Contract awarded on St. Mary Dam project

Work is set to start on repairing a major part of the system that has been called “The Lifeline of the Hi-Line.”

U.S. Sen. Jon Tester, D-Mont., announced last Thursday that a more-than $88 million contract that is funded through his bipartisan infrastructure law has been awarded to Montana-based NW Construction to complete the St. Mary Diversion Dam Replacement project.

The contract is part of the up to $100 million Tester secured for the Milk River Project through the bipartisan Infrastructure Investment and Jobs Act.

Tester was one of the small group of Democrats and small group of Republicans who negotiated the bill that provides more than $1 trillion in infrastructure funding over 10 years.

Tester included repairs and rehabilitation of the St. Mary Diversion and Conveyance Works, part of the Milk River Project irrigation system that also provides water to towns and for recreation, in the infrastructure bill, by specifying funding for projects with requirements matched by the St. Mary Diversion Dam and Canal. The $100 million in the act does not require reimbursement by the Milk River Project water users and will be used to fund the replacement of the St. Mary Diversion Dam and Headworks.

“As a third-generation farmer, I know how critical this project is to thousands of families living in rural Montana,” Tester said in a release last Thursday. “Montanans have made clear that replacing the St. Mary’s Dam is long overdue, which is why I made sure to secure this funding in my bipartisan infrastructure law. I am glad to see a Montana company is running this project and I look forward to seeing shovels hitting the dirt to get the dam repaired and rehabilitated so Montanans have access to the water they need for decades to come.”

Repairs decades in the making

The St. Mary Diversion was one of the first projects the U.S. Bureau of Reclamation was authorized to build after its creation in 1902, with the project authorized in 1903. It diverts water from the St. Mary River on the border of Glacier National Park through a system of dams, dikes, siphons and canals across the Blackfeet Indian Reservation into the North Fork of the Milk River. The water then flows into Canada before returning to Montana.

The system, built to provide water for irrigation, often provides half or more of the water that flows through the Milk River each year, as much as 90 percent in some drought years. Before it was built, the river dried up in the fall of 6 of 10 years.

It comprises Sherburne Dam, which stores water in Lake Sherburne on Swift Current Creek; a dike that diverts the water into St. Mary River, the diversion dam that diverts water into the conveyance works, then 29 miles of canals, gigantic metal siphons and the concrete drop structures that drop the water into the North Fork of the Milk River. Most of the system is on the Blackfeet Indian Reservation.

The system took years to complete, often using heavy equipment drawn by teams of horses. Much of the conveyance works was completed by 1915.

The water flows through the North Fork of the Milk into Canada before returning to Montana and eventually flowing into the Missouri River near Nashua below Fort Peck Reservoir. It provides water for irrigators in the Milk River Valley as well as municipal water for communities along the river including Havre, Chinook and Harlem along with providing water to the northern part of Fort Belknap Indian Reservation.

The project was authorized as an irrigation system with funding for its operation and maintenance primarily coming from the irrigators using it.

The system typically provides half or more of the water in the Milk River. In drought years like last year, and what appears to be coming this year, it can supply up to 90 percent of the water in the river.

Before the diversion was built, the Milk River dried up by the fall in 6 of 10 years.

As repair costs rose, the system was patched together for decades, and, more than 20 years ago, users began to warn that if major rehabilitation wasn’t done soon, the system would fail, which would be catastrophic to the region.

The system has been patched together for decades. The Milk River Project, which includes the diversion, was authorized as an irrigation project, so irrigators using the water had to pay for most of the upkeep and repairs. Major repairs and rehabilitation usually could not be funded.

More than 20 years ago, a coalition of Milk River water users started pushing for repairs to the project before catastrophic failure occurred. The state formed the St. Mary Rehabilitation Working Group in 2003 to push for repairs and rehabilitation of the system.

That catastrophic failure occurred in one location in 2020, when the last concrete drop structure where the conveyance works flows into the Milk River collapsed, requiring shutting the system down. A major — highly successful — effort to get the structure done by fall was added to scheduled work on other drop structures that had problems.

Rehabilitation now in the works

The $88,321,400 project award last week to NW Construction Inc. out of Bozeman is intended to ensure water users along the Milk River continue to benefit from the diversion and conveyance works while protecting bull trout through the Endangered Species Act.

The fish, listed as threatened under the endangered species act, is found in Idaho, Washington, Oregon, Nevada and in Montana including in the headwaters of the St. Mary River, which flows into Canada.

U.S. Fish and Wildlife Service determined in 1999 that the diversion dam was detrimental to bull trout, preventing easy movement upstream for spawning.

The plans in the contract deal with that. BOR says the replacement project includes a low head diversion dam and rock ramp for upstream passage for the fish, a new headworks structure, a canal fish screen, a check structure downstream of the fish screen and a fish bypass to return fish to the river.

The first round of funding, $2.5 million, was announced in January and was used for planning and project design in 2022. Tester’s release said the senator directly negotiated and wrote the provision of his legislation that provides up to $100 million to rehabilitate the Milk River Project, and, in December 2020, he urged Bureau of Reclamation Commissioner Camille Touton to make the St. Mary’s diversion a top priority and get the resources out the door as quickly as possible.

The release said Tester worked across the aisle for months to negotiate his bipartisan infrastructure law with a group of five Republicans, four Democrats and the White House, and he was the only member of Montana’s congressional delegation to vote for it.