Tucson staff propose zoning rules for large‑scale data centers, including definition, setbacks and public review

City of Tucson planning staff on Tuesday presented a draft zoning code amendment aimed at regulating large‑scale data centers, saying the change is intended to create clear standards for where and how very large server facilities could be built.

"Tonight's meeting is focused on a proposed update to our zoning code to create regulations for large scale data centers," Corin Manning, director of the Department of Planning and Development Services (PDSD), told attendees, saying the work follows Mayor and Council direction to prepare standards after a high‑profile proposal drew public attention.

The draft would classify a "large‑scale data center" as facilities (or contiguous facilities under common ownership) with a gross floor area greater than 50,000 square feet and housing networked computer and telecommunications equipment used for remote storage, processing and distribution of data. Staff said the floor‑area threshold is intended to capture hyperscale campuses and avoid developers splitting a campus into smaller buildings to evade rules.

Why it matters: staff emphasized zoning is the city's primary land‑use lever — it can set setbacks, height, screening and public‑review procedures — even as energy sourcing and utility regulation generally remain outside municipal zoning authority. Still, staff said land‑use rules can require applicants to disclose anticipated energy consumption and energy mix publicly so decision‑makers have information about potential system impacts.

Key provisions in the draft

- Review process and siting: New or very large data centers would not be allowed by right. Instead, staff recommended permitting them through a Mayor and Council special‑exception process in the I‑2 Heavy Industrial zone or through a Planned Area Development (PAD) or Planned Community Development (PCD), all of which include public hearings and neighborhood meetings.

- Definition: a gross floor area threshold of greater than 50,000 square feet for a single facility or contiguous facilities under the same ownership.

- Expanded notice: staff proposed widening notice requirements (to roughly a half‑mile and notification of neighborhood associations within 2 miles) so more residents and groups receive advance notice for large proposals.

- Setbacks: staff proposed a 400‑foot setback from urban residential and other noise‑sensitive uses and a 200‑foot setback from commercial or office zones, and solicited feedback on whether those distances are adequate.

- Noise and generators: the draft would require an independent noise study with limits measured at the property line, sound‑attenuation (screening or walls) around backup generators, and operational limits that prioritize battery backup first and restrict routine generator use and maintenance to weekday daytime hours. Staff said a "no load shifting" provision would prohibit running generators instead of grid power for normal operations.

- Landscaping and parking: a 20‑foot enhanced landscape buffer and a low minimum parking ratio (reflecting limited onsite staffing) are proposed, along with continuing compliance with existing Environmental Resources Zone (ERZ), WASH, hillside and airport glare rules.

Public participation and timeline

Staff said this was the first of four community meetings and outlined the approval path: staff will post community feedback online, hold a Planning Commission study session (scheduled for March 18), a Planning Commission public hearing (tentatively in April) and ultimately a Mayor and Council public hearing. Planner Carver Strew said the Technical Advisory Committee (TAC) of about 13 members — including watershed representatives and Pima County DEQ — informed the draft but was only advisory.

What residents asked

Attendees raised repeated concerns about generators (diesel fuel, emissions and safety), whether the proposed setbacks are adequate, and whether the city could or should pursue an outright ban. Staff repeatedly said Mayor and Council asked staff to prepare regulatory "guardrails" and that any prohibition would be a separate policy decision for elected officials. Several commenters asked how the city would coordinate with neighboring jurisdictions, citing a recent Marana decision on a proposed data center.

Next steps

Staff asked attendees to submit written comments (the only format that will be recorded in the official meeting record) and said they will compile FAQ responses and post materials and poll results on the PDSD website. The Planning Commission will review the proposal at the study session and public hearing before Mayor and Council acts.