Arizona water director Tom Buschatzke is not ready to say which urban area his office will next determine lacks enough water for new housing growth, but it could be Pima County, he acknowledges.

Buckeye in Maricopa County, long one of the fastest growing cities in the U.S., is not the first place in Arizona that state water officials concluded lacks enough groundwater to support its projected homebuilding β€” and it likely will not be the last.

That's the outlook from Arizona Department of Water Resources Director Tom Buschatzke, whose office by state law must determine if new developments in Arizona's urban areas have enough assured water supplies to support a century's worth of expected housing growth.

His comment came just after new Gov. Katie Hobbs released on Monday an ADWR report, previously kept under wraps, showing the groundwater basin underlying Buckeye, west of Phoenix, will fall 4.4 million acre-feet of water short of what's needed to serve subdivisions β€” already approved to be builtΒ β€” over the next 100 years.

That's equivalent to the amount of Colorado River water the Central Arizona Project canal system delivers to Tucson and Phoenix over four years.Β 

The report's release comes close to two years after ADWR made a similar water supply determination for Pinal County, effectively blocking much new home development in that previously rapidly growing area.

New home development relying on groundwater in other fast-growing urban areas, including Pima County, could or will in the coming years face similar legal roadblocks to subdividing under state law, Buschatzke is predicting.

At the same time Hobbs released the Buckeye report, she took a second action that will be broader and potentially farther reaching in the long run. She ordered creation of a new Water Policy Council, representing virtually every major water interest group in the state, that will try to find ways to update the pioneering, 1980 Arizona Groundwater Management Act that first allowed the water agency to limit groundwater pumping to protect declining aquifers in urban areas including Tucson and Phoenix.

Restrictions don't completely protect aquifers

A longtime homebuilders' lobbyist, Spencer Kamps, noted, however, that these restrictions on homebuilding won't stop development and won't completely protect the aquifers in such areas. That's because the state's requirement for assured water supplies only applies to new subdivisionsΒ β€” not to apartments, commercial development or industry. Kamps is deputy director of the Phoenix-based Home Builders Association of Central Arizona.

Under the 1980 Arizona Groundwater Management Act, subdividers for all new homes built in the state's three most populous countiesΒ β€”Β Maricopa, Pinal and Pima β€” must prove they have an assured water supply for 100 years. They're required to prove both that there's enough groundwater under the subdivision and that a three-county water district can find enough renewable supplies to replenish that or another aquifer to compensate for the subdivision's pumping.

"The assured water supply issue first daylighted in Pinal County. Now, it's daylighted in the West Valley" of the Phoenix metro area, Buschatzke said in an interview this week. "Sooner or later, it’s going to daylight everywhere.

"Groundwater is finite, and we've been allocating it 40-plus years" for new development in state-run water management areas surrounding cities across the state, Buschatzke said. Those areas include the Tucson Active Management area in Pima and southern Pinal counties, and similar areas in Santa Cruz County and surrounding Phoenix and Prescott.

He's not ready to say what will be the next urban area his office will find lacks sufficient water for 100 years of new housing growth. Pima County, where large portions of unincorporated areas rely on groundwater, could be the next place this happens, "but I don't want to say that will be the next area," Buschatzke said.

"It has to happen" that other areas will be found lacking sufficient groundwater for new growth, he said. "We will be working on updating our groundwater models that we have for Active Management Areas. As we continue to work on updating those models and improving the science, we'll start seeing where that (assured water supply issue) starts to daylight specifically."

Other water supplies may need to be brought in

In the Tucson area, Green Valley and surrounding southern Pima County communities, unincorporated areas north of Tucson to SaddleBrooke in Pinal County, and unincorporated areas southeast of Tucson depend almost exclusively if not exclusively on groundwater.

A federal study released in 2021 found that increased water demand and expected future reductions in deliveries of CAP water will trigger major declines in groundwater levels in the unincorporated southern and southeastern suburbs and in both incorporated and unincorporated north- and northwest-side suburbs such as Oro Valley, Catalina and SaddleBrooke.

For Buckeye, Buschatzke said ADWR officials are "very confident" in results from their computer-based groundwater models showing "there is not going to be sufficient groundwater to build all the homes in the pipeline or that might be planned," in that area's surrounding Lower Hassayampa Sub-Basin that stores groundwater.

"Some other types of water supplies may need to be brought into this area, if those houses are to be built," he said.

Only developments that already have state approved assurances of water supply in that area can move forwardΒ β€” "I don't expect to be able to approve anything new," Buschatzke said.

Until and unless other water supplies can be found, the state's action effectively slams the brakes on new subdivisions in Buckeye, a city whose population has been projected to rise from about 123,000 in 2022 to about 872,000. That's if all 27 master-planned communities that have been approved by the city are eventually built, says Buckeye's water master plan, released in April 2020.

Reached for comment, Buckeye city spokeswoman Annie DeChance said Tuesday that city officials are reviewing close to 300 pages of findings in the just-released state report, in order to respond later.

"We need time to analyze the data. Once we have an opportunity to fully review the report; we’ll be able to respond and provide input," said DeChance.

She emphasized, however, that all Buckeye homes and businesses already developed and those "in the process of being built" have been shown to have an assured, 100-year water supply. For the period beyond that, "we're looking at other, alternative sources besides groundwater," DeChance said. She declined to elaborate because "we have a bunch of nondisclosure agreements involved."

Groundwater is 41% of state's water supplyΒ 

Hobbs accompanied her order for the Buckeye study's release on Monday with a third directive, besides creating the water policy council. She also created the Governor's Office of Resilience, aimed at fashioning "water, energy and land use solutions," she said in a news release. The office will coordinate activities among a wide range of interests, including state agencies, tribal governments, universities and outside organizations, "to address Arizona’s water challenges from a local, state, regional and national level," Hobbs said.

The water policy council will update groundwater management tools and protect groundwaterΒ β€” which serves as 41% of the state’s water supply, Hobbs said.

"The critical need for these updates comes from needing to close groundwater poaching loopholes. There are effectively no restrictions on groundwater pumping and lack of support for smaller communities" in rural areas outside of the state-run Active Management Areas near cities, she said.

More specifically, Hobbs cited the recently disclosed news that "a Saudi Arabian conglomerate isΒ pumping local groundwater nearly unchecked in La Paz County today, to grow water-intensive crops and send them to the other side of the planet." She was referring to The Arizona Republic's reporting that the Saudi firm Fondomonte was paying $25 an acre to lease close to 10,000 acres of Arizona-owned state land to grow alfalfaΒ β€” with no limits placed on its water use.

Hobbs also gave the public a preview pf her executive budget proposal for fiscal year 2023-24, specifically a provision that would allocate funds to help rural communities strike a balance between water use and recharging of aquifers. In her State of the State address Monday, Hobbs urged legislators to follow the footsteps of past Arizona leaders who have "reached across the aisle for decades to find pragmatic solutions for a drought unlike anything in modern times.”

The Central Arizona Project is a 336-mile canal in Arizona that supplies Colorado River water for the Phoenix and Tucson area, agriculture and several Native-American tribes. Construction began in 1973 and was substantially complete by 1994. This portion is located near Sandario Road and Mile Wide Road west of Tucson on March 17, 2021. Video by: Mamta Popat / Arizona Daily Star

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Contact Tony Davis at 520-349-0350 or tdavis@tucson.com. Follow Davis on Twitter@tonydavis987.