Item #3 - Large-Scale Data Center Regulations Memo(PDF, 233KB)

Date: 
April 29, 2026 for May 6, 2026 scheduled meeting 
Page: 1 of 8 
To: 
Planning Commission 
From: 
Koren Manning, Director of Planning and Development Services, 
and Executive Secretary 
Subject: 
C8-25-04 Large-Scale Data Center Regulations Unified 
Development Code Amendment (Citywide) 
 
Issue – This study session item is being held to present a proposed code amendment to the Unified 
Development Code (UDC) to establish regulations and standards for large-scale data centers. This 
amendment was initiated by Mayor and Council during their August 6, 2025 study session (see 
Attachment A for the Legal Action Report from that meeting). At that time, Mayor and Council directed 
City staff to develop regulations for this use. This request was part of the motion Mayor and Council 
adopted to not consider the proposed Project Blue data center annexation and Development Agreement. 
A second Mayor and Council Study Session was held on April 7, 2026. during which Mayor and Council 
provided additional feedback on the proposed code amendment (see Attachment B).  
 
The proposed code amendment would establish a definition of large-scale data centers and establish use-
specific standards. The proposed code amendment has been developed with input from a Technical 
Advisory Committee (TAC), four community engagement meetings and community survey, and Mayor 
and Council feedback.  
 
Staff Recommendation – Staff recommends the Planning Commission set the Unified Development 
Code Amendment to establish regulations for Large-Scale Data Centers for a public hearing on June 3, 
2026. 
 
Background – At the August 6, 2025, Mayor and Council study session regarding the proposed “Project 
Blue” annexation, Mayor and Council directed staff to develop zoning regulations for large-scale data 
centers. Staff then brought this request before the Planning Commission for an initial Study Session, 
and formed a Technical Advisory Committee to inform the development of the proposed standards, as 
detailed below.  
 
On September 9, 2025, the Zoning Administrator issued a Determination which established large-scale 
data centers as the most appropriately classified use per the Unified Development Code as a Generating 
System land use (see Attachment C). This use is not currently permitted by-right in any zone, has no 
use-specific standards, and may only be developed through a rezoning process to a Planned Area 
Development (PAD). This Determination anticipated a later UDC code amendment process 
to establish a new defined use, development standards, and review process for large-scale data centers. 
 
 
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PLANNING COMMISSION MEMORANDUM 
C8-25-04 Large-Scale Data Center Regulations  
UDC Amendment Study Session (Citywide) 
 
On September 17, 2025, Planning and Development Services Department (PDSD) presented 
preliminary information at a study session to the Tucson Planning Commission (See Attachment D). 
That presentation included an overview of the demand for data centers, how facilities are currently 
classified in the UDC, and potential regulatory components such as definitions, zoning classifications, 
use-specific standards, and review procedures. PDSD staff also requested and received initial feedback 
on potential regulations for large-scale data centers from Planning Commission members. 
 
Community Outreach and Stakeholder Engagement 
Following direction from Mayor and Council and the Planning Commission study session, staff 
initiated research and analysis of regulatory approaches used in other jurisdictions and formed a 
Technical Advisory Committee (TAC) to provide subject matter expertise. The TAC was formed with 
input from the City Manager’s office, Mayor and Council, the Planning Commission, and suggestions 
from local experts on Data Centers operations, Water, Environmental, and Energy issues. The TAC met 
four times over a three-month period to identify key issues, review best practices, and provide 
recommendations related to land use compatibility, infrastructure impacts, and environmental 
considerations associated with large-scale data center development. Membership of the TAC and 
meeting notes are provided in Attachment E.  
 
In addition to convening a Technical Advisory Committee (TAC), PDSD staff sought input 
and feedback on the proposed regulations through public outreach efforts. Staff held four 
public community meetings in February and March 2026, offered in both in-person and virtual 
formats. More than 200 participants attended the four meetings, and more than 1,100 comments 
were received through surveys, discussions, and written feedback. Each meeting included 
presentations, open discussion, and opportunities for participants to provide input. Please see the 
Compilation of All Public Comments (see Attachment F) for additional information on public feedback.  
 
Throughout the process, there has been coordination between the development of standards for large-
scale data centers and the City’s Large Quantity Water User Ordinance, with overlap between the staff 
as well as stakeholders involved in each process.  
 
