Standing up to the United States

Hey there, time traveller!
This article was published 14/02/2025 (258 days ago), so information in it may no longer be current.

Recent events have thrown Canadian relations with its economically more powerful southern neighbour into sharp relief.

Most commentators appear shocked by the U.S.’s use of bully-boy tactics to get its own way. But that should not surprise anyone. They tried that over a century ago in a now mostly-forgotten dispute over water use.

After a tense standoff, Canada prevailed when the Americans backed down.

Around the turn of the last century, the United States set its eyes on the waters of the St. Mary River which rises in the U.S. and flows across the international boundary from Montana into Alberta. Canadian irrigation schemes depended on water from the St. Mary River.

American corporations contended that Canada had no right to this water since the river rose in the U.S., and therefore its waters were the property of the United States. United States’ water law west of the Mississippi generally holds that the person who appropriates water first has the right to continued access and its use.

The U.S. government argued that laws affecting water use did not apply to trans-boundary issues, and it proposed to divert the water from the St. Mary River to feed a planned irrigation scheme in eastern Montana.

To do this, they wanted to divert water from the St. Mary River into the Milk River, which also rises in the U.S. and flows north into southern Alberta, before it curves southward and re-enters the United States.

If the U.S. were to proceed with this scheme, irrigated agriculture in Alberta would have been devastated. Canada protested that water use in the western United States was based on the right of prior appropriation and so the U.S. was legally obliged to honour that principle and not in any way impede the flow of the St. Mary River into Canada.

The U.S. countered that such laws did not apply internationally, so Canada had no legal right to American water and the United States intended to proceed with its project to divert water from the St. Mary River into the Milk River where it would eventually re-enter the United States. Clearly, the U.S. had no interest in a negotiated compromise.

Faced with an economic catastrophe to southern Alberta’s agriculture, Canada took a strong stance.

Refusing to back down, Canada threatened to construct a canal in Alberta designed to intercept any water diverted into the Milk River and redivert it back into the St. Mary River, where it would continue to supply Canadian irrigation projects.

To convince the Americans that this was no idle threat, Canada surveyed a 72.4-kilometre diversion canal and began its construction.

By any standards this was a massive undertaking: it was nine metres wide and capable of holding more than two metres’ depth of water.

By 1904 most of the canal’s first 25 kilometres were flooded. Surveying and construction crews worked feverishly to complete the remaining stretch of canal. Where roads cut across the canal, and with no time to build the necessary bridges, dynamite charges were placed, ready to blast out the obstructing roads and let the rediverted water flow freely into Canada.

The U.S. blinked first.

Realizing that the Canadians were deadly serious, they agreed to negotiate trans-boundary water allocation. These negotiations eventually resulted in the Boundary Waters Treaty of 1909 and the creation of an International Joint Commission to adjudicate any future water disputes.

Was this a gigantic bluff on Canada’s part? Maybe.

The diversion would probably not have worked, since parts of the hastily built canal cut though gravel and sand deposits.

It is almost certain that most, if not all, of the diverted water would have seeped into the ground long before it reached its destination. It would have brought Canada little economic benefit. But the thinking then, it seems, was “If we can’t have the water, then neither will you!”

The results of this dispute can still be seen in the landscape of southern Alberta near the town of Milk River, where sections of the completed canal, still mostly dry, serve as a visible reminder of the importance of a strong stance when dealing with a more powerful adversary.

Danielle Smith should take note.

John Lehr is professor emeritus with the Department of Geography at the University of Winnipeg.