The southwest is dry. Today, a key water source is under threat.

Despite the oppressive drought that has plagued the region for more than 20 years, California has largely avoided reducing its use of the Colorado River. But now that reservoir levels have dropped drastically, the Golden State could be forced to use less water, a prospect that would only strain a state that is already asking residents in some areas to stop. to water lawns and take shorter showers.

California’s Imperial Valley, with its vast tracts of farmland, uses more water than its neighboring water districts – and could be the target of much of the cuts. The state will also have to deal with water users in Arizona and Nevada, who face their own internal limitations and pressures.

« You can’t overestimate how difficult it is, » said Felicia Marcus, a member of Stanford University’s Water in the West program and former chair of the California State Water Resources Control Board. « Each state has its own set of policies. »

Over the past 20 years, as the effects of climate change have become more apparent, water authorities in their respective states have been able to reach agreements on moderate reductions. But it was not enough.

Supplies to Lake Mead and Lake Powell are dangerously low, holding just over a quarter of their total capacity – and threatening the dams’ ability to generate electricity and supply water to its nearly 40 million users. At its highest level in the 1980s, Lake Mead could have submerged the Empire State Building to its top floor. Now water levels have dropped nearly 200 feet, or 20 stories, exposing a stark white « bathtub ring » around the perimeter rock faces.

The new reality will force the region to move away from a source of water it has relied on for centuries and, in some cases, to make difficult choices that are sure to reverberate nationally. – like continuing to grow alfalfa for livestock feed or switching to more drought resistant crops. The conditions set out in the coming weeks could offer a new model for how America adapts to the increasingly difficult realities of climate change.

In Arizona, a state that is meant to bear the brunt of cuts under past deals, Tom Buschatzke, the state’s lead negotiator on Colorado River issues, said water users want the burden also be assumed by other States.

“They see, across the basin, benefits for everyone who uses Colorado water in the basin,” Buschatzke said. « And they want an outcome in which there is some level of fairness in the sharing of risks that come with the benefits. »

The regional drought only made matters worse. Last month the water got so low it revealed submerged human remains that had been dumped in the lake.

Speaking before a Senate committee in June, Bureau of Reclamation Commissioner Camille Calimlim Touton said the situation is serious and states will need to find a way to reduce the use of 2 to 4 million acres- feet in 2023, which is Arizona’s full year. contribution, if not more.

This type of inducement from the federal government is quite common, Marcus said, but states are usually motivated to do whatever it takes to avoid the Department of the Interior intervening with a unilateral decision, which he has the legal power to do. As Nevada’s top Colorado River negotiator, John Entsminger, puts it, « the feds don’t have scalpels, they have broad swords. »

Yet the negotiations – preceded by a century of struggles for access – will almost certainly be thorny. Water authorities also face their own political pressures at home, from industries, farmers, tribes and families who will have to reckon with the outcome of their negotiations.

“Nobody wants to raise their hand and volunteer to take big cuts because it makes it easier for everyone,” said John Fleck, professor of practice in water policy and governance at the University of New -Mexico and director of Water Water of the university. Resource program.

The predicament in which Western states currently find themselves goes back 100 years, when rights were shared.

Under a 1922 pact, the Colorado River states are divided into an upper basin and a lower basin, each entitled to approximately half of the river’s water. The upper basin is controlled by a system of state and local dams, while water in the lower basin is managed by two federal dams: the Hoover Dam outside of Las Vegas and the Glen Canyon Dam on the US border. Arizona and Utah.

The upper basin hasn’t been close to using its full share of water in the past century, Fleck said, while the lower basin, which includes Arizona, Nevada and California — with its vast population and vast agricultural land – has overused its share. . The Golden State is the largest user of the basin, claiming 4.4 million acre-feet per year. An average Californian family uses between 1 and 1.5 acre-feet of water per year.

The mighty water districts of California have superior rights to the river, while Arizona and Nevada have secondary rights. But those designations are less likely to matter this time around, given the volume of the cut demanded and the urgency of the situation in the reservoirs.

“Proportionally everyone is going to take big cuts,” Fleck said. « And there’s going to be a stare, a chicken game, between Arizona and California. »

Under a 2007 agreement between the seven basin states, any supply shortages would be borne first by Arizona and Nevada, followed by California. (Nevada has the smallest claim to the river of the three, while Arizona’s claim is close to the same size as the Imperial Irrigation District in California.)

Another deal saves California from taking a cut until Lake Mead’s water falls below 1,045 feet.

The federal government expects it to drop to 1,039 by the end of December.

Agreements aside, it wouldn’t be fair to let Arizona and Nevada bear the entire burden of a reduction that could equal their entire water allocations, said lead researcher Anne Castle. at the Getches-Wilkinson Center for Natural Resources, Energy and the Environment at the University of Colorado School of Law.

« You can stick to your legal theories and watch the system crumble, » she said. « But that doesn’t help anyone. »

Yet there are deeply rooted beliefs about water rights in the West, particularly in California.

Of the Golden State’s four water districts with access to the Colorado River, the Imperial Irrigation District—which stretches from the Joshua Tree National Forest to the Mexican border—is by far the largest, using about 2.6 million acre-feet per year to supply water. to 474,000 acres of Imperial Valley farmland and nine communities.

Residents there have long asserted the importance of maintaining their access to the river, the only source of water for an area that is one of the country’s main food producers, and imperial officials note that the district ceded part of its water in Los Angeles, San Diego and Coachella Valley almost 20 years ago.

« It’s our cornerstone, » said Antonio Ortega, government affairs and communications manager for the district, of the river. « We don’t have groundwater here in Imperial Valley, so all of our water is water we get from the Colorado River. »

But with such a large reduction from the federal government and worsening drought conditions in the West, other water users and river experts say it will be difficult for regions with heavy agriculture like the imperial valley to avoid a reduction.

« It’s just simple math, » said Buschatzke, Arizona’s top water negotiator. « Leaving aside the politics, putting aside the arguments about who has priority and not, they’re going to have to be reduced. »

When asked if the district was willing to accept a reduction, Ortega said, « I think it’s very clear, not just based on the hydrology, but based on the severity of the situation. , that everyone is invited to do their part. »

Any deal with the Imperial Valley District would likely include action on long-standing efforts to restore the Salton Sea, a lake that provides important habitat for migratory birds in an arid part of the state, even if runoff farm laden with fertilizer has made it inhospitable to fish and other wildlife.

States must come up with a plan by August to shut off the water in 2023, when the Bureau of Reclamation meets to set annual operations for Lake Mead and Lake Powell.

The cuts are something of an emergency measure, born out of an urgent need to keep the Lake Mead and Lake Powell dams functioning. The Colorado River states are expected to renegotiate the broader guidelines by 2025, when the 2007 agreement expires.

But the cuts aren’t likely to lift anytime soon — or maybe ever. Water levels in the river have dropped since the original agreement in 1922, and with continued drought in the West, there is no indication that the states will be able to return to their full allocations.

Marcus at Stanford considers this round of cuts to be overdue after incremental cuts which she said were not enough.

« If we had done it sooner, we wouldn’t be as close to events as we are right now, » Marcus said. « So you really have to get real and have these serious conversations. »