CORVALLIS — Rescue volunteers responded to a call of two men in the water at a dangerous diversion dam on the Bitterroot River on Tuesday afternoon.
Corvallis Fire Chief Jim Knapp said the men managed to get themselves to shore after “scrapping their way out” of the treacherous boil just below the low-head irrigation dam.
Their black Labrador dog had to be retrieved from a log by Bitterroot Search and Rescue volunteers.
“Both guys swallowed some water, but they managed to get themselves out,” Knapp said. “Luckily, their dog found a log to grab onto. Its rescue was a little bit risky.”
A volunteer had to get in the water and allow the back current to pull him in close enough to grab the dog while the search and rescue boat stayed far enough downstream not to get dragged into the boiling water under the dam.
“They did a great job on that,” Knapp said.
The low-head irrigation dam is located about three miles downstream from the Woodside Fishing Access Site.
Last summer, a 6-year-old girl drowned after her family’s raft became trapped behind the dam. Several other boaters had close calls at the site as well.
The dam spans the reach of the Bitterroot River. Like other low-head dam structures, when water flows over its crest and drops to the lower level, it creates a backwash that traps and recirculates anything that floats.
When a person is caught in the backwash, they are carried first to the face of the dam where the water pouring over the structure will push them underwater and downstream to a point called the boil.
The boil is where water either goes downstream or moves back toward the dam. When a person struggles to the surface, they are carried again to the face of the dam to repeat the deadly cycle.
The dam looks deceptively easy to cross from the river level, but the hydraulic is there no matter how high or low the water level is flowing.
Montana Fish, Wildlife and Parks placed signs at upstream access sites to warn of the hazard. More signs were posted just above the dam that directs water to the Supply Ditch to provide floaters with a warning to avoid to dangerous structure.
Knapp said the men said they were inexperienced and couldn’t avoid going over the dam.
“It’s a horrible spot in the river,” Knapp said. “You can put as many signs up as you want, but the river at that spot is deceiving. If you get too far to the east, you can’t make it to the west bank in time.”
Bitterroot Search and Rescue volunteers have already had a training session at the site. Corvallis Fire plans one soon.
There are rescue throw bags situated near the dam for people to use in case of trouble.
“We know we’re in for a long and extended runoff this year,” Knapp said. “Let’s hope that this is the last one this year, but I’m afraid we’ll be back again.”
The men’s raft remained in the boil under the dam for half an hour after rescue volunteers arrived on the scene.
“It just kept doing circles for a good half hour before it finally was spit out,” Knapp said.