PHOENIX, AZ (April 3, 2026) — Phoenix has reached a major milestone in what city officials say will become a critical part of Arizona’s long-term water strategy. Construction is now about halfway complete on the state’s first advanced water purification plant, a $300 million project designed to convert wastewater into high-quality drinking water.
City leaders marked the occasion last Thursday at the Cave Creek Water Reclamation Plant by filling one of the new treatment basins with 1 million gallons of water, a symbolic step underscoring the scale of the project and its role in the city’s future water supply. The facility is part of the city’s Pure Water Phoenix program, an initiative aimed at expanding Phoenix’s use of highly treated recycled water as drought, population growth, and pressure on traditional water sources continue to reshape water planning across the region.
Nazario Prieto, assistant director of the Phoenix Water Services Department, said the project is designed to strengthen the city’s long-term water reliability.
“Long term, it ensures that Phoenix residents have water security now well into the future,” Prieto told PHXTV.
He said the advanced purification plant will become increasingly important over the next decade as Phoenix works to diversify its water portfolio and reduce dependence on more vulnerable supplies.
“Over time, in the next 10 years, this will be an integral part of Phoenix’s water resource portfolio,” Prieto said.
Construction on the facility began in 2024 and is expected to be substantially complete next year. After that, the plant will enter a yearlong demonstration and testing phase, during which the purified water will be used to recharge groundwater basins. That process is intended to verify performance and ensure the water meets Arizona Department of Environmental Quality standards before direct potable reuse begins.
Once operational, the plant is expected to treat about 8 million gallons of wastewater per day and produce roughly 6.75 million gallons of potable water per day, enough to serve an estimated 25,000 to 30,000 homes. Prieto said the water will pass through multiple levels of treatment before reaching its final purification stage, including reverse osmosis, one of the most rigorous filtration methods used in water treatment.
“This water, once it’s treated, it’s going to run through an entire reverse osmosis process,” he said, noting that the water will already have undergone extensive treatment before reaching that stage.
City officials describe the Cave Creek facility as Arizona’s first large-scale advanced water purification plant and a potential model for future water infrastructure investments statewide. Phoenix expects the plant to be fully operational by 2029, when direct potable reuse can begin and treated water can enter the city’s drinking water distribution system.
Tucson is moving in a similar direction, though it is not yet as far along in construction. Tucson already operates an extensive reclaimed water system for non-potable uses such as irrigation, aquifer recharge, and habitat restoration, offsetting about 4.7 billion gallons of potable water annually through a separate recycled-water network that serves nearly 1,000 customers. The city’s reclaimed water is not currently part of its drinking water system.
Through its Pure Water Tucson initiative, however, Tucson is laying the groundwork for advanced water purification as part of its broader One Water 2100 plan. The city has advanced plans for a demonstration facility tied to the Tres Rios Water Reclamation Facility that would treat about 2.5 million gallons per day and further purify recycled water for future potable use. Tucson officials describe advanced water purification as a critical long-term strategy for strengthening local water resilience, much like Phoenix is now doing at Cave Creek.
Together, the two projects show how Arizona’s largest cities are increasingly treating water reuse as more than a conservation measure. It is becoming part of the long-term infrastructure needed to support future growth, reduce pressure on traditional supplies, and strengthen water security in an increasingly arid state.