When the River Runs Dry

Editor's Note: This article appears in Governing's Q2 2026 Magazine. You can subscribe here.

The Colorado River starts nearly two miles above sea level, in a pass in Rocky Mountain National Park. It’s fed by creeks and snow melt from the Never Summer Mountains, so named by the Arapaho for their year-round mantle of snow. In the remote wilderness where the Colorado begins its life, there is no such thing as political controversy or administrative clashes. That’s not the case over the path it travels across seven states and into Mexico.

More than 40 million people depend on water from the Colorado River Basin. Since 1922, a series of formal agreements have determined how it’s shared among states in the “Upper Basin” (Wyoming, Utah, Colorado, Nevada, Arizona and New Mexico) and the “Lower Basin” (Arizona, California, New Mexico, Nevada and Utah). Existing guidelines expire at the end of 2026, and despite two years of negotiations, states were unable to agree on a post-2026 framework by a February deadline.

“It’s a collective failure of will that I think history will judge very, very harshly,” says Felicia Marcus, a former chair of the California State Water Resources Control Board. “There will be enough blame to go around.” Marcus has had a hand in the region’s water issues for decades. She believes things might have gone differently if the federal government had played a stronger role and set the tone for negotiations by putting forth “ugly” steps it would take if states couldn’t agree, she says.

Failed negotiations mean the federal Bureau of Reclamation will impose guidelines on the states. These are expected in the summer; Interior Secretary Doug Burgum has said “nobody will be happy” with what is coming.

The immovable force that stymied negotiators isn’t political. It won’t go away no matter what framework Reclamation devises. “Mother Nature is driving this train,” says Kathryn Sorensen, research director at Arizona State University’s Kyl Center for Water Policy. The water situation in the basin is dire. A landmark 2020 study by scientists at the U.S. Geological Survey found that basin streamflow had decreased 20 percent over the past century. Brad Udall, senior scientist at Colorado State University’s Colorado Water Center, says that the drop since 2020 is almost 35 percent. “That’s enormous and more than disturbing,” he says. Lake Mead and Lake Powell, the two major reservoirs in the system (and the largest in the nation) are at less than a third of their capacity.
The problem exemplifies “tragedy of the commons” scenarios becoming more common around environmental services, where actions driven by one party’s need have negative consequences on a shared resource. “Generally, it takes government intervention to avert the tragedy of the commons,” Sorensen says. “No elected official wants to be the one who decides who gets water and who doesn’t, and that fact is independent of whether it’s a Republican or Democratic administration.”

Burgum’s warning applies to other resource challenges governors face: what’s coming will be difficult. Rivers, forests and species diversity don’t have political boundaries. Regional cooperation — and shared commitment to conservation — offer hope.

Arizona was already concerned about what might lie ahead before Burgum’s announcement.

When states missed the February deadline, the Bureau of Reclamation published alternatives for a new agreement for public comment. The University of Arizona’s Udall Center saw potential in one of them for a 77 percent cut to the Central Arizona Project, a delivery system that carries water from the river across deserts to more than 80 percent of the state’s population. That’s because federal legislation established that in times of shortage, the CAP’s water supply would be the first to be limited. (California, where half of all people who depend on the Colorado River live, holds senior rights in the Lower Basin.)

That means Arizona is facing a unique situation in these negotiations. The Colorado River is supporting vast and growing metropolitan areas like Phoenix, even as the state retains fewer rights to the water.

Arizona has already taken more mandatory cuts than any other Colorado River user over the past 20 years. It is unfair for the state to continue balancing a multistate water crisis on its back, says Brenda Burman, who was also previously a commissioner of the Bureau of Reclamation. Burman and other state leaders say the federal government’s proposed frameworks require too much sacrifice from Lower Basin states. They want to see more releases from reservoirs in the Upper Basin to stabilize the system.

Upper Basin governors see things differently. When the negotiation deadline passed, they issued a joint statement underscoring that water users there “live within the means of the River by adapting our uses every year based on available supplies.” The implication: Lower Basin states do not.
In some ways, the current collision course between states was set a hundred years ago, when the 1922 Colorado River Compact first divvied up water between Upper Basin and Lower Basin states. The agreement allocated 7.5 million acre-feet per year to each, with the Upper Basin obligated to send that amount to the Lower. (One acre-foot of water, enough to supply two families for a year, would cover an acre of land one foot deep.) At the time of the compact, the river’s annual flow was believed to be 16.5 million acre-feet. But the river has not had an average flow of this size in modern history. Since 2000, the average has been less than 12 million.

There wasn’t a firm scientific basis for this even division of resources. “The original idea was that they were going to figure out how much irrigable land there was in every state and allocate the water based on that irrigable land,” Udall says. There was more such land than there was water, he says, so this approach was abandoned. A hundred years ago, none of the parties could have imagined the massive population centers now in the region, or where humans and households might have the greatest need for water. Three-fourths of the people who depend on the river live in the Lower Basin.

