Arizona has found there isn’t enough groundwater for all the housing development already approved in the Phoenix area and is stopping developers from building some new subdivisions, a sign of looming problems in the West and other places where overuse is drought-ridden. and climate change are straining water supplies.
The decision by state officials very likely marks the beginning of the end of the explosive development that has made the Phoenix area the fastest-growing metropolitan region in the country.
The state has said it will not revoke building permits already issued and is instead counting on new water conservation measures and alternative sources of water production needed for already approved housing estates.
On Thursday, Gov. Katie Hobbs, a Democrat, said Arizona was not drying up immediately and that new construction would continue in major cities like Phoenix. An analysis by the state looked at groundwater levels over the next 100 years.
“We will manage this situation,” she said at a news conference. “We’re not out of water, and we’re not going to run out.”
Maricopa County, which includes Phoenix and its suburbs, gets more than half of its water supplies from groundwater. Most of the rest comes from rivers and aqueducts, as well as recycled wastewater. In practice, groundwater is a limited resource; its replenishment may take thousands of years or longer.
The groundwater shortage announcement means Arizona will no longer grant new permits to developers in some areas of Maricopa County to build homes that depend on well water supplies.
Phoenix and nearby large cities, which must get separate permits from state officials every 10 to 15 years for their development plans, also would not get approval for any homes that depend on groundwater beyond what the state already allows.
The decision means cities and developers must seek alternative water sources to support future development — for example, by seeking access to river water from farmers or Native American tribes, many of whom face shortages of their own. The rush to buy water is likely to shake up Arizona’s real estate market, drive up home prices and threaten the relatively low cost of living that has made the region a magnet for people from across the country.
“Housing affordability will be a challenge going forward,” said Spencer Kamps, vice president of legislative affairs for the Home Builders Association of Central Arizona, an industry group. He noted that even as the state restricts home construction, commercial buildings, factories and other types of development can continue.
Even so, the change will serve as a signal to developers, said Sarah Porter, director of the Kyle Center for Water Policy at Arizona State University. “We see the horizon of the end of sprawl,” she said.
Groundwater shortages would likely not disrupt planned growth in the short term in major cities such as Phoenix, Scottsdale and Mesa, Ms. Porter said.
“There is still capacity for development within designated cities,” Ms. Porter said, referring to cities whose growth plans have already been approved by state water officials. Those cities wouldn’t be able to get permits to build homes that depend on groundwater above that amount.
The new restrictions would be felt hardest and most immediately in small towns and unincorporated stretches of desert along the edges of the Phoenix metro area — where lower-cost homes are mostly built. “Those were the hot spots for growth,” Ms. Porter said.
The announcement is the latest example of how climate change is reshaping the American Southwest. A 23-year drought and rising temperatures have lowered the Colorado River, threatening the 40 million Americans in Arizona and six other states that rely on it — including residents of Phoenix, which gets water from the Colorado through an aqueduct.
Rising temperatures have increased the rate of evaporation from the river, even though crops require more water to survive these higher temperatures. The water Arizona receives from the Colorado River has already been significantly reduced under a voluntary agreement among seven states. Last month, Arizona agreed to protective measures which would further reduce his supply.
As a result, Arizona’s water supplies are being squeezed from both directions: the disappearing groundwater and the shrinking Colorado River.
And the water shortage could be more severe than the state analysis shows because it assumes Arizona’s supply from Colorado will remain constant over the next 100 years, which is uncertain at best.
The Phoenix area occupies a valley in southern Arizona, surrounded by mountain ranges and cut by the Salt and Gila rivers. The landscape is full of lush golf courses, baseball diamonds, agricultural fields and swimming pools, contrasting with the brown, rocky terrain that surrounds it.
Arizona’s water woes have begun to seep through state politics. When she took office in January, Governor Hobbs made a commitment to her first main address tighten controls on groundwater use throughout the state.
As evidence of this commitment, Governor Hobbs she issued a message which she says was suppressed by the previous Republican-led administration. An area west of Phoenix, called the Hassayampa sub-basin, turned out not to have enough water for new wells. As a result, the Arizona Department of Water Resources said it would no longer issue new permits for homes that rely on groundwater in the area.
But the Hassayampa is just one of several subwatersheds that make up the larger groundwater basin beneath metropolitan Phoenix. Thursday’s state announcement essentially extends that finding beyond the Phoenix area.
One place that is very likely to feel the impact of the new restrictions is Queen Creek.
When Arizona created its groundwater rules more than 40 years ago, Queen Creek was still mostly peach and citrus groves and vast farmland. Today, it’s one of the fastest-growing places in Arizona, where families come to fish on an “oasis” lake fed by recycled sewage. The city’s population of 75,000 is projected to grow to 175,000 by the time it is built in a decade.
But to do that, the city needs to find more water.
“We’re looking at about 30,000 acre-feet,” or about 9.8 billion gallons a year, said Paul Gardner, Queen Creek’s director of services.
With not enough groundwater to meet its needs for future growth, Queen Creek is looking for water wherever it can, exploring proposals such as diverting it through a canal from western Arizona, expanding the Bartlett Lake reservoir by adding more towns to the project to build higher dam.
Unlike Phoenix, Queen Creek does not have a “designation” from the state — essentially a determination that the city has enough water to support new homes. Without that designation, any proposed development must prove to the state that it has a 100-year supply. Developers without this seal of approval would now have to look to sources other than groundwater.
Even as the state is taking steps to try to slow the depletion, the Kyle Center warned that Arizona is still pumping too much groundwater. New industrial projects are draining groundwater without limit, and demand for water is outpacing any gains from conservation efforts, the center said in a 2021 report.
Despite increasingly urgent warnings from the state and water management experts, some developers warn that construction will not stop anytime soon. The Arizona Water Management Agency has issued construction permits for about 80,000 apartment buildings that have not yet been built, a state official said.
Cynthia Campbell, Phoenix’s water resources management consultant, said the city is largely dependent on river water, and groundwater accounts for only about 2 percent of its water supply. However, that could change drastically if Arizona were to be hit with drastic cuts in allocations to the Colorado River, forcing the city to pump more groundwater.
Many outlying developments and towns in growing Maricopa County have been able to build participation in a state-authorized program that allows subdivisions to draw groundwater in one location as long as they pump it back into the ground elsewhere in the watershed.
Ms. Campbell said the idea that you could balance water supplies like that had always been a “legal fiction” that now appears to be unraveling as the state takes a harder look at where groundwater supplies are dwindling.
“This is a hydrological disconnect coming home to the shelter,” Ms Campbell said.
In remote areas, “a lot of developers are really scared, they’re scared,” Ms. Campbell said. “The reality is that it all came back to bite us.