Is AI Coming For Your Water?
When I called up ClimateFast, their community organizer, Anna, was surprised to hear from me. The group doesn’t hear from many journalists interested in a key facet of their advocacy and outreach: Arguing for transparency around AI data centers and water usage in nearby communities and ecosystems.
The climate action group in the Greater Toronto Area — whose aim is building strong, informed public pressure to take urgent, substantial and just action on climate change — has been ramping up educational webinars on a topic that’s hitting close to home: A proposed data centre in Etobicoke, a Toronto suburb, that was approved to use up to 40 litres of water per second for cooling purposes. This data centre, to be built by Microsoft to address the growing energy needs of its AI tools such as Copilot, would need 1.2 billion litres of water a year, the equivalent of 500 Olympic-sized swimming pools.
“There isn’t a lot of transparency of how Microsoft is addressing this issue,” and what it does to strain the water supply,” says Anna, who doesn’t want her last name used. Microsoft Vice Chair & President Brad Smith released a statement in January outlining their five-point plan for minimizing local impacts — and pushback — from their data centres in the U.S. But Anna says there haven’t been any specific details about the source of the water for the Etobicoke centre, and it will use municipal drinking water. If the municipal supply is greatly affected, though, she adds, it could lead to shortages or elevated water bills for some nearby communities.
At least eight projects are underway to build hyperscale data centres in Canada, according to the CBC. The sites include High River, Alberta, Moose Jaw and Regina in Saskatchewan, and Quebec City.
Canada is slowly waking up to a worrisome trend already entrenched in the U.S. As AI data centres are being developed across the country, can legislation or grassroots advocacy inspire new approaches to ensuring these facilities don’t steal and pollute nearby water sources?
AI data centres are starting to dot the country. It’s been reported that Toronto is host to more than 70 other Toronto existing or planned data centres. Canada is standing at around 287 data centres in total, and even Dragon’s Den star Kevin O’Leary has his sights set on building a massive data centre 500 kilometres from Edmonton, with construction planned for 2028.
The controversy for these data centres is largely on their energy consumption: they consumed an estimated 460 terawatt-hours in 2022, which is roughly equivalent to 71% of Canada’s total electricity generation that same year, according to the International Energy Agency.
All that energy consumption leads to hot servers that require instant cooling. A centre’s array of server rooms that emit high heat as they work hard to deliver the answers to those questions we pose on Copilot. The rooms are cooled in a process that begins by piping coolant (a mix of highly purified water and chemicals) over the processing chips within the servers. This cooling liquid absorbs the heat, takes it away from the chips to a heat exchange unit where the pipes are cooled by the water. Once the coolant is cool once more, it can recirculate to the server rooms again.
The now-hot water is then piped to an area where fans and water vapour dissipate the heat to the air and cool the water. Some of the water evaporates while the rest is recirculated through the cooling process several times before being discharged back into the nearby water source, which would be Lake Ontario in the case of the Etobicoke AI data centre. Overall, up to 80%of the water evaporates.
The issue for community groups and environmental NGOs has been double-pronged: AI data centres require so much water, nearby supplies and lakes could be starved dry. Also, the water going back to those sources is not only warmbrimming with chemicals such as phosphates and nitrates that could instigate the spread of harmful algal blooms. Algae in natural water bodies are often “starved” of phosphorus and nitrogen, so when a data centre discharges phosphates and nitrates, it acts like high-strength liquid fertilizer.
A medium-sized data centre gobbles up roughly 110 million gallons per year for cooling purposes, equivalent to the water consumption of approximately 1,000 households.
We are already seeing a big shift in pushback as water is a mobilizing issue for many communities. It’s time for the companies running these data centres to be transparent about concerns we have about wastewater discharge and sustainable water consumption.
– Helena Volzner, senior source water policy manager at the Alliance for the Great Lakes.
A 2014 report from the U.S. Department of Energy found that data center resource demand (both water and electricity) has tripled over the last decade and is expected to triple again in the next three years. Another report found that the data center industry directly or indirectly draws water from 90% of U.S. watersheds.
