Missouri Basin and Arkansas-Rio Grande-Texas Gulf Regions

St. Mary Siphon Updates

Overview

The Milk River Project (Project) was authorized by the Secretary of the Interior on March 14, 1903 and provides water to 110,000 acres of cropland and is a source of potable water for several communities. The Project provides irrigation water for approximately 110,000 acres on eight irrigation districts, about 110 individual Project pumpers, the Fort Belknap Indian Reservation, communities along the Milk River, and the Bowdoin National Wildlife Refuge.

St. Mary canal is the primary water supply for the Milk River Project, conveying 600 cfs from St. Mary River to Milk River from April through October. The St. Mary Canal Siphon consisted of two 90-inch riveted steel barrels that traverse the valley from the inlet, transition to an 84-inch diameter pipe at the river crossing, and then back to a 90-inch diameter pipe as they ascend the valley slope to the outlet. It was constructed in two phases, with the downstream barrel completed between 1912 and 1915 and the upstream barrel after 1925. The siphon reached the end of it's functional life-span on June 17, 2024 and will be replaced and this webpage will provide updates about the progress of the replacement over the next year.

The St. Mary Diversion Dam and Canal were completed in 1915 as part of the Milk River Project in north-central Montana. The dam is located near Babb, Montana and approximately 0.75 miles downstream from Lower St. Mary Lake.

Multimedia

Milk River Joint Board of Control Photo Gallery

St. Mary Initiative

"The St. Mary EQIP initiative will help to offset potential affects like increased soil erosion and decreased forage production on ag operations that usually irrigate with water from the Milk River Project. The initiative will also provide alternatives to ranchers that use the St. Mary Canal as a livestock barrier or for stockwater.

The St. Mary Initiative will be funded through the Environmental Quality Incentives Program (EQIP) using the Act Now application process. Applications eligible for the St. Mary Initiative will be accepted on a continuous sign-up basis. To be considered for this funding cycle, applications must be received by Feb. 28, 2025. Applications received after that date may be considered in other relevant ranking pools. St. Mary Initiative applications will be processed in the order received and those that rank above the established minimum ranking score of 50 will be pre-approved as funds are available. Farmers and ranchers that apply won't need to wait for all applications to be ranked to find out if their application was funded."

From USDA news release: Initiative Provides Assistance to Farmers and Ranchers Directly Impacted by the St. Mary Siphon Failure

Point of Contact

Steve Darlinton

Project Manager
(406) 247-7322
sdarlinton@usbr.gov
Bureau of Reclamation
Montana Area Office
P.O. Box 30137
Billings, MT 59101
(406) 247-7300