Flagstaff, federal partners to scope appraisal study for Red Gap Ranch regional water supply

FLAGSTAFF — The City of Flagstaff and the Bureau of Reclamation presented a multi-agency value-planning study on Monday that ranks development options for the city’s Red Gap Ranch and other regional water sources and sought direction to develop an appraisal-level scope of work.

Council and water-commission members indicated support to proceed with scoping an appraisal study after presentations from federal and city staff and public questions about costs, water quality, ecological impacts and wildfire vulnerabilities.

The appraisal study would be an early feasibility-level analysis that refines alternatives identified by the weeklong value-planning workshop: (1) develop municipal production wells at Red Gap Ranch with local treatment and optional aquifer storage and recovery (ASR); (2) variants that locate treatment nearer Flagstaff or at intermediate sites such as Twin Arrows; (3) expand nearer-field municipal wells; and (4) import Colorado River water via long-distance conveyance. The value-planning team ranked Red Gap Ranch alternatives highest, with Red Gap plus ASR scoring best in the team’s paired-ranking criteria.

Why it matters

Flagstaff has long-term projections showing a water shortfall under buildout scenarios. Study authors and city staff framed the appraisal work as intended to inform decisions about resiliency and redundancy — particularly after recent wildfire and power-shutdown risks that threaten the city’s existing supplies and its ability to operate local wells.

What the presentation covered

City and federal presenters summarized decades of planning and past investments. The city purchased Red Gap Ranch in 2005 for $7.9 million; the ranch includes about 8,500 deeded acres within roughly 24,000 acres of contiguous holdings and previously developed municipal-size wells. The Arizona Department of Water Resources (ADWR)…