How the 100-Year-Old Colorado River Compact Laid the Foundation for the West’s Current Water Crisis

On November 24, 1922, seven men from Arizona, California, Colorado, Nevada, New Mexico, Utah, and Wyoming signed their names to a four-page document called the Colorado River Compact. Along with a series of subsequent agreements known as the Law of the River, the compact determined the fate of nearly every drop of water flowing through the Southwest and parts of the Intermountain West—a land of red rock plateaus and sagebrush expanses, of isolated mountain ranges and deep canyons, all connected and sustained by thousands of threads of water that gather into the thundering Colorado.

The compact’s goal was to jump-start “the expeditious agricultural and industrial development” of this arid country, and in that, it succeeded. On the river’s journey through seven states, two countries, and 30 federally recognized tribal communities, the river irrigates some of North America’s most productive farmland and helps electrify some of its biggest cities. Yet, like the Bible or the U.S. Constitution, the compact was written in a different era, and applying it to our modern lives can be challenging. Population growth has outpaced anything early planners anticipated, while climate change and aridification are shrinking snowpacks and depleting the soil of moisture. “For many years, we’ve been using more water than nature provides,” says Kevin Moran, associate vice president of regional affairs at the Environmental Defense Fund. “And now we’re coming to a moment of reckoning.”

Had the men who crafted the compact taken into account either Indigenous knowledge or reliable scientific data, this reckoning may have been avoidable. But they did not, and today the vast, interstate plumbing system for which they laid the groundwork is on the brink of collapse.

To hammer out the compact, Delph Carpenter, Colorado’s brilliant and bullheaded representative, officially met with the other representatives 27 times. The protracted negotiations were, in part, a result of the fact that each of the men had a specific number of acres he hoped to develop within his state’s borders. To fully and consistently irrigate those acres, each representative asked for a specific quantity of water, rather than a percentage of the river’s annual flow. This was a critical mistake. By allocating fixed quantities, the representatives created a system in which, to this day, states can draw the same amount of water from the Colorado in dry years as they can in wet years, and during the megadrought of the past two decades, this has helped drain the river’s reservoirs to historically low levels.

Worse yet, the delegates compounded that blunder when they sought to determine how much water the Colorado River carried in the first place. The gauges they relied on to calculate the river’s flow had only been installed in the early 1900s, and the ensuing decades happened to be abnormally wet. According to popular history, this brief, atypical sample duped the compact’s negotiators into believing the river transported more water than it really did.

Yet Carpenter and the other men were not simply unwitting victims of unsophisticated science, argue John Fleck and Eric Kuhn in their 2019 book, Science Be Dammed. Fleck, the former director of the University of New Mexico’s Water Resources Program, and Kuhn, the retired general manager of the Colorado River Water Conservation District, dug through archives and learned that, in 1916—seven years before the compact was signed—a California hydrologist named E.C. LaRue had determined there wasn’t enough water to irrigate all the irrigable land within the basin. LaRue was so concerned that, before the compact negotiations even began, he wrote Herbert Hoover, then the secretary of commerce and the future chair of the Colorado River Compact Commission, to offer his expertise to the delegates. He was ignored.

“These people came together in 1922 trying to make a deal,” Fleck said in a presentation earlier this year to a Southern California chapter of the League of Women Voters. “They were trying to carve up the river so development could happen, and it was a lot easier to do if they picked a big number.”

At this systemwide scale, water is measured in acre-feet, the amount needed to cover an acre of land with water one foot deep. (For reference, the average suburban home in the Denver area uses about half an acre-foot of water each year.) The men who signed the compact chose to believe the river’s average natural flow just upstream of the border with Mexico, at Yuma, Arizona, was more than 20 million acre-feet per year—a figure they arrived at through their own poor understanding of hydrology and reliance on a single, erroneous Bureau of Reclamation report. The actual annual average, based on long-term tree-ring reconstructions by researchers at the University of Arizona and the University of Colorado Boulder, is about 15.5 million acre-feet. During the drought of the past 20 years, it’s been about 13 million acre-feet.

Equally wrongheaded, Kuhn says, was the men’s belief in stationarity, a concept he defines as “the idea that the river would always be the same as it was.” Modern science shows that the river’s long history is punctuated with megadroughts—information the Indigenous peoples living within the river basin also could have shared, had the men who wrote the compact consulted them. And while that document may have solved water disputes between Western states, it did so at a great cost—to the canyons and cultural sites that were flooded by reservoirs, to the fish and other aquatic life whose rivers were sucked dry, and to the people who had depended on and stewarded the Colorado River for millennia.

Under the Law of the River, the people or communities with the oldest claims to a river’s water are known as senior rights holders and get first dibs. By this logic, Native Americans should control much of the river, but the compact allocated no water to the tribes living within the river basin. Various lawsuits in the 20th century changed that by returning about three million acre-feet to them—just under a quarter of the river’s modern flow—but a long history of anti-Indigenous policies have left many tribes without the resources and infrastructure to get that water to their communities. As a result, some 40 percent of homes in the Navajo Nation, which spans northwestern New Mexico, northeastern Arizona, and southeastern Utah, currently lack running water. Yet in Scottsdale, Arizona, 62 percent of homes have private swimming pools.

