Where Does Flagstaff's Water Actually Come From?

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I sat in on a Compass Realty meeting this month where Lee Williams from the City of Flagstaff walked us through the history of the city's water supply. If you are buying, selling, or just curious about a home in the Flagstaff area, this is worth knowing.

Flagstaff Water Sources: Wells, Springs, and Lakes

Flagstaff's water does not come from a single place. It has been pieced together over more than a century:

  • Inner Basin wells and springs: Dating back to the 1890s when all water came from melted snow from the San Francisco Peaks (true distilled water).

  • Upper Lake Mary: Developed in the 1940s.

  • Woody Mountain wellfield: Drilled in the 1950s and 1960s.

  • Lake Mary wellfield: Added in the 1980s.

  • Local wells: Drilled from the mid 1990s to today.

Surface water, mainly Upper Lake Mary, is the cheapest source to treat and deliver. The catch is that it depends entirely on snowpack, so supply shifts with the seasons and weather years. That is a major reason the city has leaned so heavily on groundwater wells.

Depending on which part of Flagstaff you live in, your tap water may even taste a little different, since it is a blend of groundwater and surface water that shifts seasonally.

Water Storage and Backup Power During Outages

Flagstaff keeps nine reservoirs on the hillsides, holding roughly two days of water supply in the summer and four days in the winter. Despite steady population growth since the late 1980s, overall water usage has stayed roughly the same thanks to the city's award-winning water conservation program.

That storage capacity is critical for another reason. Arizona Public Service (APS) periodically conducts Public Safety Power Shutoffs (PSPS) during high wind events to prevent wildfire risks. APS adopted this practice after California wildfires were traced to power lines sparking in heavy winds, and these shutoffs have occurred around Flagstaff multiple times.

The city confirmed that potable water continues flowing to residents as normal during a PSPS event. Backup generators keep the water system running, so a power shutoff does not result in a water shutoff.

The 100 Year Plan: Red Gap Ranch

One of the most notable updates from the briefing is Flagstaff's long-term water security plan.

In 2005, the City of Flagstaff purchased Red Gap Ranch for $7.9 million. The property consists of roughly 8,500 acres located about 40 miles east of the city near Meteor Crater. The city has since drilled 11 wells at the site, which is designed to serve as a long-term backstop capable of securing Flagstaff's water supply for the next 100 years. City officials confirmed that Flagstaff currently has more than enough water capacity for the immediate years ahead.

Connecting Red Gap Ranch to Flagstaff requires constructing a 40-mile pipeline, which remains a long term project:

  • Appraisal Study (2025): The Bureau of Reclamation agreed to begin scoping an appraisal study as the initial federal step toward a possible pipeline.

  • Feasibility Study: The initial appraisal study takes about a year, and if approved, the subsequent full feasibility study could run another two to four years.

Red Gap Ranch is an active, funded project, but full pipeline infrastructure remains several years away.

Impact on Future Developments: The Starlight Community

For buyers and investors watching the proposed Starlight master planned community (approximately 2,000 planned residences) on the west side near Woody Mountain Road and I-40, water infrastructure plays a central role.

As of 2026, the project continues moving through the city's development review process, including a formal development agreement currently under city council review. It is a key location to track if you are looking at growth on the west side of town.

Key Flagstaff Water Facts for Homebuyers

  • Deep Water Table: The water table sits more than 1,000 feet below the surface in most parts of Flagstaff. This contrasts sharply with the Phoenix area, where groundwater typically sits only a few hundred feet down, making drilling significantly cheaper in the desert valley.

  • Local Due Diligence: If you are weighing a move to Flagstaff or anywhere in Northern Arizona, water rights, sources, and infrastructure are essential questions to review early in your search.

I am always happy to talk through local market details, infrastructure updates, and neighborhood nuances. Feel free to reach out anytime with questions about Northern Arizona real estate.

Cassity Trexler

The Trexler Team | Compass