Water Report | Purely Water Solutions | Scottsdale, AZ

Three Water Supplies and Treatment in Scottsdale

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Before the 1980s, Scottsdale was 100% reliant on groundwater. Today, more than 90% of the city’s total water supply comes from renewable surface water sources and recycled water. This diversified portfolio helps ensure a reliable, long-term supply for future generations.

Depending on the season, weather, and customer demand, your tap water may come from a single source or a blend of sources.

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Surface Water

Scottsdale’s primary surface water supply is from the Colorado River, delivered via the Central Arizona Project (CAP) canal to the CAP Water Treatment Plant at the Scottsdale Water Campus in north Scottsdale.

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• The CAP Plant has a capacity of up to 70 million gallons per day and consists of three facilities:

• CAP I and II: Use conventional treatment (pretreatment, coagulation/flocculation, sedimentation, filtration, and disinfection).

• CAP III: Uses advanced ultrafiltration membrane technology plus disinfection.

• Granular activated carbon (GAC) is used throughout to improve taste and odor and reduce disinfection byproducts.

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The city also draws surface water from the Salt and Verde Rivers via the Salt River Project (SRP). This water is treated at the Chaparral Water Treatment Plant (near Hayden Road and East McDonald Drive), which uses ultrafiltration membranes and GAC. It has a capacity of 27–30 million gallons per day.

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Groundwater

A smaller portion of Scottsdale’s supply comes from deep aquifers. The city maintains 21 active wells and operates treatment facilities such as the Central Groundwater Treatment Facility and the North Indian Bend Wash Granular Activated Carbon Treatment Facility (addressing contamination from the Superfund site).

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Private companies responsible for historical Trichloroethylene (TCE) contamination fund the operation and maintenance of these facilities. Groundwater is treated to standards exceeding federal and state requirements, with oversight from the EPA, ADEQ, and Maricopa County.

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Recycled Water

The Advanced Water Treatment Plant (AWT) at the Scottsdale Water Campus is one of the largest and most advanced water recycling facilities in the world. It treats wastewater from homes and businesses to ultrapure standards that exceed federal drinking water regulations.

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• Treated recycled water supports turf irrigation and is injected into local aquifers for recharge.

• Since 1998, the facility has enabled recharge of over 70 billion gallons into the aquifers — enough to fill State Farm Stadium approximately 120 times.

• This program has been key to aquifer sustainability and long-term supply security.

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Scottsdale’s Water Portfolio for 2025 (most recent available data):

• Central Arizona Project (Colorado River): 71%

• Salt River Project: 13%

• Recycled: 8%

• Groundwater: 8%

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Scottsdale continues to invest in advanced purification, aquifer storage and recovery wells, smart metering, and infrastructure to further diversify supplies and prepare for potential Colorado River reductions.

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This reliable, high-quality water infrastructure supports the excellent performance of modern tankless water heaters, filtration systems (like Halo 5), and whole-house solutions such as Halo Water Filtration — helping homeowners and businesses in the Valley enjoy efficient, worry-free water use for years to come.

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Source: City of Scottsdale Water Quality Reports and official water supply pages. Data current as of 2025–2026 reports.