A series of agreements since 1922 have established apportionments to states within each basin’s share, but the division established in 1922 remains a sticking point. Things would be different now if there had been a “pro rata” system of some sort from the beginning, says Udall. “The Lower Basin grew into its share and uses it,” Udall says. “The Upper Basin has never grown into its share. It uses about 60 percent of what it was allocated in 1922.” This is an ongoing source of tension, exacerbated by dwindling supply and overspending of reserves in Lake Powell and Lake Mead over more than 20 years of unprecedented drought.

Upper Basin states, meanwhile, see reservoirs as necessary protection against future shortages, as well as resources for population or industrial growth. It’s easy to understand this impulse — the 2026 snowpack in the Rocky Mountains is the worst on record, and more periods of drought are sure to follow. Upper Basin states point to Lower Basin agriculture as a prime source of overuse, including in Arizona’s Yuma County, one of the driest places in the U.S.

Meanwhile, the whole region is changing. A growing number of scientists are using the term “aridification” to describe what’s happening in the Colorado River Basin. “Drought is a temporary phenomenon, and what we have here is not a temporary issue,” Udall says. “We will not return to pre-drought times — our future is, in fact, warmer and drier.” The winter of 2026 exemplifies the compounding effects of warming. Following a disappointing rainy season in January and February, March was unseasonably warm. The accumulated snowpack melted early. Early melts mean more water goes into the atmosphere and less to the watershed. It evaporates from the soil and leaves of early plants, no longer a local resource.

States can’t control what nature provides, but they can control how they use the water they have. Basin states have set standards for water management and conservation that are likely to become increasingly important and necessary in other regions. California’s Orange County is home to the largest facility in the world that is purifying wastewater for groundwater recharge; 100 percent of its wastewater makes its way back into its aquifer.

Arizona and Nevada are investing in a plant in Los Angeles County that will recycle enough wastewater to greatly reduce the area’s reliance on releases from Lake Mead for drinking water. A groundbreaking project in Monterey County is purifying agricultural runoff as well as wastewater. These and other facilities in the state are moving toward direct potable use of recycled water. The San Diego County Water Authority is producing enough water from a desalination plant to offset reliance on Colorado River water. Basin states are considering investing in its desalination facilities in exchange for the water San Diego won’t need from the Colorado River.
People like to focus on the fight, and dire predictions about Arizona’s future water supply. But the state also has a positive vision to share, says Patrick Adams, senior water policy adviser to Gov. Katie Hobbs. Arizona is using less water now than it did in 1957, even as its population has grown sevenfold. Its conservation efforts stretch back decades; Tucson enacted an ordinance limiting lawn irrigation in 1903. The era of the lawn is long past in Phoenix, says Sorensen, accomplished not by banning them but by raising summer water bills. Phoenix has done a remarkable job reducing per capita water use, says Anne Castle, a senior fellow at the University of Colorado Boulder’s Getches-Wilkinson Center. But there’s still more opportunity. “They’re going to have to do more integrating land use planning, rezoning and subdivision approvals with water availability and requiring low water use ordinances or covenants for new development,” Castle says.

Arizona is unique in the world as a desert that has aquifers underneath it, and this groundwater is the state’s largest water source. “While that might sound like a blessing, it’s very much a double-edged sword,” Udall says. “What it allows society and Arizona to do is build massive places like Maricopa County on something that’s completely unsustainable in the long run.” Groundwater still makes up 41 percent of the state’s water supply, more than the 36 percent it receives from the Colorado.

Since 1980, Arizona has worked to recharge the aquifers that enabled its growth. A treatment facility in Scottsdale has returned purified wastewater to its drinking water aquifer for 30 years, nearly 2 billion gallons a year. Some of the Colorado River water carried along the Central Arizona Project goes to recharge basins. The Central Arizona Project has worked to protect Lake Mead, to put water back into it, says Burman. “We have saved over 5 million acre-feet just on our own, more than any other state, and that has gone into Lake Mead,” she says. “We have stepped up, we have done it ourselves, and we are willing to do more.”

Arizona has become one of the country’s biggest markets for data centers, but the state’s bottling industry is using more water than they are. The biggest share of its water, about 72 percent, goes to agriculture. Buying land from growers and retiring it would mean more water for urban areas, but it’s a strategy the state is not eager to embrace. Growers in Yuma supply nearly all the leafy green vegetables Americans consume from November through March.

States are still negotiating among themselves and lobbying the federal rule makers. Lower Basin states made a post-February commitment to reduce their use of Colorado River water by 1.25 million acre-feet through 2028. They subsequently announced an expanded conservation plan that could bring total systems savings over that period to 3.2 million acre-feet. “Those who benefit from the largesse of the river should contribute to the protection of the river,” says Tom Buschatzke, director of the Arizona Department of Water Resources. “An attitude of shared sacrifice, that ethic, is what needs to be the basis for multistate collaborative outcomes.” This will remain true into the future, no matter what framework comes next. What the Colorado River will provide to every basin state over the next century is an open question.

“This feels like a climate change impact the likes of which the Earth and human society has not faced before,” Udall says. It’s not the same as storms and fires that come and go. “Climate change has changed our water supplies in such a fundamental way that an historic 100-year-old agreement is no longer even remotely possible to implement. We need to completely rethink how we operate human society around a declining source of water.”