With low rains this year, where does Arizona’s water supply stand?

Arizona’s rainfall total this year is significantly below normal.

What does it all mean for the State’s water supply? We asked Sarah Porter, Director of ASU’s Kyl Center for Water Policy.

“This was a record dry year,” Porter said. “I think a lot of us feel as if it was a bone dry year, and it was extra hot.”

The Colorado River supplies about 40 percent of Arizona’s water and the SRP reservoir system in Phoenix supplies around 30 percent, according to Porter. Given the recent dryness and heat, Porter believes both areas are under great stress.

SRP claims that this was the driest year on record for Arizona. The second driest year, in comparison, still had twice as much precipitation as this year.

Porter said the SRP systems seem to be “in pretty good shape,” as their water capacity still stands at 80 percent. This is due to the wet winters Arizona has faced in the last three years.

Yet, the Colorado River is not as lucky. Porter believes that, due to its size and use across several states, it is difficult to manage.

“The inflows were historically low for Lake Powell,” Porter said, “It was the second lowest inflows since Lake Powell was first built.”

What does that mean for Arizona? Due to the negotiations that took place over Arizona’s Drought Contingency Plan, or DCP, Porter believes that the state has a plan for the conservation of available water. The plan was signed back in 2019 as a “worse case scenario” plan for severe droughts.

Porter believes the state will not experience any cuts of deliveries of water until 2022 because of the long timeline built into the DCP. These cuts will primarily affect agriculture in Pinal County and water banks across Arizona looking to store Colorado River water for the future.

“We’re now coming to terms with the idea that we don’t have this large amount of extra water in the system to support additional municipal growth,” Porter said.