Mississauga city council has directed the city’s administration to prepare a pause on major data-centre developments while it reviews how the facilities fit within its employment lands and infrastructure network.

The interim control bylaw would prohibit new large-scale digital infrastructure facilities — including artificial intelligence, cloud computing and hyperscale data centres — for up to one year. It could be extended for a second year if more time is required to complete the study.

The motion passed unanimously, and the bylaw is expected to return for a final vote on Sept. 16.

The application at the centre of the debate, a two-storey data centre proposed by Prologis Canada at 0 Tenth Line West, remains under review after council referred it back to staff in April.

Prologis has submitted parallel rezoning applications for the approximately 39-acre property northwest of Tenth Line and Argentia Road. One would permit an approximately 220,000-square-foot data centre, while the other proposes two single-storey industrial buildings. Both seek site-specific exceptions to the property’s employment zoning.

The site’s proximity to electrical infrastructure was central to its selection. At a June town hall, Prologis vice-president of data-centre preconstruction Brett Skyllingstad said it was chosen largely because it is “right next to the transmission lines.”

Prologis has said the facility would use a closed-loop cooling system to limit water consumption and that the company would pay for the electrical infrastructure upgrades required to serve it.

The company estimates the project would support approximately 790 construction jobs annually during development, create about 75 permanent positions and generate more than $1.6 million a year in municipal property tax revenue.

City staff recommended undertaking the comprehensive review without imposing an interim control bylaw. That approach would have allowed data-centre applications to continue through the existing approvals process while the study was underway.

Mayor Carolyn Parrish, who did not vote on the pause, expressed reservations about council departing from that advice and potentially losing business and property tax revenue. However, she acknowledged residents’ “fear of the unknown.”

“We don’t know what data centres are going to do to our communities,” Parrish said.

Ward 9 Coun. Martin Reid acknowledged the potential loss of revenue but emphasized that the measure is a pause rather than a permanent prohibition.

Staff will study zoning, infrastructure capacity and the economic and environmental effects of data centres, including possible community benefits from developers.

If adopted, the bylaw would appear to make Mississauga the first Canadian municipality to impose a citywide moratorium on new data centres.

Ontario’s Planning Act permits interim control bylaws for up to one year, with a possible one-year extension. However, they can be appealed to the Ontario Land Tribunal, leaving questions about the scope of Mississauga’s restriction.

Hamilton rejected a similar one-year bylaw in a 10-6 vote after councillors raised concerns about investment, litigation and research-related projects.

“I think it will hold back Hamilton and reduce opportunity for many, many Hamiltonians and for generations to come,” Mayor Andrea Horwath said.

Burlington also rejected a moratorium but ordered a policy review after receiving a site plan application for a 5,163-square-metre data centre requiring approximately 20 megawatts of electrical capacity.

Toronto, meanwhile, is reviewing the zoning and infrastructure implications of AI data centres, including projects that could proceed under existing zoning without a rezoning application or council approval.