Flagstaff water managers present resiliency scenarios as wildfire and aridification raise supply uncertainty

Summary

City water staff and consultants told the Water Commission that under multiple drought-and-wildfire scenarios Flagstaff will need a new long‑term supply in coming decades, with recommended planning volumes ranging roughly 6,500–12,000 acre‑feet and near‑term contingency supplies of about 4,800–5,000 acre‑feet in catastrophic scenarios.

Flagstaff Water Resources Manager Erin Young and consultant Brad Hill told the Flagstaff Water Commission the city must plan for a range of futures — including hotter, drier conditions and wildfire impacts — and that those scenarios change the timing and scale of when new supplies will be needed.

In opening the presentation, Young summarized the city’s current portfolio: “We pull water from the inner basin of the San Francisco Peaks,” she said, and the utility also relies on Upper Lake Mary, several groundwater wellfields (Woody Mountain, Lake Mary and inner‑city wells) and reclaimed water. Young said reclaimed water and conservation shift the need for new supplies but do not eliminate it.

The presentation centered on scenario modeling Brad Hill prepared to test “resiliency and redundancy” — variations that include slower recharge to Upper Lake Mary, reductions in Lake Mary well‑field pumping, and the loss or temporary shutdown of wells after a severe wildfire. Hill told commissioners, “never to pick a single future because you’ll be wrong,” and said scenario planning is intended to “bracket the timing and when a new supply is needed.”

Why it matters: the city’s 2013 designation of an adequate 100‑year water supply ties some future water availability to…

Flagstaff water managers present resiliency scenarios as wildfire and aridification raise supply uncertainty

Summary

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