Canal pipe breaks, threatening a northern Montana irrigation project and drinking water

Two century-old steel pipes that help convey water from a river on the Blackfeet Indian Reservation to a river that helps irrigate northern Montana cropland have failed, causing local flooding and raising concerns about the availability of drinking water for at least 14,000 residents this summer, including in the city of Havre.

No injuries or deaths have been reported since the first 7.5-foot (2.3-meter) pipe split open Monday morning, causing flooding in the rural area east of Glacier National Park near the U.S.-Canadian border. The gushing of water caused some washouts 50 feet (15 meters) deep and destabilized the concrete footings holding a second pipe, which broke Monday afternoon, the U.S. Bureau of Reclamation said.

Staff closed the headgates that diverted St. Mary River water into a 9-mile (14-kilometer) canal after the first pipe was breached, but the Bureau of Reclamation expected it to take up to 36 hours for that canal to drain through the broken pipes. The water, which was flowing at 600 cubic feet per second when the first pipe broke, was down to a trickle Tuesday afternoon, said Ryan Newman, the bureau's Montana area manager.

The pipes, which were built between 1912 and 1926, are part of a siphon system to carry St. Mary River water across a ravine over the river and uphill to another canal that feeds it into the North Fork of the Milk River.

The break comes a month before a $100 million replacement project on the headgates was expected to begin and during the peak irrigation season.

The agency’s 2023 study of the headgates replacement project warned that a failure would affect farmers through reduced crop production and could place a strain on local businesses and communities.

The economic impact of the failure of the pipes will depend on how long it takes crews to restore the flow of water to local producers, who are between 200 and 350 miles (320 and 560 kilometers) from the diversion. The Bureau of Reclamation will start working on those assessments, Newman said. Design work on a project to replace the pipes, which was underway before the pipes failed, is about 60% complete, he said.

Officials with the Milk River Project, the organization set to oversee the headgates replacement project, labeled the breach a “catastrophic failure,” which could result in an economic disaster for north-central Montana, the Flathead Beacon reported. Farmers with 120,000 acres (about 46,000 hectares) of land from Havre to Glasgow rely on the irrigation water, Newman said.

The flooding scoured the hillside, damaged property, eliminated an access road to a motel and a horse boarding facility in Babb, Montana, and could cause utility disruptions in the surrounding areas, officials said.

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This story has been updated to correct that replacement work on the headgates, not the pipes, was scheduled to start next month.