The Interior Department has proposed five possible alternatives for a new framework governing Colorado River water cuts after current guidelines expire in 2026.
A wide-ranging set of options unveiled by the agency Wednesday reflects the differing positions of states, tribes, environmentalists, water districts and other water users on how the river should be governed into the future.
States first agreed to Interim Storage Guidelines in 2007 as water levels in reservoirs dropped during seven years of drought, only to agree to an even stricter set of cuts in 2019 as the continuing drought put even greater pressure on water supplies. The states spent the past two years negotiating even more drastic water-saving measures, finally landing on an agreement last year.
But the existing framework governing how cuts are divvied up will only be effective through the end of 2026, leaving the Bureau of Reclamation and state negotiators to hammer out a replacement.
"These alternatives represent a responsible range from which to build the best and most robust path forward for the Basin," Reclamation Commissioner Camille Touton said of the five options. "I have confidence in our partners and the Reclamation team in continuing this work to meet the needs of the river for the future.”
One option would be to release water from Lake Powell based on its elevations, with releases ranging from 9.5 million acre-feet to 5 million acre-feet. Lower Basin states could see cuts of up to 3.5 million acre-feet, which would be triggered based on combined storage in Lakes Powell and Mead and would be distributed based on the current priority system.
The second would be to base Lake Powell releases on that reservoir's levels combined with those of Lake Mead, as well as the 10-year running-average hydrology and Lower Basin deliveries. Cutbacks would be triggered based on the combined storage of the two reservoirs.
The third option would allow for Lake Powell releases ranging from 11 million acre-feet to 5 million acre-feet based on the storage in Upper Basin reservoirs. It would require shared contributions from states in the basin, with Lower Basin states potentially needing to conserve up to 4 million acre-feet, which would be triggered by combined seven-reservoir storage and recent hydrology.
The fourth plan — based on components suggested by both the upper division states, the lower divsion states, and tribes — suggests Lake Powell releases should be determined primarily based on Lake Powell elevation, but gives weight to some Lake Mead elevation scenarios. Releases would range from 13 to 5 million acre-feet. Both the upper and lower basis would need to pitch in contributions in times of shortages, with the Lower Basin seeing up to 2.1 million acre-feet in possible cutbacks, which would be triggered by combined seven-reservoir storage.
Reclamation also presented a "no action" alternative, as required by the National Environmental Policy Act.
The Colorado River is governed by a complex set of long-standing agreements, federal laws, and court decisions collectively deemed the “Law of the River.” The Colorado River Compact of 1922, one of the river’s foundational governing documents, formally split the Upper and Lower Basins and allocated 7.5 million acre-feet of water to each.
According to the press release, Reclamation will analyze these alternatives in a draft environmental impact statement. After a public comment period, it seeks to publish a final EIS. It hopes to have a record of decision in 2026.
This spring, basin states presented Reclamation with conflicting ideas on which path it should follow when crafting a post-2026 framework for water cuts.
Negotiators from both sides disagreed over whether the Lower Basin states — Arizona, California and Nevada — should continue to bear the brunt of cuts in times of severe shortage or if additional burden should be extended upstream to Colorado, New Mexico, Utah and Wyoming.
The Lower Basin states’ plan proposed cuts of up to 1.5 million acre-feet annually if the Colorado River basin’s “total system contents” — the amount of water in Flaming Gorge, Blue Mesa, Navajo, Powell, Mead, Mohave, and Havasu — drop below 58% full. This, in part, was meant to help the Lower Basin account for the “structural deficit” causing water losses in Lake Mead each year, which is partially driven by evaporation and river seepage.
If the system were to fall below 38% of its normal capacity under the Lower Basin proposal, both basins would be subject to a combined curtailment of up to 3.9 million acre-feet annually, including the Lower Basin’s 1.5-million-acre-feet cut. The extra reductions would be split, with the Lower Basin states and Mexico responsible for 50% and the Upper Basin states responsible for 50%, according to that proposal.
The Upper Basin plan, on the other hand, proposed that the Lower Basin take up to 1.5 million acre-feet of cuts in years when Lakes Powell and Mead — the system’s two primary reservoirs — sink below 70% of their 8.5-million-acre-feet capacity. Their plan would require Arizona, Nevada and California to take up to 2.4 million acre-feet of additional reductions on top of the 1.5-million-acre-feet cut if both reservoirs were less than 20% full.
