How Colorado River states would share water cuts under new federal proposal

Hoover Dam (top right) and Lake Mead on May 11, 2021, on the Arizona and Nevada border. A high-water mark or bathtub ring is visible on the shoreline. Lake Mead is down 152 vertical feet.

HOOVER DAM — Federal officials on Tuesday released a draft plan with options for emergency measures to prop up Colorado River reservoirs, including one that for the first time envisions cuts that would be shared by all users across the watershed regardless of their established rights to water.

The plan spells out proposals to modify a 2007 shortage-sharing agreement and will be open for public comment for 45 days. If adopted this summer, it will affect dam releases starting next year.

But officials with the U.S. Interior Department and its Bureau of Reclamation made clear that they view these options as placeholders, "bookends" between which consensus might be reached, while the states and tribes that share the river continue to seek consensus over the spring. The government will gather comment and refine its options by summer.

Speaking at a news conference in front of picture windows with a view of Lake Mead's "bathtub ring" caused the huge reservoir's retreat, U.S. Reclamation Commissioner Camille Calimlim Touton said the Colorado Basin's residents and ecosystems require new solutions for unprecedented strains.

“Fundamentally it is one community composed of 40 million people and landscapes that need us to get this right," she said.

Federal officials acknowledged that relying solely on either existing legal priorities or on every user's pro-rata share of the river would create great hardship. They hope to avoid that if states and tribes can mix and match a better set of options.

“It is our hope and our fervent desire that the tools laid out in the (draft) never have to be used,” Deputy Interior Secretary Tommy Beaudreau said. Still, he asserted that the department has a responsibility to protect the system and the 40 million people who use it, and will act this year if the parties don't reach agreement.

Representatives from the river states said they're making progress behind the scenes and are gaining confidence that they can reach a deal that does not throw out the old legal priorities or completely cut off cities and others that don't enjoy the same legal priorities as many farmers.

"I am more optimistic than at any time since we started the conversations last summer," Arizona Department of Water Resources Director Tom Buschatzke said. "There's a renewed spirit (of cooperation) among the Lower Basin states."

Those states — Arizona, California and Nevada — must bear the brunt of new reductions because they're the only three that fully put their water entitlements to work. Buschatzke said they may be able to reach a consensus before Interior chooses a preferred plan, and that it could preserve key needs such as a health and safety allowance for municipal water providers regardless of their legal preference. After that, the old system of first-in-time, first-in-right could govern other cuts needed to keep water in the reservoirs.

If the government chooses a plan to split cuts by percentage among all users, it could have profound effects on farm irrigation districts that traditionally have enjoyed some of the strongest legal rights to the river. Some three-quarters of the Colorado is spread on farm fields.

The U.S. Bureau of Reclamation's vision offers two possible ways of saving 2 million acre-feet of water a year, representing more than 15% of what the shrinking river has replenished to reservoirs in an average year this century. The two options differ substantially in how they dole out those cuts.

One would rely on legal priorities, forcing new usage cuts on some but rewarding those users who staked the earliest claims to the river or gained preference through the legal or political systems over the years. The other is a departure from previous allocation methods, splitting cuts among the three Lower Colorado River Basin states by percentage according to how much they use.

The Colorado River is stretched thin: Can the 100-year-old rules that divide it still work?

California holds the largest share — 4.4 million acre-feet — and has the most to lose in this proposal. Arizona is normally entitled to 2.8 million acre-feet, but already has given up some water based on its junior rights. Nevada is the other Lower Basin state and has a much smaller allocation, at 300,000 acre-feet.

The four Upper Basin states have not yet developed all the water that was allocated to them. They don’t face cuts in this proposal, but still must live within the limits of a river that does not offer as much as negotiators attributed to it in an interstate compact 100 years ago.

Whichever option Interior Secretary Deb Haaland ultimately chooses, her staff made clear Tuesday that the need for swift action is urgent.

“The Colorado River Basin provides water for more than 40 million Americans,” Beaudreau said in a statement before releasing the draft plan. “It fuels hydropower resources in eight states, supports agriculture and agricultural communities across the West, and is a crucial resource for 30 tribal nations.

“Failure is not an option.”

Cocopah Tribal Vice Chair Rosa Long called on residents throughout the watershed to conserve water in their homes to ensure the river keeps flowing. “Our action today will have a profound impact on the world our children and grandchildren will inherit.”

Long chairs the Ten Tribes Partnership, negotiating on Indigenous communities' behalf. She noted that the river is more than an economic driver for her people.

"This is where our creation story came from," she said.

