Officials need to plan for bad — but not quite the worst — scenarios when it comes to the Colorado River Basin and the water supply for 40 million people, experts say.
The Bureau of Reclamation announced Friday another year of water cuts in Arizona and Nevada, based on releases from Lake Mead in Nevada and Lake Powell on the Utah-Arizona border. The report does not call for cuts from California, the third Lower Basin state.
In upriver states — Colorado, New Mexico, Utah and Wyoming — experts are watching reservoir releases with water supplies, environmental needs and the potential of forced water cuts in mind.
“The reservoirs, the big ones Powell and Mead, are not only not going to recover, but they’re actually going to decline to pretty scary elevation levels,” John Berggren, a regional policy manager for Western Resource Advocates, a nonprofit that focuses on environment and policy. “If we face another winter like the one we just got … you could be very quickly in a pretty dire place.”
The Bureau’s announcement Friday came in the form of a report known as the 24-Month Study, which provides updates on water conditions in the basin as well as how much water is flowing into and out of key federal reservoirs.
The August report is particularly important: Each August, officials look ahead to the basin’s projected conditions for the following January and use those forecasts to guide their decisions on how to store and release water in reservoirs.
The report calls for Arizona to cut 512,000 acre-feet, about 18% of its annual apportionment, Nevada to cut 21,000 acre-feet, or 7% of its annual apportionment, and Mexico to cut 80,000 acre-feet, or 5% of its annual allotment.
Lake Powell’s elevation on Jan. 1 is projected to be 3,538.47 feet — approximately 162 feet below what is considered full and 48 feet above the minimum level to produce power.
That means the reservoir is on course for a planned release of 7.48 million acre-feet of water for water year 2026, from Oct. 1 to Sept. 30, 2026. More reductions are possible if conditions continue to deteriorate.
This year, the Bureau is managing the system in the midst of dry conditions and high-stakes negotiations over sharing the Colorado River. Forecasts for the amount of water flowing into Lake Powell and Lake Mead have shrunk with each monthly update. The reservoirs’ water levels have only slightly recovered from 2022, when they reached historic lows.
It is also the last year the Bureau will use the 2007 management rules, which have been widely criticized for allowing the reservoirs to drop to crisis levels in 2022. The seven basin states, 30 tribal nations and the federal government have spent over two years fighting over what the new rules, which go into effect next August, will look like.
“If the states don’t get their shit together it’s a huge ‘hot mess,’” Berggren said, when asked how much of a hot mess the basin is in.
Mexico and the United States are in separate negotiations over water management after 2026.
Planning for the minimum
The Bureau’s monthly update projects three scenarios of monthly conditions in the Colorado River Basin two years out — a most probable outcome as well as the maximum and minimum scenarios.
The basin needs to be looking at the minimums, said John Fleck, a former science journalist, author of two books about the basin, and Utton Center writer in residence at the University of New Mexico School of Law.
He said the most-probable forecast is overly optimistic, while the minimum forecast has been the most accurate over the course of 2025.
This month’s minimum report showed 4.84 million acre-feet flowing into Lake Powell, or 50% of average.
The basin is entering into dangerous territory, Fleck said.
“We need to be thinking closely about the risks of a very bad year and thinking about what we’re going to do in the case of a very, very bad year,” he said.
Officials and experts watch water levels to gauge how much water is in the savings bank for people, economies and environments in the sprawling river basin. It’s a buffer that helps provide stability to the entire basin, but that buffer has shrunk too much, Fleck said.
The water levels also change how dams operate.
If the water falls too low — elevation 3,490 at Lake Powell, for example — the Bureau of Reclamation can’t release water through the main outlets at Lake Powell, where the flowing water generates hydroelectricity.
It would have to stop supplying reliable, cheap electricity to customers across some Western states and to switch to outlets lower down on the dam which were not meant for continued use, Fleck said.
The reservoirs are not yet low enough to be worried about “dead pool,” when water can’t flow through outtakes to downstream communities at all, the experts said. But it’s not headed in the right direction either.
“To the extent that we continue using water right now, at the rate that we’ve been using it, we run the risk of a catastrophic system crash that would require draconian deep water use cuts across the basin,” he said.
Potential for forced water cuts in Colorado, Upper Basin states
Colorado River Basin communities are also running headlong toward another risk: forced water cuts.
A hundred years ago, state representatives negotiated an interstate agreement for how the Upper Basin and Lower Basin are required to share water called the 1922 Colorado River Compact.
Under the agreement, the Upper Basin can’t cause the river’s flow to be depleted below a certain amount of water. The two sub-basins disagree on what exactly the amount is: The Lower Basin says it is 82.5 million acre-feet on average over 10 years. The Upper Basin said the 10-year average can’t fall below 75 million acre-feet, Berggren said.
Each year the Bureau sets Lake Powell’s releases influences this 10-year, rolling average. And each year those releases are on the smaller end of the spectrum, i.e. like this year’s 7.48 million acre-feet release, the entire 10-year average slides a little closer to that 82.5 million acre-foot mark.
That 10-year average flow was forecast to be about 82.8 million acre-feet by September 2026, according to Fleck and other Colorado River experts, Jack Schmidt and Eric Kuhn. That would leave the Upper Basin still slightly above the tripwire, they said.
If those flows fall below the tripwire, it spells chaos for the basin.
The Lower Basin states could enforce the compact, saying they have the right to force water cuts in upstream states. This could happen within the next two years, Berggren said.
Such a “compact call” would lead to a legal battle that could take a decade, cost hundreds of millions of dollars, and leave the basin’s future in the hands of the Supreme Court.
Since this has never been done before, it’s not even clear how states, including Colorado, would administer forced shortages, experts say.
All while climate change could continue to overstress the basin’s water supplies. And water users — farmers, ranchers, industries and communities — are left with uncertainty over how they’re supposed to manage and share the water.
“We don’t know how the system would be managed if this ends up in the Supreme Court and we don’t have a post-2026 deal (between states),” Berggren said.