After a year of heated disputes over Colorado River water usage cutbacks, the seven states that depend on it for survival have agreed to a consensus-based plan submitted by the three Lower Basin states.

The proposal, drafted by California, Arizona and Nevada, would commit those three states to collective conservation of at least 3 million acre-feet of system water by the end of 2026, when the Colorado River’s current operating guidelines are set to expire.

Of that total, 1.5 million acre-feet at minimum would be conserved by the end of next year, the states declared in a proposal sent to Bureau of Reclamation Commissioner Camille Touton.

The Colorado River, which serves about 40 million people throughout the West, is divided into a Lower and Upper basin, which respectively include California, Arizona and Nevada, and Wyoming, Colorado, Utah and New Mexico.

Each basin is allocated 7.5 million acre-feet of water, for a total of 15 million acre-feet. A typical U.S. suburban household uses about one acre-foot of water annually.

Of the total savings, 2.3 million acre-feet will be compensated with federal funding from the Inflation Reduction Act in order to support near-term water conservation, the Department of the Interior announced Monday.

“I commend our partners in the seven basin states who have demonstrated leadership and unity of purpose in developing this consensus-based approach to achieve the substantial water conservation necessary to sustain the Colorado River System through 2026,” Deputy Interior Secretary Tommy Beaudreau said in a statement.

The consensus-based plan comes almost two months after the Interior Department’s Bureau of Reclamation issued a draft Supplemental Environmental Impact Statement (SEIS) with proposed alternatives for consumption cutbacks.

Last year, the seven basin states missed an initial mid-August deadline to present a unified plan themselves and ultimately agreed to a new target date of Jan. 31 — aware that the Bureau would likely present its own alternatives if they again failed to meet that one.

What ended up materializing at the end of January were two competing offers: a joint document from six out of the seven states and a separate proposal from California.

While the six-state plan had sought to distribute evaporation losses across the basin, leaving California with the biggest reductions, the Golden State’s proposal included larger cuts for Arizona.

“California worked hard with our basin states partners to achieve consensus between all seven states to protect the Colorado River system for the duration of the current guidelines,” JB Hamby, California’s Colorado River Commissioner, said in a statement Monday.

The newly proposed consensus-based action will meet the goals presented in the federal SEIS document, according to the agreement.

Another advantage of the proposal, according to the states, is that their plan “does not require any unilateral exercise of federal authority to achieve these levels of conservation.”

In a separate letter accompanying the Lower Basin proposal, all seven states encouraged the Bureau of Reclamation to suspend the current draft SEIS comment period, which is set to close on May 30. Instead, they called for a recirculation of that SEIS that includes the Lower Basin plans.

“California and our partners in Arizona and Nevada have developed a plan to better perform and protect the Colorado River system than either action alternative identified in the current draft SEIS,” Hamby said.

The California commissioner lauded the new plan for its ability to “generate unprecedented volumes of conservation that will build elevation in Lake Mead,” the biggest reservoir on the Colorado River.

Hamby also touted the deal’s capacity to “build upon partnerships within and between states, urban water agencies, agricultural irrigation districts, and Basin Tribes who rely upon and share the Colorado River.”

Tom Buschatzke, director of the Arizona Department of Water Resources, cited the “collaborative nature of this proposal” as “the path forward to successful management of the basin.”

“This proposal provides robust protection for Lake Powell and Lake Mead and will help bolster storage volumes in these two critical reservoirs,” he said in a statement.

At a press conference on Monday, Buschatzke emphasized that the joint plan is not an official agreement but “an agreement to submit a proposal and an agreement to the terms of that proposal, to be analyzed by the federal government.”

John Entsminger, Nevada’s chief Colorado River negotiator, acknowledged in a statement that the plan is “not a panacea for the river.”

However, he stressed that it is “a consensus solution that will help manage near-term water demands while serving as a bridge to negotiate the post-2026 operating criteria.”

“The Colorado River Basin has a warmer and drier future ahead and reducing water use, increasing water efficiency,” added Entsminger, who is also Southern Nevada Water Authority’s general manager.

“Maximizing water recycling and reuse is paramount to a sustainable future for the 40 million people that depend upon this critical water supply,” he said.

Following the announcement of the deal, the governors of all three states weighed in as well, issuing a joint press release voicing their support.

Arizona Gov. Katie Hobbs (D) praised the water managers for their “months of tireless work” and called upon the states to continue to “address the long-term issues of climate change and overallocation.”

Nevada Gov. Joe Lombardo (R) echoed Hobbs’s sentiments, stressing the importance of “equitably advancing our mutual goal of conserving our shared water resources.”

California Gov. Gavin Newsom (D) likewise urged Western states to “work together to address this crisis,” noting that the entire U.S. West “is on the frontlines of climate change.”

“This historic partnership between California and other Lower Basin states will help maintain critical water supply for millions of Americans as we work together to ensure the long-term sustainability of the Colorado River System for decades to come,” Newsom added.

—Updated at 2:14 p.m.