Federal actions could trigger Colorado river litigation

The reason is that this year's planned cut in releases from Powell to Mead will for the first time lower the 10-year total of such releases below what the three Lower River Basin states, including Arizona, say is the minimum amount of water they're supposed to get from the four Upper Basin states in that period.

Under its most recent plan for the river, announced last month, the U.S. Bureau of Reclamation will reduce releases from Powell to Mead by about 20% this year. That amounts to a reduction of 1.48 million acre-feet to be released, from an original planned release of 7.48 million acre-feet.

The 1.48 million acre-feet is somewhat less than the total amount of water that the Central Arizona Project canal system delivers from the river to Phoenix and Tucson over two years.

If water releases from the four Upper Basin states to the Lower Basin states end up averaging less than legal minimum levels for releases over a decade, Arizona and the other Lower Basin states, California and Nevada, could very well take the Upper Basin states and the federal government to court.

A lawsuit would allege that the releases violate minimums set by the 1922 Colorado River Compact that all seven states agreed to. The Upper Basin states are Wyoming, New Mexico, Utah and Colorado.

More immediately, if water releases from Powell fall below what's legally required under the compact, it will mean that until that legal issue is settled — which would likely take years — Arizona and the other Lower Basin states will get even less water out of Lake Mead than they otherwise would have. That's even after taking into account the cuts they'll have to swallow in water use from any future action by Reclamation to cut water use over 20 years.

The compact, approved in 1922, requires the Upper Basin states to insure that 75 million acre-feet of Colorado River water is delivered to the Lower Basin states over a decade. In 1944, the U.S. and Mexico agreed to a treaty obligating this country to allow another 1.5 million acre-feet of river water to flow into Mexico every year.

That boosted the Upper Basin's 10-year water delivery obligation to 82.5 million acre-feet, the Lower Basin states have said. 

Until now, the Upper Basin states have managed to meet the 82.5 million acre-foot delivery release level and then some every decade. But this year's plans to cut releases from Powell to Mead by 20% will reduce the most recent, 10-year total of water deliveries to 81.3 million, said Eric Kuhn, an author who has tracked compact compliance issues for years.

"This failure to comply with the bedrock agreement among the seven Colorado River states is itself a serious development that Arizona will assess and will respond to accordingly in time," the Arizona Department of Water Resources said after Reclamation announced its plans on April 17 to cut releases from Powell to Mead.

ADWR made no explicit threat to sue in that statement. But state officials have made it clear they're prepared to sue. They have agreed to pay the high-powered, New York City-based global law firm Sullivan and Cromwell $3 million to fight the compact issue in court, if necessary.

"We have rights in the compact that require the Upper Basin to release 75 million acre-feet over 10 years plus half the Mexican treaty obligation. That keeps the Lower Basin in business," said Terry Goddard, president of the Central Arizona Project's governing board and a former Arizona attorney general.

"Otherwise, they get the whole amount," said Goddard, referring to the Upper Basin states. "Those are the rules we’ve lived with for 100 years and they're thumbing their nose at them."

"A long-term solution that doesn’t recognize our rights under the Colorado River Compact is not a solution. We need to stand firm on that; that’s Arizona's birthright," Goddard said.

The Upper Basin states, however, have said they don't consider themselves to be legally bound to deliver one-half of the water needed to meet the Mexican treaty obligations.

They also say the 1922 compact doesn't require them to "deliver" a minimum amount of water — it requires them not to deplete so much water that deliveries fall below a minimum level. And it's human-caused climate change, not their actions, that are depleting the river, they say.

These issues have never been taken to court, much less settled, so however a lawsuit turns out is likely to set a major legal precent for future cases involving the compact. 

Kuhn has said that if the courts rule the Upper Basin isn't liable for failing to release enough water because climate change is to blame for lower releases, that could open the floodgates for similar claims to be made in court involving other rivers involved in interstate legal issues, such as the Rio Grande that runs through Colorado, New Mexico and along the Texas-Mexico boundary.

But if Colorado River river flows keep getting drier, and the river's reservoirs keep dropping, things could get to a point where the river carries so little water that the compact issue becomes irrelevant, said Kuhn.

One reason is that the Upper Basin states now are using only 4 million acre-feet a year, not counting evaporation. That's far less than those states are legally allowed to take under the compact, he said.

But 2 million of that is covered by what is known as "present perfected rights," a term used to describe water rights on the river that are older then the 1922 compact, said Kuhn.

He calls those rights "legally untouchable." 

If the river gets low enough that only 2 million acre-feet are available for the Upper Basin states, it's very unlikely that the Upper Basin wouldn't be allowed to use that water due to compact obligations, Kuhn said.

"A court might have a different opinion, but I think it’s pretty commonly accepted," said Kuhn of the legal validity of these rights.