might become in an era of global warming. As far as Washington hearings go, the testimony was an obscure affair, which was perhaps fitting: Udall is the head of an obscure organization, the Western Water Assessment. The bureau is located in the Boulder, Colo., offices of the National Oceanographic and Atmospheric Administration, the government agency that collects obscure data about the sky and seas. Still, Udall has a name that commands some attention, at least within the Beltway. His father was Morris Udall, the congressman and onetime presidential candidate, and his uncle was Stewart Udall, the secretary of the interior under Presidents John F. Kennedy and Lyndon Johnson. Bradley Udall’s great-great-grandfather, John D. Lee, moreover, was the founder of Lee’s Ferry, a flyspeck spot in northern Arizona that means nothing to most Americans but holds near-mythic status to those who work with water for a living. Near Lee’s Ferry is where the annual flow of the Colorado River is measured in order to divvy up its water among the seven states that depend on it. To many politicians, economists and climatologists, there are few things more important than what has happened at Lee’s Ferry in the past, just as there are few things more important than what will happen at Lee’s Ferry in the future.
The importance of the water there was essentially what Udall came to talk about. A report by the National Academies on the Colorado River basin had recently concluded that the combination of limited Colorado River water supplies, increasing demands, warmer temperatures and the prospect of recurrent droughts “point to a future in which the potential for conflict” among those who use the river will be ever-present. Over the past few decades, the driest states in the United States have become some of our fastest-growing; meanwhile, an ongoing drought has brought the flow of the Colorado to its lowest levels since measurements at Lee’s Ferry began 85 years ago. At the Senate hearing, Udall stated that the Colorado River basin is already two degrees warmer than it was in 1976 and that it is foolhardy to imagine that the next 50 years will resemble the last 50. Lake Mead, the enormous reservoir in Arizona and Nevada that supplies nearly all the water for Las Vegas, is half-empty, and statistical models indicate that it will never be full again. “As we move forward,” Udall told his audience, “all water-management actions based on ‘normal’ as defined by the 20th century will increasingly turn out to be bad bets.”
