Work to repair damaged diversion infrastructure in Montana isn’t expected to be completed before freeze-up this winter
Water flow in southern Alberta’s portion of the Milk River remains minimal as construction work continues on failed and fragile structures in Montana that prevented water diversion into the Milk from the St. Mary River.
The Milk River has run nearly dry this summer due to system failures in May on the U.S. side of the border. Low flows forced cancellation of irrigation for about 40 Alberta farmers and led to water use restrictions in the Town of Milk River and villages of Coutts, Alta., and Sweetgrass, Montana.
It is unlikely the work will be completed this fall in time to allow any water to be diverted into the Milk, said Milk River Watershed Council executive director Tim Romanow.
Good weather has aided construction on two canal drop structures, but work might not be done in time for water diversion before freeze up.
“Drop 2 is pretty much nearing completion. They’ve got a bit more earth work to do,” said Romanow.
“Drop 5, they’ve got some more work. They’ve probably got at least three weeks worth of work still, which pushes them into October.”
Any flow of water after that will likely be only enough to test the system, he added.
“There’s a very narrow window there to get much water in before it could potentially freeze up and cause damage to the rest of the infrastructure.”
Some cattle producers in the region usually rely on the river as one barrier to keep cattle in pastures. With the river nearly dry, some have put up temporary fencing to contain cattle and allow better use of available grazing.
“There’s been a bit of creative work trying to manage all those challenges and still be able to do some pasture rotation,” said Romanow.
On the U.S. side, Lake Sherburne Dam and Fresno Reservoir are part of the system. Romanow said water might be released from Sherburne in preparation for winter, which could result in higher water flow in the St. Mary River, which feeds into the St. Mary Reservoir on the Alberta side, south of Lethbridge.
Town of Milk River Mayor Peggy Losey said residents have complied with spring and summer water restrictions and reduced water use by almost 50 percent.
“It was so impressive. We’ve had a lot of co-operation,” said Losey.
“We asked people to use the water conservatively as much as possible and to not water their lawn at all.”
The result has been lawns like Losey’s own, which she described as being “pretty crunchy.” However, residents were allowed to hand water gardens and flowerpots and some hauled water from the nearby Village of Warner to supplement their needs.
The town doubled its water storage capacity a few years ago, and Losey said engineers now estimate there will be enough water to carry the town and the villages of Coutts and Sweetgrass through the winter.
“They’ve done some math, and they say that because everybody here has done so well at conserving the water, they think we’re pretty good for the winter,” said Losey.
As a contingency, the town is working with Alberta Environment on a potential water line from Ridge Reservoir.
Water conservation plus some rain on the Labour Day weekend have allowed the town to ease restrictions slightly for September, so residents can now water perennial trees and shrubs during specific hours on Mondays and Thursdays.
“Just so the trees and the shrubs will have some base moisture going into the winter so they don’t winterkill,” Losey said.
In the rest of the Alberta part of the watershed, Romanow said council members along with Alberta Environment and federal fisheries officials have checked fish habitat in the Milk. They’ve found few large fish, likely because they had no escape from predatory birds due to low water levels and shrinking pools.
However, the silvery minnow, an endangered species, seems to have managed well, he said, has have other smaller aquatic species.
“Water quality has been interesting. Because of the natural flow from springs and some of the groundwater up-swelling, we’ve had some really high almost brackish water in terms of the salt content.”
A unique international border crossing arrangement organized by Medicine Hat-Cardston-Warner MP Glen Motz aided construction work in Montana. It allowed concrete, sand and gravel to be trucked from Alberta into Montana over a shorter distance, saving time and money on the construction projects, Romanow added.
Border crossing restrictions in place due to the pandemic are hurdles for those wanting to see the projects and discuss potential next moves to upgrade the system.
“I’m really hopeful, when this border opens up, that it’s going to give us an opportunity to really work together on some common sense solutions,” said Romanow.
“Alberta and Canada have a role to play in making sure the whole system works, too. There certainly isn’t going to be an objection from Montana any more, talking about joint storage projects on the Canadian side. There’s a big recognition that we’re in this together.”
Montana’s St. Mary canal system, with its five drop structures and reliance on gravity and siphons to convey water, is 100 years old, but costs to upgrade it have been deemed prohibitive by the water users who would be responsible for much of the expense.
However, now that Americans have faced water restrictions this summer, it could prompt some action, Romanow speculated.
“I think they have a better recognition of where their water comes from and how vulnerable their systems are.… I think the irrigators have all known, but now it’s opened up the eyes of the greater community (in Montana). This is a very precarious position that we’re all in.”