A data center project near Tucson will use the equivalent of about two golf course’s worth of water a year once fully built out, a new draft agreement between city and Project Blue released Monday says.
The data center complex proposed near the Pima County fairgrounds and another within the city limits would become both the top water and electricity user in the area, officials said.
The Tucson City Council is expected to discuss Project Blue for the first time during its afternoon study session on Aug. 6. No action will be taken at the meeting because the discussion is for information only, City Manager Tim Thomure said Monday.
The first action the council must take will be to consider annexation of the the 290-acre parcel of land near the fairgrounds. That could happen when the council meets Aug. 19 and be final by October, the city says.
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“Feasibility studies are under way for a third site in the metro area, but outside of Tucson city limits,†a fact sheet the city released Monday on Project Blue says.
The draft agreement released Monday outlines only the southeast and metro-area projects.
Tucson City Hall.Â
Utility usage
The first phase of the southeast side complex will see four data centers built, which will require an average of about 440 acre-feet of water per year, the city says.
A single acre-foot of water is the volume of water it takes to cover one acre to a depth of one foot. An acre-foot equates to 325,851 gallons of water, or enough to serve three single-family ÃÛÁÄÖ±²¥ for an entire year, .
Up to 10 data center buildings will be housed on that 290-acre parcel of land near the fairgrounds. Once fully operational, the complex will use about 870 acre-feet of water per year in-total, the city said in its .
That amount of water is roughly equivalent to what two golf courses in Pima County would use annually, Thomure said Monday.
The complex will have a “Potential Power Capacity†up to 350 megawatts for the first four buildings, and up to 600 megawatts in-total for the complex when fully built out.
County officials have said that Project Blue will become one of Tucson Electric Power’s largest customers over time.
A second site mentioned in the draft development agreement is “under exploration†and is within the city limits.
Thomure said it will likely run along the 19-mile pipeline intended to deliver reclaimed water that Project Blue will build for its needs.
The second site will be “slightly larger†than the one near the fairgrounds, Thomure said Monday.
Once fully operational, the second data center project will use up to 1,040 acre-feet of water per year, according to the city’s fact sheet. That’s about two-and-a-half golf courses, Thomure said.
The second site would have power capacity of up to 700 megawatts, the city says.
In-total, the two Project Blue sites would use up to 1,910 acre-feet of water per year, which is about 6 percent of the city’s reclaimed water system, according Thomure’s of the draft development agreement.
Thomure said this would make Project Blue Tucson Water’s largest customer.
Water caps
The draft agreement sets water allocation caps for both potable and reclaimed water.
But breaking those caps won’t result in the city cutting off Project Blue’s water. Instead there will be extra charges based on monthly and annual water use.
The maximum 30-day allotment of potable water allowed during construction is 10,695 hundred cubic feet. By comparison, 10 CCF is equivalent to 7,480 gallons of water, .
Once construction of the southeast site’s first phase is complete, it will use drinking water for up to three years, while the project’s developer builds an 18-mile pipeline to carry reclaimed water from the regional wastewater treatment plant on the northwest side to the data center complex, the Star has previously reported.
During that period, the site will be allotted 84,225 CCF of potable water per 30-day period, and have an average annual allotment of 440 acre-feet of potable water per year, according to the draft agreement.
After the reclaimed system is connected, the southeast complex will be allotted 2,206 CCF of potable water every 30 days.
And once that reclaimed water system is built out, the southeast-side complex will be allotted 164,438 CCF of reclaimed water every 30 days, and an average allotment of 870 acre-feet of reclaimed water per year, according to the draft agreement.
The second project, in the metro area, will be allotted 194,524 CCF of reclaimed water every 30 days once the pipeline is completed, and an average allotment of 1,040 acre-feet of reclaimed water per year, according to the draft agreement.
If either project exceeds water usage for its 30-day allotment, or over its annual allotment, Tucson Water will charge the data centers more money.
Penalties
Under the draft agreement, penalties for using more water than agreed to will be imposed on the data centers.
“We’re kind of capping them on a monthly basis (and) on an annual basis,†Thomure said Monday. “If your annual use exceeds 10% over, then you pay a tier one additional rate, which is 150%. And then if you you go 20% over, it’s a 200% (charge).â€
If Project Blue doesn’t get it corrected over a period of time, then they start paying “liquidated damages,†Thomure said Monday, which will be adjusted for inflation over time according to the draft agreement.
‘Water positivity’
Officials have touted the project’s pledge to be “water positive.â€
Project Blue will do this by investing directly into projects, which could include efforts “to conserve or secure new water resources to offset†the project’s consumptive use.
Project Blue’s water bills will consist of two charges: the base water rate and a Water Positivity Charge, “which is the cost of acquiring or developing additional water supplies to replenish Consumptive Water Use,†according to the draft agreement.
Thomure said the Water Positivity Charge will start at about $750 per acre-foot of water. The draft agreement states that rate will adjust for inflation.
“Any ‘water positivity charge’ proceeds received by Tucson Water will be used to meet the requirement for Project Blue to offset the water they will be using,†Thomure said in an executive summary. “Project Blue also has the option to directly invest in their own efforts to provide water savings or resources to Tucson Water, which can in turn, reduce their “water positivity charge.†For example, Project Blue could purchase water credits, fund water conservation programs, etc.â€
“As such, Project Blue can offset their water use by providing new water to the community, they can pay the “water positivity charge†to Tucson Water to generate the water, or a combination of both over time,†Thomure wrote.
The draft development agreement lists several options for Project Blue to take. They include investments in “direct potable reuse through funding of advanced water treatment technology, outreach, or education,†PFAS removal technology, stormwater capture infrastructure, river and wetland restoration “to increase stormwater and surface water infiltration.â€
Further it can invest in water conversation programs, metering infrastructure to “enable early leak detection,†as well as procurement of “additional water supply, inter-basin water transfer, long term storage credits, or water rights from outside sources†and projects aligned with the city’s Climate Adaptation Plan or its One Water 2100 plan, the document says.
