Hi-Line irrigation in question after St. Mary siphon blowout (2024)

BABB — Bill Powell said he'd seen worse, but he still fretted over the gaping ravine cut through his property by a torrent of water unleashed from burst irrigation canal pipes Monday.

The St. Mary Canal siphon, comprising two 7.5-foot diameter steel pipes in a system built from 1912-15, failed suddenly and completely. One pipe ruptured just before 9 a.m., when a newly developed crack rapidly grew into a massive blowout that sent 300 cubic feet of water per second, or 2,244 gallons each second, rocketing out onto the grassy hillside the pipes traverse.

The staggering force of the water — the pipe's quarter-inch steel flapped like soft plastic around the rupture — eroded the earth and concrete supports of the second pipe, which failed that afternoon. The combined 4,488 gallons of water rushing out each second inundated Powell's business, the Hook's Hideaway bar, restaurant, motel, campground and roping arena, and created a flow of mud and gravel that mostly filled the adjacent St. Mary River.

The siphon pipes are part of the Milk River Project, which diverts water from the St. Mary River on the east side of Glacier National Park and sends it instead into the Milk River farther east. The pipes, located north of Babb near the U.S.-Canada border, sit about 9 miles downstream from where a diversion dam on the St. Mary River marks the beginning of the St. Mary Canal. The canal stays at higher elevation than the river; the pipes allow water to flow down a steep hillside from the canal, over the St. Mary River and then up and over a smaller hill to the east.

A facility operator at the site saw the failure occur shortly after he tried to plug the crack, according to Steven Darlinton, a U.S. Bureau of Reclamation project manager. The operator closed the diversion dam about 15 minutes later, stopping more water from entering the canal, but the 9-mile canal was still draining through the ruptures by midweek, a process that officials said could take three days. Stream gauge data showed the canal flowing at 596 cubic feet per second at the time of the rupture. Flow dropped dramatically that day and was down to about 17 cubic feet per second on Wednesday. No injuries were reported during the incident.

The Milk River runs across Montana's largely agrarian Hi-Line region. The Milk River Project, a series of canals, reservoirs and siphons that augment water flow in the river, provides irrigation and drinking water for a roughly 160-mile stretch east of Havre. The enhancements provide for about 60% of the water in the river during a normal year, according to the BOR, and up to 80% in drier years.

The Milk River Project irrigates somewhere between about 120,000 and 180,000 acres across nearly 700 farms, according to varying figures from the project's Joint Board of Control, made of irrigation districts the project serves; the BOR, which oversees and operates the infrastructure; and the Blackfeet Water Department. (Much of the project’s infrastructure, including the siphon, is located on the Blackfeet Reservation.) The project provides drinking water for 12,000 to 18,000 people, according to those agencies, including the city of Havre, home to about 9,000 people.

Irrigation impacts

Darlinton, who has been a project manager on the Milk River for a decade, said that the agency would hold back enough water in Fresno Reservoir northwest of Havre to provide drinking water for municipalities. But the 110-mile stretch from Fresno Reservoir to Nelson Reservoir, northeast of Malta, will likely run dry a month early, drastically shortening the time farmers can irrigate and ranchers can provide water for livestock.

"Irrigation is going to be a significant impact," Darlinton said. "We’re looking at water being out between Fresno and Nelson around mid- to late July. With irrigation running it was mid-August."

A 2023 BOR study, part of an analysis of replacing the St. Mary diversion dam that feeds the canal, concluded that a failure of the canal system would cause severe and widespread impacts across the stretch of the Hi-Line that relies on the Milk River for irrigation. Economic impacts, the agency determined, would likely extend beyond farmers and also hurt local and regional businesses, families and broader economies.

Ryan Newman, the BOR's Montana area manager, told the Associated Press this week that design work to replace the siphon pipes, which the agency had been eyeing long before Monday's failure, was 60% complete.

In an office next to the stricken siphon pipes on Tuesday, Darlinton said there had been signs the system could catastrophically fail. Infrastructure along the project is deteriorated and in need of replacement, he said, but funding has been a perpetual barrier to major upgrades.

Farmers who use water from the Milk River Project are collectively responsible for 75% of the system's operating and maintenance costs, according to the terms of a more than century-old agreement that led to the project's creation. The federal government covers the rest. That means it's up to Congress to send additional money for larger projects, like the diversion dam replacement.

"There has been signs, whether it’s a crack in the siphon that we’ve repaired, whether it’s through a temporary welding patch," Darlinton said. "If you look at the pipe, it’s pretty patched and welded a lot. So we’ve been working through that. The reason that we haven’t been able to do more than that is due to lack of funding."

Next week, he said, a technical team including BOR engineers and geologists and an engineer contracted by the irrigation districts is set to inspect the site as the agencies develop short- and long-term solutions. The agencies are scheduled to present preliminary information at a public meeting in Malta on July 9.

"We’re probably going to focus on two things," he said. "Is there a temporary solution to move water quickly this year, and then look at a permanent fix that HDR (engineering firm) is currently designing."

"There are no solutions off the table," said Jennifer Patrick, project manager for the Milk River Joint Board of Control. "We are looking at everything."

"All water operations at this point have ceased, said Patrick, whose Malta-based organization advocates for fair and affordable water distribution from the Milk River Project.

The Milk River Joint Board of Control sent a letter to federal officials asking that they exhaust all funding options before placing the financial burden on Milk River irrigators.

Local impacts

This week, Darlinton said, the BOR's primary focus is restoring vehicle access and power to Powell's business, which became suddenly isolated when the torrent washed out the only road in. On Tuesday, BOR equipment operators used a bulldozer and front loader to build a new roadbed down the hillside to Hook's Hideaway and coat it with trucked-in gravel.

Powell, 65, said a BOR worker came by his house, which wasn't affected by the blowout, just after 9 a.m. Monday to warn him of the failure and advise him to let steers out of a rapidly flooding corral. A worker navigated a rush of waist-deep water to let them out, he said, and water was flowing about 4-feet deep near some of his buildings. Powell's only access to the area was down a steep, un-roaded hillside north of the pipes that wasn't affected.

Water rushed around the bar he built 28 years ago by having a barn enclosed, he said, but didn't come into the structure. He did find mud in a crawlspace underneath, he said, leaving some concern about foundation damage. The motel sits on higher ground, but the corrals and roping arena below the bar was a mess of soft, deep mud and heaps of logs, gravel and large rocks all deposited by the water. The flow also caused severe erosion around the well that provides drinking water to the business, and he wasn't sure if it was still working.

The 15 rooms in the motel go for $210 a night, and Powell had to cancel 30 bookings for this weekend — $6,300 in lost revenue.

But Powell didn't fault the BOR for the failure. The agency has been a good neighbor, he said, and he likes the workers, most of whom are locals. As a former longtime rancher who once had 600 head of cattle, he said, he'd been through other, worse hardships in life. He just hoped road access and electricity would be restored soon.

K. Webb Galbreath, the Blackfeet Water Department director, visited the site shortly after the pipe failed Monday.

"I couldn’t really believe it, you know?" he said. "There’s one video where the metal's kind of flapping and it looks like plastic, and I believe it’s quarter-inch steel. There’s a lot of power behind that water. It's kind of amazing that something like that would happen."

He too didn't fault the BOR.

"I don’t think this is a fault of anybody or anything — it’s just old," he said. "It’s probably 50 years past its prime."

Paul Hamby reported from Billings.