ASU Study: No Water Supply Crisis In Arizona, Yet

August 25, 2011

A study by Arizona State University’s Morrison Institute finds that the widespread perception that Phoenix and Tucson are facing a water crisis may be overstated.

Some insist there is not enough water to sustain Phoenix and Tucson. Others say there is plenty of water if managed carefully. ASU researcher Grady Gammage, Jr says neither is correct, but we are right to be concerned.

“We probably have been overstating how comfortable we should be about our water situation,” Gammage said.

But that situation hasn’t yet reached crisis stage. Current resources supply enough water to support 8 to 10 million people in what Gammage calls the Sun Corridor, essentially Maricopa, Pinal and Pima counties in central and southern Arizona.

But now that climate change has entered the equation, Phoenix and Tucson will have to make some tradeoffs.

Photo courtesy Salt River Project.
The Ted Roosevelt Dam near Phoenix, which supplies water to central and southern Arizona.

“Does agriculture survive? Do we continue to plant as much grass as we have in the past?" Gammage said. "Should we live at higher densities? Should we live in different places?”

Climate change may reduce the average annual amount of water by as much as 15 percent, according to the study. Gammage said the rest of the country can learn from the southwest.

“We can store about three to five years worth of the Sun Corridor’s water supplies,” the researcher said. “And we’ve been banking water underground for future use in a way that virtually nowhere else in the country is doing.”

The ASU study received some funding from the Salt River Project, which delivers water and electricity to much of central Arizona.