News that Arizona will have to give up more than a quarter of its annual Colorado River water allocation next year left state leaders in the paradoxical position of both celebrating their success at dodging an even worse fate and contemplating a lawsuit to challenge the federal plan.
The U.S. Interior Department announced Aug. 21 that its plan to preserve water stored in Lake Mead and Lake Powell would cut 1.25 million acre-feet of deliveries to the river’s Lower Basin states in each of the next two years, including 760,000 acre-feet from Arizona. Painful as it will be, it’s what Arizona and its neighbors in California and Nevada had offered to save, essentially to buy time to work out a longer-term deal with the four other states that use the river.
The plan is intended to protect critical levels at Hoover and Glen Canyon dams for the next two years, but even such deep cuts are not guaranteed to do so, observers say.
“We are on the knife’s edge,” said Jennifer Pitt, Colorado River program director for the National Audubon Society. “The reservoirs have been allowed to decline to the point that there is no buffer.”
For now, the shortage plan avoids what could be much larger cuts that Interior and its Bureau of Reclamation have determined they still have authority to impose if conditions worsen over the next decade.
“With this plan, we saved Arizona from forced federal cuts that would have crippled our economy and America’s national security,” Gov. Katie Hobbs said in a statement. “The 77% cut to (the Central Arizona Project’s) water supply that the federal government considered in January would have been an unacceptable disaster.”
Will Arizona sue the feds?
Arizona is nonetheless girding for a potential lawsuit. Interior Secretary Doug Burgum simultaneously finalized the two-year plan and 10-year “framework” that still allows for the government to short Arizona in ways the state considers excessive and out of compliance with its rights under the Colorado River Compact.
“We definitely are reserving our rights to assess compact compliance and to take appropriate action if and when we decide to do so,” Arizona Water Resources Director Tom Buschatzke said.
The state might be wise to test a case sooner rather than later, said Sarah Porter, director of Arizona State University’s Kyl Center for Water Policy. Waiting too long to challenge either Interior’s authority to issue the larger cuts that it envisions or the plan’s likelihood to violate the 1922 river compact’s guarantees to the Southwest risks waiving the right to make such claims when conditions worsen, she said.
“Arizona simply cannot risk waiving those challenges,” Porter said. “It has too much to lose.”
Arizona has set aside a litigation fund and hired a firm that would defend its rights, but has not yet said whether a lawsuit is imminent.
A potential compact lawsuit would go straight to the U.S. Supreme Court and would seek an interpretation of a clause in that seven-state pact that says the four states of the Upper Basin “will not cause” the flow of the river to the Lower Basin “to be depleted” to less than 75 million acre-feet over any 10-year period, essentially guaranteeing a rolling average of 7.5 million a year for Arizona, California and Nevada to share.
Interior’s plan to release as little as 6 million next year is likely to trigger that clause for the first time.
The Upper Basin states of Colorado, Wyoming, Utah and New Mexico have said the clause does not oblige them to ensure a 7.5 million acre-foot supply to their downstream neighbors, especially when the four up-river states are not using the 7.5 million that the compact also granted them. Colorado’s river commissioner, Becky Mitchell, made the case again during an Aug. 20 livestreamed forum sponsored by PBS.
“It’s a commitment to not cause a depletion,” Mitchell said, not to ensure that the Lower Basin gets more. The Upper Basin typically uses up to 5 million acre-feet a year, and considerably less in drought years like this one when headwater streams that supply farmers dry up.
“What I can’t promise is to deliver water when it’s not there,” Mitchell said.
The Upper Basin’s argument ignores history, Porter said. The reason the Upper Basin, along with Arizona and Nevada, wanted a compact in the first place was to prevent California from taking most of the water, she said. California agreed to limits, she said, but would never have agreed to make its rights inferior to those of the upstream states. If the Upper Basin has no obligation to guarantee the Lower Basin’s compact allocation, then theoretically it could drain the entire river and blame climate change.
“I don’t think it’s a slam dunk by any stretch of the imagination for the Upper Basin,” Porter said.
The competing interests of water and hydropower
Beyond a compact challenge, or in conjunction with one, Arizona is assessing its right to insist that Interior use water stored behind smaller Upper Basin dams to backfill Lake Powell and Lake Mead before it imposes deeper cuts on the Lower Basin.
