New 160-acre data center proposed in Sahuarita

A proposed eight-building data center campus on 160 acres just west of Sahuarita could reshape a currently vacant stretch of desert, even though no formal application has been submitted and many basic details remain unknown. The development, called Project Gravel, is being evaluated on land near West Twin Buttes Road in unincorporated Pima County. County records show the site would include large server buildings, a private electrical substation, internal roads and parking areas, placing a major industrial use near residents and communities south of Tucson.

The property is owned by Sahuarita Holdings, LLC, which controls three parcels at approximately 2480 West Twin Buttes Road. Two parcels are zoned for rural homesteads, a designation intended for ranch-style homes, mobile homes and spacious setbacks that preserve a rural setting. The third parcel is zoned for general industrial use. That portion of the property previously operated as a mining and agricultural chemical plant under several companies from the early 1980s through 2006. It has been vacant since Sahuarita Holdings bought the land in 2011.

Project Gravel is described in county documents as an eight-building data center development. Each building is expected to cover roughly 203,000 square feet, an area comparable to about three and a half football fields. The plans also call for a dedicated substation, roads and parking lots. A traffic study indicates that buildings would begin operating as they are completed, with the entire project expected to be built out by 2029. The records do not identify the eventual data center operator, the number of jobs, construction costs, or projected water and electricity needs.

Environmental and site investigations have been underway since at least August 2025. Contractors have been examining the property’s environmental condition, floodplain status, cultural resources and history of previous industrial uses. A cultural resources inventory map prepared for the project is included in the county material. Those reviews appear to be part of early due diligence rather than evidence that the project has received approval. Project Gravel has moved through county staff review quietly, and the records obtained do not show that a formal permit application has been filed.

That status became particularly important when the Pima County Board of Supervisors approved a 120-day moratorium on new data center permits and applications in unincorporated areas. The vote was 3-2, with Supervisors Steve Christy and Rex Scott opposed. The pause is intended to give county staff time to revise zoning rules for data centers, potentially extending until mid-January and possibly requiring additional action by the board before it expires. The moratorium could affect Project Gravel because the proposal has not yet received a permit.

The board amended the measure so it would apply to data centers that have not been issued permits, rather than blocking only future projects that had not yet submitted applications. County officials said that distinction could cover Project Gravel while excluding Project Blue, a separate data center development near the Pima County fairgrounds that has already received permits. A county spokesperson said the amendment was not adopted with knowledge of any Project Gravel permit submission. The other project, Project Blue, is a multiphase campus planned on a 120-acre site near Pima County Airfield, with an initial phase that could support up to four buildings and later expansion to as many as 10.

Project Blue has become the backdrop for the county’s new scrutiny. Public awareness of that development came late, in part because confidentiality agreements limited county staff from discussing it outside conversations with the developers. The Pima County Board of Supervisors later sold 120 acres to Beale Infrastructure for $24.5 million for the Project Blue site. Tucson’s City Council subsequently approved annexing the property, a move that would provide water access through Tucson Water. The county says the proposed zoning update will address issues raised by the data center debate, including definitions, review procedures, development and design standards, noise studies, mitigation and compliance with conservation land systems.

The county is seeking public feedback on those changes through an online survey and planned an open house from 6 to 8 p.m. Sept. 16 at the Pima County Public Works Building, 201 N. Stone Ave. More detailed information was expected to be posted online after the proposed amendments were finalized. County Development Services also said the draft changes would go before the Planning and Zoning Commission on Sept. 15. The moratorium gives officials time to consider how data centers should be reviewed before the revised rules are adopted.

Project Gravel is separate from another possible data center proposal associated with land near the Rancho Sahuarita planned community. Residents there have organized after learning that landowner Jeremy Sharp had spoken with data center developers. Sahuarita town officials have said they have received no official submissions or applications for that site, which is within town limits. The Project Gravel property, by contrast, is outside Sahuarita and north of a tailings pile, near the tracks between East Toro Road and Twin Buttes Road. The town has said it receives development applications only for property inside its boundaries.

The landowner, Sahuarita Holdings, is a subsidiary of Idaho-based W.R. Henderson Construction, according to Arizona Corporation Commission records. For now, Project Gravel remains a proposal under county review rather than an approved development. Its eventual effect on traffic, groundwater, power infrastructure and nearby neighborhoods cannot be determined from the available records because the project’s operator, resource demands and final permitting path have not been disclosed. The county’s moratorium and zoning rewrite will determine what requirements the project must meet if its owners decide to move forward.