Click the link to read the article on the AZCentral website (Brandon Loomis). Here’s an excerpt:
June 18, 2025
Key Points
- Arizona officials present details of a new proposal to share future shortages on the Colorado River.
- The “supply-driven” solution would base allocations on the river’s actual flows, not on storage in the reservoirs.
- Upper Basin states say the plan has problems, but Gov. Katie Hobbs insisted Arizona will defend its river allocation and demand other states take cuts.
Negotiators for the seven states arguing over diminished Colorado River water are discussing an option they hope will end their deadlock, one that Arizona officials say would focus less on who gets what and more on what the river can realistically provide. They’re calling it the “supply-driven” solution, Arizona Water Resources Director Tom Buschatzke said, and it links the required water deliveries out of Glen Canyon Dam to what might naturally be flowing downstream at Lees Ferry if the dam weren’t there. The Rocky Mountain states upstream from there would have to let that amount pass, and the Southwestern states would have to live within its limits. It’s intended as a fair way of adapting — and shrinking — the region’s use of a river whose flow was once thought to exceed 15 million acre-feet of water a year but, in the last 25 years, has averaged 12.4 million…
A Colorado State University climate scientist recently projected that the region’s warming trajectory could drop the flow to 10 million by the end of this century — a plunge of about a third of the water that the first state negotiators agreed to divvy up with the 1922 Colorado River Compact…
So far, agreement about what’s fair has appeared distant. The Lower Basin states of Arizona, California and Nevada have the bulk of the region’s population and farm production, and have fully developed and then started to cut back on the half of the river’s flow that the compact awarded them. The Upper Basin states of Colorado, New Mexico, Utah and Wyoming have not fully developed their share of the water — a share that no longer fully exists. They have balked at cutting their existing uses to meet the compact’s requirement that they send at least half of the river’s flow of a century ago now that a changing climate has exposed the folly of the compact’s numbers. The supply-driven model would generally mandate a flow past Lees Ferry to the Southwestern states equal to a rolling three-year average of the natural flow that the mountain snowmelt provides, Buschatzke said. There would be upper and lower bounds on that number, to account for needs such as protecting reservoir levels that are safe for Glen Canyon and Hoover dam operations. Those bounds are as yet unidentified.
