Global Warming Will Melt Glaciers, Empty the Great Lakes, Force Canada to Divert Rivers, Build Dams and Sell Water To The US
AN HOUR SOUTH of Lethbridge, Alberta, and twenty minutes from Montana, Milk River is one of the last Canadian towns before the border. The one-block downtown is Prairie minimalist: a Chinese restaurant near a lonely stop sign, beyond it a bank, and across the highway, yellow and green grain elevators. Just west of town, the pavement peters out to a gravel range road, and to the south the Milk River surges with flood water. From the Rockies to Medicine Hat, this usually dry country, where researchers scour barren coulees for dinosaur bones, was awash in six days of uninterrupted rain. Pincher Creek declared an emergency; High River faced its namesake. Though troubling, this spring’s wet weather provided an ironic counterpoint to my objective: to find the century-old Spite Canal, an artifact of Canadian-American history born of drought and embodying the enmeshed nature of the two countries’ relationship with water.
Looking north across treeless hills, I saw a conspicuously straight line emerge from the rain. My rental car vibrated over a Texas gate, and minutes later I scrambled up a grassy embankment. Beyond it was a ditch about two metres deep that followed the contour of the land northward. This crude trench — unmarked, largely unremembered, and now crumbling back into the prairie — is the physical fact on the ground that induced Teddy Roosevelt’s chest-beating America to sign a treaty with Canada that is still lauded today.
Its origins can be traced to the late 1800s when settlers north and south of the forty-ninth parallel relied on two rivers: the St. Mary and the Milk. Both flow from Montana into Canada before diverging; the St. Mary carrying on to Hudson Bay, the Milk turning back into Montana after looping 250 kilometres through Canada. Rising high in the mountains, the snow-fed St. Mary ran strongly all summer; the Milk, born in the foothills, often dried to a trickle. That led the Americans to launch a plan in 1901 to divert water out of the St. Mary and move it across the foothills to the Milk and their ranches in Montana.
Alarmed Canadian homesteaders turned to Ottawa, but Roosevelt ignored Canada’s plea to halt the plan, so the Albertans fought back. If the Americans were going to “steal” water and divert it to the Milk, they would take it back as it flowed north, drastically reducing water levels before it turned back into the United States. In 1903, the Albertans began digging a canal to recapture the disputed water. Washington finally paid attention, and in 1909, the two countries signed the landmark International Boundary Waters Treaty. The International Joint Commission the treaty created had as its first task settling the St. Mary-Milk River dispute, which it did by dividing the water equally