On a 110-degree day several years ago, surrounded by piles of sand and rock in the desert outside of Las Vegas, I stepped into a yellow cage large enough to fit three standing adults and was lowered 600 feet through a black hole into the ground. There, at the bottom, amid pooling water and dripping rock, was an enormous machine driving a cone-shaped drill bit into the earth. The machine was carving a cavernous, 3-mile tunnel beneath the bottom of the nation’s largest freshwater reservoir, Lake Mead.
Lake Mead, a reservoir formed by the construction of the Hoover Dam in the 1930s, is one of the most important pieces of infrastructure on the Colorado River, supplying fresh water to Nevada, California, Arizona and Mexico. The reservoir hasn’t been full since 1983. In 2000, it began a steady decline caused by epochal drought. On my visit in 2015, the lake was just about 40% full. A chalky ring on the surrounding cliffs marked where the waterline once reached, like the residue on an empty bathtub. The tunnel far below represented Nevada’s latest salvo in a simmering water war: the construction of a $1.4 billion drainage hole to ensure that if the lake ever ran dry, Las Vegas could get the very last drop.
For years, experts in the American West have predicted that, unless the steady overuse of water was brought under control, the Colorado River would no longer be able to support all of the 40 million people who depend on it. Over the past two decades, Western states took incremental steps to save water, signed agreements to share what was left and then, like Las Vegas, did what they could to protect themselves. But they believed the tipping point was still a long way off.
Like the record-breaking heat waves and the ceaseless mega-fires, the decline of the Colorado River has been faster than expected. This year, even though rainfall and snowpack high up in the Rocky Mountains were at near-normal levels, the parched soils and plants stricken by intense heat absorbed much of the water, and inflows to Lake Powell were around one-fourth of their usual amount. The Colorado’s flow has already declined by nearly 20%, on average, from its flow throughout the 1900s, and if the current rate of warming continues, the loss could well be 50% by the end of this century.
Earlier this month, federal officials declared an emergency water shortage on the Colorado River for the first time. The shortage declaration forces reductions in water deliveries to specific states, beginning with the abrupt cutoff of nearly one-fifth of Arizona’s supply from the river, and modest cuts for Nevada and Mexico, with more negotiations and cuts to follow. But it also sounded an alarm: one of the country’s most important sources of fresh water is in peril, another victim of the accelerating climate crisis.
Americans are about to face all sorts of difficult choices about how and where to live as the climate continues to heat up. States will be forced to choose which coastlines to abandon as sea levels rise, which wildfire-prone suburbs to retreat from and which small towns cannot afford new infrastructure to protect against floods or heat. What to do in the parts of the country that are losing their essential supply of water may turn out to be the first among those choices.
The Colorado River’s enormous significance extends well beyond the American West. In addition to providing water for the people of seven states, 29 federally recognized tribes and northern Mexico, its water is used to grow everything from the carrots stacked on supermarket shelves in New Jersey to the beef in a hamburger served at a Massachusetts diner. The power generated by its two biggest dams — the Hoover and Glen Canyon — is marketed across an electricity grid that reaches from Arizona to Wyoming.
The formal declaration of the water crisis arrived days after the Census Bureau released numbers showing that, even as the drought worsened over recent decades, hundreds of thousands more people have moved to the regions that depend on the Colorado.
Phoenix expanded more over the past 10 years than any other large American city, while smaller urban areas across Arizona, Nevada, Utah and California each ranked among the fastest-growing places in the country. The river’s water supports roughly 15 million more people today than it did when Bill Clinton was elected president in 1992. These statistics suggest that the climate crisis and explosive development in the West are on a collision course. And it raises the question: What happens next?
Since about 70% of water delivered from the Colorado River goes to growing crops, not to people in cities, the next step will likely be to demand large-scale reductions for farmers and ranchers across millions of acres of land, forcing wrenching choices about which crops to grow and for whom — an omen that many of America’s food-generating regions might ultimately have to shift someplace else as the climate warms.
California, so far shielded from major cuts, has already agreed to reductions that will take effect if the drought worsens. But it may be asked to do more. Its enormous share of the river, which it uses to irrigate crops across the Imperial Valley and for Los Angeles and other cities, will be in the crosshairs when negotiations over a diminished Colorado begin again. The Imperial Irrigation District there is the largest single water rights holder from the entire basin and has been especially resistant to compromise over the river. It did not sign the drought contingency plan laying out cuts that other big players on the Colorado system agreed to in 2019.
New Mexico, Colorado, Utah and Wyoming — states in the river’s Upper Basin — will most likely also face pressure to use less water. Should that happen, places like Utah that hoped to one day support faster development and economic growth with their share of the river may have to surrender their ambition.
The negotiations that led to the region being even minimally prepared for this latest shortage were agonizing, but they were merely a warm-up for the pain-inflicting cuts and sacrifices that almost certainly will be required if the water shortages persist over the coming decades. The region’s leaders, for all their efforts to compromise, have long avoided these more difficult conversations. One way or another, farms will have to surrender their water, and cities will have to live with less of it. Time has run out for other options.