PHOENIX — Arizona will not approve construction of new housing on the rapidly growing edges of metro Phoenix that rely on groundwater thanks to years of overuse and a decades-long drought that is undermining its water supply.
At a press conference on Thursday, Governor Katie Hobbs announced the restrictions that could affect some of the fastest growing suburbs in the nation’s fifth-largest city.
Officials said developers could still build in affected areas, but would have to find other sources of water to do so, such as surface or recycled water.
The state’s decision was prompted by a projection that showed that over the next 100 years, demand in metro Phoenix for nearly 4.9 million acre-feet of groundwater would not be met without other action, Hobbs said. One acre-foot of water is about enough for two to three American households per year.
Despite this decision, the governor said the state was not short of water. “Nobody who has water is going to lose their water,” Hobbs said.
Officials said the move would not affect existing owners who have already secured water supplies.
Hobbs added that there are 80,000 unbuilt homes that will be able to move forward because they already have Assured Water Supply Certificates in the Phoenix Active Management Area, a designation used to regulate groundwater.
Years of drought in the West, compounded by climate change, have increased pressure among Western states to use less water. Much of the focus has remained on the dwindling Colorado River, a primary water source for Arizona and six other western states. In the past two years, Arizona’s supply from the 1,450-mile-west power plant has been cut twice.
Phoenix depends on imported water from the Colorado River and also uses water from the state’s Salt and Verde rivers. A small portion of the city’s water supply comes from groundwater and recycled wastewater.
The drought has made groundwater – held in underground aquifers that can take many years to replenish – even more vital.
Under a 1980 state law designed to protect state aquifers, Phoenix, Tucson and other Arizona cities have restrictions on how much groundwater they can pump. But in rural areas, there are few limitations to its use.
Long pumped by farmers and rural Arizona residents with little oversight, Hobbs and other state officials recently vowed to take more action to protect the state’s groundwater supplies.
In fast-growing Phoenix suburbs such as Queen Creek and Buckeye, developers have relied on unallocated groundwater to show they have an adequate water supply for the next 100 years, which Arizona needs for building permits in some areas.
“Developers are relying on groundwater because it’s frankly cheaper and easier for them, and they’ve been able to move through the process much faster,” said Nicole Klobas, chief counsel for the water resources department of arizona.
With the new restrictions, this will not be possible.
“It closes that pathway,” said Kathryn Sorenson, research director at Arizona State University’s Kyl Center for Water Policy.
Given that the rule largely affects cities and towns outside of Phoenix and major cities in the metro area, Sorenson said developers would “probably be evaluating whether they want to continue to buy relatively inexpensive land … and incurring the cost of developing a whole new water supply versus buying land which is probably more expensive without designated city limits.