Arizona is facing a “challenging situation” when it comes to water availability in the state, according to a leading expert on water policy.
Kathryn Sorensen, director of research at the Kyl Center for Water Policy at Arizona State University, stated that Arizona’s water system is under significant strain due to overallocation of the Colorado River, compounded by a historic drought across the region.
Access to water from the Colorado depends on what we call a ‘hierarchy of water rights, Sorensen explained. Certain Native American communities and farmers enjoy ‘senior rights,’ meaning they get priority access to water from the river. Other areas then have to get by with less.
She noted that Arizona relies heavily on groundwater aquifers, which were filled over tens of thousands of years and do not get renewed annually at a significant rate. “If you pump too much, you’re basically ‘mining’ that groundwater and depleting it,” Sorensen said, meaning less water would be available for future generations.
While acknowledging Arizona has taken steps to conserve water through measures like improving use of reclaimed water and finding ways to augment supplies, Sorensen stressed that more work and innovation is still needed. Earlier this year, a poll found most Arizonans believe the state should be doing more to regulate groundwater pumping and prioritize conservation and restoration projects.
The agricultural sector uses approximately 70 percent of Arizona’s water, according to Sorensen, with some crops requiring up to 6 acre-feet of water per acre of farmland. An acre-foot equals about 326,000 gallons. “Urban developments actually use much less, probably 1-2 acre-feet per acre,” she stated. “So as population has grown and farmland has been converted to urban uses, there has been a natural water savings.”
However, experts predict Arizona will be even hotter and drier in the future, and stress that it’s important to understand land use choices directly impact water availability.
The situation is challenging and likely requires continued efforts to regulate, conserve and innovate. Responsible land use choices are sure to be essential for ensuring water access for future generations of Arizonans.