Full Breakdown
Arizona Joins Nevada Lawsuit Over Federal Colorado River Water Cuts
By Drooid · · How we work
The Legal Challenge
Arizona announced Friday it will intervene in Nevada’s federal lawsuit contesting the U.S. Interior Department’s new operating plan for the Colorado River. The suit, filed in Nevada federal court in August, argues the plan forces the three Lower Basin states—Arizona, California and Nevada—to absorb mandatory water reductions while exempting the four Upper Basin states—Colorado, New Mexico, Utah and Wyoming. Arizona’s intervention seeks to protect its legal rights to Colorado River deliveries and preserve the two-year Lower Basin conservation agreement for 2027-2028.
Background & Context
The Interior Department’s “record of decision,” signed in August 2026, establishes a ten-year framework that would cut 1.25 million acre-feet of water use annually from the Lower Basin for the next two years. Under the proposed split, Arizona would reduce its allocation by 760,000 acre-feet per year, California by 440,000 acre-feet, and Nevada by 50,000 acre-feet. The three states had already pledged to conserve more than 3.2 million acre-feet through 2028.
Data & Statistics
- Arizona’s projected cut: 760,000 acre-feet per year (? 27 % of its allocation).
- Total Lower Basin cuts: 1.25 million acre-feet per year for 2027-2028.
- Nevada’s potential reduction: up to 213,556 acre-feet annually (about 71 % of its entitlement).
- Conservation pledge: > 3.2 million acre-feet saved by the Lower Basin states through 2028.
- CAP risk: officials warn the federal cuts could slash the Central Arizona Project’s Colorado River allocation by roughly 77 % over the next two years.
All figures are drawn from statements by Arizona Department of Water Resources Director Tom Buschatzke and the filing details of Nevada’s lawsuit.
Official Statements & Responses
Arizona officials emphasized continued cooperation with Nevada and California on the Lower Basin agreement while challenging the federal environmental review.
John Entsminger, general manager of the Southern Nevada Water Authority, noted that both states share concerns about flaws in the federal review and remain committed to a negotiated solution.
Criticism & Opposition
Utah House Speaker Brad Rogers criticized the lawsuit, arguing that legal action “makes a difficult situation harder” for the basin’s overall water management.
Conflicting Reports & Gaps
Sources differ on the exact percentage impact to Nevada’s allocation: one report cites a 71 % reduction (213,556 acre-feet) while another mentions the same volume without specifying a percentage. The timing of how the 3.2 million-acre-foot conservation savings will be allocated among the three states remains unsettled.
Verbatim Quotes
- “Arizona’s decision to join Nevada’s legal challenge reflects a shared commitment to ensure decisions affecting the Colorado River are based on a transparent, scientific, and legally sound process,” — John Entsminger, authority general manager
- “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,” — Katie Hobbs, Arizona governor
- “Arizona’s decision to join our lawsuit is 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.” — Gov. Joe Lombardo, Nevada governor
What’s Next
The Interior Department’s operating framework took effect on October 1, and the mandated reductions to Arizona’s water deliveries are scheduled to begin January 1, 2027. The lawsuit remains pending in U.S. District Court with no hearing date set. Arizona officials say they will continue negotiating the Lower Basin agreement while pursuing the legal challenge.