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Minutes for Water Commission

MINUTES
WATER COMMISSION
THURSDAY

MARCH 19, 2026
  HYBRID MEETING
COUNCIL CHAMBERS
211 WEST ASPEN AVENUE
             4:00 P.M.

 
 
1.
Call to Order
  • Chair Ron Doba called the meeting to order at 4:00 p.m.
NOTICE OF OPTION TO RECESS INTO EXECUTIVE SESSION
Pursuant to A.R.S. §38-431.02, notice is hereby given to the members of the Commission and to the general public that, at this meeting, the Commission may vote to go into executive session, which will not be open to the public, for legal advice and discussion with the Commission’s attorneys for legal advice on any item listed on the following agenda, pursuant to A.R.S. §38-431.03(A)(3).
  • Chair Doba welcomed the new Water Commission Member (Caroline Reed). Members of the Commission each gave a brief introduction.
 
2.
Roll Call
NOTE: One or more Commission Members may be in attendance telephonically or by other technological means.
PRESENT:
RON DOBA HALEY PAUL
DONALD BILLS MATTHEW GARCIA
JOHN NAUMAN CAROLINE REED
ROBERT VANE

Staff & Others Present: Vice Mayor Miranda Sweet, Shannon Anderson, Lee Williams, Tiffany Antol, Erin Young, Tamara Lawless, Marion Lee, Andrea Armstrong, Jolene Montoya, Emily Melhorn, Christina Rubalcava, Bill Case, David Chambers, Sandy Petersen

 
3.
PUBLIC PARTICIPATION

Public participation enables the public to address the Commission about an item that is not on the agenda. If you wish to address the Commission, please state your name and address for the record. The Arizona Open Meeting Law prohibits the Commission from discussing or taking action on an item which is not listed on the prepared agenda. The Commission members may, however, respond to criticism made by those addressing the Commission, ask staff to review a matter, or ask that a matter be place on a future agenda. Public comments should be limited to three minutes reading time.
 
4.
APPROVAL OF MINUTES - November 20, 2025

Moved by Commissioner John Nauman, seconded by Commissioner Robert Vane
Vote: 7 - 0 - Unanimously


 
5.
NEW BUSINESS

A. Data Centers Land Use and Large-Volume Water Users — Erin Young and Tiffany Antol

Tiffany Antol - Zoning Code Manager, provided an update with a PowerPoint Presentation that covered the Data Center Land Use. The following topics were discussed:
  • Zoning Code Amendment Chapters 10-40 & 10-80 Data Center Land Use
  • Existing Allowances for Data Centers
  • City's Proposed Zoning Code Text Amendment — Overview of Proposed Amendment
Tiffany and staff are seeking some feedback from the Water Commission on the best approach for dealing with land uses that can be heavy large water uses.

Chair Ron Doba asked Tiffany what is meant by state-level preemption regarding the following presentation slide. He asked if that would be forced to allow a data center by the state.

Tiffany said yes, noting that they were recently required to allow middle housing and accessory dwelling units, and that she has spent much of the past two years addressing new state mandates affecting what is permitted in the zoning code.

Commissioner Robert Vane asked if numbers 10 and 11 are mutually exclusive on the following presentation slide:

Commissioner Vane asked whether the system is a closed-loop system, noting that he does not consider a cooling tower to be closed-loop, as he understands cooling towers to be open, evaporative systems. Tamara Lawless responded that they wanted clarification on that terminology. She reached out to Annikki Chamberlain, a consultant who works with large industrial users and institutions, who provided the following input:
  • A closed-loop system must be connected to a heat rejection mechanism, which is typically water-based—most commonly a cooling tower. While the chilled water side of the system may operate as a closed loop, the heat rejection side is generally an open-loop system. As a result, it can consume significant amounts of water through evaporation and blow down, along with additional losses due to mechanical and operational factors.
Commissioner Donald Bills asked about item 7 on the following presentation slide:
Regarding the noise generated, Commissioner Bills noted a 10-decibel difference between the daytime and nighttime sound ranges and asked if Tiffany could provide a frame of reference for what those decibel levels represent. Tiffany responded that she would need to follow up with that information.

Commissioner Bills also noted that sound is not only heard but can be felt, and asked about wildlife sensitivity to noise generated by data centers. Tiffany responded that she does not have specific studies available at this time to address that topic.

