Supplemental Environmental Impact Statement for Near-term Colorado River Operations

The Bureau of Reclamation has released the Record of Decision for the final Supplemental Environmental Impact Statement for Near-term Colorado River Operations. The supplement is to the December 2007 Record of Decision associated with the Colorado River Interim Guidelines for Lower Basin Shortages and Coordinated Operations for Lake Powell and Lake Mead, referred to as the 2007 Interim Guidelines.

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This ROD implements the Preferred Alternative identified in the Final SEIS. It revises the 2007 Interim Guidelines for the near-term operation of Glen Canyon and Hoover Dams to address the potential for continued low-runoff conditions in the Basin by making limited adjustments to the 2007 Interim Guidelines Record of Decision.

Reclamation published the Notice of Availability of the Final SEIS in the Federal Register on March 8, 2024, for a 30-day public review period. The Final SEIS analyzed two alternatives in detail:

  • The No Action Alternative, required by the National Environmental Policy Act, describes the continued implementation of existing agreements that control operations of Glen Canyon and Hoover Dams.
  • The Proposed Action ("Lower Division Proposal"), which is the Preferred Alternative, models changes to operations for both Glen Canyon Dam and Hoover Dam. The Proposed Action includes assumptions for reducing releases, if needed, down to 6.0 million acre-feet from Lake Powell with the goal of keeping Lake Powell elevation above 3,500 feet and assumptions for a total of 3 maf of SEIS conservation through 2026 with a minimum of 1.5 million acre-feet physically conserved by the end of calendar year 2024. Under the Proposed Action, tier-based reductions and contributions shall be limited to the existing 2007 Interim Guidelines, Lower Basin DCP, and Minute 323.

Purpose and Need

The purpose of the SEIS is to supplement the 2007 Interim Guidelines to modify guidelines for operation of Glen Canyon Dam and Hoover Dam to address historic drought, historically low reservoirs, and low runoff conditions in the Colorado River Basin. The need for the modified operating guidelines is based on the potential that continued low runoff conditions in the Colorado River Basin could lead Lake Powell and Lake Mead to decline to critically low elevations, impacting operations through the remainder of the interim period (prior to January 1, 2027).


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Last Updated: 5/9/24