Tucson Water customers to see no immediate change under river cutback plan

With Lakes Mead and Powell now nearing their all-time low elevations, those worst-case conditions could occur as soon as next year, unless the current El Niño weather system ushers in good snowfall this winter in the Upper Basin states where most river flows originate. Those states are Colorado, New Mexico, Utah and Wyoming.

Under more favorable conditions, the cut to the Lower Basin states would be much smaller, perhaps as little as 1.25 million acre-feet a year, or 16.6% of the Lower Basin’s total annual supply.

The final environmental report incorporates some elements of the Lower Basin states’ proposal that would cut 1.25 million acre-feet annually, and could end up cutting another 350,000 acre-feet a year, the city’s news release said.

But the report’s assumptions about the Lower Basin states’ proposal “are preliminary and do not establish Tucson’s final Colorado River reduction, or voluntary conservation contribution,” the city’s news release said. 

“Separate federal operating plans and annual operating guidelines will determine actual reductions,” it said. 

The bureau’s proposal is for a 10-year plan to establish a framework for cutting river water use, with specifics being revisited and potentially revised every two years.

Overall, Tucson’s initial review of the new federal report will focus on the following matters, the city release said:

• Water reliability, in that Tucson’s diversified water portfolio, conservation programs, groundwater recharge, and stored-water reserves provide important safeguards as Colorado River operating conditions change.

• Colorado River allocation: The final environmental impact statement doesn’t establish Tucson’s CAP reduction for 2027 or 2028. Tucson Water is coordinating with the Central Arizona Project, the Arizona Department of Water Resources and regional partners to evaluate potential impacts.