Flagstaff staff recommends conditional permits and strict water, noise and renewable-energy limits for data centers

Planning staff on Wednesday recommended that the Flagstaff Planning and Zoning Commission recommend to City Council a zoning text amendment that would make data centers subject to conditional-use permits and impose limits on water use, low-frequency and overall noise, and a strict renewable-energy expectation.

Tiffany, the staff presenter, said the city has two options under review: add a specific definition for "data center" and require conditional-use permits for those facilities, or ban data centers as a primary use by placing the prohibition in the code definition. "Data centers would currently be considered a permitted use in the heavy industrial and the heavy industrial open zone and would be a conditional use in the light industrial zone," she said, noting staff had been asked to take a proactive look at whether the current code and zones are appropriate.

Why it matters: the proposals respond to resident and stakeholder concerns about water consumption, noise (including low-frequency "feelable" sound), and energy use. Tiffany said staff is trying to reconcile General Plan goals on carbon neutrality, maintaining natural quiet and protecting scarce water resources with the practicalities of where industrial uses can be located.

The staff-backed proposal would add a land-use definition for data centers, require conditional-use permits (subject to Planning and Zoning review and appeal to City Council), and include several technical conditions: a minimum 200-foot setback where a parcel abuts residential zoning or uses; operational noise limits measured at the property line (staff proposed targets roughly equivalent to normal conversation—about 60 dBA daytime and 50 dBA at night—and an accompanying low-frequency dBC metric); a required baseline noise study including low-frequency measurements to enable enforcement; decommissioning standards for when a data center use ends; and a prohibition on evaporative or water-based heat-rejection systems. "Evaporative or water-based heat rejection systems ... and water-cooled chillers is prohibited," Tiffany said, framing the prohibition as the Water Commission's preference to avoid large new water demands.

Staff also strengthened the renewable-energy expectation: "100% renewable energy for all data center energy needs shall be used to the greatest extent feasible," Tiffany said, adding that applicants would need to work with local energy providers and explain constraints where full onsite renewable supply is not achievable.

Staff displayed zoning maps showing the heavy industrial and heavy industrial-open zones together total roughly 196 acres (about 165 acres heavy industrial and 31 acres heavy industrial open), and identified several areas—near the LEAF facility and jail, the Village at Aspen Place, the Picture Canyon trailhead, the Trails End subdivision and the Walnut Canyon/Route 66 corridor—as places where the proposal would apply. Tiffany emphasized that many of those parcels are city- or county-owned and that a 200-foot setback would sharply reduce eligible sites adjacent to residential areas.

Public input and enforcement: Tiffany said staff had received a large volume of emails—most opposed to data centers—raising water and energy as primary concerns. On enforcement, staff noted the city enforces nuisance noise through the police code and that a baseline study is critical to determining measurable exceedances over time.

Commissioners asked technical and legal questions. Commissioner Mary Norton asked whether the tech park near JW Powell and the airport is pre-zoned for tech; staff said it is zoned highway commercial and that some commercial zones allow industrial-type uses. Norton and others probed why a prohibition could not be listed in the land-use table; staff said that approach would require frequent, detailed edits every time a new land-use category is raised and that placing a prohibition in the definitions is the workable option given how the code is structured. Commissioners also questioned whether other industrial uses run 24/7 and how the noise standards would be applied; Tiffany said many heavy industrial uses do operate continuously and that the city relies on nuisance-based noise enforcement when necessary.

What was not decided: the commission heard staff's recommendation—staff recommended proposal one, not an outright ban—but the transcript ends with discussion and clarifying questions; there is no recorded motion or vote on PZ 260018 in the provided segment. The next formal step is the Planning and Zoning Commission's recommendation (if made) and subsequent City Council consideration.

Supporting details: during roll call the commission approved minutes from the March 11 meeting after a correction noting Commissioner CJ Lukey requested a draft amendment about data centers; Mary Norton moved to approve and CJ Lukey seconded the motion, which passed by voice vote. Tiffany said staff consulted the Water Commission and sustainability staff, and that economic-vitality staff prepared a memo but could not attend in person.

The commission's discussion highlighted competing policy goals: preserving locations for heavy industrial uses versus protecting nearby neighborhoods' water supplies, quiet and environmental quality. Staff's proposal attempts to allow data centers in limited circumstances while applying technical conditions intended to reduce water use, capture and limit low-frequency noise, and encourage renewable energy.

Tiffany closed by noting staff had attached all public comments received and that staff was seeking the commission's input before a future formal recommendation to City Council.