Arizona, California and Nevada agreed to take less water from the drought-stricken Colorado River. This is a breakthrough agreement that, for now, prevents the river from falling so low that it would endanger the water supply of major western cities such as Phoenix and Los Angeles. and also for some of America’s most productive farmlands.

V agreement, announced Monday, calls on the federal government to pay about $1.2 billion to irrigation districts, cities and Indian tribes in three states if they temporarily use less water. The states also agreed to make additional cuts beyond those related to federal payments to provide the overall cut needed to prevent the river from collapsing.

Combined, these cuts will amount to about 13 percent of total water use in the lower Colorado Basin—one of the most aggressive the region has ever seen, and will likely require significant restrictions on residential and agricultural water.

The Colorado River provides drinking water to 40 million Americans in seven states, as well as part of Mexico, and irrigates 5.5 million acres of farmland. Electricity generated by dams at the river’s two main reservoirs, Lakes Mead and Powell, powers millions of homes and businesses.

But due to drought, population growth and climate change in recent years, the flow of the river has fallen by one-third from historical averages, threatening to provoke a water and energy disaster in the West.

California, Arizona, and Nevada get their share of their water from Lake Mead, which is formed by the Colorado River at the Hoover Dam and is controlled by the federal government. The Bureau of Reclamation, an agency under the Department of the Interior, determines how much water each of the three states receives. Other states dependent on the Colorado River receive their water directly from the river and its tributaries.

“This is an important step forward towards our shared goal of laying a sustainable path for the basin that millions of people call home,” Bureau of Reclamation Commissioner Camille Kalimlim Tuton said in a statement.

This past weekend’s agreement is only valid until the end of 2026 and still needs to be formally adopted by the federal government. At this point, all seven states that depend on the river, including Colorado, New Mexico, Utah and Wyoming, could face a bigger reckoning as the decline likely continues.

The Colorado River talks were sparked by a crisis: Last summer, water levels in Lakes Mead and Powell, the two largest reservoirs along the river, dropped so much that officials feared the hydroelectric plants they were powering would soon stop working.

There was even a risk that reservoir levels would drop so low that water would no longer reach the inlet valves that control runoff from the lakes, essentially drying up the river downstream.

Faced with that prospect, the Department of the Interior last June asked seven states to find a way to reduce their water use by two to four million acre-feet of water per year. (An acre foot is about the amount of water used by two or three households a year.) The states failed to reach an agreement, even though water levels in the two reservoirs remained dangerously low.

This inertia led the federal government to lay the groundwork for unilateral cuts for these states. Adding to the pressure, the Interior Department said last month it could ignore age-old rules determining which states should bear the brunt of the cuts and propose a different formula instead.

The federal government has given states until May 30 to comment on the prospect of unilateral cuts. But behind closed doors, the Biden administration has been negotiating with states to reach an agreement and avoid the need for cuts that will certainly run into legal problems and ultimately delay any action.

Under the agreement announced Monday, most of the 2.3 million acre-feet reduction will come from water districts, farm operators, cities and Native American tribes who have agreed to take less water to qualify for federal subsidies offered under the inflation in 2022. Reduction law. These payments will amount to about $1.2 billion.

Another 700,000 acre feet will come from California, Nevada and Arizona, which have agreed to cuts among themselves in the coming months. (Under the terms of the agreement, as many as 200,000 acre feet of these clearings may qualify for compensation through other federal programs, but these arrangements have yet to be worked out.)

If states don’t define those 700,000 acre feet in additional cuts, the Department of the Interior has said it will suspend the water supply, which could run into legal and political problems.

Collectively, the reductions will save three million acre feet over the next three and a half years on top of existing agreements. That’s a lot less, on an annualized basis, than what the federal government demanded last summer.

The Department of the Interior was able to negotiate less drastic cuts thanks to an unusually wet winter when snow levels in the Colorado Basin were well above average, especially in California. This is expected to significantly increase the amount of water in the river, at least temporarily.

The terms of the deal were described to The New York Times by a senior Interior Department official who was involved in the negotiations and spoke on the condition that his name not be released. Washington Post announced elements of the deal last week.

The structure of the agreement allows the Biden administration to bypass the issue of which states will bear the brunt of the cuts for now.

The Department of the Interior declined to provide a breakdown showing how much of the 2.3 million acre-feet of federally compensated voluntary cuts would come from each state. And finding an additional 700,000 acre feet remains a challenge for the lower basin three states.

As a result, what until recently looked like a match between the states in a cage has resulted in an outcome that is more bearable for the states involved, if not entirely desirable.

The rules governing the river, which date back to 1922, state that most of Arizona’s supply from the Colorado River will be reduced to near zero before California’s cuts occur. While Arizona will continue to see significant cuts in its water supply, the deal effectively removes the threat of drastic cuts.

“I’m very pleased with this offer,” Tom Buschatske, director of the Arizona Department of Water Resources and the state’s lead negotiator, said Monday. “I think there’s a lot of justice in that.”

Sarah Porter, director of the Kyle Water Policy Center at Arizona State University, called the agreement a positive step, but it can only offer a delay. “Before 2026, we may again be in this danger zone,” she said.

California, too, is doing better than it could otherwise. The Department of the Interior has raised the issue of cutting supplies in each state equally as a share of total consumption. Because California uses more water from Colorado than any other state, it would lose the most—a shock to Southern California farmers, as well as cities like Los Angeles and San Diego. This problem is solved mainly through voluntary layoffs.

Bill Hasenkamp, ​​Colorado River resource manager for the Southern California metropolitan water district, said the agreement could provide several years of stability for Los Angeles, San Diego and other California cities that depend on Colorado water.

The bigger challenge will be to reach an agreement after 2026, when the federal government may not want to spend as much on water conservation and states can’t expect more winters of heavy rain and snow. “We know that the future will be in third place compared to the past,” said Mr. Hasenkamp.

The deal is also a sort of victory for the Biden administration, which at times seemed unsure of how to respond to the growing crisis. Last year, he twice set deadlines for reaching agreements between the states, which they did not comply with. The Interior Department said the agreement shows states can work with the federal government to address Colorado’s decline.

This view will also be tested soon. The department said its next step would be to look into the implications of the states’ deal before deciding how to proceed. In the meantime, the next round of negotiations on what to do after 2026 should start next month.

Jack Healy report provided by Phoenix.