NewsMontana and Regional News

Actions

Groundbreaking for the St. Mary Diversion Dam Rehabilitation Project

groundbreak.jpg
St. Mary Diversion Dam Rehabilitation Project.png
Posted
and last updated

The Bureau of Reclamation held a groundbreaking ceremony Tuesday morning for the St. Mary Diversion Dam Rehabilitation Project in Glacier County, aiming to secure water resources for irrigated lands and communities in north central Montana.

The project is a collaborative effort between three primary stakeholders, the Bureau of Reclamation, the Blackfeet Nation, and the Milk River Irrigation Project Joint Board of Control. It is funded by President Biden’s Bipartisan Infrastructure Law, which includes $8.3 billion appropriated to Reclamation in installments from 2022-2026. Reclamation has allocated $100 million for the St. Mary Diversion Dam Replacement Project.

Project Manager for the Bureau of Reclamation, Steven Darlinton, explains, “The first plan for design was in 2004. We've had many iterations, but the big issue has always been funding, and we finally got funding as part of the Bipartisan Infrastructure Law recently, and that allowed us to start the construction of this $88.3 million project.”

The Groundbreaking Ceremony began with a Blackfeet prayer, followed by a speech given by Blackfeet Chairman Rodney Gervais. In his speech, Gervais said, “This is our land. This is our water. And moving forward, just to have that understanding that together we can do some good things”. He added, “We will help people. We will make sure that water flows down that river.”

The current dam was completed in 1915, and consists of a concrete weir and sluiceway that diverts water from the St. Mary River into the St. Mary Canal. The new construction will supply water resources for 110,000 acres of irrigation land and communities.

Key features of the replacement are:

  • Low Head Diversion Dam
  • Rock Ramp
  • Headworks Structure
  • Canal Fish Screen
  • Check Structure
  • Fish Bypass
  • Control Building
  • Operation and Maintenance Building 

The new structure will include a large fish bypass to allow the movement of bull trout, which the current dam lacks. The upper St. Mary River Basin is home to the only bull trout population east of the continental divide, and has been listed as a threatened species since 1999. Darlinton says, “We're going to protect the environment with bull trout while also helping the local economy and supplying water to the irrigators of the river project.”



Reclamation is currently in the process of developing the site to build a bypass canal, which will make sure water continues to be delivered during construction. For the next year, dewatering systems and other site preparations will be completed, with official construction on the project beginning next year. The project is scheduled to be completed in 2027.

For more information on the St. Mary Diversion Dam Rehabilitation Project, click here.