The Department of Interior, Washington, D.C., signed a new Record of Decision May 9 to implement the Lower Basin’s commitment to conserve 3 million acre-feet of water by 2026.
The decision supplements the 2007 Interim Guidelines to address continued low runoff conditions in the Colorado River Basin.
The Colorado River Basin has experienced over two decades of drought, exacerbated by climate change. Recent low runoff has caused historic declines in Lakes Powell and Mead, necessitating revisions to the 2007 Guidelines to protect the 40 million people, 5.5 million acres of irrigated farmland, 30 Basin tribes and environmental resources dependent on the river, according to the decision.
The selected alternative involves water users in Arizona, California and Nevada voluntarily conserving three million acre-feet in Lake Mead by 2026, with 1.5 million acre-feet conserved by the end of 2024. This exceeds the requirements of the 2007 Interim Guidelines and the Lower Basin Drought Contingency Plan, potentially adding nearly 37 feet to Lake Mead’s elevation by 2026. If Lake Mead’s level is projected to drop below 1,025 feet, the Lower Basin States must provide a plan to prevent it from reaching 1,000 feet.
For Lake Powell, the alternative allows for mid-year adjustments to release 6 million acre-feet if necessary to maintain elevations above 3,500 feet. Actions under the Upper Basin Drought Contingency Plan, such as drought response releases, will continue without new contributions from the Upper Basin States.
The conservation volumes are voluntary but mandatory under agreements with the Bureau of Reclamation. Up to 2.3 million acre-feet will be federally compensated, with the rest compensated by state or local entities. Arizona alone conserved nearly 950,000 acre-feet in 2023 through the Intentionally Created Surplus Preservation Program.
The Record of Decision, mandated by the National Environmental Policy Act, modeled the selected alternative against historic and forecasted dry hydrologies, showing that it maintains critical elevations in both Lakes Powell and Mead through 2026.
