MISSOULA — It's not as large an operation as tearing out the Milltown Dam, but nonetheless just as important to restoring an important Clark Fork tributary for fish habitat.
In less than two hours Monday morning, workers with Aqua Terra Restoration were able to demolish what took pioneers months to build, as they tore out the main section of the old dam on Rattlesnake Creek, a major milestone in the $1.3 million project.
The dam used to provide Missoula's main water supply, but hadn't been a source since the 1980s because of water quality concerns. It was not only blocking important fish habitat, but presented a very real flooding risk for the city if the dam had failed.
And as crews hammered the old dam to pieces, it became apparent just how rickety it was, with a hollow core and aging timbers that just fell away.
"When you start to see pieces of the project come together, we have pools that have been built already," Rob Robertson with Trout Unlimited said. "And fish are already colonizing the pools, while we're doing the project. We're building riffles. We're putting in vegetation. We have a lot more to go. A lot of finishing touches. So, everyday just brings in focus, more into reality and you can kind of see what the final vision is going to be like out here."
And crews continue to take extra measures ensuring they don't ruin fish habitat even as past damage is fixed.
The demolition is creating tons of concrete and other debris. But the project includes multiple measures to make sure the current water quality and habitat downstream isn't damaged in the process.
"We pump any dirty water up to a filtration area way up in the field away from the creek. It settles out," Robertson said. "The water that goes back into the creek eventually is much cleaner than what comes out. Two pumping stations, including our bypass channel. And then we also have straw waddles, and other filtration areas around all of our top soil, all of our exposed earth. And we're using water trucks to keep dust down as well."
In fact, Robertson says there's already been evidence of trout in the pools and riffles which have already been constructed, an indication the water is clean and the plans are working.
The project is between the city, Trout Unlimited, Montana Fish, Wildlife and Parks and other partners. Demolition on the joint project should be finished in a few weeks. Then attention will turn to building the new stream bed, planting new vegetation and completing final details.
