Post-2026 Colorado River Operating Guidelines
The process replacing the rules that expire at the end of 2026 - timeline and documents, no speculation.
Western Reservoir Conditions·Daily·No. 45·
- The 2007 Interim Guidelines, the 2019 Drought Contingency Plans, and related international agreements with Mexico expire at the end of 2026.
- Reclamation released the Draft Environmental Impact Statement for post-2026 operations on ; the public comment period closed with 18,127 submissions.
- Reclamation published the Final Environmental Impact Statement on , and the Department of the Interior issued the Record of Decision on , after the seven basin states did not reach a consensus framework.
- The Record of Decision adopts a Decision Framework covering 2027 through 2036 and was issued together with the first two-year set of operating guidelines, for operating years 2027 and 2028. Reclamation states that subsequent guidelines are expected at two-year intervals.
- Under those guidelines the Lower Division States are apportioned 6.25 maf, a reduction of 1.25 maf: Arizona 2.04 maf (a cut of 760,000 af), California 3.96 maf (a cut of 440,000 af) and Nevada 250,000 af (a cut of 50,000 af).
Why new rules are needed
Operations of Lake Powell and Lake Mead are currently governed by the 2007 Interim Guidelines and the 2019 Drought Contingency Plans. Per Reclamation, these - together with related agreements under the 1944 Water Treaty with Mexico - are scheduled to expire at the end of 2026. The Post-2026 process is the multi-year NEPA process to determine operations for Lake Powell and Lake Mead and other water-management actions after that date. Source: USBR Colorado River Post-2026 Operations.
Timeline so far (from USBR's post-2026 pages)
| Date | Event |
|---|---|
| December 2007 | 2007 Interim Guidelines adopted; designed to run through 2026 |
| 2019 | Upper and Lower Basin Drought Contingency Plans signed, also through 2026 |
| 2023 | Public scoping for the post-2026 NEPA process; Reclamation published a Scoping Summary Report |
| November 20, 2024 | Reclamation publicly released the alternatives it anticipated analyzing in the Draft EIS |
| January 17, 2025 | Alternatives Report published, documenting operational elements of each alternative |
| January 9, 2026 | Draft EIS released for public download |
| January 16, 2026 | 45-day formal comment period opened with Federal Register publication |
| March 2, 2026 | Comment period closed: 18,127 submissions, including 785 unique submissions and over 17,000 form letters; two public meetings held |
| July 31, 2026 | Final Environmental Impact Statement published, with a Federal Register Notice of Availability the same day |
| August 21, 2026 | Record of Decision issued: Decision Framework for Colorado River Guidelines, Coordinated Operations of Lake Powell and Lake Mead (2027 to 2036), together with the 2027 and 2028 Operating Guidelines |
| End of 2026 | Current guidelines, DCPs, and related international agreements expire |
| 2027 and 2028 | First set of guidelines under the new framework takes effect; Lower Division apportionment 6.25 maf, a 1.25 maf reduction |
Sources: Post-2026 Operations home, the Decision Documents page, and the 2027-2028 Operating Guidelines (PDF), all usbr.gov, accessed August 25, 2026.
What happens next
The 2007 rules govern operations only through 2026, and water year 2027 begins on October 1, 2026. The NEPA process is now complete: Reclamation published the Final EIS on July 31, 2026 and Interior issued the Record of Decision on August 21, 2026, establishing a framework through 2036 with operating guidelines set in two-year increments. Reclamation has said a seven-state agreement can still be incorporated if the basin states reach one. This page reports process facts only and is updated as Reclamation publishes them; it makes no predictions.
Related: the current shortage tiers · Lake Mead today · Lake Powell today