The Biden-Harris administration October 25 announced next steps in the efforts to protect the stability and sustainability of the Colorado River System and strengthen water security in the West. The Department of the Interior’s Bureau of Reclamation released a revised draft Supplemental Environmental Impact Statement (SEIS) as part of the ongoing, collaborative effort to update the current interim operating guidelines for the near-term operation of Glen Canyon and Hoover Dams to address the ongoing drought and impacts from the climate crisis.
In order to protect Glen Canyon and Hoover Dam operations, system integrity, and public health and safety through 2026 – at which point the current interim guidelines expire – an initial draft SEIS was released in April 2023. Following a historic consensus-based proposal in partnership with states – which committed to measures to conserve at least 3 million-acre-feet (maf) of system water through the end of 2026 enabled by funding – Reclamation temporarily withdrew the draft SEIS to allow for consideration of the new proposal.
The revised draft SEIS includes two key updates: the Lower Basin states’ proposal as an action alternative, as well as improved hydrology and more recent hydrologic data. The release of the revised draft SEIS initiates a 45-day public comment period.
“Throughout the past year, our partners in the seven Basin states have demonstrated leadership and unity of purpose in helping achieve the substantial water conservation necessary to sustain the Colorado River System through 2026,” said Deputy Secretary Tommy Beaudreau, who led negotiations on behalf of the Administration. “Thanks to their efforts and funding, we have staved off the immediate possibility of the System’s reservoirs from falling to critically low elevations that would threaten water deliveries and power production.”
Lake Powell and Lake Mead at “historically low levels”
“The Colorado River Basin’s reservoirs, including its two largest storage reservoirs Lake Powell and Lake Mead, remain at historically low levels. Today’s advancement protects the system in the near-term while we continue to develop long-term, sustainable plans to combat the climate-driven realities facing the Basin,” said Reclamation Commissioner Camille Calimlim Touton. “As we move forward in this process, we are also working to ensure we have long-term tools and strategies in place to help guide the next era of the Colorado River Basin.”
Key components of revised draft SEIS
Reclamation conducted updated modeling analyses using June 2023 hydrology for the No Action Alternative, Action Alternatives 1 and 2 from the initial draft SEIS, and the Lower Division proposal. The results of that modeling indicate that the risk of reaching critical elevations at Lake Powell and Lake Mead has been reduced substantially. As a result of the commitment to record volumes of conservation in the Basin and recent hydrology, the chance of falling below critical elevations was reduced to eight percent at Lake Powell and four percent at Lake Mead through 2026. However, elevations in these reservoirs remain historically low and conservation measures like those outlined by the Lower Division proposal will still be necessary to ensure continued water delivery to communities and to protect the long-term sustainability of the Colorado River System.
Based on these modeling results, Reclamation will continue the SEIS process with detailed consideration of the No Action Alternative and the Lower Division Proposal. The revised SEIS designates the Lower Division Proposal as the Proposed Action. Alternatives 1 and 2 from the initial SEIS were considered but eliminated from detailed analysis.
Funding key to increase conservation efforts
Investing is key in the efforts to increase near-term water conservation, build long term system efficiency, and prevent the Colorado River System’s reservoirs from falling to critically low elevations that would threaten water deliveries and power production. Because of this funding, conservation efforts have already benefited the system this year.
This includes eight new System Conservation Implementation Agreements in Arizona that will commit water entities in the Tucson and Phoenix metro areas to conserve up to 140,000-acre feet of water in Lake Mead in 2023, and up to 393,000-acre feet through 2025. Reclamation is working with its partners to finalize additional agreements. These agreements are part of the 3 maf of system conservation commitments made by the Lower Basin states, 2.3 maf of which will be compensated through funding from the Inflation Reduction Act, which invests a total of $4.6 billion to address the historic drought across the West.
Through the Bipartisan Infrastructure Law, Reclamation is also investing another $8.3 billion over five years for water infrastructure projects, including water purification and reuse, water storage and conveyance, desalination and dam safety.
To date, the Interior Department has announced the following investments for Colorado River Basin states, which will yield hundreds of thousands of acre-feet of water savings each year once these projects are complete:
Long-Term Planning Efforts to Protect the Colorado River System
The process announced October 25 is separate from the recently announced efforts to protect the Colorado River Basin starting in 2027. The revised draft SEIS released today would inform Reclamation’s ongoing efforts to set interim guidelines through the end of 2026; the post-2026 planning process advanced last week will develop guidelines for when the current interim guidelines expire.
(Editor’s note: The San Diego County Water Authority supports a consensus-based approach for long-term solutions to water supply issues in the Colorado River Basin. The content of the USBR news release has been edited by WNN.)
