Large Colorado River reservoirs are now so depleted that another dry year could plummet to dangerously low levels, a group of well-known scholars warn in a new analysis.
Researchers are urging the Trump administration to step in and cut dramatically across seven river-dependent states, including California, Arizona, Nevada, New Mexico, Colorado, Utah and Wyoming.
“There’s a real problem, and we should address it sooner than later,” said Jack Schmidt, director of Utah State’s Colorado River Research Center. “Everyone needs to consider how to cut it right now.”
The Colorado River provides water to cities from Denver to San Diego, 30 native tribes and agricultural communities from the Rocky Mountains to northern Mexico.
The river has been in use for a long time, and its reservoir has declined dramatically amidst its persistent arid conditions since 2000. Research shows that warming climates driven primarily by the use of fossil fuels have almost dry years.
A slight snowfall in the Rocky Mountains last winter has been added to the river system. Researchers analyzed the latest federal data and found that if the winters coming up are equally dry, the river’s main reservoirs approach very low levels unless water usage is significantly reduced.
“The results are tough,” the experts released Thursday. If next year turns out to be a repetition of the year, they wrote, total water use would be at least 3.6 million feet above the natural flow of the river – about the same as in California.
In such a scenario, water use in the area again exceeds the river flow for more than four minutes.
Researchers said snowy winters can always bring some relief. But they said the federal government has said the Southwest will likely have above-average temperatures and below-average precipitation over the coming months.
They called on the Home Office, which oversees river dams and management, to “take immediate action.”
“To avoid this potential outcome, immediate and substantial reductions are needed,” the researchers wrote. “Currently, taking measures to reduce consumption usage across the basin will reduce the need to implement radical measures over the next few years.”
Near Las Vegas, Lake Mead, the country’s largest reservoir, currently only 31%.
Upstream of the Grand Canyon, Lake Powell is the second largest reservoir in the country, 29% of its capacity.
Federal officials say they want to well outweigh Lake Powell, where water through low levels of Glen Canyon Dam can pass downstream.
Officials say these four 8-foot steel tubes can create bottlenecks that limit how much water will run in California, Arizona, Nevada and Mexico. Federal officials in tubes that could further restrict water flow when the reservoir level was low last year.
Researchers used key thresholds established by federal managers to perform the analysis by examining what is called “realistically accessible waters” in Lake Mead and Powell.
“A crisis is unfolding in front of our eyes for a near-term period,” the researcher released a report. “The gap between ongoing water use and the reality of actual water flowing in the Colorado River poses a serious, short-term threat.”
After a series of dry years, heavy snowfall at Rocky Mountain in 2023 provided some relief to the depleted reservoir. Then, in 2024, the average river flow continued, compared to the previous quarter century. However, this year, snowmelt runoff in the upper reaches of the river accounted for only about 70% of the average.
Representatives from the seven states were to develop new rules to address the shortage since 2026, when the current rules expired.
While these negotiations continue, Schmidt and other researchers said the situation calls for immediate action to reduce demand for the river.
“We believe (Burner Bureau) landfills need to address all this now and start implementing cuts,” Schmidt said, adding that all seven states should share cuts.
Interior Ministry spokesman Alyse Sharpe said the Reclamation Bureau is closely monitoring conditions and as the current regulations approaches, “it is actively involved with partners in the Colorado River Basin to develop new long-term operational agreements.”
“This is a moment that requires urgency, collaboration and transparency,” Sharp said in an email. “We remain committed to working with basin states, tribes, Mexico and stakeholders to ensure a sustainable and resilient future for the Colorado River system.”
In recent years, seven states have adopted a series of progressive water saving plans to prevent reservoirs from reaching dangerously low levels.
As part of these agreements, farmers in California’s Imperial Valley were voluntarily part of their time in exchange for payments through programs that received federal funds during the Biden administration.
Experts said they are unsure whether the Trump administration will be able to use more funds for these types of water-saving efforts.
Uncastle, a senior fellow at the Gettys Wilkinson Center at the University of Colorado Law School, said he co-authored the report, saying it was intended as a “wake-up call” for water managers in the Colorado River Basin.
Castle said reducing water use would be politically difficult, but she said the seven states have a history that “shows out of the federal government and ultimately becomes a solution agreement.”
He said the focus should be “to ensure that we are not in a deeper hole in this short-term management issue.”
