Working group discusses fix on St. Mary Diversion

The St. Mary Rehabilitation Working Group had a meeting Friday to discuss the collapse that occurred last Sunday of a drop structure in the St. Mary Diversion and Conveyance Facilities that supply much of the water in the Milk River each year.

“We need to get something done in the summer so that we’re not saddled with this in the winter with winter costs or heaven forbid start up in the spring without having really made any gains,” St. Mary Rehabilitation Working Group Co-Chair and Montana State University Phillips County Extension Agent Marko Manoukian said. “... I look to move this thing forward and get it fixed as soon as possible.”

The final drop structure in the system, Drop Structure 5, a concrete canal-like structure that routes water down the last hill toward the Milk River, failed and collapsed May 17.

St. Mary Working Group Co-Chair Lt. Gov. Mike Cooney said the state is looking at what options they have to help fix the structure.

“Obviously, we want to do everything that we can to make sure we address this situation so that we can get it up and running as quickly as possible,” he said. “... We know this is going to take a lot of work and effort. I appreciate everybody’s efforts on this so far and we’re here to partner, we’re here to help and look forward to what everybody else has to say.”

Sen. Steve Daines, R-Mont., told the working group the St. Mary Diversion has one of the highest cost shares for users and that needs to change.

He, Sen. Jon Tester D-Mont., and Rep. Greg Gianforte R-Mont., introduced in May of 2019 the St. Mary’s Reinvestment Act to shift the funding for operations and maintenance of the system so the federal government would pay about 75 percent of the cost for the upgrades, which is awaiting action in Congress.

“I think it highlights the urgency of passing legislation and that we got that I’ve put forward to change that federal cost share,” Daines said. “... I sent a letter to the Bureau of Reclamation urging them to move quickly to determine this qualified as emergency, extraordinary maintenance work which is the first step in getting this drop structure repaired quickly.”

He said they will come together as a delegation to fix this quickly as possible and to make sure it doesn’t happen again.

“Greg’s got the bill on the House side, so we’re going to work with the good Senator Daines and Tester and try to get this across the line,” Tripp McKemey of Gianforte’s office said.

Henry Ring of Tester’s office said they will be working in any way they can on the cost share, whether legislatively and administratively to make sure that the large cost doesn’t fall on the water users.

Daines asked Milk River Joint Board of Control Project Manager Jenn Patrick what their assessment is of another drop structure, Drop Structure 2, failing at this time.

“We thought Drop 2 would fail first,” she said. “... It looks the worst. It is the worst. We were on that path. I would say if possible we need to assess it at this point in time.”

Bureau of Reclamation Montana Area Manager Steve Davies said he concurs with Patrick and the Drop 2 structure was scheduled to be awarded funds for repairs this fiscal year by the Joint Board of Control and Reclamation was going to lead the effort to assess it because funding was available to pursue that.

He said the Bureau recognizes the seriousness of this issue and is not underestimating the magnitude of this situation.

He said this had the attention at the right levels at Reclamation.

He said they don’t know the exact cause of the failure, he believes water likely breached the concrete slab, got underneath the slab and caused erosion underneath it and caused further collapse.

“There is still water within the canal even though the canal has been shut off since Sunday,” he added. “The last of the drop structures of the end of the 29-mile canal as far as the technical response a lot of groundwork — we have a technical team assembled, our technical team of engineers from our technical service center for each regional office and area office will be on site Wednesday. They have been collaborating with the Joint Board and their consultant, HDR engineering that’ll factor in and I’ll explain why, as well as DNRC support.”

People were going to be on site Saturday, he said, to gather topography, drone imagery and so on to feed into what the project is going into.

Davies said they also have received cultural collaboration from the Blackfeet Reservation.

“This team that is going on site Wednesday is looking holistically in terms of what are our options — everything is on the table. We’re looking at is there a temporary fix? What is that temporary fix? And is that full canal capacity at 600 or something less? What is the cost of that? What’s the time frame? And how does that differ from a full repair?” he said. “So, we are looking at the full spectrum of what’s possible.”

Drop 2, he said, was scheduled to be replaced this year because it was deemed at risk of failure.

“We are very much aware that actions at 5 need to include what we’re going to do with 2,” he said. “We’re a little bit ahead of the curve in terms of designs for a fix on a permanent repair. We had actually embarked on efforts to replace Drop 5 in the 2013-2014 time frame and switched to Drop 2 at that time because we deemed 2 to be higher risk of failure.”

Designs are fully done on Drop 2, that is ready now, he said, adding that design can transfer right to Drop 5.

He said he doesn’t have a temporary or permanent fix along with the timeline for this, but it is in motion with the technical team and they’ll be on site assessing that out.

Davies said, Fresno and Nelson Reservoir are full, which will help with the water supply.

“It gets us to where we can supply water from there right now,” he said. “Our current projections and we went through this with the Joint Board (Friday) morning, that, based on that supply at Fresno and Nelson, and with flows projected into Fresno we have till mid-July before we have to stop irrigation, start shutting it down. This gets us through what I’m sure Jenn and Wade will describe as kind of their first irrigation season,” he said.

He said water supply will not be available for the second half of the irrigation season unless there is rainfall or a possible temporary fix that starts putting water in this.

“Right now, under the best of circumstances we don’t see any repair being in place at least through August,” he added. 

Patrick said the board wants to move forward with Drop 2 and Drop 5 and then move on getting structures back in place.