Butte’s Blacktail Creek is home to all sorts of critters.
On a recent afternoon, near the popular Ulrich-Schotte Nature Trail, a mink hopped across the path as red-winged blackbirds perched on fence posts.
But one less-than-welcome neighbor, the beaver, was nowhere to be found. The trouble they cause with their dam building is the focus of a new project.
Skip Lisle of Grafton, Vt., and Amy Chadwick, of Missoula, along with her husband, Howard Williams, have partnered with Butte-Silver Bow County to install three “Beaver Deceivers” at culverts in the creek. The structures, made of cedar and concrete reinforcement wire, take up space so beavers won’t try to dam the whole channel.
If beavers begin to build a dam, a special 15-inch-diameter tube will keep water flowing through the culvert.
The beavers plug culverts all along Blacktail Creek, Chadwick said. The dams can cause flooding problems for nearby residents — Chadwick pointed to sandbags stacked by a home nearest to the creek — and can cost municipalities thousands of dollars to dismantle.
Lisle, of Beaver Deceivers International, has been creating the structures for 20 to 30 years, and Chadwick and Williams are training under him, she said.
Chadwick has been doing watershed assessments and stream and habitat assessments for 15 years. She said beavers are important to a stream’s ecosystem, and recently have been recognized as a stream restoration tool, she said.
Still, there had to be a non-lethal way to maintain their presence — but mitigate their troublesome dam building.
Enter the Beaver Deceivers, which has proven effective in keeping culverts free of dams, they said.
“The word is spreading (about the Beaver Deceivers) because there is such a need,” Chadwick said.
She said the city-county may spend between $12,000 and $15,000 a year removing beaver dams. But a device like those put in Blacktail Creek cost $3,000, all-inclusive, and she said she’s hoping they’ll last 20 years.
Money for the Butte project comes via the Mile High Conservation District from the Department of Natural Resources and Conservation, as well as the city-county. The latter supplied the materials and helped with the installations.
“They pay for themselves in the first year,” Chadwick said of the Beaver Deceivers.