Arizona is joining a fight against the Trump administration’s 10-year plan for managing the Colorado River that could slash the state’s share of water.
The Arizona Department of Water Resources filed a motion Friday to intervene in Nevada’s earlier lawsuit, claiming the federal government’s plan for the shrinking river would “devastate Arizona’s economy,” the agency’s director said in a news release.
“The State’s towns, cities, tribes, farmers, factories, and businesses cannot survive without sufficient water from the Colorado River,” attorneys for the state claim in the motion.
Nevada filed a lawsuit in late August against several federal agencies, arguing that their plan places a heavier burden on the Lower Basin states. The amount of water in the Colorado River is dwindling because of climate change, which is reducing the amount of snow and runoff that fills reservoirs like Lake Mead and Lake Powell, and mid-20th century agreements that promised water users more water than actually exists. Because the seven states that rely on the Colorado River couldn’t reach an agreement on how to manage the water, the federal issued a plan intended to better balance the amount of water in the river with the amount withdrawn.
Arizona and Nevada argue they have already taken steps to conserve water and are being unfairly targeted.
“The Lower Basin states have contributed millions of acre-feet of water toward stabilizing the river system. With more than 5.5 million acre-feet of Arizona water left in Lake Mead since 2014, no state has sacrificed more,” Arizona Department of Water Resources Director Tom Buschatzke said in an Oct. 16 statement. “The US decision puts the entire burden of sacrifice on the shoulders of three states. We are joining Nevada in challenging that framework.”
The Colorado River is divided between Upper Basin states — Colorado, New Mexico, Utah and Wyoming — and Lower Basin states: Arizona, Nevada and California. The 1922 Colorado River Compact allocates 7.5 million acre-feet of water annually to each of the two basins, as well as a smaller portion for parts of México. The U.S. states in each basin divide their shares.
An acre-foot is the equivalent of almost 326,000 gallons of water, enough water to cover a football field in roughly a foot of water. In Arizona, one acre-foot typically is enough to serve three single-family homes for a year, according to the Arizona Department of Water Resources.
California gets the largest share of Colorado River water: 4.4 million acre-feet per year, or about 27%. The state’s Lower Basin peers get smaller allocations. Arizona receives 2.8 million acre-feet, or about 17% annually. Nevada receives 300,000 acre-feet, or about 2% annually, according to Congressional reports and a California public policy analysis.
“We will not accept a forced federal plan that solves this crisis on the backs of our families, farmers, and businesses.”
The U.S. Bureau of Reclamation’s plan requires the Lower Basin states to shoulder potential cuts. For Arizona, the proposal means a reduction of 760,000 acre-feet per year — about a quarter of the state’s water allocation and the largest cut among the three Lower Basin states. California would be required to cut 440,000 acre-feet per year and Nevada 50,000 acre-feet. The cuts could amount to up to 3 million acre-feet.
The federal government is not requiring cuts for Upper Basin states. Instead, the government is asking the upstream states to voluntarily contribute 200,000 acre-feet each of the two years.
“Arizona has always been willing to do our part to protect the Colorado River, but we will not accept a forced federal plan that solves this crisis on the backs of our families, farmers, and businesses,” Arizona Gov. Katie Hobbs said in a statement Friday.
In a complaint Arizona filed with its motion to join Nevada’s lawsuit, the state claims there was a flaw in the federal government’s environmental review underpinning the decision. Every federal option considered “assumed that the Upper Basin States would make no meaningful reduction in their own use, no matter how little water the River produced.
“The alternatives placed the full burden of any resulting shortfall on the Lower Basin,” the complaint says.
Western water rights are prioritized according to a “first in time, first in right” doctrine, meaning those who claimed or purchased river water first are prioritized over water users who did so later. That means Arizona’s Colorado River rights are lower priority than California’s, which were acquired earlier.
“Such reductions could effectively dry up the Central Arizona Project canal system, as well as many of our on-river communities and would more than double the water cuts agreed to in the Lower Basin Agreement,” Buschatzke said.
Nevada’s August lawsuit came just three days after the U.S. Department of the Interior formally announced its Colorado River plan in August. In it, Nevada claims the cuts “will cause devastating environmental, socioeconomic, and health and human safety impacts to southern Nevada and its citizens.”
The lawsuit also claims that the federal government’s plan violates several requirements within the Law of the River, based on a series of records that include compacts, treaties, laws and court decisions that manage the Colorado River.
Nevada Gov. Joe Lombardo welcomed Arizona’s decision to join the lawsuit, saying in a Friday statement that it’s “an important step in challenging a federal plan that unfairly burdens the Lower Basin and fails to require the Upper Basin to make meaningful reductions.”
Arizona says joining Nevada’s lawsuit would allow it to avoid filing a separate but similar lawsuit, and allow the borderlands state to represent its own interests.
“Arizona believes that taking this action now provides the best path forward for protecting Arizona water users,” Buschatzke said.
This story was produced as part of the Western Environmental Reporting Collaborative, a partnership between Arizona Luminaria, High Country News, Report for America and local news organizations across the West.
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