Water concerns have been growing in Arizona as the state’s share of the Colorado River has been cut. Running out of water is still a distant concern for most residents. But for the unincorporated community of Rio Verde Foothills, water stopped flowing this year when the nearby city of Scottsdale shut off the taps.
Typically, when developers split land into six or more lots of a certain size those are considered "subdivisions." Developers are then required to prove that they have a 100-year supply of water, thanks to Arizona’s 1980 Groundwater Management Act.
But builders can get around that requirement with unregulated “wildcat” developments and other loopholes.
→ EPCOR makes its case to provide water to Rio Verde Foothills residents
David McKay is the manager of the Arizona Department of Water Resources’ Assured and Adequate Water Supply Programs. He said some developments avoid this requirement, either because they were split before the law was enforced, or because they were designed to avoid having to prove a 100-year water supply.
“It's really on the homebuyer to make sure that that water supply is there whenever they purchase those properties,” McKay said.
Sarah Porter is the director of Arizona State University's Kyl Center for Water Policy. She said that the way some lot splitting was done in Rio Verde contributed to its water problems “through development of five or fewer homes” and through the process of lot splitting.
Many subdivisions, Porter said, rely on cities that go through a process to become what are called assured designated providers.
"To get that, the city has to prove that it has water that's physically, legally and financially available to meet current demand for the next 100 years,” Porter said.
With cuts from sources like the Colorado River, Porter said cities are working to make the best use of what they have.
"So cities now are reclaiming about 93% of the water that enters the wastewater treatment system, and that's very good,” she said.
Population growth is often brought up when it comes to water use.
But according to Porter: “Growth is not a direct driver of the water challenges that we're seeing.” And instead, “bigger, older cities tend to be growing more dense. And as cities become more dense, the per capita demand for water tends to go down.”
Porter said that’s because those cities focus on “getting better and better at how they manage water and at using the, you know conservation and reclaiming water, reusing water.”
As for subdivisions, Heidi Kimball with Sunbelt Holdings, a real estate developer, said developers and city officials are working together to find some of those solutions.
“The city of Phoenix is talking about toilet to tap,” Kimball said. “We're gonna see that kind of creation of a new 'bucket’ because we have to.”
Porter said those solutions are more effective than some may assume.
“In the past 20 years, the population has grown about 45% and water demand grew 14%,” Porter said.
McKay said that on the policy side, the city or county in question is responsible for ensuring developments meet the assured water supply.
“I think there's a lot of anxiety out there,” McKay said. “And the thing is, that when we look at an assured water supply, we're looking really, really far into the future.”
But McKay said it’s still important to be proactive and find alternate sources for the future.
