The Bureau of Reclamation has released the Colorado River Basin August 2023 24-Month Study, which determines the tiers for coordinated operation of Lake Powell and Lake Mead for 2024.
Glen Canyon Dam, which impounds Lake Powell, provides water for a 1,320 MW hydroelectric powerhouse and Hoover Dam, which impounds Lake Mead, provides water for a 2,078 MW hydropower plant.
These operating conditions are based on agreements under the 2007 guidelines and lower basin Drought Contingency Plans and will be in effect until the near-term guidelines from the Supplemental Environmental Impact Statement (SEIS) are finalized. Reclamation is analyzing the consensus-based Lower Division States proposed alternative for the SEIS.
Based on projections in the 24-Month Study, Lake Powell will operate in a Mid-Elevation Release Tier with a 7.48 million acre-feet (maf) release in water year 2024. Consistent with existing agreements, Lake Mead will operate in a Level 1 Shortage Condition, an improvement from the Level 2 Shortage Condition announced last year, with required shortages by Arizona and Nevada, coupled with Lower Basin Drought Contingency Plan water savings contributions. Mexico’s water delivery will be reduced consistent with Minute 323.
Lake Mead’s release in 2023 is projected to be the lowest in 30 years, about 1.5 maf lower than an average normal year, reflecting extensive, ongoing conservation efforts in the Lower Basin states, above-normal inflows in the lower basin below Hoover Dam, and conservation in Mexico.
Investments in system conservation and improved hydrology this year have provided an opportunity to recover some reservoir storage. At the same time, the Colorado River system continues to face low elevations, with Lake Powell and Lake Mead at a combined storage of 36%.
“The above-average precipitation this year was a welcome relief, and coupled with our hard work for system conservation, we have the time to focus on the long-term sustainability solutions needed in the Colorado River Basin. However, Lake Powell and Lake Mead – the two largest reservoirs in the United States and the two largest storage units in the Colorado River system – remain at historically low levels,” said Reclamation Commissioner Camille Calimlim Touton. “As we experience a warmer, drier west due to a prolonged drought, accelerated by climate change, Reclamation is committed to leading inclusive and transparent efforts to develop the next-generation framework for managing the river system.”
Reclamation is simultaneously developing near- and long-term guidelines for Lake Powell and Lake Mead operations. The SEIS in progress focuses on near-term actions, which would be applicable from 2024 through 2026 based on potential changes to limited sections of the 2007 Interim Guidelines. Reclamation temporarily withdrew the SEIS so it could fully analyze the consensus-based Lower Division States proposed alternative and will publish an updated draft SEIS for public review and comment with the consensus-based proposal as an action alternative later this year.
A consensus-based proposal commits to measures to conserve at least 3 maf of system water through the end of 2026, when the current operating guidelines expire.
The long-term guidelines, informally referred to as Post 2026 Operations, will revisit the 2007 Interim Guidelines in full, as well as other operating agreements that expire in 2026, including Drought Contingency Plans and Minute 323. In June, Reclamation initiated the formal process to develop the long-term operating guidelines.
Until the updated near-term guidelines are finalized once the SEIS is complete, Reclamation will continue to implement the plans developed over the past two decades that lay out detailed operational rules for these critical Colorado River reservoirs through 2026.
