CAP official urges vigilance as Colorado River runoff falls; Arizona launches coalition to defend CAP

Mitch Basky, stakeholder outreach coordinator for the Central Arizona Project, told the Oro Valley Water Utility Commission on a September meeting that long‑term drying and higher temperatures across the Colorado River Basin have reduced runoff and left major reservoirs at substantially lower levels, putting pressure on deliveries to Arizona communities.

“Essentially, what you’re looking at in the last five years is we’ve had, either above or close to normal, snowpack, but the runoff has been very, very disappointing,” Basky said. He described “aridification of the basin” that leaves drier soils that absorb more meltwater and shorten the runoff period.

The update focused on operational and political risks for CAP, the 336‑mile system that delivers Colorado River water to central and southern Arizona. Basky said Lake Powell and Lake Mead were about 30% full at the end of the prior month and that long‑term average inflows have fallen: “the average for the last 60 years about 10,400,000 acre‑feet, the average for the last 30 or so years 9.6, and then the average during this long drought has been 8.3.”

Why it matters: CAP supplies are a primary source for many Arizona cities, and Oro Valley depends on CAP allocations and recharge projects to limit groundwater pumping. Basky told the commission that continued low inflows, constrained operating decisions at Lake Powell, and negotiations among the seven basin states could produce deeper cuts to deliveries if no…