- Arizona Republicans sent a formal letter opposing the federal draft plan for the Colorado River.
- Lawmakers argue the proposal places most water reductions on the Lower Basin states.
- Officials warn the plan could affect Arizona communities, agriculture, and industry.
- The delegation asked the Department of the Interior to withdraw and revise the proposal.
Wednesday, March 4, 2026 — A group of Arizona lawmakers is urging federal officials to reconsider a proposed plan that would guide operations of the Colorado River after 2026.
Yesterday, Congressman Andy Biggs and several members of Arizona’s Republican congressional delegation announced 
that they had submitted a formal comment letter to Interior Secretary Doug Burgum criticizing the Draft Environmental Impact Statement for the Post-2026 Operational Guidelines for Lake Powell and Lake Mead.
The proposal, prepared by the Bureau of Reclamation and the Department of the Interior, outlines several options for managing water shortages in the Colorado River system after the current rules expire in 2026.
Arizona lawmakers argue the draft plan unfairly targets the Lower Basin states, which include Arizona, California, and Nevada.
Concerns About Disproportionate Water Reductions.
According to the delegation’s March 2, 2026, letter to the Interior Department, the alternatives outlined in the draft would impose all required reductions on the Lower Basin while allowing Upper Basin states to increase their use of water.
The lawmakers wrote that the Lower Basin represents about 75 percent of the basin’s population and economy, along with 76 percent of jobs and 78 percent of crop sales.
They argue that placing the majority of water reductions on those states could have major economic and social consequences.
“The waters of the Colorado River are foundational to the economy of the Basin and the upcoming decisions that will be made by the Secretary will be felt in the West for generations,” the letter states.
The delegation also expressed concern that the draft plan could lead to large reductions in Arizona’s Colorado River supply, which is delivered primarily through the Central Arizona Project canal system.
Potential Impacts on Communities and Industry.
In their letter, the lawmakers said the Colorado River supports a wide range of economic activity in Arizona, including agriculture, advanced microchip manufacturing, and critical mineral production.
They warned that the proposed alternatives could threaten these sectors if significant water reductions occur.
The letter also states that more than six million Arizona residents depend on water delivered through the Central Arizona Project and that rural communities located along the river could face major reductions in water supplies.
In addition, tribal water supplies could be affected if the proposed reductions move forward.
The draft environmental review itself acknowledges that the alternatives could result in “widespread impacts on social and economic conditions,” including situations where municipalities might need to pursue alternative water sources or even hauled water to maintain basic services.
Legal Questions Raised About the Draft Plan.
The Arizona delegation also raised several legal concerns about the draft environmental review.
Among them is the claim that the analysis does not adequately address the delivery obligations of the Upper Basin states under the Colorado River Compact of 1922. The lawmakers also argue that the draft fails to fully consider the United States’ obligations under the United States–Mexico Water Treaty and other elements of the long-established framework known as the Law of the River.
Because of these issues, the delegation asked the Department of the Interior to withdraw the draft document and produce a revised version that more fully evaluates alternatives and legal obligations.
Calls for a Balanced Basin Agreement.
Arizona officials say they remain committed to working with the other Colorado River Basin states and federal agencies to reach a long-term agreement.
The delegation’s letter states that the Colorado River system works best when risks and reductions are shared more evenly among the basin states.
Officials also emphasized that the decisions made in the coming years will affect water supplies, infrastructure, and economies across the western United States for decades to come.
Brenda Burman, general manager of the Central Arizona Project, said Lower Basin states have already taken significant steps to conserve water.
“Arizona and our Lower Basin partners have sacrificed to contribute nearly 9 million acre-feet of water to help save the river system,” Burman said in the March 3, 2026 announcement. “Now it’s time for our Upper Basin neighbors who benefit from the river to show responsibility and step up with real reductions.”
Federal officials are expected to review comments submitted on the draft environmental analysis before issuing a final plan for managing Lake Powell and Lake Mead after 2026.