Chair Doba asked Tiffany to clarify closed-loop mechanical cooling systems, noting that such systems recirculate water through cooling towers and may still require additional water for evaporation. Tiffany explained that water needs depend on the specific data center and system type, and that staff prefers not to specify exact technologies since some facilities use air-cooled systems. She noted that both energy and water use are key factors under review. Staff recommends avoiding prescriptive technology language, but can include it if the Water Commission prefers, with wording to cover both water and air-cooled systems.

Commissioner Vane observed that several requirements seem targeted specifically at data centers and asked whether this could create litigation risk or enforcement challenges compared with other heavy industrial applicants. Tiffany replied that it would not, noting that the Commission already applies distinct development standards for different land uses.

Chair Doba asked about proposal number 2. Tiffany explained that it would outright prohibit all data centers, a recommendation requested by the Planning and Zoning Commission, and noted that this is not staff’s preferred approach but was included in response to the Commission’s direction.

Chair Doba asked if any cities in the state prohibit data centers. Tiffany confirmed that some do and explained that the draft proposal was prepared to give the Commission the option to implement a similar prohibition.

Chair Doba asked if the Water Commission simply wanted to discuss the matter today. Tiffany confirmed, explaining that they hope to provide the Planning and Zoning Commission with a general sense of whether the large water user component is being considered. This would clarify why those parameters are not included in the zoning code, allowing the zoning process to continue while the Water Commission’s work on large water users proceeds concurrently.

Erin Young - Water Resources Section Director, provided an update with a PowerPoint Presentation that covered the Existing Assessment of New Industries: Process & Policies Overview; Proposal for a Large-Volume Water User Policy. The following topics were discussed:
  • Engineering Review Process
  • Water Services Process and Policy
  • Specific Water Policies (2014 Council-Adopted Water Policies)

Commissioner Vane asked whether Water Services can veto large users or require them to provide their own water if identified as high-volume users. Lee Williams, Water Services Director, responded that he is unsure and would need to investigate the agency’s authority in this regard.

Commissioner Vane asked whether Water Services could recommend to the City Council or Planning and Zoning Commission that a proposed use is not sustainable if they lack veto power. Lee Williams stated he would need to research but noted that a Water-Sewer Impact Analysis (WISA) would indicate what the user must provide. Tiffany added that no application would be approved without an approved WISA, and that rezoning or conditional use permits are generally not approved if the city cannot serve the property. While Water Services may not have authority to deny an application under current codes, the Planning and Zoning Commission or City Council could consider these factors, and prohibiting water-cooled systems would be the clearest approach, though it would not prevent Water Services from providing water if requirements are met.

Commissioner Vane asked whether the regulations for data centers should include a specific water use limit or rely on the existing Water Services review process for large users. He noted that Water Services already has a functioning process and suggested there may be no need to include a specific requirement in the data center regulations.

Tiffany reviewed the proposal options and suggested that the simplest and most enforceable approach would be to prohibit water-cooled systems entirely. Under this approach, data center mechanical cooling systems would be required to use air-cooled heat rejection systems, while the use of evaporative or water-based systems—including cooling towers, evaporative condensers, absorption systems, and water-cooled chillers—would be prohibited.

Chair Doba asked whether this would prevent data centers from using water, and Tiffany clarified that it would only require air-cooled systems, not preclude data centers entirely.

Tiffany outlined two additional options for mechanical cooling systems. The performance-based option will allow limited water use if annual usage meets a defined threshold, subject to city approval and ongoing reporting. The hybrid option would default to air-cooled systems, allowing exceptions only if a defined water use threshold is met, with sub-metering, annual reporting, and documented system design approval required.

Commissioner John Nauman asked about the monthly variation in water use for data centers and how building at elevation might affect the type of cooling systems they could use. Tiffany stated that she does not have that information.

Chair Doba asked whether the state could require the city to accept a data center if the necessary resources are not available. Tiffany responded that while the state can require the city to include certain land uses in its zoning code or permit them through zoning, it does not necessarily compel provision of resources.

Erin Young stated that data centers could be required to recycle water, and if at least 80% is recycled, the city would recover much of it through the wastewater system, keeping the facility effectively closed-loop. She noted that prioritizing this approach would ensure efficient use of available water, and data centers could also help fund connections to the reclaimed water system or upgrades to the wastewater treatment plant, benefiting all users.

Emily Melhorn, Water Conservation Specialist, stated that limiting data centers to air-cooled systems would restrict their size to what air cooling can manage, while still allowing operation. Allowing water-cooled systems makes it harder to control facility size. She noted there are various ways to maximize efficiency within either cooling system type.

