Tucson City Council will consider proposed changes to its large water user ordinance Tuesday, but some environmental advocates and Tucson residents say the changes don’t go far enough.
The city council rushed to approve a new ordinance in August 2025 to protect the city from large water users like data centers with the intention of consulting the community to revisit and strengthen the ordinance within a year.
The 2025 ordinance was a response to public outrage over Project Blue, a massive data center that could have used hundreds of millions of gallons of water a year. In order to access that water, the land where the data center is being built had to be annexed into Tucson. The city council rejected the annexation request.
In the last year, city officials met with a stakeholder group to analyze the ordinance and propose changes to better safeguard Tucson’s water supply.
Local environmental leaders said the invite-only stakeholder discussions fall short of wider community outreach. The city has added a public hearing to its Sept. 22 meeting to gather more community input on the proposed changes.
Environmentalists also say the changes don’t properly establish measurable requirements and the threshold for water use that defines a “large water user” is too high.
How many gallons makes a “large water user”?
The original ordinance defined large water users as those who use 7.48 million gallons of water per month (10,000 centum cubic feet or ccf) and required users to submit a water service application in order to connect to the city’s water supply. Tucson Water has recommended changes that leave that threshold at 10,000 ccf, but local advocates say it should be 2,500 ccf or 1.87 million gallons of water a month on average.
About 15 water users fall within the 7.48 million gallon a month threshold, most of them golf courses, according to Catlow Shipek, senior program director of Watershed Management Group. Shipek said reducing it to 1.87 million gallons would pull in an additional 56 users.
Both the 15 and 56 users are existing Tucson Water customers and would not be impacted by the new ordinance. But advocates say knowing how many users and which industries fall within the existing and proposed thresholds would help clarify who could be affected.
Catlow Shipek along with Lisa Shipek, a co-executive director of Watershed Management Group, presented some of the organization’s recommended additional changes in an online information session last week. Watershed Management Group is a nonprofit organization that advocates for water restoration and protection in Southern Arizona. Tucson Water officials have not disclosed who Tucson’s large water users are, Catlow Shipek said during the presentation.
Ward 6 council member Miranda Schubert’s office also requested that list and did not receive it, she told Luminaria. The information is considered customer data which is protected, Schubert said in a follow-up message.
An Arizona household uses an average of 126 gallons of water per day, according to an analysis from Making Action Possible Southern Arizona. WIth that daily average, it would take a household more than 160 years to use 7.48 million gallons of water — the monthly threshold for large water users.
“That is a bananas amount of water,” Schubert said.
Ward 3 council member Kevin Dahl also agrees that the threshold should be lower, but did not give a specific number. He intends to make that decision based on what he hears during the Sept. 22 public hearing and the meeting discussion, Dahl told Arizona Luminaria. He said he plans to approve the recommendations understanding that they can go back and continue to change the ordinance.
“I think what we need to do now is lower the cap, so we have some industry come in under it,” Dahl told Arizona Luminaria. “So we can get some experience with it before we do a whole lot of changing to it.”
Offsetting water that can’t be reused
The current ordinance asks that large water users present a water conservation plan with their application to the city. This includes both new users or existing ones that are already at the threshold and are requesting an increase in water use.
Among the changes Tucson Water is suggesting is the requirement that the applicant use reclaimed water to offset at least 30% of its water use, or more if the city’s water director determines a higher maximum use of reclaimed water is warranted.
The ordinance requires the city’s water director to consult with its chief resilience officer and decide whether the user’s water conservation plan “demonstrates that the large quantity water user will use water as efficiently as is practicable and ensure that water is not wasted.”
Get involved
Tucson City Council will host a public hearing on the proposed changes to its large water user ordinance at its Sept. 22 meeting, which starts at 5:30 p.m., at 225 W. Alameda St.
Residents can sign up to speak during a Tucson City Council public hearing by filling out a card at the start of the meeting and handing it to the city clerk. Public hearings are scheduled for one hour and each speaker has 5 minutes to share their thoughts.
Public comments can be also emailed to cityclerk@tucsonaz.gov.
Watershed Management is suggesting a performance metric be added — a 2-to-1 water demand offset of consumptive water, meaning water that cannot be reused.
For example, Catlow Shipek explained, if a new water user is planning to use 70 acre feet of water per year, or about 22.8 million gallons, and 30% of that, or 6.8 million gallons (21 acre feet), is lost on site, meaning it can’t be returned to the wastewater treatment facility, the user would have to offset about 13.6 million gallons in a year (42 acre feet). To meet the suggested 2-to-1 offset, the user could pay into existing water conservation programs within the Tucson Water service area, like turf removal or green stormwater infrastructure.
Dahl said he has proposed net-zero water development for new, large industries, which would require the water user’s plan to include things like “waterless urinals, complete rainwater harvesting, and state-of-the-art water conservation.” The company would then pay an in-lieu fee for water conservation measures elsewhere that equal the amount of water they expect to consume annually.
“The simple idea is that new industries would make no impact to our water supplies by doing maximum water conservation and paying for conservation elsewhere in the system to make up for what they would be using on an annual basis,” Dahl told Luminaria in a follow-up email.
Closing loopholes
Tucson Water is also suggesting a language change that considers “aggregate” water use at a customer’s “premises, campus or location,” as the amount that determines whether the customer will be considered a large water user.
Schubert said this closes a loophole, as users sometimes use multiple meters to avoid hitting the threshold.
Watershed Management’s proposed changes would also require the city to count reclaimed water as part of overall water usage. Currently, users who use reclaimed water are charged for it at a subsidized rate, Schubert said. As of 2024, all but one of the 17 golf courses Tucson Water services use reclaimed water, according to a Pima County memorandum. But water used on golf courses tends to be mostly consumptive as it’s used only once to water the turf.
Schubert said the main pushback they have heard in trying to enact stricter water use guidelines is that it’s “another example of Tucson not being business friendly.” But the goal of the ordinance is not to ban or cap water use in Tucson, she said, but to require users to come up with a conservation plan.
“It’s requiring businesses to explain why they are justified in using that much water,” Schubert said. “And what we have heard from constituents is that, yes, jobs are very important for our local economy, but not at the expense of our long-term sustainability and, you know, having drinking water and being habitable for future generations.”
With Arizona expected to take a 30% cut in Colorado River water distribution, environmentalists and local leaders are thinking about the future of Tucson’s water supply and sustainability.
Tucsonans should be thinking about ways to be more sustainable “regardless of what’s happening on the Colorado River,” Catlow Shipek said.
“I think this change will help us define what our values are,” Catlow Shipek said. “It will make it so not every new water user is a battle — a political battle — but one that can have clear objectives and have a clear path forward for any new business or any new water user.”
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