The state of Arizona has decided that there isn’t enough groundwater for all of the housing construction already approved in the Phoenix area, and it will block developers from building some new subdivisions, a sign of a looming problem in the West and elsewhere where overuse and drought lead to change. Climate to stress the water supply.
It is very likely that the decision of state officials will mean the beginning of the end for the explosive development that has made the Phoenix area the fastest growing metropolitan area in the country.
Maricopa County, which includes Phoenix and its suburbs, gets more than half of its water supply from groundwater. Most of the remainder comes from rivers and canals as well as recycled sewage. In practice, groundwater is a finite resource; Its renewal can take thousands of years or more.
Declaring groundwater shortages, what the state calls “unmet demand” for water over the next 100 years, means Arizona will no longer grant developers in areas of Maricopa County new permits to build homes that depend on wells for water.
Phoenix and nearby large cities, which must receive separate permission from state officials for their development plans every 10 to 15 years, will also be denied approval for any homes that rely on groundwater beyond what the state has already allowed.
The decision means that cities and developers must look for alternative sources of water to support future development — for example, by trying to buy access to river water from farmers or Native American tribes, many of whom face shortages of their own. This rush to buy water is likely to roil the Arizona real estate market, making homes more affordable and threatening the relatively low housing costs that have made the area a magnet for people from all over the country.
“Housing affordability will be a challenge going forward,” said Spencer Camps, vice president of legislative affairs for the Central Arizona Homebuilders Association, an industry group. He noted that even as the state places restrictions on home building, commercial buildings, factories, and other types of development can continue.
Sarah Porter, director of the Kiel Center for Water Policy at Arizona State University, said the change would be a signal to developers. “We see a horizon at the end of the span,” she said.
The state says it will not revoke permits already issued and instead rely on water conservation measures and alternative sources of water production for approved projects.
Ms. Porter said groundwater shortages likely won’t derail planned growth in the short term in major cities such as Phoenix, Scottsdale and Mesa.
“There is still capacity for development within the designated cities,” Ms. Porter said, referring to cities whose growth plans have already been approved by state water officials. Those cities will not be able to get approval to build any homes that rely on groundwater beyond that amount.
The new constraints will be felt most acutely in the small towns and unincorporated stretches of desert along the fringes of the Phoenix metro area — where most low-cost homes tend to be built. “Those were hot spots for growth,” Ms. Porter said.
The ad is the latest example of how climate change is reshaping the American Southwest. A 23-year drought and rising temperatures have lowered the level of the Colorado River, threatening the 40 million Americans in Arizona and six other states that depend on it — including residents of Phoenix, which gets water from Colorado by canal.
Rising temperatures have increased the rate of evaporation from the river, even as crops require more water to survive these higher temperatures. The water Arizona receives from the Colorado River has already been significantly cut off by a voluntary agreement among the seven states. Last month, the state of Arizona approved conservation measures that would reduce its supply.
The result is that Arizona’s water supply is under pressure from both directions: the disappearance of the water table as well as the shrinking of the Colorado River.
And the water shortage may be more severe than the state’s analysis shows because it assumes that Arizona’s supply of Colorado will remain constant over the next 100 years, which is uncertain at best.
The Phoenix area occupies a valley in southern Arizona, fringed by mountain ridges and cut by the Salt and Gila rivers. The landscape is filled with lush golf courses, baseball diamonds, farm fields and swimming pools, contrasting with the brown rocky terrain that surrounds it.
The county uses about 2.2 billion gallons of water per day—more than double what New York City uses, despite having half the population.
Arizona’s water problems are starting to seep through state politics. In January, the new governor, Katie Hobbs, a Democrat, pledged in her first major address to tighten oversight of groundwater use across the state.
As evidence of that commitment, Governor Hobbs released a report that she said was suppressed by the previous administration, which was led by Republicans. It showed that an area west of Phoenix, called the Hassayamba Sub-Basin, did not have enough water for new wells. As a result, the Arizona Department of Water Resources said it will no longer issue new permits in that area to build homes that rely on groundwater.
But Hassayamba is just one of several sub-basins that make up the larger aquifer basin beneath Greater Phoenix. The state’s announcement Thursday essentially extends the discovery through the Phoenix area.
On Thursday, Governor Hobbs tried to reassure Arizona that the state did not run dry immediately and said growth would continue in major cities like Phoenix.
“We will manage this situation,” she said in a press conference. “We have not run out of water and we will not run out of water.”
Queen Creek is one of the places most likely to feel the impact of the new restrictions.
When Arizona created its own groundwater bases more than 40 years ago, Queen Creek was still mostly peach and citrus orchards and vast farmland. Today, it is one of the fastest growing places in Arizona, where families go fishing in an “oasis” lake fed by recycled sewage. The city’s population of 75,000 is expected to grow to 175,000 by the time it is built decades from now.
But to do any of that, the city needs to find more water.
“We’re looking at about 30,000 acre feet,” said Paul Gardner, Queen Creek facilities manager, or about 9.8 billion gallons annually.
Not having enough groundwater to supply its needs for future growth, Queen Creek is looking for water anywhere it can, exploring proposals such as transporting it through a canal from western Arizona, and expanding the Lake Bartlett reservoir by joining other towns in a project to build a higher dam.
Unlike Phoenix, Queen Creek does not have a “rating” from the state—essentially, a determination that the city has enough water to support new homes. Without this designation, every proposed state development would have to prove it has a 100-year supply. Developers who do not have this seal of approval will have to look for sources other than groundwater.
Even as the state takes steps to try to slow depletion, the Keel Center warns that Arizona is still pumping too much groundwater. In its 2021 report, the center found that new industrial projects are absorbing groundwater without restriction, and the demand for water outweighs any gains from conservation efforts.
Despite increasingly dire warnings from the state and water experts, some developers note that construction won’t stop anytime soon. A state official said the Arizona water agency has granted building permission for about 80,000 lots that are yet to be built.
The city is largely dependent on river water, said Cynthia Campbell, a consultant with the Phoenix Water Resources Department, and groundwater is only about 2 percent of the water supply. But that could change dramatically if Arizona experiences drastic cuts in its Colorado River allotments, forcing the city to pump more groundwater.
Many outlying developments and towns in the Maricopa County stretch have been able to build by enrolling in a state-authorized program that allows subdivisions to absorb groundwater in one location if they pump it back into the ground elsewhere in the basin.
The idea that you could balance water supplies like that was always a “legal fantasy”, Ms Campbell said, and now appears to be unraveling as the state takes a more serious look at places where groundwater supplies are running low.
“This is the hydrological disconnect that comes home to take up residence,” said Ms. Campbell.
In remote areas, “a lot of developers are really anxious, they’re terrified,” Ms. Campbell said. “The truth is, everything has come back to catch up with us.”