The Pima County Board of Supervisors voted 3 to 2 on September 23 to freeze new data center permit applications for 120 days, citing “imminent negative public health impacts” from the industrial-scale power and cooling demands of data center operations. The vote was close, the language was blunt, and the timing was no accident: the county has watched a wave of large-scale proposals accumulate while its health and zoning frameworks were never built to evaluate them.

For anyone buying, selling, or advising on commercial real estate in the Greater Tucson corridor, the vote is not primarily a story about data centers. It is a story about what happens when a fast-moving asset class outruns the regulatory infrastructure designed to evaluate it, and who bears the cost when the rules finally catch up.

The Moratorium and Its Exemption Clause

The 120-day pause applies to developers who have not yet filed permit applications for site improvements including grading, paving, flood control, and construction. Projects with applications already on file are exempt. Board Chair Jen Allen described the moratorium, the county health risk assessment, and proposed zoning code amendments as “three legs of a stool.”

That carveout matters enormously. “Project Gravel,” an eight-building data center development spanning 160 acres near Sahuarita, remains in play. Its owner, Sahuarita Holdings LLC, a subsidiary of Idaho-based W.R. Henderson Construction, filed environmental and cultural assessments at least as early as August 2025. The project predates the county’s tightened disclosure policies, which themselves followed public backlash over a separate proposal near the county fairgrounds known as “Project Blue.” So the largest data center proposal in the county’s pipeline sails through the moratorium because it got in the door first.

That is not a loophole. It is a feature of how entitlement processes work. Developers who understand the regulatory calendar secure approvals before opposition can crystallize. Developers who do not find themselves negotiating with a county that has just declared their project a public health concern. The lesson for commercial real estate advisors is as old as zoning itself.

The Deeper Question Behind the Health Claims

Supervisor Rex Scott, one of the two no votes, argued that the health review “paints with far too broad a brush” and lacks localized scientific studies specific to data center impacts. That is a fair legal and evidentiary objection. The county resolution leans on Pima County’s existing respiratory and cardiovascular health vulnerabilities relative to the rest of Arizona as the justification for heightened scrutiny, a real epidemiological baseline but not a study of any specific facility.

What the Board is really doing is buying time. The 120-day clock exists to let the county health department complete a risk assessment, accept public comment on proposed zoning amendments, and establish standards before more projects reach the application stage. Supervisor Andres Cano framed the action in terms of public health responsibility and the need to set clear standards before approving additional projects. Board Chair Allen explicitly characterized the moratorium as temporary.

The risk for developers and investors is that “temporary” can become permanent if the risk assessment produces findings the county cannot politically ignore. The Arizona Chamber of Commerce recognized how fast public sentiment has shifted: earlier this year it launched a satirical “Arizona Offline Pledge” in response to moratorium calls statewide. What looked like a peripheral concern six months ago is now actionable county policy in the state’s second-largest metro.

What This Means If You Are Buying Land or Developing in Southern Arizona

The Pima County moratorium is the most formal expression yet of a statewide debate over data center development, but it will not be the last. Navajo leaders have raised objections to a proposed data center near Horseshoe Bend. Municipal governments across the Phoenix Valley are watching how Tucson navigates its process before deciding whether they need their own regulatory frameworks.

For a commercial real estate investor or developer looking at industrial or semi-industrial land in Pima County or the broader Arizona growth corridors, three things have changed.

Permit timing is now a strategic variable, not an administrative step. Project Gravel survives this moratorium because it moved early. Developers and their legal counsel need to know which projects are inside the exemption window and which are not. An application filed before a moratorium takes effect carries a fundamentally different risk profile than one filed after the freeze.

Highest-and-best-use assumptions need re-underwriting. Land with general industrial zoning adjacent to rural residential parcels has been a legitimate data center target for years. Pima County is now explicitly reviewing whether its zoning code adequately distinguishes between traditional industrial uses and the power density of a modern data center campus. That review creates valuation uncertainty for positions underwritten on pre-review assumptions.

Environmental and community due diligence is no longer optional at the LOI stage. The county resolution cites Pima County’s existing health vulnerabilities as the basis for heightened scrutiny. Any project that introduces significant power infrastructure, water consumption, and traffic near established residential areas now carries a community-opposition risk that belongs in the underwriting model from the first conversation. A real estate attorney and land use consultant with specific Arizona zoning experience is not a nice-to-have: it is the difference between a project that closes and one that stalls in a 120-day review with the option to extend.

The moratorium gives the county time to build a framework. It gives developers and investors the same window to understand exactly which side of the exemption line they are on, and to find advisors who can navigate what comes next.