What Trump's tinkering around with water at the Canadian border could be about

WASHINGTON, D.C. — While Canadians have been focused on Donald Trump’s hounding them about becoming the “51st state” and squeezing their cross-border trade, the U.S. president has been quietly fiddling around with the rules for waters along the Canada-U.S. border.

In late April, the president signed House Joint Resolution 140 into law, rolling back a Biden-era mining moratorium on more than 200,000 acres of U.S. federal lands near the Boundary Waters watershed in Minnesota that drains into Canadian waters.

Proponents are keen for the development of minerals and geothermal energy in the region, but critics fear mining will undermine water protections.

The rollback is a one-off, and scholars of the border waters treaties between Canada and the U.S. think it’s unlikely that Trump plans to renounce the long-standing agreements. But he has raised boundary waters as a bone of contention before.

In 2025, the president reportedly threatened former Prime Minister Justin Trudeau with cancelling the 1908 treaty demarcating the U.S.-Canada boundary, while also saying he wanted to revisit the countries’ sharing of lakes and rivers. That water-sharing regime is governed by a number of treaties and conventions, with the 1909 Boundary Waters Treaty (BWT) the main foundational agreement for U.S.-Canada boundary waters.

Where threatening the treaties could be useful to Trump is trying to introduce them again as a bargaining chip for other negotiations, said Daniel Macfarlane, a professor at Western Michigan University’s School of Environment, Geography, and Sustainability.

Making it easier on him is the fact that the pacts are vulnerable because they feature a notable lack of enforcement mechanisms.

“He likes to make threats, like ‘I’ll end the Boundary Waters Treaty’ that he perceives as important to Canadians,” said Macfarlane. “It’s just another weapon in his ‘art of the deal’ when it comes to maybe a trade agreement or something.”

But he notes that there’s no indication that Trump sees the treaties as an obstacle to his bigger priorities, the way he sees Canadian imports as a threat.

“It’s not bugging him too much, I don’t think, because it’s not blocking the things he wants to happen, as we see with him approving the mining,” Macfarlane added.

Even if Trump wanted to withdraw the United States from the BWT, doing so would be politically and diplomatically consequential and jeopardize interconnected pacts, such as the Great Lakes Water Quality Agreement, putting both countries at risk.

“Politicians of all stripes and colours threaten a lot of things. Whether they actually do it in the end, I would think that you don’t want to cut off your nose to spite your face,” said Richard Paisley, director of the Global Environment Facility International Waters Governance Initiative at the University of British Columbia.