What could future Colorado River water cuts look like? States look to this year’s weak snowpack to find out.

If any of the Colorado River management options were used to manage this year’s sub-par snowpack, Arizona, California and Nevada would be forced to slash 17% to 43% of their legal share. Coloradans would be focused on voluntary conservation.

Colorado River officials are debating six options for how to manage the overstressed river after 2026 with the goal of reaching a seven-state agreement by May. Under this year’s water conditions, all of the proposed plans would call for mandatory cuts in the three Lower Basin states with reductions ranging from 1.3 million to 3.2 million acre-feet. The basin’s legal share of the river is 7.5 million acre-feet, although estimates say its actual use is higher.

Under most of the different management options, Colorado and its sister states in the Upper Basin would be asked to voluntarily conserve up to 500,000 acre-feet of water. One acre-foot roughly equals the annual water use of two to three households.

In Arizona, the state that would be hardest-hit, cities, farms and tribes are already making alternative plans, Tom Buschatzke, Arizona’s Colorado River negotiator, said. 

“The impacts are going to be meaningful,” Buschatzke, who is also director of the Arizona Department of Water Resources, said. “They are going to have some pain attached to them.”

This Fresh Water News story is a collaboration between The Colorado Sun and Water Education Colorado. It also appears at wateredco.org/fresh-water-news.

It’s been a tough water year for parts of Colorado and the Colorado River Basin. In Colorado, the snowpack on the Western Slope — where the Colorado River starts — ended up with a below average peak this winter. 

Across the basin, more than 20 major reservoirs and tributaries can expect a lower-than-usual water supply between April and July, according to the Colorado Basin River Forecast Center. 

Lake Powell, one of the immense reservoirs that provides storage for millions of water users in the basin, will likely receive less than 70% of its normal inflows from the Upper Basin region of Colorado, New Mexico, Wyoming and Utah.

It’s the kind of water year that starts to worry officials about late-summer irrigation supplies and wildfire risks, according to fire officials, irrigators and water providers.

With this year’s conditions, Colorado River states would be conserving or cutting back on their water use under any of the six plans dominating current planning discussions: two competing proposals from basin states — one from the Upper Basin and one from the Lower Basin — and four options from the federal government. 

The fifth federal option, called the “no action” alternative, is theoretical and a required part of the federal planning process. It would not sustainably manage the river, officials say.

The final management plan won’t be decided until later this year or early in 2026.

How would the Upper Basin manage the river?

If the Upper Basin’s proposal were being used to manage the river basin, the Lower Basin states would be reducing their use by 1.5 million acre-feet this year. 

The proposal calculates cuts by taking a snapshot every Oct. 1 of the water level at Lake Powell and the amount of water stored in Lake Powell and Lake Mead. This year, Powell’s surface was 3,577 feet above sea level and the combined storage in both reservoirs was 17.8 million acre-feet on Oct. 1, about 36% of their combined capacity, according to Colorado’s Colorado River team.

Colorado and the other Upper Basin states would take more voluntary action, like conserving water or releasing water from reservoirs further upstream if needed.

Sticking to voluntary conservation would be a win for the Upper Basin, where officials have said they should not be required to cut their use because their water supply is already unpredictable and limited by each year’s precipitation. 

The Upper Basin, located upstream of the basin’s biggest reservoirs, lakes Mead and Powell, relies on smaller reservoirs to try to pace the flow of water from year to year. The Lower Basin depends on the vast storage in lakes Powell and Mead to pace its water supply, which offers more predictability over a longer time span.

What would cuts look like under the Lower Basin’s plan?

Arizona, California, Nevada and Mexico would also cut their use by a total of 1.5 million acre-feet this year if their own proposal were to manage the river basin.

Arizona would cut its use by 760,000 acre-feet; California, by 440,000; and Nevada, 50,000. Lower Basin officials estimated Mexico would have to cut its use by 250,000 acre-feet, but those reductions are being decided in separate negotiations between Mexico and the U.S.

The Upper Basin would not be required to cut its use at all this year under the Lower Basin proposal, Buschatzke said. (If the basin’s water supply was even worse, the Upper Basin would be required to share in the water cuts instead of voluntarily conserving.)

In Arizona, one water project, the Central Arizona Project, would take the brunt of the hit, Buschatzke said.

The 336-mile water delivery system serves cities, like Phoenix and Tucson, and several tribes, including one of the project’s largest users, the Gila River Indian Community.

Other cities and farms along the Colorado River, like Bullhead City, Lake Havasu City, Kingman and the Cibola Valley Irrigation District, could also take a hit. That’s dependent on how Arizona decides to distribute cuts inside the state, Buschatzke said.

“We will be able to continue to live sustainably within the CAP service area, but it’s going to cost more money,” he said. 

It will mean that creative things, like treating wastewater so it can be used to drink, will have to be developed and deployed, which also means significant infrastructure costs of hundreds of millions of dollars, Buschatzke said.

The state will face tough decisions about how to use water, like choosing between restoring ecosystems along rivers or diverting that water to support other uses. 

“We’ve been talking about these things for many, many years, but it’s coming to the fore now where some policy decisions are going to have to be made,” Buschatzke said.

What would water cuts look like under the federal plans?

The Lower Basin states are ready to face 1.5 million acre-feet in cuts, but some of the federal plans would call for cuts up to 3.2 million acre-feet in a year like 2025, according to an analysis by the Upper Colorado River Commission.

The commission used a federal study of reservoir levels and projected inflows from February to gauge the minimum, maximum and probable water cuts in the Lower Basin. The Lower Basin’s outlook hasn’t changed much since February, Chuck Cullom, the commission’s executive director, said in early April. 

Here’s how the Lower Basin would have to cut its use under each federal option:

• Federal Authorities: 1.3 million to 3 million acre-feet, likely 2.5 million in cuts
• Federal Authorities hybrid: 1.5 million to 3.2 million acre-feet, likely 2.8 million in cuts
• Cooperative Conservation: 1.5 million to 2.7 million acre-feet, likely 2.3 million in cuts
• Basin hybrid: 1.5 million to 2.1 million acre-feet, likely 1.8 million in cuts

Under water sharing agreements, California can use 4.4 million acre-feet of Colorado River water; Arizona, 2.8 million acre-feet; and Nevada 300,000 acre-feet.

For Colorado and other Upper Basin states, cuts will not be mandatory under the federal plans. Instead, the states would commit to other actions, like voluntary conservation.

Here’s how much the Upper Basin would aim to conserve under each federal option:

• Federal Authorities’ alternative does not call on the Upper Basin to conserve water.
• Federal Authorities’ hybrid: Up to 200,000 acre-feet per year of conservation
• Cooperative Conservation: Up to 500,000 acre-feet per year of conservation, with a yearly average of 200,000 acre-feet
• Basin hybrid: Up to 200,000 acre-feet per year of conservation

There’s not enough detail at this point in the negotiations to say exactly how much the Upper Basin would try to conserve based on this winter’s water conditions, Cullom said.

Under a former water conservation pilot project — the System Conservation Pilot Program — the Upper Basin has been able to cut its use by a maximum of 37,800 acre-feet. That was in 2023, a very wet year with a much higher snowpack across the Western Slope than in 2025.

“What we’ve observed is that there’s greater participation in voluntary programs when there’s more water in the system. So that’s what the modeling reflects,” Cullom said. “The commitment is that we would develop conservation programs. They’re voluntary, so they would be targets to achieve, not requirements.”