Emily Melhorn emphasized the importance of sub-metering to detect leaks and ensure efficient water use. She explained that cooling towers can typically reuse water up to seven times before mineral buildup risks damaging the equipment, which is costly. Discharged water often contains chemicals and acids, limiting its return to the city system. She noted that Flagstaff has few cooling towers, which is why the expertise of Mimir Consulting has been relied upon.

Commissioner Haley Paul asked whether large water users that exceed anticipated usage could face additional scrutiny, requirements, or higher fees, and whether such an approach is worth considering. She also asked if there would be value in allowing these users if they generate a certain number of jobs, and whether options beyond water-cooling technology are being explored.

Chair Doba noted it is difficult to respond without specifics on a proposed data center. Tiffany explained that if data centers are allowed, the Water Commission could provide guidance on zoning locations and recommendations, particularly limiting cooling systems to air-cooled technology, while a more comprehensive policy for large water users is developed. She emphasized the importance of protecting current water resources and ensuring adequate service for new land uses.

Tiffany asked whether the Water Commission prefers a more restrictive or medium approach to water use. She noted that a stricter approach could be adopted now, with the option to amend the zoning code later if a comprehensive policy for large water users is developed. She is seeking the Commission’s recommendations specifically on the water-related elements of proposal number 1 and their expertise on water issues for data centers.

Chair Doba asked for comments on proposal number one. Commissioner Vane stated that existing mechanisms for managing large water users are sufficient and recommended against overly prescriptive regulations. He suggested including a requirement that any data center using a water-based cooling system must operate as a closed-loop system.

Chair Doba instructed Tiffany to require closed-loop systems for water-cooled data centers. Tiffany confirmed that the language will provide the option for air-cooled systems, and any water-cooled system must operate as a closed-loop system.

Commissioner Paul asked whether the WISA is sufficient for staff review. Lee Williams said it is, as it is the standard process for all developments. Commissioner Nauman noted that while low water use is manageable, high-water use raises concerns about priority during scarcity, especially given the potential political influence of a data center.

Tamara Lawless, Water Services Program Manager, clarified that the term “closed-loop system” does not necessarily indicate minimal water use. Even if a system is labeled as closed loop, it may apply only to part of the operation, and the total facility could still have significant overall water consumption.

Chair Doba asked whether the Commission is familiar with any constructed data centers that use closed-loop systems. Erin Young responded that the Kyl Center for Water Policy website lists all the data centers they are aware of.

Emily Melhorn clarified that all water-cooled systems include a closed-loop component, which chills water so it can absorb more heat during circulation. She emphasized that the presence of a closed-loop system alone does not inherently improve overall efficiency.

Chair Doba suggested that they might be approaching the issue incorrectly. Emily Melhorn responded that if water cooling were to be allowed as an option, simply requiring a closed-loop system would not be sufficient; additional measures would be necessary to manage water use effectively.

Commissioner Nauman stated that more research is needed to make informed decisions. He noted that information is required on the benefits of air-cooled systems, the specifics of closed-loop systems, and water use for data centers of various sizes; without this data, rational decisions cannot be made.

Commissioner Paul asked whether prohibiting water-cooling technology was an option. Tiffany confirmed that air-cooled systems could be required, eliminating water use, and asked if this were the approach the Water Commission would recommend to the Planning and Zoning Commission.

Commissioner Paul asked whether other cities have implemented a policy requiring only air-cooled systems and prohibiting water-cooling technology.

Commissioner Vane asked whether using air-cooling systems would automatically increase energy use.

Tiffany stated that the city could start by requiring air-cooled systems, and as more information about closed-loop systems becomes available, the code can be refined in the future.

Commissioner Nauman asked whether decisions on data center water use should be based on current resources or projected availability 10 to 20 years into the future. Erin Young explained that the city has 32,000 acre-feet of physically available water, with current usage at 10,000 acre-feet and regional build-out projected at 26,000 acre-feet, leaving a delta. She noted that for uses exceeding roughly 5,200 gallons per acre per day, policies should be in place to address situations where demand surpasses available resources.

Chair Doba stated that it was time to close discussion on this item. He noted support for air-cooled systems, emphasizing a desire to avoid encouraging data centers that would require the city to provide water for cooling purposes.

B. Discussion of Upcoming Revisions to the Landscape Development Plant List — Tamara Lawless
  • This item was suggested to be moved to next month's Water Commission meeting by Tamara Lawless and the Commissioners due to time.
C. Discussion of Proposed Changes to the Plumbing Code — Tamara Lawless

Tamara Lawless, Water Services Program Manager, presented a quick overview of proposed changes.

