The Boulder County Board of Commissioners voted unanimously Tuesday to prohibit data centers using more than 50 kilowatts of power, banning all but the smallest facilities in unincorporated Boulder County.
The new rule is among the most restrictive data center regulations in Colorado. This summer, Longmont banned only hyperscale data centers, which use far more power. Several cities, including Denver, Brighton, Lafayette, Littleton and Fort Collins, have imposed temporary moratoriums while they study the issue. Boulder County’s new rule follows its own six-month moratorium.
Colorado has no statewide regulations specifically governing data center development. Lawmakers rejected bills that would have offered incentives for data centers or imposed new regulations in May but are expected to revisit the issue in 2027.
The county’s decision comes amid growing opposition to data center development nationwide. About half of U.S. states have restrictions or moratoriums. In this month’s elections, voters backed measures limiting data center development in 40 of 41 local ballot initiatives.
“We saw on Election Day around the country a message from Americans that they’re concerned about the regulation of big tech and the implications that that has on people’s lives, livelihoods and ability to thrive,” County Commissioner Ashley Stolzmann said. “Those similar implications that we heard across the country, we’ve heard in our community also.”
Commissioners voiced concerns about data centers’ electricity and water consumption, noise pollution and emissions. Xcel Energy anticipates that new data centers will account for 62% of its projected energy growth. A Lawrence Berkeley National Lab study estimates that data centers could account for 6% to 12% of U.S. electricity consumption by 2028. A mid-sized data center uses around 300,000 gallons of water a day, about as much as 1,000 households.
The new restriction applies to unincorporated Boulder County, not the City of Boulder or other municipalities. Data centers using 50 kilowatts or less would be allowed only in industrial zones. That’s a relatively small amount of power for a data center, enough to operate a facility ranging from a refrigerator-sized unit to a small server room.
In the City of Boulder, hyperscale data centers are not specifically defined in the land-use code. Proposals would need to be evaluated individually, according to city planning spokesperson Cate Stanek. Generally, land uses not listed in the code are prohibited. Stanek said adding data centers to the code would require further study and “may be considered in 2027.”
Commissioners approved the restriction despite a unanimous recommendation from the county Planning Commission to delay the decision. The advisory body urged more research and a joint work session before proceeding.
“It just seems we’re not ready,” Planning Commissioner Rachel Lee said.
The path to 50 kilowatts
County staff began exploring changes to the land-use code in June after commissioners asked for ways to prohibit data centers. Staff proposed a 75-kilowatt limit, based on a definition from Energy Star, a federal energy efficiency program.
“Once a server room reaches 75 kilowatts, it starts to resemble something like a data center,” county senior planner Ethan Abner told commissioners at a Nov. 10 meeting. He said power consumption provides a useful proxy for potential land-use impacts.
Commissioner Marta Loachamin proposed lowering the threshold even further, to 50 kilowatts.
“Fifty was the number that was coming to my mind. I don’t have a calculation,” she said, explaining that she wanted to account for impacts the county might not have considered.
The other commissioners agreed to the lower limit, though Commissioner Claire Levy acknowledged uncertainty.
“I don’t know that any of us knows it’s the right number,” she said of the 75-kilowatt limit.
Stolzmann said the lower limit would provide a greater buffer against potential impacts.
Not in our backyard?
Before the vote, the county shared its proposal with local governments, boards and Xcel Energy. Only the City of Boulder shared feedback.
Boulder Senior City Planner Chris Ranglos shared the county’s concerns about the environmental impacts, but also encouraged commissioners to consider the needs of Boulder’s growing quantum computing industry, which could benefit from local data centers.
Boulder is home to more than 30 quantum companies and JILA, a leading quantum research institute operated jointly by CU Boulder and the National Institute of Standards and Technology.
Some planning commissioners worried the restrictions could hurt local businesses while shifting the environmental impacts to neighboring communities.
“We want to consume these things, but we want other communities and other places to be able to house and produce these things,” Planning Commissioner Bryan Kominek, executive director of a solar agricultural learning center, said. “It’s our community saying: ‘Not in our backyard, but it’s okay in other people’s backyards.’”
Several planning commissioners argued that Boulder County would be better equipped to regulate data centers responsibly than neighboring jurisdictions.
“Data centers are likely coming, whether we like it or not,” said Planning Commissioner Gavin McMillan, a planning and development consultant. “The way that this code is written, it basically bans them in Boulder County.
“If we make it impossible to build them here, they are going to get built somewhere, and it’s probably going to be in a neighboring community.” Instead, he said, “we need to think about how we can be the model of how this happens here.”
Stolzmann rejected the “not in my backyard” criticism, saying other municipalities “could and should” adopt similar regulations.
“I think what we came up with is threading the needle, allowing for computing and technology but not rushing too quickly into unfettered access to data centers and huge facilities that can impact people’s utility bills and their access to water and their access to peaceful enjoyment of their property,” she told Boulder Reporting Lab. “I invite other communities to join us in what we’ve done.”
