In February, the seven Colorado River Basin states failed for a second time to come up with post-2026 operating guidelines for the Colorado River. The Upper Basin states – made up of Colorado, Utah, New Mexico and Wyoming – argue that the Lower Basin – made up of Arizona, California and Nevada – should take on the brunt of the cuts.
Despite the stalemate in negotiations, representatives from the Lower Basin have offered substantial cuts to their allocations, according to the Arizona Department of Water Resources: 27% for Arizona, 17% for Nevada and 10% for California.
A total of 40 million people rely on Colorado River water – which comes out to about 6 million Arizonans.
A majority of Arizonans get their water from the Central Arizona Project, a 336-mile long canal system that transports Colorado River water from Lake Havasu to central and southern Arizona. It serves 80% of Arizonans by supplying water to Phoenix, Tucson and surrounding areas.
Tucson’s CAP aqueduct was completed in 1993 – but before that, the city relied solely on groundwater, according to John Kmiec, the director of Tucson Water.
While Tucson’s current allocation of CAP water is a little under 145,000 acre feet per year, it does stand to lose some of its Colorado River water under proposed post-2026 operating guidelines.
Basin states clash over shrinking supply
Prolonged drought, climate change, and overuse have reduced river flows, forcing tough decisions ahead of new post-2026 Colorado River operating guidelines. Upper Basin states say they already use less water and shouldn’t face deep reductions, while Lower Basin states, that are historically allocated more water and more dependent on it, are being pushed to scale back.
Climate pressures and long-term risks
Tucson water stakeholders caution that long-term risks remain despite the city’s recent success in building a surplus. Climate change is driving hotter temperatures and more persistent drought across the Southwest, which impacts the flow of the Colorado River over time. Additionally, a below-average snowpack in the Colorado Rockies means less runoff.
Navigating the future
Lawmakers shared updates on how they’ve been advocating for state water users and outlined how Tucson is preparing to manage its future water needs. Despite ongoing deadlock in Colorado River negotiations, Lower Basin states have proposed significant voluntary cuts to their water use, according to the Arizona Department of Water Resources.
