Proponents of a dam on southern Alberta’s Milk River say it would provide water for irrigation, livestock and wildlife
MILK RIVER, Alta. — The possibility of building a dam on the Milk River in southern Alberta is once again being explored.
The 1,173 kilometre long river begins in Montana and flows across the international border into southern Alberta, an arid region of the province.
In Alberta, it is joined by the north fork of the Milk, much of which is diverted from the St. Mary River in Montana through a diversion canal and siphon. Then it flows back into Montana and south past the Sweetgrass Hills.
It’s an arid region that is often short of water, and two years of especially dry conditions have brought the idea of a dam and greater water storage back into contention.
John Ross, chair of the Milk River Watershed Council Canada, said the council might seek to upgrade a 2003 engineering report to see if a dam, at that time estimated to cost $200 million, is feasible. If so, he said it could secure water for irrigation, livestock and wildlife.
“We have looked at the off-stream storage sites, and re-evaluated some of the ones, and realized that they would be completely inadequate to meet the needs of what the river basin of the Milk River would actually need,” Ross said.
“It would actually secure water supply for the towns of both Milk River and Coutts. In addition, it would also secure water and in-stream flow needs for fish and wildlife, right through the summer and also right through the winter time.”
Cheryl Bradley, a biologist active in southern Alberta conservation efforts, said previous studies on Milk River dam proposals showed a poor cost-benefit ratio, and she does not think the situation has markedly changed since the 2003 study was shelved.
“I think there is a great desire among residents in this basin to have a more stable source of water. I can understand that desire, but I always go back to, ‘well, at what cost,’ ” said Bradley.
“I’m not sure it’s worth putting a major expensive dam on the Milk River that floods a lot of native grassland and that will result in major environmental impacts downstream and will disrupt migration of fish species and things like that. I don’t think those risks are worth the few additional acres of irrigation that would come.”
Proposals and plans to dam a river are always complex, but this one has the additional challenge of international relations. Flow and diversion of the Milk River is subject to provisions of the International Joint Commission, and demands on available water have sometimes been contentious.
Ross said Montana has been approached about building a dam on the Milk River on the Canada side.
“We have been talking kind of indirectly, at a grassroots level,” he said.
“A few years back, there would have been more opposition to it. I think there’s a lot more understanding now. We’ve talked back and forth on the benefits of actually operating the river as one and not just as a separate U.S. and Canadian side.”
The diversion infrastructure in Montana that puts water into the north fork of the Milk, which then flows into Canada, has long been a source of concern for the MRWCC. It is badly in need of upgrades, but Montana has shown no appetite to undertake expensive construction that would have to be done in winter, after water demand eases.
“If we could actually have a dam on the Milk River, we could work with our American friends and hold water for them and release it, and they could actually shut off their diversion and repair it during the summer when it costs a lot less. So it would maybe help decrease the cost of building a new diversion for the Americans, too,” said Ross.
“Down in the States there’s over a billion dollars worth of economic development that comes from that diversion.”
Several Montana towns, including Havre, rely on the diversion system for municipal supplies as well as some irrigation. Two reservoirs created by the Fresno and Sherburne dams are part of the state’s supply system.
Ross speculated that a dam on the Canadian side would allow Fresno to address silt issues that threaten supplies to Montana users.
“In a perfect world, which I like to live in once in awhile, it makes complete sense,” said Ross about a dam west of the Milk River townsite.
“There’s always going to be pushback. This project has actually been eyed since somewhere in the 1980s and was highlighted as a need way back then.”
In fact, the Alberta government approved a dam on the Milk River in 1985, on a site 16 km west of the town, at an estimated cost of $30 million in 1995 dollars. The plan was shelved when the federal government withdrew support.
Bradley agreed that opposition to any new proposal is likely.
“I think in a dry area we always wish there was more water, and I think as a society, we’re willing to spend a lot in hope that we can keep our kids close to our communities … and provide new economic opportunities, but at some point I think we have to recognize limits.”