Initial Technical Advisory Committee Meetings 
As noted above, a Technical Advisory Committee (TAC) was organized by PDSD to provide 
technical expertise and stakeholder input during development of the proposed amendment. The TAC 
included representatives from utilities, environmental organizations, the technology sector, planning 
professionals, and community organizations. A total of four meetings were held, with the initial three 
taking place between November 2025 and January 2026 to review draft concepts, discuss potential 
regulatory approaches, and identify key land-use considerations associated with large-scale data centers.  
 
During the first meeting on November 17, 2025, staff provided background on the Mayor and Council 
direction to develop regulations for large-scale data centers and reviewed the scope of the code 
amendment process. TAC members discussed the current regulatory context, including the role of 
zoning in addressing land use impacts and the limitations of zoning related to regulating water and 
energy consumption directly. Members also reviewed examples from other Arizona jurisdictions and  
identified priority issues for the Tucson ordinance, including noise impacts, water use considerations, 
energy infrastructure, design compatibility, and public engagement.   
 
The second meeting on December 15, 2025, focused on the discussion of potential regulatory topics and 
approaches for the amendment. TAC members reviewed possible definitions and size thresholds for

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PLANNING COMMISSION MEMORANDUM 
C8-25-04 Large-Scale Data Center Regulations  
UDC Amendment Study Session (Citywide) 
 
large-scale data centers, zoning districts in which such use may be permitted, and potential review 
processes. The group also discussed expanded public notice requirements and the role of development 
agreements as a tool to address considerations that cannot be regulated through zoning. Members 
emphasized the importance of clear public communication and robust notification processes for future 
proposals.  
 
The third meeting on January 12, 2026, continued the discussion of potential development standards, 
including setbacks; noise mitigation measures; generator operation and backup power systems; 
landscaping and heat mitigation strategies; wildlife and environmental protections; and design 
considerations. Members also discussed approaches for addressing community concerns related to water 
and energy use through coordination with other City policies and ordinances, including the Large 
Quantity Water User Ordinance and relevant sustainability plans.  
 
Feedback from the first three TAC meetings helped inform the proposed standards. These proposed 
standards were then presented to the public in February and March. For the meeting notes and 
presentations from all TAC meetings please see Attachment E. 
 
Public Meetings and Community Feedback  
Staff conducted four public meetings in February and March 2026 to present proposed regulations for 
large-scale data centers and gather community feedback. The meetings included two in-person sessions 
held at Pueblo High School (February 19) and Rincon/University High School (March 5), as well as two 
virtual meetings (February 23 and March 4). Across all meetings, more than 200 individuals 
participated, and hundreds of written comments were submitted through surveys, meeting discussions, 
and follow-up feedback. 
 
Each meeting included a staff presentation providing an overview of the proposed regulations, followed 
by opportunities for public input. Engagement formats varied by session and included open comment 
periods, small group discussions to facilitate dialogue, and structured question-and-answer segments to 
allow for more detailed feedback and clarification.  
1. February 19 (In-Person): Approximately 51 attendees; included a mix of previously 
engaged community members, students, and residents seeking information.  
2. February 23 (Virtual): Approximately 61 attendees; many participants new to the topic.  
3. March 4 (Virtual): Approximately 48 attendees; greater participation from professionals 
and retirees, with more detailed, technical feedback.  
4. March 5 (In-Person): Approximately 40 attendees; including many attendees familiar with the 
topic who may have participated previously.  
Overall, the primary themes raised during the outreach process included concerns related to water 
availability, energy consumption, noise and generator operations, environmental impacts, and 
transparency regarding potential community benefits (See Attachment F for comments received as of 
April 27, 2026). Feedback generally fell into the following categories:  
1. Water Scarcity (most frequently raised concern) - The overwhelming sentiment was that 
Tucson does not have adequate water to support large-scale data centers. Residents repeatedly 
questioned where the water will come from, argued that "adequate water supply" in the desert is 
impossible long-term, and called for a strengthened Large Quantity Water User Ordinance. Many 
stated that only recycled water, not potable or groundwater, should be permitted, with some 
calling for mandatory closed-loop cooling systems.