Trying to avoid legal battles over Colorado River water

The states and Interior have sought to protect the river without tripping a legal fight between states or their various water users. University of Arizona law professor Robert Glennon said that while he had not had time to review the draft on Tuesday and couldn’t comment on whether it might trigger a lawsuit, the option of apportioning cuts by percentage is a necessary game-changer.

Since 2000, water demand and evaporation have outstripped the river’s flow by about 15%, causing a rapid decline in storage and threatening power production and even the most secure of water rights downstream of Hoover Dam. Federal and state officials in 2007 agreed to a list of reductions that deepen as Lake Mead drops farther against the dam, but so far they have not kept up with the pace of losses.

The Bureau of Reclamation plans to rewrite those guidelines when they expire in 2026, but last year decided it couldn’t wait that long to impose stricter measures to protect federal dams and their storage. Tuesday’s proposed options are meant as a bridge to keep water in Lake Mead and Lake Powell until 2026.

“This is serious business,” Glennon said. He added that the focus will now shift to California’s Imperial Irrigation District, the river’s largest user and one with old water rights that so far have immunized it against cuts.

Imperial board member J.B. Hamby said a plan that makes cuts entirely by percentage rather than using legal priorities would unduly harm California and his district's farmers. But he said he does not expect it to come to that as the states continue working toward consensus.

"We need to come up with something more granular," he said. "I feel confident that we're going to be able to work things out."

Whatever irrigators’ response, Glennon said the crisis demands shared cuts. Draining the Central Arizona Project canal to cut off Phoenix and Tucson but continue to fully supply farms would create its own cascade of problems, he said.

“It would be unthinkable to say Phoenix is cut off so (Imperial) can keep growing alfalfa” for export, Glennon said.

In a written statement, Arizona Gov. Katie Hobbs said any outcomes that would decimate the water supply of population centers or force the states into a courtroom are "unacceptable — and we will continue to double down on our efforts to find a consensus path forward.”

It can't come to that, said Southern Nevada Water Authority General Manager John Entsminger. Like his counterparts in Arizona and California, he said he's gaining confidence that the parties can reach a deal that would avoid litigation. That's partly because everyone understands it's not feasible to cut off the Lower Basin's cities, he said. He equated such a prospect to "multiple Katrinas," because it would displace millions just as the 2005 hurricane displaced Gulf Coast residents.

This year's promising snowpack may provide a buffer helping to reach a deal for at least the next three years, he said. After that, Entsminger said, the stakes get higher in a longer-term rewrite of dam operation rules.

"We have to take this in edible increments," he said.

Reservoirs on Colorado River can give no more

The river has suffered not just from overuse, but from a warming climate. Longer growing seasons and greater heat stress have forced the West’s forests to transpire more water, while drying soils have sponged up more of the snowmelt that feeds the river. The result is that even near-normal snowpack like the Rocky Mountains experienced in 2021 can result in far below-average flows into the reservoirs. Over years, this contributed to a “megadrought” that scientists say is the region’s driest in 1,200 years.

This year’s abundant snowpack appears poised to slow but not reverse the losses.

The seniority doctrine, known as prior appropriation, was a wedge that kept the states from proposing a unified vision for sharing new cuts earlier this year. Instead, six of the states coalesced around an idea that included proportionate cuts to account for evaporation and leaks, losses that are estimated to cost the river 1.5 million acre-feet a year.

An acre-foot, or roughly 326,000 gallons, is the government’s measuring unit for water.

On average since drought began in 2000, the river has flowed about 12 million acre-feet a year, and the Bureau of Reclamation has users need to slash use by between 2 million and 4 million acre-feet. Until now the region has maintained deliveries by draining the reservoirs that had years’ worth of supplies, but they are approaching levels where the stores could give no more.

Besides evaporation and leaks, the six states, including Arizona, proposed accelerating cuts that all accepted in a 2007 agreement, but which are tied to declining storage in Lake Mead. The reservoir hasn’t yet sunk to the point of inflicting harrem on California water users, who take the most and enjoy a high legal priority under previous court and congressional decisions. California water users, including the Imperial district, balked at a plan that cut uses proportionately instead of by legal priority.

“At this time,” Imperial's Hamby said in January, “the modeling proposal submitted by the other six basin states is inconsistent with the Law of the River and does not form a seven-state consensus approach.”

Brandon Loomis covers environmental and climate issues for The Arizona Republic and Reach him at or follow on Twitter @brandonloomis.

Environmental coverage on and in The Arizona Republic is supported by a grant from the Nina Mason Pulliam Charitable Trust. Follow The Republic environmental reporting team at and @azcenvironment on Facebook, Twitter and Instagram.

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This article originally appeared on Arizona Republic: Colorado River states to share water shortages under federal plan