Why is California going it alone in Colorado River talks?

After a key deadline passed this week without an agreement on how to address the Colorado River crisis, California now sits at sharp odds with six other states over how to take less water from the shrinking river.

After California rejected a plan offered by the rest of the region, the state has entered a high-stakes political tug-of-war. So why did the state that uses most of the Colorado River’s water go it alone?

California seems to be banking on its priority water rights, while the other states have come together to show the federal government they support a plan that would get California to give up more water.

“The strongest thing going for the other basin states is some relative consensus. And the best thing California has to offer is the law,” said Rhett Larson, a professor of water law at Arizona State University.

“I think they’re playing to their strengths,” Larson said. “California is trying to play its best card, which is ‘The law is on our side.’ And the other six states are trying to play their best card: ‘We’re on each other’s side.’”

The parties are at an impasse as the federal government begins to weigh alternatives to quickly reduce water use and prevent the river’s reservoirs from reaching dangerously low levels.

The Colorado River, which feeds cities, agricultural areas and tribal nations from the Rocky Mountains to the US-Mexico border, has been stretched to breaking point by chronic overexploitation, drought and the effects of global warming. The river’s two largest reservoirs, Lake Mead and Lake Powell, have dropped to their lowest levels since they were filled.

Federal officials had asked each of the seven states that depend on the river to come up with alternatives to water cuts by the end of January.

Under the proposal submitted by Arizona, Colorado, Nevada, New Mexico, Utah and Wyoming, a large portion of the proposed water cuts would be made by accounting for evaporation and other water losses along the lower portion of the river — a calculation that would translate to particularly large reductions for California, which uses most of the river.

In its proposal, California reiterated previous commitments for Southern California’s water authorities to reduce water use by 400,000 acre-feet per year through 2026, a reduction of about 9%. The proposal also calls for additional cuts in Arizona, California and Nevada on a graduated scale if Lake Mead levels continue to fall to critically low levels.

California Secretary of Natural Resources Wade Crowfoot said the state’s proposal was “timely, practical and achievable in a manner that works within applicable law.”

The so-called “Law of the River” is based on the 1922 Colorado River Compact, which divided the water among the seven states, as well as various court decisions and agreements of the last century. California’s Agricultural Water Authorities, particularly the Imperial Irrigation District and Palo Verde Irrigation District, hold priority water rights dating back more than a century, giving California a privileged position under the system of pre-establishment of water rights, often referred to as “first-time.” is designated, right first.”

Less than four years ago, states appeared to be resolving issues amicably, agreeing on water reductions in an agreement called the Drought Contingency Plan. Those reductions weren’t nearly enough, however, as reservoirs continued to recede during the worst drought in centuries.

And tensions have been rising in recent months, particularly between California and the rest of the region.

JB Hamby, the chair of California’s Colorado River Board, said in a submission letter that the state’s proposal would “minimise the risk of legal challenge.”

Arizona water authorities released a statement Wednesday critical of California’s proposal, which they say “reflects strict adherence to a California definition of the law of the river.”

“But there are differing interpretations of what this law of the river actually means,” the Arizona Department of Water Resources and the Central Arizona Project said, adding that the six-state proposal is the “most equitable and efficient way” to go the law to deal with the river’s severe water deficit due to drought, climate change and overexploitation.

After both sides submitted wildly different proposals, the Federal Bureau of Reclamation will begin examining the alternatives as part of a review focused on revising the rules for handling congestion.

Negotiations between the seven states are set to continue, but the impasse between California and the other states remains.

In the coming months, federal officials will play a key role in analyzing and considering the proposals.

Whatever emerges from this process, the rift between the states now appears likely to spark litigation and end up in court, Larson said.

“I think at this stage it’s inevitable and that’s the direction things are going. And I also think it might be the best of our available options right now,” Larson said. “We’re clearly not pulling together at the moment, and I think it’s probably time to try litigation.”