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PLANNING COMMISSION MEMORANDUM 
C8-25-04 Large-Scale Data Center Regulations  
UDC Amendment Study Session (Citywide) 
 
2. Energy Demands & Utility Costs - Residents are concerned that data centers will strain the 
existing electrical grid, force construction of new natural gas generation, and raise utility rates 
for existing customers. Multiple commenters specifically cited Project Blue as an example of 
ratepayers potentially subsidizing a data center. Many stated that 100% renewable energy with 
no offsets or credits be required, and that data center developers, not ratepayer, bear the full cost 
of new infrastructure.  
3. Opposition to Data Centers - A significant portion of comments stated they are opposed to any 
data centers in Tucson at all. Common refrains included "No data centers, period," "ban 
hyperscale data centers," "full moratorium." Some framed this as a resource issue, others as an 
environmental or political one (surveillance, AI, corporate interest, etc.).  
4. Setbacks - Many commenters stated the proposed 400-foot setback from residential areas is far 
too small. Requests ranged from 1,000 feet to 2 miles. Commenters cited noise, air quality, heat 
island effects, and visual impact on Tucson's natural views.  
5. Definition & Size Threshold – Many commenters stated that the proposed 50,000 sq ft 
threshold for defining a "large-scale data center" is too high. They further stated that the 
definition should be based on energy consumption (e.g., megawatts) or water use rather than 
square footage alone, since technology changes and smaller facilities can still have enormous 
resource impacts.  
6. Noise and Generator Use – Significant concern was voiced about generator noise and air 
quality impacts. Commenters asked for strict, clearly defined noise standards with enforceable 
limits that address sound frequency and duration. Many voiced outright opposition to any diesel 
backup generators in favor of battery only backup.  
7. Neighborhood Notification Process – Commenters felt that the proposed expanded public 
notification process for large-scale data centers is inadequate and should be expanded beyond 
the proposed quarter-mile. Commenters also suggested a citywide public notice of the 
neighborhood meeting, and mailed notification to renters as well as property owners.   
8. Enforcement & Accountability – Recurring concerns were voiced about what happens if a data 
center operator violates the City’s zoning regulations or conditions of the data center’s approval. 
Many commenters asked for stronger, clearly defined enforcement measures, such as ongoing 
monitoring requirements, utility shutoffs, or other meaningful consequences, rather than relying 
solely on fines.  
9. Climate & Environmental Compatibility - Commenters stated that large data centers conflict 
with Tucson's Climate Action Plans, contribute to heat island effects, increase ozone and 
particulate pollution from generators, and destroy natural habitat.  
 
Fourth Technical Advisory Committee Meeting  
A fourth TAC meeting was held on March 9, 2026, focused on reviewing feedback received during 
the February–March 2026 community outreach process and discussing potential revisions to 
the proposed large-scale Data Center regulations. Staff presented an overview of the draft 
regulations previously shared with the public and summarized comments received from four 
community meetings, with concerns primarily focused on water availability, energy use, noise, air 
quality, equity considerations, and broader issues related to technology and artificial intelligence. TAC 
members mainly discussed the following topics: 
 
1. Challenges of addressing some concerns through zoning regulations, particularly those related 
to energy generation and water consumption, and emphasized the importance of clearly 
communicating the role and limitations of zoning. 
2. Potential modifications to the proposed standards in several areas, including the use definition

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PLANNING COMMISSION MEMORANDUM 
C8-25-04 Large-Scale Data Center Regulations  
UDC Amendment Study Session (Citywide) 
 
and size threshold, expanded public notice requirements, separation from residential and 
commercial areas, noise mitigation measures, and standards for backup power systems such as 
generators and battery storage. 
3. Energy implications, including generator operations, potential impacts on air quality, 
and coordination with utility providers during maintenance or emergency events. 
 
Feedback from the fourth TAC meeting helped inform the refinement of the proposed development 
standards (see Attachment E for a full summary of the TAC materials).  
 
Mayor and Council Study Session 
On April 7, 2026 Mayor and Council held a study session on the proposed regulations for large-scale 
data centers. During this study session, PDSD staff presented an update on the development of the 
proposed regulations. These included a summary of the TAC's work, engagement with community 
members, and key takeaways from public outreach. The proposed regulations and options for revisions 
to specific standards were also presented. 
 
