The rulebook predates the machines.
In Ontario, water is governed province-first: every large taking is licensed, one application at a time. But that framework was written before AI data centres became a category of water user — and closing that gap is now the policy question, right here on the Great Lakes.
In Ontario, taking 50,000 or more litres of water a day from the environment requires a Permit To Take Water — the same order of magnitude a single large data centre can consume.
Government of Ontario — Permit To Take Water · Ontario Water Resources Act, O. Reg. 387/04
Water use and permitting are a provincial responsibility, administered by the Ministry of the Environment, Conservation and Parks against the Great Lakes–St. Lawrence River Basin agreement.
Government of Ontario; Great Lakes–St. Lawrence River Basin Sustainable Water Resources Agreement
Data centres are emerging as a new category of water user, and it is not yet clear how much they draw — or whether a permit written for farms and factories is the right tool.
Michelle Jadormeo, 2025–26 Geoffrey F. Bruce Fellow in Canadian Freshwater Policy
“Canadian freshwater policy cannot remain reactive in the face of global, geopolitical and rapid technological change.”
Toronto and the data centres rising across the Great Lakes draw on the same basin. Jadormeo’s work maps the “policy gaps and regulatory blind spots” in that oversight — the argument being that a province cannot permit its way through the boom one application at a time.