The Upper Basin has balked at requests to use those dams, known as the system’s “upper initial units,” for assuring the Lower Basin’s supply, and the federal government has not specified the degree to which it will use them for that purpose.
“We believe the upper initial units are there to protect compact compliance,” Buschatzke said.
One Arizona water official questioned whether Interior has the legal right to impose cuts of this scale to preserve hydropower generation at Glen Canyon Dam when it could release more from river outlet tunnels that are deeper than the power plant intakes.
The authorizing legislation for Glen Canyon and the upstream dams prioritized water delivery over hydropower, said Ted Cooke, a board member on the Water Infrastructure Finance Authority of Arizona. The federal shortage plan appears to favor hydropower instead by keeping Lake Powell’s surface above those intakes when another 4 million acre-feet below them could be released before the reservoir hit “dead pool” below the outlet tunnels.
“They’re excluding 4 million acre-feet that’s sitting in Lake Powell that they’re not willing to release because it would potentially damage the infrastructure,” said Cooke, who formerly managed the Central Arizona Project and was a candidate for Reclamation commissioner before the Trump administration withdrew his nomination without explanation last year.
Porter agreed that congressional authorizations favored the dams for water delivery, with the added benefit of generating power to help pay for the projects. But she said it’s not clear that the government’s plan is meant to protect hydropower generation. Reclamation has said the bypass tunnels were not intended to pass all of the water that must be released from Powell on a consistent basis, and past uses have damaged those tunnels and required repair.
Hydropower advocate Leslie James rejected the argument that authorization for Powell and the upstream dams treated hydropower as a lesser objective. The Colorado River Storage Project Act includes a list of purposes, she said in an email.
“Hydropower is one and NOT secondary,” she wrote.
The Colorado River Energy Distributors Association has argued this in court against the environmental group Save the Colorado and has prevailed, said James, CREDA’s past president and now an adviser to the organization.
Drawing on the water banked in past years
Arizona will lose 760,000 acre-feet of its compact-allocated 2.8 million acre-foot share of the river in both 2027 and 2028. If conditions worsen and more is needed after two years, Interior’s plan calls for consulting states and then potentially taking 3 million acre-feet from the Lower Basin, a dramatic cut that Arizona officials say could entirely drain CAP’s former supply of up to 1.6 million acre-feet.
An acre-foot is roughly 326,000 gallons and could supply three or more households for a year. Most of the water in Arizona and across the Colorado River watershed is used on farms.
Metro Phoenix cities supply some 38% of their tap water through CAP’s river allocation, Kyl Center Research Director Kathryn Sorensen said. Another 38% comes from local supplies out of Salt and Verde river reservoirs, and the rest from wells.
City water managers have planned to start pumping more groundwater to make up the difference, including water that the state and cities previously stored in the ground using excess deliveries from the Colorado. These and other alternatives will insulate residential customers in the near term, Buschatzke and others said. Meanwhile, the state is looking to develop new sources, including from exchanges beyond state lines.
While the crisis may not be immediate for cities, experts say the one at the reservoirs and for the environment that relies on them is precarious.
“If we don’t get a really wet winter we’re in big trouble next year and the year after that,” said Pitt, whose work with Audubon focuses on restoring natural habitats in the Colorado River Delta using what little water is left for the environment.
Some have pinned hopes for that wet winter on the developing El Niño, a weather pattern that often brings more moisture to the Southwest but can be hit-and-miss in the mountains where most of the Colorado’s water originates as snow.
“Unfortunately,” Buschatzke said, “when you look at the Colorado River Basin and the Upper Basin, there's no real correlation between El Niños and a wet year or El Niños and a dry year.”
Brandon Loomis covers environmental and climate issues for The Arizona Republic and azcentral.com. Reach him at brandon.loomis@arizonarepublic.com.
Environmental coverage on azcentral.com and in The Arizona Republic is supported by a grant from the Nina Mason Pulliam Charitable Trust.
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This article originally appeared on Arizona Republic: Arizona avoids disaster with Colorado River plan, but could still sue
