Arizona is becoming a member of Nevada’s legal problem to the federal authorities’s new Colorado River guidelines, including the state dealing with the deepest near-term cuts to the struggle over how federally mandated cuts are divided among the seven basin states.
Arizona Gov. Katie Hobbs (D) and the Arizona Department of Water Resources announced Friday that the state has intervened in the August lawsuit Nevada filed against the U.S. Department of the Interior. Arizona officers said the federal plan fails to maintain the Upper Basin states of Colorado, Utah, Wyoming and New Mexico accountable for delivering water to Lake Mead and could lead to Lower Basin cuts of up to 3 million acre-feet a 12 months.
“We are drawing a line in the sand,” Hobbs said in a assertion. She said Arizona would proceed working with Nevada and California to carry out their own two-year Lower Basin settlement while the case strikes through court.
Tom Buschatzke, the division’s director and Arizona’s lead Colorado River negotiator, said intervening was obligatory to shield the state’s legal rights to the river while conserving a negotiated end result with California and Nevada on the desk.
Nevada, the Colorado River Commission of Nevada and the Southern Nevada Water Authority filed go well with Aug. 24, turning into the first state to problem Interior’s closing plan launched Aug. 21.
Under the federal framework, Nevada’s 300,000 acre-foot allocation could be cut by as much as 213,556 acre-feet, or about 71 %, if Lower Basin shortages attain the framework’s outer restrict — leaving Southern Nevada with less than 86,500 acre-feet a 12 months.
An acre-foot is about 326,000 gallons, roughly enough to cowl a soccer area in a foot of water or provide two to three households for a 12 months. Southern Nevada used about 198,000 acre-feet in 2025, according to the water authority.
Gov. Joe Lombardo (R) said in a assertion Friday that Arizona’s resolution is “an important step in challenging a federal plan that unfairly burdens the Lower Basin.” He said Nevada stays dedicated to a negotiated answer but will not settle for a framework that places the state’s water provide at risk.
Southern Nevada Water Authority General Manager John Entsminger said Arizona shares Nevada’s considerations about flaws in the federal environmental review and the course of used to develop the post-2026 framework. He said the company is still working with California and Arizona to finalize a Lower Basin settlement to cut back near-term calls for on Lake Mead.
The three Lower Basin states proposed that settlement in May, committing to preserve more than 3.2 million acre-feet through 2028. Interior adopted the near-term break up for 2027 and 2028, under which Arizona will have to cut back its use by 760,000 acre-feet a 12 months, California by 440,000 and Nevada by 50,000.
Arizona officers said the stakes are particularly high for the state because the Central Arizona Project, which carries river water to Phoenix and Tucson, holds comparatively junior water rights. Without the Lower Basin settlement, they said, the project’s Colorado River allocation could be cut by 77 % over the next two years.
Arizona said it plans to problem elements of the federal authorities’s closing environmental review and the closing plan itself, which it argues unlawfully fails to require releases from Upper Basin reservoirs to Lake Mead.
Nevada’s lawsuit has already drawn pushback upstream. Utah’s House speaker criticized the go well with shortly after it was filed, saying it made a troublesome state of affairs tougher.