On August 21, the Secretary of the Interior released its Record of Decision (ROD) for the Decision Framework for Colorado River Guidelines: Coordinated Operations of Lake Powell and Lake Mead (2027-2036). The decision tracks the FEIS that was released July 31, 2026, calling for the Secretary to adopt operating guidelines every two years that are consistent with a 10-year adaptive Decision Framework that includes a set of operational sideboards, although there are a few notable differences:

• The ROD adopts only the maximum 3 million acre feet volume of shortage for the Lower Basin states and does not adopt the reductions the FEIS attributed to Mexico (approximately 600,000 acre feet).
• The ROD declines to adopt any specific distribution of the Lower Basin shortage volumes; instead, it states, “specific shortage volumes, distributions, and conservation activities within the analyzed ranges for the operational sideboards will be established through Operating Guidelines.”
• The ROD describes the Lower Basin surplus guideline as “Up to 500 [thousand acre feet] in addition to any available surplus nearing or during flood control releases,” whereas the FEIS described it as “in addition to Flood Control and Quantified Surplus.” It is less clear whether surplus will still be available under Quantified Surplus conditions., a question that is likely purely academic at this point given the historically low elevations of the reservoirs.   

As part of the ROD, the Secretary also issued the inaugural Operating Guidelines for years 2027 and 2028 in anticipation of commencing operations October 1, 2026. The Guidelines reduce the Lower Basin states' Colorado River apportionment by 1.25 million acre feet, adopting the Lower Basin States' Proposal for sharing the shortage: (1) 760,000 acre feet from Arizona; (2) 440,00 acre feet from California; and (3) 50,000 acre feet from Nevada. The Secretary allows flexibility if the Lower Basin states do not adopt the proposal or conditions in Lake Mead fall below or exceed certain elevations. Specifically, if projections show Lake Mead dropping below 1,010 feet—the amount critical for hydroelectric power—emergency consultations will be triggered. The Guidelines also: 

(1) Call for Lower Basin users to conserve 700,000 acre feet of water through voluntary agreements.

(2) Place restrictions on banking conserved water in and withdrawing banked water from Lake Mead.

(3) Create a Federally Managed Water Resources Pool to assist with satisfying Native American water obligations. 

These Guidelines govern operations through the end of 2028 only and expressly do not set a precedent for future management of the river. The Secretary must initiate the process for the next set of guidelines no later than October 1, 2027, ensuring that subsequent rules will be tailored to the hydrologic and operational conditions facing the system at that time.

 What it means: The next two years of Arizona's water supply are set. What's not: how the state will handle the cuts and new conservation rules.