Dangerous Bitterroot River dam being fixed

Boating on the Bitterroot River, Missouri is going to be whole lot safer come spring.

Construction is set to begin right after the New Year to rework the dangerous, century-old Supply Ditch Diversion Dam downstream from Corvallis. The current low-head irrigation dam creates a re-circulating hydraulic current that can swamp boats and trap floaters. There have been numerous boating accidents at the site, including one that killed a 6-year-old girl in 2013.

The dangerous undertow develops because of a large hole immediately downstream of the dam.

The plans call for filling that hole in with large rocks and creating ramps that boaters will be able to navigate much more safely, said Mollie Davidson, the lead Morrison-Maierle engineer for the project. “Rather than have a steep drop off that creates that roller hydraulic, there will be gradual ramp,” Davidson said. While boaters will be able to cross the dam at any point, the most desirable spot will be on the left side of the river where the ramp will be less steep, she said. The project is being paid for through several different agencies and the irrigators. The Army Corps of Engineers provided a $300,000 grant, which Davidson said made the project possible. “That grant was extremely huge,” she said. Other funding sources included a $125,000 Renewable Resource Grant from the Montana Department of Natural Resources and Conservation and $40,000 from Montana Fish, Wildlife and Parks. The Bitter Root Conservation District also chipped in $10,000 and irrigators paid $50,000.