With human-driven climate change being added into the Colorado River equation over the past 20-plus years, it should come as no surprise that the system is faltering. Hotter summers lead to more water evaporating from reservoirs. Desperately dry soil means that even record snow years fail to fill the region’s waterways or replenish its depleted groundwater. As a result, reservoirs such as Lake Mead and Lake Powell—the linchpins that allow the river system to store water from wet years to use in parched years—are shrinking at an alarming rate. In 2021, Upper Basin reservoirs were partially drained to send emergency water downstream to Lake Powell. Even that wasn’t enough. Unless drastic action is taken soon, the Bureau of Reclamation predicts that, by 2024, Lake Powell could fall to dead pool, the water level at which electricity generation is no longer possible. Lake Mead isn’t far behind.

Although it’s unlikely that Las Vegas will suddenly wake up to dry faucets, rolling blackouts may become more frequent. Electricity costs will likely rise. Residents of Page and LeChee, Arizona, stand to lose their drinking water because the intake for their pipes could soon be above Lake Powell’s waterline, sucking nothing but air. Meanwhile, water levels in Lake Mead fell so low in 2021 that on January 1, 2022, emergency provisions recently added to the Law of the River triggered automatic cuts for junior water users for the first time, and a second round of cuts has already been announced for 2023. Farmers in Pinal County, Arizona, were among the first to have their allocations slashed because, in order to secure federal funding for a canal to divert Colorado River water, in 1968, Arizona agreed that the water rights of those using the canal would be subordinate to other states. “Roughly 30 to 40 percent of land in agricultural production [in that county] is being fallowed as we speak,” says the Environmental Defense Fund’s Moran. “That’s the biggest single impact so far in terms of the economy and people’s lives.”

Many communities are also voluntarily reducing their liquid footprints: Nevada has banned water-guzzling ornamental lawns; Los Angeles is working on a recycling system that will allow gray water from baths, showers, and sinks to be reused as potable water; and in the Denver area, water use dropped 22 percent between 2002 and 2015, thanks in large part to a public relations campaign to change residents’ water use habits. Only about 15 percent of Colorado River water, however, goes to municipalities, while 70 percent is used by farms—many of which are growing alfalfa for camels in Saudi Arabia and cows in Korea. “We can support a lot of people,” Kuhn says. “What we can’t support is a lot of grass.”

To stave off disaster, the Bureau of Reclamation told the seven states governed by the compact in June 2022 that they had two months to come up with a plan to cut the amount of Colorado River water they use by an additional two million to four million acre-feet annually, or it would do it for them. The states failed to meet the deadline, and at press time, the federal government hadn’t forced any cuts upon them.

Anne Castle, a senior fellow at the Getches-Wilkinson Center for Natural Resources, Energy, and the Environment at the University of Colorado Law School and a former assistant secretary of the interior, says that although the deadline passed, the pressure to come up with an agreement has not abated. And while states are trying to come up with a compromise, Upper Basin states such as Colorado are “taking the position that the Lower Basin needs to bear the brunt of the responsibility for reductions in overall usage,” Castle says. That reasoning is partially based on the fact that the Lower Basin has historically used more water than it is allowed by the compact, while Colorado, Wyoming, New Mexico, and Utah have used less.

Ultimately, though, every state will have to make sacrifices. “The gap between supply and demand is so large that, both mathematically and politically, no one basin, no one state, no one sector of the economy can reduce its use sufficiently to fill the gap,” Castle says. “It’s got to be a basinwide agreement, where everybody bears a share of the burden.”

One hundred years ago, the fate of the Colorado River was decided by seven men who ignored scientific evidence and failed to seek out Indigenous knowledge. The centennial anniversary of their effort is “a poignant moment,” Moran says. It’s a time to reflect on what they accomplished and what they got wrong. In 2026, key components of the Law of the River expire, and the federal government is required to replace them with new rules guiding the future of the watershed.

One of the most important changes that can be made, say Kuhn and others, is to rectify the compact’s first mistake and begin allocating percentages of the river’s flow instead of fixed amounts. Additionally, water managers must do a better job of incorporating Native American needs and perspectives. “The fact that we have tribes in the Colorado River basin with households that don’t have access to clean drinking water is a huge public health issue,” says Castle, who also serves on the Colorado River Basin Water and Tribes Initiative at the University of Montana. “That’s an inequity we need to remedy, and [now is] a good time to ensure that everybody in the basin has that basic human right.”

In an open letter published this past July, a coalition of 14 basin tribes accused the Department of the Interior of leaving them “in the dark” as the states and federal government deliberated over how to save the Colorado River from collapse. And while it’s still too soon to say how inclusive that process will be, many experts are cautiously hopeful that the negotiations surrounding the new 2026 management guidelines will let all of the river’s stakeholders weigh in on its future. Already, towns, cities, environmental advocates, farming groups, Native American tribes, scientists, and other water users are writing letters, submitting comments, conducting studies, holding forums, and speaking out about how to protect the river, while making sure its people and wildlife thrive.

This is the start of a new century of river management. This time, the states can’t pretend they can control a river so ancient it wears a path through some of the strongest rocks on Earth. This time, they must listen to the river itself.