Tucson approves strict data center zoning in Arizona, requiring council vote for any facility over 20 MW

The Tucson City Council voted 6-1 on August 5, 2026, to adopt new regulations for large-scale data centers. City officials say the facilities will be among the most highly regulated land uses in Tucson.

The ordinance is not effective immediately. The new regulations take effect on September 4, 2026.

Any data center exceeding 25,000 square feet or 20 megawatts of power use will require adoption or a major amendment of a Planned Area Development or Planned Community Development. The process includes neighborhood coordination, a zoning examiner hearing, and final consideration by the mayor and council.

City materials record the result as 6-1. KJZZ reported that Ward 4 Councilmember Nikki Lee abstained because she wanted the council to return with a revised ordinance incorporating concerns raised at the hearing.

The vote came one day short of a year after the council declined to proceed with the proposed annexation of the Project Blue site.

What the ordinance actually does

The ordinance does not permit qualifying data centers by right anywhere in Tucson. Every facility that crosses either threshold must secure its zoning through the PAD or PCD process.

The code defines a large-scale data center as a facility exceeding 25,000 square feet or using more than 20 megawatts of energy. The definition can apply to multiple facilities or part of a facility on a contiguous site.

Qualifying facilities must be at least half a mile from designated residential zones, residential uses, and schools. They must also be at least 1,000 feet from commercial and office zones.

An Environmental Resource Report can lead the zoning administrator to require additional separation from natural areas, riparian corridors, or open space. Buildings are limited to 50 feet in height, and structures can cover no more than 40% of the site.

The remaining land must generally be preserved as natural open space. If the mayor and council approve off-site mitigation instead, the code requires protection at a minimum ratio of two acres elsewhere for every acre displaced on the project site.

Applicants must submit a baseline noise study prepared by an independent acoustic engineer. Generators and other noisy equipment require solid screening walls or rooftop screening, and operators must comply with Tucson’s noise limits.

The framework requires a combination of batteries and generators for backup power. Low-emitting sources must be used before higher-emitting equipment, while generator operation is restricted to circumstances including outages, grid instability, utility requests, preventive maintenance, and scheduled testing.

Water rules depend partly on the project’s anticipated consumption. Facilities must certify that they have an adequate water supply.

Projects subject to Tucson’s Large Quantity Water Users Ordinance must complete its application and conservation-plan process. When that ordinance does not apply, potable water cannot be used for data center cooling.

City planning officials described the framework as placing data centers alongside generating systems among Tucson’s most tightly reviewed land uses. That is a strong local standard, although available official material does not establish that it is the single strictest data center ordinance in Arizona.

Why the council did not ban them outright

Public testimony ran overwhelmingly in favor of a complete ban, rather than approval of the proposed framework. Residents raised concerns about water consumption, power demand, noise, heat, property values, surveillance, and the effect on communities already carrying environmental burdens.

City legal staff advised that both a moratorium and a ban could create legal risks under state law. Proposition 207, the Private Property Rights Protection Act, can require compensation when a new land-use restriction reduces a property owner’s rights or property value.

Community organizers argued that Proposition 207 contains a public health and safety exception that could provide a route to stronger restrictions. They urged the council to investigate whether evidence about pollution, noise, heat, and resource use could support that approach.

Speakers also raised environmental-justice concerns involving areas south of Tucson and communities near the San Xavier District of the Tohono O’odham Nation. Their concern was that smaller jurisdictions outside city limits could still be affected by facilities built on eligible Tucson sites.

Ward 6 Councilmember Miranda Schubert introduced an amendment making clear that the council intends to keep looking for a legal pathway to sharply limit or ban large data centers. The amendment was adopted as part of the ordinance.

Council members framed the zoning framework as an immediate legal safeguard once it takes effect. Without data center-specific rules, a developer could seek approval under the city’s existing land-use system without the new setbacks, environmental review, noise controls, and council-level scrutiny.

The Project Blue backdrop

The ordinance grew out of the fight over Project Blue, a data center campus proposed for nearly 300 acres of Pima County land. The county approved the project’s planning framework and land sale while the end user remained undisclosed during the public review.

On August 6, 2025, the Tucson City Council unanimously declined to proceed with annexation of the site. That decision did not cancel the county project, but it prevented the developer from gaining access to Tucson city water through the proposed annexation.

Construction has since proceeded on county land. Residents have acted as informal watchdogs, monitoring water trucks arriving at the site and asking where the water originated.

That year of protests, community meetings, and coordination with organizers elsewhere helped produce an August 5 hearing where public opposition was nearly unanimous. Speakers also criticized the city’s earlier engagement process and argued that the technical advisory structure did not adequately represent residents who opposed data centers in principle.

What happens next for residents and operators

The regulations take effect September 4. From that date, a developer proposing a facility above either the 25,000-square-foot or 20-megawatt threshold will have to use the PAD or PCD process and satisfy the applicable separation, environmental, noise, water, energy, landscaping, and open-space requirements.

The council has directed staff to continue researching stronger restrictions, including the legal viability of a ban. City officials will also have to determine how compliance is monitored after a facility begins operating.

At the county level, the Pima County Board of Supervisors was scheduled to consider a 120-day moratorium on data centers in unincorporated areas on August 11 while the county works on its own zoning-code amendments.

For operators, the Tucson framework means a slower and more public development process with no guarantee of final approval. Meeting the numerical threshold no longer leads simply to a building-permit review, because the mayor and council retain discretion over every qualifying proposal.

For residents, the ordinance remains a compromise that many hearing participants did not want. It creates a substantial zoning barrier but stops short of the ban they requested.

What Tucson approved is not a prohibition. It is a new set of safeguards scheduled to take effect September 4, paired with a commitment to keep investigating whether state law leaves room for something stronger. Residents who filled the council chamber made clear that they intend to watch both promises closely.