Milk River Joint Board of Control, State of Montana and Reclamation moving forward with permanent repairs of two drop structures on the St. Mary Canal

At approximately 3 p.m. on Sunday, May 17, a concrete drop structure failed on the Bureau of Reclamation’s Milk River Project St. Mary Canal, northwest of the town of Cut Bank in northern Montana, located completely within the Blackfeet Indian Reservation.

This concrete drop structure is the last of five drop structures that use gravity and siphons to convey water through the 29-mile long St. Mary Canal to the North Fork of the Milk River. Water is diverted into the canal from the St. Mary River, near Glacier National Park and supplies irrigation and municipal water to irrigators and communities along the Hi-line.

The Milk River Joint Board of Control, Bureau of Reclamation and the State of Montana, through the Department of Natural Resources and Conservation, conducted an engineering site inspection on May 27 to assess the damage and determine if an interim fix was feasible to move water this year. The team concluded that the complexities and costs associated with providing an interim solution to run water this irrigation season could not be justified considering the anticipated costs and minimal gains in water supply. Subsequently, the decision was made to immediately replace the Drop 5 structure as well as Drop 2, another high risk drop structure, with the intent of completing construction by late this summer. This may allow late delivery of water to Fresno Reservoir, near Havre for additional storage for next season. Currently, Fresno Dam and Nelson Reservoir have above average storage levels and will be used to provide continued irrigation deliveries into July. Municipal water shortages below Fresno Dam are not anticipated at this time.

Moving forward, the Milk River Joint Board of Control, with the assistance from Reclamation and the Montana Department of Natural Resources and Conservation will complete a full replacement of Drop 2 and Drop 5 structures. The Joint Board and HDR Engineering will manage the construction project and has selected Sletten Construction Companies to perform the construction. Collaboration with the Blackfeet Tribe to complete cultural clearances and permitting will be accomplished before construction begins.

The majority of construction of the Milk River Project was completed between 1906 and 1940. The canal was constructed between 1907 and 1915 and is the primary water source for eight irrigation districts, the Fort Belknap Indian Irrigation Project, contract pumpers, and several municipalities downstream of Havre serving approximately 140,000 acres of land.

Details and updates on facilities and operations managed by Reclamation’s Montana Area Office will continue to be posted on our website at https://www.usbr.gov/gp/mtao/.