Mayor and Council conveyed that they were in support of the potential revisions suggested by staff and 
informed by public feedback. They also acknowledged the concerns that community members expressed 
during the engagement process with regard to the amount of water and energy required for a large-scale 
data center to operate, with unknown community benefits. However, it was also acknowledged that 
technology is changing rapidly and conditions for development may be more favorable sometime in the 
future. Furthermore, Arizona State Statute limits the City’s ability to place a moratorium on large-scale 
data centers for longer than 120 days without justifying the prohibition or risk legal action from potential 
developers. Mayor and Council offered several notes for revisions to the first draft of the amendment 
language: 
 
1. Several council members supported the inclusion of an energy consumption threshold as part of 
the definition of a large-scale Data Center 
2. There was consensus on enhanced public notice standards  
3. Several council members supported limiting large-scale data centers to PAD or PCD applications 
instead of allowing them within the I-2 zone due to environmental justice concerns.  
4. Several council members requested that staff continue to investigate what other localities have 
done to regulate large-scale data centers. 
 
Mayor and Council then directed staff to present their findings and draft materials to the Planning 
Commission for additional feedback and consideration. 
 
Present Consideration(s) – The proposed amendment to the Unified Development Code would 
establish a regulatory framework for large-scale data centers. The proposal introduces a definition for 
large-scale data centers and establishes where and how these facilities may be permitted, along with use-
specific standards intended to address land use compatibility, environmental impacts, and operational 
considerations (see Attachment G, Proposed Code Amendment Fact Sheet). 
 
Large-Scale Data Centers Unified Development Code Proposal   
Throughout the process of research, advisory input from the TAC, and public input, staff developed a 
proposal for UDC code changes. The proposal is based on best practices, regional considerations, and 
precedents already established in the UDC. Below is an overview of the proposed regulations (see draft 
code amendment in Attachment H).

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PLANNING COMMISSION MEMORANDUM 
C8-25-04 Large-Scale Data Center Regulations  
UDC Amendment Study Session (Citywide) 
 
 
Definition and Size Threshold  
Proposed Regulation: The proposed definition includes both a square footage and a power 
consumption threshold, minimum floor area of 25,000 square feet, or power consumption of 50 
Megawatts. The proposed definition for a large-scale data center is as follows: 
 
 
A facility, multiple facilities, or portion of a facility on a contiguous site with the same controlling 
ownership interest, and a gross floor area greater than 25,000 square feet or uses greater than 50 
megawatts (MW) of energy, housing networked computer systems and/or telecommunications 
equipment used for remote storage, processing, and distribution of data. 
 
In addition to the regulations proposed below, any large-scale data center would need to comply with 
all existing Commercial Rainwater Harvesting Standards, Environmental Resource Zone (ERZ), 
and Watercourse Amenities, Safety, and Habitat (WASH) regulations contained within the Unified 
Development Code.  
 
Review Process and Zoning  
Proposed Regulation: Large-Scale Data Centers are permitted through adoption or major amendment 
of a Planned Area Development (PAD) or a Planned Community Development (PCD). Large-Scale Data 
Centers are not permitted as of right or through a special exception in any other zone. Establishing or 
amending a PAD or PCD is a rezoning process subject to Mayor and Council review. 
 
Separation from Residential and other Non-Industrial Uses  
Proposed Regulation: Must be located a minimum of 1,320 feet (one quarter mile) from residential 
zones as well as certain uses (nursing home, residential care facilities, educational uses) and 600 feet 
from commercial or office zones.  
 
Public Notice  
Proposed Regulation: Require an enhanced public notice of all property owners within a half mile, and 
all Neighborhood Associations within 2 miles, which is consistent with Planned Community 
Development notice requirements, for the required neighborhood meeting and public hearing before the 
Zoning Examiner. Additional notice is being proposed due to the broader impacts of large-scale data 
centers, and the typically low-density surrounding areas where large-scale data centers are likely to be 
proposed. 
  
Water Supply Certification and Restriction on Potable Water Use  
Proposed Regulation: Reaffirm requirements to comply with the City’s Large Quantity Water User 
Ordinance. Additionally, if an applicant is not subject to the Large Quantity Water User Ordinance, the 
use of potable water for data center cooling is prohibited and an applicant is required to demonstrate 
access to an adequate water supply. A mitigation plan may also be required to address impacts during 
drought or local water emergency.  
  
