Arizona Preps For Climate Change To Strain Water Supplies Even More

Arizona water suppliers say they are already preparing for changes in the climate that will strain water resources and make some parts of the state more vulnerable to drought.

Climate change models from the federal government show that Arizona is getting hotter, and that means more water supply challenges in the coming decades.

“Some parts of southwest Arizona could experience more than 140 days of temperatures above 100 degrees within 20 years,” Cronkite News reported, citing a climate change model from the U.S. EPA.

But Arizona water utilities and state officials say they are ready for the challenge. They have already been contending with difficult drought conditions: The state has issued a drought emergency declaration every year since 1999, the report said.

Water systems in the state “are all required to develop plans to deal with drought or system failures. Additionally, any new water utility must demonstrate to the [state] that there’s adequate water supply before the utility will be approved by the Arizona Corporation Commission,” the report said.

Jake Lenderking, water resources manager at EPCOR Utilities, Arizona’s largest regulated water utility, noted that his system is already responsive to changes in water use.

“Simply, our water demand throughout the year follows the weather,” he said, per the report. “In the winter, people use less water. In the summer, there are more daylight hours, and there is more heat. A lot more heat would drive water use up.”

The utility is trying to understand how water use patterns will vary as the state gets hotter. It partnered with other water suppliers to study demand for water in the Salt River basin.

“We’ve seen water demand, in general, go down,” Lenderking said. “There’s this big overlying trend, in the Southwest we see it going down a lot faster.

“One of the things that we don’t know today is: Do we still see this general trend as it gets hotter and hotter? We may see demand increase, or it may decrease even more,” he said. “That’s something we’re trying to study.”

Michelle Moreno, spokeswoman at the Arizona Department of Water Resources, emphasized the state’s preparedness.

“There are some rural areas in the state that rely exclusively on groundwater,” she said, per the report. “If we’re not getting any rain, those water systems have that drought plan. If our wells aren’t able to produce enough water, we’re going to tap into another system.”

“Here in Arizona, we manage water very differently than other states,” she said. “There are mandatory conservation requirements for different types of users.”

Scientists say there is a risk of severe drought in the Southwest in the coming decades.  

“A new study, published [in October] in Science Advances, says that climate change will make a similar mega-drought far more likely in the American Southwest. In fact, this kind of phenomenon could become a near certainty: If carbon emissions continue unabated, the risk of a mega-drought could exceed 99 percent,” The Atlantic reported.

Study author Toby Ault described the threat.

“This will be worse than anything seen during the last 2,000 years and would pose unprecedented challenges to water resources in the region,” he said. “As we add greenhouse gases into the atmosphere — and we haven’t put the brakes on stopping this — we are weighting the dice for mega-drought conditions.”

To read more on drought visit Water Online’s Water Scarcity Solutions Center.