Chair Doba asked whether reduced-flow fixtures are readily available at stores like Home Depot, and Tamara confirmed they are. He also asked about rebate programs, and Tamara explained that the city offers rebates for high-efficiency toilets that meet the Maximum Performance (MaP) score and use less than one gallon per flush, exceeding the current code of 1.28 gallons per flush.

Chair Doba asked when the updated plumbing codes would go into effect. Tamara stated that she did not know and would need to follow up with that information.

Chair Doba asked about rebate eligibility, noting the decrease required to qualify. For example, if someone replaces a 1.6-gallon-per-flush toilet with a 1.28-gallon-per-flush model, would they be eligible for the rebate. Tamara confirmed that they would, explaining that the program is designed to incentivize exceeding current code requirements.
 
6.
OLD BUSINESS

A. Proposed Updates to the Water Conservation Ordinance in the City Code — Tamara Lawless

Tamara Lawless, Water Services Program Manager, presented a quick overview of proposed updates to the Water Conservation Ordinance in the City Code.

Commissioner Vane asked about Lake Elaine in relation to Tamara’s mention of larger bodies of water and artificial lakes in the ordinance, noting that the lake has not been continuously maintained. Tamara explained that, if the ordinance were passed, it would specify that Lake Elaine would not be refilled due to its lack of maintenance, and that the restriction in the ordinance would apply in this case.

Chair Doba asked whether filling Lake Elaine would be prohibited under the proposed ordinance. Tamara stated that water bodies not continuously maintained would not be refilled, and new similar projects would not be constructed, as they require significant infrastructure and do not align with good water conservation practices. Chair Doba asked about a potential court order, and Tamara said she was unsure. Commissioner Vane noted that enforcing this restriction would “force the issue,” which he viewed positively.

Commissioner Paul asked whether the ordinance disallows potable water irrigation on non-functional turf. Tamara clarified that turf in purely aesthetic, non-functional areas would not be irrigated under the ordinance. Commissioner Paul suggested targeting these areas for rebate opportunities, and Tamara noted that a multi-year rebate program could provide funding for converting such turf to native or drought-tolerant landscaping.

Chair Doba asked Tamara if she wanted a formal recommendation to move this forward to City Council. Tamara stated that the next internal step is to meet with the PROSE team to ensure they are comfortable with the provisions for athletic fields, as there may be minor adjustments to that section. After that review, the next step would be to take the ordinance to City Council.

Commissioner Paul asked for clarification on whether the golf course is comfortable with the 9 a.m. to 5 p.m. irrigation restriction and whether it provides sufficient operational flexibility. Tamara stated that she believes it does, noting that the restriction was presented at previous stakeholder meetings and the golf course representatives seemed comfortable with it.

Chair Doba asked whether the restrictions on golf courses apply to overall water use or specifically to irrigation, noting that golf courses might irrigate using water from lakes on their own property. Tamara clarified that the restriction applies specifically to irrigation and does not address water used for filling purposes.

Chair Doba requested a motion to recommend the modifications to the conservation ordinance to City Council. Commissioner Haley Paul moved the motion, and Commissioner Donald Bills seconded it.

Chair Doba commented on Lake Elaine, noting that, while he is not an attorney, he believes there may be a court order requiring it to be filled and that the date of the court order could potentially preempt the ordinance. Tamara stated that the City Attorney, Sterling Solomon, may need to provide an official statement or opinion on which takes precedence.
 
7.
INFORMATIONAL ITEMS TO/FROM THE CHAIR, COMMISSION MEMBERS, OR STAFF

Lee Williams, Water Services Director, highlighted several items for the Commission’s attention. He stated that the department is working with Stantec Engineering to pilot a MBR portable plant at Wildcat Hill and is also exploring a pilot advanced water purification trailer in partnership with Hazen and Sawyer. Lee noted that the division had begun preparing its annual report to the Water Commission. Additionally, he reminded commissioners to exercise caution when using “reply all” in emails, as it could violate the Open Meeting Law.

Erin Young asked if a representative from Continental could make a final statement on Lake Elaine. Sandy Petersen, President of the Continental Country Club in Flagstaff, clarified that the settlement agreement requires Lake Elaine to be filled, but notes in two places that this is subject to the availability and affordability of water. Chair Doba thanked him for the clarification.
 
8.
ADJOURNMENT
  • Meeting adjourned at 5:51 p.m.