Analysis of Colorado River Basin Storage Suggests Need For Immediate Action

John Fleck | September 11th, 2025

Annual Operating Plan for Colorado River Reservoirs 2021

U.S. Bureau of Reclamation (USBR) | December 9th, 2020

Annual Owens Valley Operations Plan for the 2023-24 Runoff Year

Los Angeles Department of Water & Power (LADWP) | April 25th, 2023

Annual Owens Valley Operations Plan for the 2024-25 Runoff Year

Los Angeles Department of Water & Power (LADWP) | June 20th, 2024

Annual Report of Activities October 1, 2013 to September 30, 2014, American River Group (ARG)

Delta Stewardship Council (Delta Council) | September 30th, 2014

Annual Report of Activities October 1, 2013, to September 30, 2014, Delta Operations for Salmonids and Sturgeon (DOSS) Technical Working Group

Delta Stewardship Council (Delta Council) | October 31st, 2014

Annual Report of Activities Water Year 2018 Stanislaus Operations Group (SOG)

Delta Stewardship Council (Delta Council) | November 1st, 2018

Annual Report of Activities, October 1, 2013 to September 30, 2014, Stanislaus Operations Group (SOG)

Delta Stewardship Council (Delta Council) | September 30th, 2014

August 2025 Most Probable 24-Month Study

U.S. Bureau of Reclamation (USBR) | August 15th, 2025

The August 2024 24-Month Study projected the January 1, 2025, Lake Mead elevation to be below 1,075 feet and above 1,050 feet. Consistent with Section 2.D.1 of the Interi

The August 2024 24-Month Study projected the January 1, 2025, Lake Mead elevation to be below 1,075 feet and above 1,050 feet. Consistent with Section 2.D.1 of the Interim Guidelines, a Shortage Condition consistent with Section 2.D.1.a will govern the operation of Lake Mead for calendar year (CY) 2025. In addition, Section III.B of Exhibit 1 to the Lower Basin Drought Contingency Plan (DCP) Agreement will also govern the operation of Lake Mead for CY 2025. Lower Basin projections for Lake Mead take into consideration additional conservation efforts under the LC Conservation Program. The August 2025 24-Month Study projected the January 1, 2026, Lake Powell elevation to be less than 3,575 feet and at or above 3,525 feet and the Lake Mead elevation to be at or above 1,025 feet. Consistent with Section 6.C.1 of the Interim Guidelines, and Section 6.E of the 2024 Interim Guidelines SEIS ROD, the operational tier for Lake Powell in WY 2026 is the Mid-Elevation Release Tier and the water year release volume from Lake Powell is projected to be 7.48 maf. Given the hydrologic variability of the Colorado River System, the actual water year 2026 operations, and being consistent with Section 6.E of the 2024 Interim Guidelines SEIS ROD, the projected release from Lake Powell in water year 2026 may be less than 7.48 maf. The August 2025 24-Month Study projected the January 1, 2026, Lake Mead elevation to be below 1,075 feet and above 1,050 feet. Consistent with Section 2.D.1 of the Interim Guidelines, a Shortage Condition consistent with Section 2.D.1.a will govern the operation of Lake Mead for CY 2026. In addition, Section III.B of Exhibit 1 to the Lower Basin DCP Agreement will also govern the operation of Lake Mead for CY 2026. Lower Basin projections for Lake Mead take into consideration additional conservation efforts under the LC Conservation Program. The 2026 operational tier determinations for Lake Powell and Lake Mead will be documented in the 2026 AOP, which is currently in development. Related scenarios: August 2025 Probable Minimum 24-Month Study August 2025 Probable Maximum 24-Month Study

August 2025 Probable Maximum 24-Month Study

U.S. Bureau of Reclamation (USBR) | August 15th, 2025

In addition to the August 2025 24-Month Study based on the Most Probable inflow scenario, and in accordance with the Upper Basin Drought Response Operations Agreement (DR

In addition to the August 2025 24-Month Study based on the Most Probable inflow scenario, and in accordance with the Upper Basin Drought Response Operations Agreement (DROA), Reclamation has conducted additional model runs in August to determine a possible range of reservoir elevations. Probable minimum and probable maximum model runs are conducted in January, April, August, and October, or when necessary to incorporate changing conditions. The Probable Minimum inflow scenario reflects a dry hydrologic condition which statistically would be exceeded 90% of the time. The Most Probable inflow scenario reflects a median hydrologic condition which statistically would be exceeded 50% of the time. The Probable Maximum inflow scenario reflects a wet hydrologic condition which statistically would be exceeded 10% of the time. There is approximately an 80% probability that a future elevation will fall inside the range of the minimum and maximum inflow scenarios. Additionally, there are possible inflow scenarios that would result in reservoir elevations falling outside the ranges indicated in these reports. Related scenarios: August 2025 Most Probable 24-Month Study August 2025 Probable Minimum 24-Month Study