Lake Sherburne and St. Mary Canal Operations

At 9:00am on Monday June 17, 2024, a catastrophic failure occurred at the St Mary Syphon over the St Mary River near Babb, Montana. USBR crews were inspecting a crack at the time of the failure and thankfully no one was hurt. Significant flash flooding of debris and water is flowing down into the St Mary River along the Canadian Reach through to the St Mary’s Reservoir. Please be careful in low-lying areas and along unstable banks. The canal diversion gates were closed at the time of the failure for the inspection.

What does this mean for the Milk River? We can expect flows to drop starting on the North Fork Milk River within about 24 hours and within approximately 48 hours near and east of the Town of Milk River. Natural flows on the Milk River in combination with the current rain should maintain approximately 5 or 6m3/s for water users. This will likely drop with depletion of the bank aquifers. All Recreational activity is not recommended immediately as flows will drop very suddenly. We will share more information regarding condition and repair or replacement timelines when available.