August 16, 2023 — The Bureau of Reclamation released the Colorado River Basin August 2023 24-Month Study yesterday, which outlines the operational tiers for Lake Powell and Lake Mead in 2024. The study is based on existing agreements under the 2007 guidelines and lower basin Drought Contingency Plans. These operating conditions will be in effect until the near-term guidelines from the Supplemental Environmental Impact Statement (SEIS) are finalized.

Projections from the 24-Month Study: Back to Tier 1.

The 24-Month Study projects that Lake Powell will operate in a Mid-Elevation Release Tier with a 7.48 million acre-feet release in the water year 2024. Lake Mead will operate under a Level 1 Shortage Condition, an improvement from the Level 2 Shortage Condition announced last year. This level requires water savings contributions and shortages by Arizona and Nevada, along with reduced water delivery to Mexico.

Lake Mead’s release in 2023 is expected to be the lowest in 30 years, approximately 1.5 million acre-feet lower than an average normal year. This decrease is attributed to extensive conservation efforts in the Lower Basin states, above-normal inflows in the lower basin below Hoover Dam, conservation in Mexico, and funding provided by President Biden’s Investing in America agenda.

According to the Arizona Municipal Water Users Association, “The wet winter has temporarily prevented Lake Powell and Lake Mead from reaching critical operational levels and has lifted the elevation of Lake Mead to above 1050 feet. Under the current operating guidelines, the elevation determines that we will return to a Tier 1 Shortage for 2024.  A Tier 1 Shortage means Arizona will have access to slightly more Colorado River water in 2024 than under the current Tier 2a Shortage. However, it is still less water than what Arizona has historically received.”

Nevada’s 8 News Now noted that with the return to Tier 1, “Southern Nevada will gain the right to use another 4,000 acre-feet of water. That’s the equivalent of about 1.3 billion gallons — enough to supply 8,000 to 12,000 more households.”  The region intends to remain focused on its water conservation efforts.

The Hill broke the numbers down:

The Tier 1 shortage means that Arizona will face 512,000 acre-feet of cutbacks, or approximately 18 percent to the state’s annual Colorado River apportionment.

Nevada, meanwhile, will lose 21,000 acre-feet, or about 7 percent of the state’s allotment.

Mexico will lose 80,000 acre-feet, or about 5 percent of the country’s annual share.

Under Lake Mead’s first-ever “Tier 2a” shortage announced last summer, Arizona contributed about 21 percent of its annual apportionment, Nevada lost 8 percent and Mexico conserved approximately 7 percent for the 2023 year.

Reclamation Commissioner’s Statement.

Reclamation Commissioner Camille Calimlim Touton stated that the above-average precipitation this year, combined with system conservation efforts, provides the opportunity to focus on long-term sustainability solutions for the Colorado River Basin. However, she emphasized that Lake Powell and Lake Mead, the two largest reservoirs in the United States, remain at historically low levels due to prolonged drought and accelerated climate change.

Development of Near- and Long-Term Guidelines.

Reclamation is currently working on both near- and long-term guidelines for Lake Powell and Lake Mead operations. The supplemental SEIS in progress focuses on near-term actions for 2024 through 2026 based on potential changes to the 2007 Interim Guidelines. Reclamation temporarily withdrew the SEIS to analyze the consensus-based Lower Division States proposed alternative and plans to publish an updated draft SEIS for public review and comment later this year.

A consensus-based proposal, agreed upon by the three Lower Basin states, commits to conserving at least 3 million-acre-feet of system water by the end of 2026 when the current operating guidelines expire.

The long-term guidelines, referred to as Post 2026 Operations, will revisit the 2007 Interim Guidelines, as well as other operating agreements expiring in 2026, including Drought Contingency Plans and Minute 323. Reclamation began the formal process for the long-term guidelines in June.

Federal-Tribal-State Partnership.

In response to Tribal feedback, the Department of the Interior established a Federal-Tribal-State partnership to promote equitable information-sharing among sovereign governments in the Colorado River Basin. All 30 Colorado River Basin Tribal Nations and the seven U.S. basin states were invited to participate in this new group, which held its first meeting last week.

2024 Operations of Lake Powell and Lake Mead.

Until the near-term guidelines are finalized, Reclamation will continue to implement existing plans developed over the past two decades that lay out operational rules for the Colorado River reservoirs through 2026.

• Lake Powell: It will operate in the Mid-Elevation Release Tier in water year 2024, with a projected release of 7.48 million acre-feet without mid-year adjustment.
• Lake Mead: The 24-Month Study projects it to operate in a Level 1 Shortage Condition for calendar year 2024, requiring water savings and shortage reductions from Arizona, Nevada, and Mexico.

President Biden’s Investing in America Agenda.

President Biden’s Investing in America agenda strengthens system conservation and efficiency programs in the Colorado River Basin, investing in long-term system efficiency improvements and climate resilience. Reclamation is investing $8.3 billion over five years for water infrastructure projects through the Bipartisan Infrastructure Law. Additionally, the Inflation Reduction Act is investing $4.6 billion to address the historic drought.

Image:

“The current water level of Lake Mead behind the Hoover Dam,” from Bureau of Reclamation’s press release.