Montana Hi-Line water source to get needed repairs through infrastructure bill

Last week, Sen. Jon Tester’s office announced a Bozeman company was awarded an $88 million contract to bring crews to the St. Mary Diversion Dam and Canal. The surge in funds galvanized repairs for the dam, which is over a century old. Tester was one of several lawmakers who crafted the Infrastructure Investment and Jobs Act, designed to bolster the country’s aging infrastructure. St. Mary Dam is just one piece of a larger system that supplies water to communities along the Hi-Line, irrigating roughly 120,000 acres. 

“The contract is to rehabilitate the aging infrastructure of the dam, which is severely dilapidated” said Steve Darlinton, a project manager with the Bureau of Reclamation’s Montana Area Office.

In Montana, the BOR oversees 20 projects, each one containing facilities such as pump stations, dams and canals. The St. Mary Diversion Dam and Canal was built to divert water from the St. Mary River, and is part of the BOR’s Milk River Project.

Formed in the early 1900s with a mandate to bring irrigation to arid portions of the Western United States, the BOR has authority over dozens of sites spanning from the Great Plains to the Pacific Ocean. Construction projects managed by the BOR peaked during the first four decades of the agency’s existence, among them Hoover Dam on the Colorado River, Grand Coulee Dam in Washington State and St. Mary Dam. 

On its way to the dam, the St. Mary River rises in Glacier National Park, and flows northeast. The St. Mary River continues into Canada, but when it reaches Babb, on the Blackfeet Indian Reservation, it flows under the St. Mary Dam. The dam diverts water from the river and feeds it into the Milk River, a 730-mile stretch of water that rolls east to the Fort Peck Indian Reservation. The dam where the two rivers meet is going on nearly 110 years old.

Funding for the upkeep of the Milk River Project’s facilities is split two ways. Milk River irrigators, those tapping into the river as a water source, pay 75% of costs while the federal government covers the remainder. The heavy financial burden on communities along the Milk River slowed progress in desperately needed repairs. Although officials have been calling for investing in the dam and canal’s infrastructure for decades, they continued to crumble.

“We started looking at options for rehabilitation as early as the 2000s,” Darlinton said, “but we just couldn’t get to a full replacement due to funding issues.”

In 2020, water stalled at the canal. A drop, a structure built across a canal to lower its bed level and keep water flowing at a slope, collapsed and halted the flow of the St. Mary River into the Milk River. When the canal failed, Darlinton said, Milk River water users were completely reliant on what water was available from the Fresno Dam and Nelson reservoirs. With thousands of acres, including two Indian reservations and the major towns that make up the Hi-Line in jeopardy of losing their water supply, the failure spurred an immediate mobilization of state, federal and tribal engineers.

The overdue funds to rehabilitate the dam came courtesy of the Infrastructure Investment and Jobs Act, also known as the Bipartisan Infrastructure Law, signed by President Joe Biden in November 2021. The law set aside over $1 trillion for renewed funding in new and previously existing infrastructure programs. Tester was one of 10 U.S. senators who negotiated the text of the bill; the core group consisted of five Democrats and five Republicans.

The infrastructure package passed through the House of Representatives with a vote of 228-206, then the Senate passed the bill by a large margin of 69-30. Tester was the only lawmaker in Montana’s federal delegation to approve the bill.

Going into the spring of 2024, nearly $5.5 billion has been allotted to Montana through the Bipartisan Infrastructure Law. Transportation and water infrastructure projects have soaked up most of that money, with $2.82 billion invested in roads, highways and bridges. Meanwhile, $2 billion has been committed to projects centered on clean drinking water, such as replacing lead pipes throughout the state. The law also secured up to $100 million specifically for facilities that have failed during the previous two years.

St. Mary Diversion Dam and Canal was the only such facility in Montana to meet those criteria. NW Construction received the $88 million contract to replace and reconstruct key components to the dam. The Bozeman-based company has also been contracted to rehabilitate Fresno Dam, downstream along the Milk River just west of Havre.

One additional feature built into the St. Mary Dam will be structures allowing bull trout to bypass the dam, Darlinton said in accordance with the Endangered Species Act. Rehabilitation of the dam is slated to begin in July of this year, with construction finishing in 2027.