A $70 million project restored water flow to the Milk River along Montana's Hi-Line, which is used by thousands for drinking water and irrigation, according to krtv.com.
On June 17, 2024, the St. Mary River Canal siphon failed catastrophically, prompting the U.S. Bureau of Reclamation to act.
In the following year, stakeholders including federal government agencies, tribal entities and contractors joined forces to complete repairs ahead of schedule. Fifty-two percent of the project was covered federally, with the remainder covered by Montana shareholders.
By June 25, 2025, water was flowing again.
Krtv.com noted that subzero temperatures and generally extreme winter weather made the repairs a challenge.
Frozen ground and rock made digging and backfill difficult. A modified concrete mix had to be employed.
"Frozen concrete just doesn't work. We've got to heat the concrete and make sure it doesn't freeze and keeping that temperature up until you've got full strength is what we're doing," Gary Lundberg, project inspector, told krtv.com in February.
"The St. Mary Diversion Dam and Canal were completed in 1915 as part of the Milk River Project (Project) in north-central Montana," according to the federal Bureau of Reclamation. "The dam is located near Babb, Mont., and approximately 0.75 mi. downstream from Lower St. Mary Lake. The existing dam consists of a 198-ft.-long and 6-ft.-high concrete weir and sluiceway. It diverts water from the St. Mary River into the St. Mary Canal through the gated headworks structure for use by the Milk River Project."
The Milk River Project Joint Board of Control noted that all the contractors for the project were Montana-based. NW Construction of Bozeman led the siphon replacement, working alongside Pro-Pipe Construction of Frenchtown, which handled the intricate welding of the 90-in. steel siphons. In all, 6,444 ft. were installed, krtv.com reported.
NW Construction crews also installed a drainage system around the pipes to ensure long-term durability.
Sletten Construction of Great Falls assembled the crucial structure that will support the siphon as it spans the St. Mary River. True North Steel in Billings fabricated the steel components.
NW Construction and Sletten Construction teamed up on the inlet and outlet structures, re-designed by HDR Engineering to handle the extreme hydraulic pressures at varying flow rates. These structures are substantial, with 40-ft. walls at the inlet, making them a significant focus of current construction efforts, krtv.com reported.
The Tribal Employment Resource Office (TERO) provided approximately 30 members of the Blackfeet Tribe to work across multiple companies and compliance offices.