Energy Disclosure   
Proposed Regulation: At the time of application, require that applicants demonstrate access to an 
adequate energy supply and disclose their proposed amount of energy and energy mix, including 
renewables.

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PLANNING COMMISSION MEMORANDUM 
C8-25-04 Large-Scale Data Center Regulations  
UDC Amendment Study Session (Citywide) 
 
Noise and Generators  
Proposed Regulation: Applicants must provide an independent noise study as well as a noise mitigation 
plan at the time of application. The code establishes strict decibel limits at the property line and requires 
annual monitoring. For generators, only Tier IV or natural gas/dual-fuel generators would be permitted, 
with requirements for “battery-first” backup systems, limits on hours of maintenance testing, and 
prohibition of “load shifting”. Additionally, data center operators could be required, at the City’s 
discretion, to identify a point of contact for community concerns about noise or other negative impacts. 
This stipulation was added after receiving feedback from both the public at large and Mayor and Council.  
 
Development Standards  
Proposed Regulation: Require a 20-foot enhanced landscaping border and right-size parking 
standards to reduce paved surfaces and mitigate urban heat island effects. Require sound blocking and 
screening for generators and other noise-producing mechanical equipment through solid screened walls 
or rooftop screening. Lot coverage is restricted to 40% where the remaining area must be dedicated to 
natural open space and any disturbed land not included in project site must be revegetated with native 
plantings. 
 
Plan Tucson Consideration(s) – Plan Tucson does not specifically address the location of large-scale 
data centers, as this land use had not been defined in Tucson even during the outreach and drafting of 
the recently adopted Plan Tucson 2025. The General Plan does speak to what should be considered with 
regard to the impacts of large-scale Data Centers.  
 
Government 4: Provide diverse, well-resourced opportunities for productive public engagement 
throughout the planning and decision-making process of City initiatives that respect and 
accommodate disabilities and diverse cultural needs by implementing a variety of interactive 
methods and communication tools to maximize inclusive participation.  
  
Climate 3: Use a variety of strategies to ensure that all residents benefit from initiatives aimed at 
resilience and sustainability.  
  
Climate 6: Develop a regional collaborative approach with public and private partnerships to 
reduce energy consumption and transition to renewable energy sources.  
  
Water 3: Encourage appropriate use of reclaimed water and other potable water alternatives.  
  
Water 7: Encourage increased water efficiency in both existing and new private and public 
developments, promoting user-level conservation practices across all water use contexts by 
expanding effective water efficiency and conservation programs across all sectors.  
  
Environment 8: Promote the designs of buildings and use of materials that mitigate or reduce 
noise pollution  
  
Economy 13: Create a business supportive climate through investment in public infrastructure 
and services, through its regulations and policies, and in building public-private partnerships.  
  
Land Use 6: Create a business supportive climate through investment in public infrastructure and 
services, through its regulations and policies, and in building public-private partnerships.

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PLANNING COMMISSION MEMORANDUM 
C8-25-04 Large-Scale Data Center Regulations  
UDC Amendment Study Session (Citywide) 
 
  
Land Use 12: Apply the Guidelines for Development Review to the appropriate Building Blocks 
in the Future Growth Scenario Map, included in chapter four, to evaluate and provide direction 
for annexations, plan amendments, rezoning requests and special exception applications, Board 
of Adjustment appeals and variance requests, and other development review applications that 
require plan compliance.  
  
Land Use 25: Work collaboratively with Arizona State Land Department, Pima County, and 
nearby major land users to identify strategic and appropriate land uses within the Southlands and 
Houghton Corridor area.  
 
Attachments: 
A. 
August 6, 2025 Mayor and Council Legal Action Report 
B. 
April 7, 2026 Mayor and Council Legal Action Report 
C. 
Zoning Administrator Determination Letter for Large-Scale Data Centers 
D. 
Planning Commission Study Session Materials, September 17, 2025 
E. 
Technical Advisory Committee Membership, Meeting Summaries, and Presentations 
F. 
Compilation of Public Comments  
G. 
Proposed Code Amendment Fact Sheet 
H. 
Draft Regulations for Large-Scale Data Centers