Developers lack enough groundwater to build in desert west of Phoenix

Rising Risks: Build up from the Great Western Drought

House to be built on January 7, 2023 in Rio Verde Foothills, Arizona, USA.

The Washington Post | Getty Images

Developers planning to build homes in the desert west of Phoenix do not have enough groundwater supplies to fuel their plans, a state modeling report found.

Plans to build homes west of the White Tank Mountains will require alternative water sources as the state grapples with historic mega-droughts and water shortages, the report said.

Water sources in the western United States are running out, and increasing restrictions on the Colorado River are affecting all sectors of the economy, including housing. But amid a statewide housing crisis, developers are bombarding Arizona with plans to build homes even as water shortages worsen.

The Arizona Department of Water Resources reported that the Lower Hassayampa subbasin, which includes Phoenix’s westernmost valley, is projected to have total unmet water needs of 4.4 million acre-feet over a 100-year period. The Department cannot therefore move to authorize the development of subdivisions that depend solely on groundwater.

“We need to speak about the challenge of our time: Arizona’s decades-long drought, the overexploitation of the Colorado River, and the combined impact on our water supply, our forests, and our communities,” Gov. Katie Hobbs said in a statement last week.

Developers in the Phoenix area must obtain state certifications proving they have 100 years’ worth of water reserves in the ground they are building over before they are allowed to build land.

The mega-drought has caused the west to have its driest two decades in at least 1,200 years, and human-caused climate change has helped heat up conditions. Arizona has experienced cuts in its water allocation on the Colorado River and is now required to curb 21% of its water use from the river, or about 592,000 acre-feet per year, an amount that would supply more than 2 million Arizona homes annually.

Despite warnings that there isn’t enough water to sustain growth in the development, some Arizona developers have argued they can circumvent the reduction in water supplies, saying new homes will have low-flow fixtures, drip irrigation, desert landscape and other drought-friendly measures. More than two dozen housing developments are in the works around Phoenix.