As the seven Colorado River Basin States prepare for November’s high-stakes negotiations with the Bureau of Reclamation (BOR) on post-2026 operating rules, a September analysis warns that time may be running out to prevent a near-term collapse in the system’s storage reserves.
The report, authored by a group of water policy experts and researchers, underscores that while policymakers are focused on long-term operating agreements, the Colorado River Basin faces a short-term emergency that cannot wait for 2026.
Shrinking safety net
The authors caution, “If next year is a repeat of this year and uses of water remain the same, we estimate that consumptive use will exceed the natural flow in the Colorado River Basin by at least 3.6-million-acre-feet (an acre-foot is 325,851 gallons).”
That shortfall would deplete already-thin reserves in Lakes Mead and Powell, leaving less than 4 million acre-feet available above critical thresholds by late summer 2026. Without swift reductions in water use, the two reservoirs that sustain 40 million people and 5.5 million acres of farmland could approach functional limits well before the post-2026 operating guidelines take effect.
Using Reclamation’s August 2025 24-Month Study and observed inflows, the authors conducted a simple mass balance assessment—total inflow minus consumptive use and evaporation losses. The findings are stark: in September 2025, Lakes Mead and Powell held 15.1 million acre-feet of active storage, but only 6.3 million acre-feet was “realistically accessible”—that is, water stored above the critical elevations needed to safely operate Glen Canyon and Hoover dams.
Lake Powell, the report notes, contained 7 million acre-feet of active storage, yet only 2.7 million acre-feet was above the 3,500-foot elevation that Reclamation now treats as its minimum protective threshold. Lake Mead held 8.1 million acre-feet, with just 3.6 million acre-feet above the 1,000-foot mark.
The authors emphasize in a press release that even a modestly dry winter could tip the balance. “If 2026 is as dry as 2025,” they caution, “our reserve of usable water could drop next year to just 3.6 million acre-feet—less than the lowest storage content recorded in March 2023.” Should that occur, the ensuing reservoir depletion season could erase another 1.4 million acre-feet before spring runoff begins.
Uncertainty and recommendations
The report said that despite wet years in 2005, 2011, 2019 and 2023, the river basin has reverted to deficit. Between 1999 and 2025, storage across 12 federal reservoirs declined 60%. Natural flow at Lees Ferry averaged about 8.5 million acre-feet last year. In comparison, total consumptive use in the U.S. and Mexico reached roughly 12.9 million acre-feet, creating a systemic shortfall of 3.6 million acre-feet.
“The river recognizes no human laws or governance structures and follows only physical ones,” the report states.
The report also cautions about emergency drought releases from upstream reservoirs such as Flaming Gorge, Blue Mesa and Navajo reservoirs. Though these can temporarily bolster Lake Powell levels under the Drought Response Operations Agreement, they are “a one-time solution.” Drawing down Flaming Gorge to protect Powell, the authors warn, “simply exacerbates future shortages,” since those reservoirs would need years of wet conditions to refill.
The authors call for “immediate and substantial reductions in consumptive use across the Basin” rather than waiting for the next round of federal rulemaking. They recommend that the Department of the Interior take short-term administrative action if the states cannot agree to voluntary cuts before the post-2026 guidelines take effect.
“It may be difficult, if not impossible, for the basin states to implement immediate, additional reductions in use,” the authors said. “That reality puts the onus on the Department of the Interior to take immediate action.”
Earlier this year, the same team proposed seven “essential pillars” for a sustainable post-2026 regime—principles such as enforceable reductions, transparent accounting and realistic hydrology assumptions. Those same pillars, they argue, “can also function as guideposts for immediate action.”
Among their specific recommendations:
• Enforceable reductions: Both Upper and Lower Basins must implement binding, shared-burden cuts in water use to match supply with reality and avoid Compact litigation.
• No federal dependency: Long-term conservation cannot rely on federal compensation; users must plan for self-funded, durable reductions.
• Conservation pools: Establish transparent, scientifically tracked storage pools in Lakes Mead and Powell for verified water savings.
• Tribal inclusion: Ensure equal participation and compensation mechanisms for Tribal Nations in all basin management decisions.
• Storage recovery: Build reservoir refill targets into mandatory use reductions and explore engineering fixes for “dead pool” access.
• Operational flexibility: Allow multi-year release flexibility to protect ecosystems while safeguarding Lower Basin allocations.
• Public health priority: Guarantee domestic and critical industrial water supplies in any worst-case scenario.
As basin state negotiators prepare to meet with Reclamation officials this November, the message from the September report is unmistakable: “Near-term actions must reflect this stark reality.” The authors stress that waiting for new guidelines risks forcing “draconian measures” later if another dry year unfolds. — Charles Wallace, WLJ contributing editor