Closed-loop systems could work for these systems, meaning the coolant remains sealed within a continuous circuit, never leaving through evaporation. But that system needs a high amount of electricity, leading to questions on energy efficiency. Closed-loop systems use more energy than open systems, as they require so-called “chillers” to keep the water cold, but they also use less water.
In almost every Canadian province, if a facility seeks to take more than 50,000 litres of water per day from the environment, they must obtain a specific permit. The only time the federal watchdogs step in is when a site is affected by the Federal Fisheries Act. That Act applies if a data centre's discharge water is too hot or contains chemicals that could kill fish. If a data center emits harmful substances into a local creek, for example, they could face federal criminal charges.
ClimateFast is disappointed in Ontario’s Bill 40 , a technology-focused bill that passed into law in December 2025, which didn’t address a vital concern for the group: If major tech companies want to install new data centres, there should be a cap on how much water they use to cool their servers. Bill 40 passed without those guardrails, and instead demanded these centres provide reports on their strategic benefit to the province — such as high-quality jobs and domestic data hosting — before they get connected to the energy grid.
“There hasn't been any acknowledgement that data centres can impact the environment,” Anna says. “And there is no mention of protecting affordability or public health.”
But ClimateFast, along with environmental groups such as Environmental Defence Canada and Friends of Earth Canada, wanted to see more stringent rules. They would like to see a cap on the water being used in these plants.
“We’ll plan to protest these decisions with days of action,” says Anna, “and we’re going to connect more with local resident groups, which will be very important to gather community around the environmental harm caused by AI data centres.”
Opposition has been loud in some areas of North America. Benton Harbor, Michigan is home to a new $3 billion data centre that many residents fear will generate noise, traffic, pollution and water supply issues. Homeowners in Nanaimo, B.C., have come out against a proposed 200,000-square foot data centre, and in Olds, Alberta, the city rejected Synapse Real Estate Corp.’s application to construct a 1,400-megawatt data centre in the town of 10,000 people.
Last year, residents of Tucson, Arizona successfully convinced their municipality to block developers of an upcoming AI data centre to access local waterways. Tucson residents clamoured to city council meetings and one woman waved a sign that read “Can’t Drink Data.” Despite the community outcry, the company is aiming to try to build the data centre without the cooperation of the county for access to the city’s water rights.
A letter sent to Congress in the U.S. in December 2025, signed by more than 230 environmental groups, called for an immediate national moratorium on the approval and construction of new data centres. They are asking to halt the rise of these data centres until federal regulations can be in place to protect community water security and prevent “runaway damage.”
“We are already seeing a big shift in pushback as water is a mobilizing issue for many communities,” says Helena Volzner, senior source water policy manager at the Alliance for the Great Lakes, a nonprofit. “It’s time for the companies running these data centres to be transparent about concerns we have about wastewater discharge and sustainable water consumption.”
Companies such as Amazon and Microsoft have told media that their data centres aren’t constantly thirsty for water. But according to the CBC, a Microsoft data centre built in the northwestern Netherlands — despite objection from local farmers — is using more than four times the expected 12 to 20 million litres of water it said it would use annually. What’s worse, the community was subsequently being asked to limit their own water use.
Anna from ClimateFast is skeptical that the climate impacts will be limited, as Microsoft’s posted statement claims. “There is always going to be positive messaging coming from these Big Data companies but until we see evidence they aren’t harming the community, it’s hard to take their word for it,” she says.
Greener solutions are available. One idea, albeit radical, is to submerge servers in a massive tank surrounded by water, which reduces water consumption by 90%. Another approach attaches liquid-filled copper plates directly to the CPUs and GPUs which uses up to 50%less water than traditional air-cooled methods.
Still, Canadians are up in arms about upcoming facilities. An AI data centre slated to be developed in the Spruce Lake Industrial Park in Saint John, New Brunswick, has led to that provincial chapter of ACORN (Association of Community Organizations for Reform Now) to issue a petition calling for the facility to be built somewhere else.
Nichola Taylor, chair of NB Acorn, says the communities always lose in scenarios when a sprawling AI data centre sets up shop. “The government, those who approved this centre, they are selling out New Brunswick here,” she says, “and what they should all be doing is actually look for greener solutions.”
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