Work continues on the St. Mary Diversion repairs

Concrete was poured on Drop 5 last week on the St. Mary Diversion and Conveyance Works, the drop near the end of the 29-mile system of dams, dikes, canals, gigantic metal siphons and concrete drop structures that failed in May.

Work on Drop 2 was planned for this year and is underway, and the work on Drop 5 was added after it failed May 17.

“2020 has been quite the year, but we all need to remind ourselves we are 12 weeks and two days from the failure and we poured our first round of concrete on Drop 5 (last Monday), and if all continues, our last round on Drop 2 in two weeks,” Milk River Joint Board of Control Project Manager Jennifer Patrick said in an Aug. 11 update.

The diversion was built more than 100 years ago by the Bureau of Reclamation as part of the irrigation system the Milk River Project, and also is used as a municipal water source by towns including Havre, Chinook and Harlem and provides recreation opportunities.

Drop 2 is moving along nicely, Patrick said, and they should be finished pouring on this structure at the end of this month.

She said all but one concrete strength test had passed in the 14-days and the other one they are confident will come around very soon, adding that this is better than the projected 28-day strength tests.

“We are optimistic these concrete qualities will extend into the Drop 5 pours as well,” Patrick said in her update. “This could decrease the schedule and I remain confident in the engineering team and contractor — if there is an opportunity to expedite things, they will make it happen.”

The diversion provides much of the water that flows through the Milk River, which typically ran dry by fall in 6-out-of-10 years before the diversion was built.

The diversion has been shut down since the drop collapsed May 17.

At the time, Fresno and Nelson reservoirs, part of the Milk River Project that use water from the diversion, were at very high levels, but have been drawn down for irrigation use.

Fresno and Nelson reservoirs had above-average storage levels and were used to provide continued irrigation deliveries up to last month.

“I cannot thank the group of guys up on the project enough, I try often with donuts, or in the offices behind the scene pushing this project to assist with border crossings, Tribal Employment Rights Office, landowner consultations, accommodations, budgets and briefings just to name a few,” Patrick said.

“We are not done yet, and have a ton of moving pieces and new guys showing up daily,” she added.

After fixing Drop 2 and 5 and Drop 1 is shored up, the next step is to work on the diversion dam, although no funding is set for that at the moment.

Under the original authorization, most of the funding for the diversion and The Milk River Project comes from users, primarily the irrigators. That pays for about 75 percent of the costs.

The work being done now was declared an emergency project, so the federal government will pick up the first 35 percent with the remainder split between the users and the federal government. The total cost is estimated at about $8 million.

Sens. Jon Tester, D-Mont., Steve Daines R-Mont., and Rep. Greg Gianforte, R-Mont., are trying to shift the funding for the system from about 75 percent provided by the users and 25 percent by the federal government so the federal government picks up about 75 percent of the cost of operation and maintenance.