The many acres of trails on the West Side of the Blue Hills Trail are often home to beavers. In years past, we've been able to tolerate a few of their permanent dams while trying to maintain the adjacent trails in the summer, and groom next to their dams in the winter.
Sad to say, too often we've resorted to trapping to remove 'nuisance beavers' (we report the problems to the County Forestry Department, and they hire out the work to a professional trapper).
All summer we've observed an active 200-foot long beaver dam that is located next to the ski trail (between intersections I and H), with about 130 feet of the trail wet enough to perhaps make it difficult to groom and ski this winter. Instead of trapping out the beavers at this spot, we decided to try a different approach. We'd like to learn how to coexist.
The first photo (below) shows this location in early September. See the small bridge? Beyond the bridge the trail has water slowly moving over the trail. We've debated various options, and yesterday (November 13th) decided to install a small beaver deceiver (pond leveler) device.
Here's what Sam, Benny, and Tom did...
· Purchased five 10-foot lengths of 4" corrugated HDPE pipe ('drain tile') and one filter
· Breached the beaver dam with the goal of dropping the water level about two feet
· Screwed the pipe sections together, and fastened the filter on the upstream end
· Drilled holes in the first 20 feet of pipe (to allow trapped air to escape)
· Attached a weight five feet from the upstream end (to hold the pipe underwater)
· Waded into the pond with the upstream end of the pipe (and the weight)
· Placed the downstream end of pipe (30 feet in length) through the breach in the beaver dam, and under the bridge on the ski trail
· Dropped the upstream end (and weight) into water that was probably five feet deep
· Placed a vertical wood post in the breach of the dam, and attached the pipe to that post
· Confirmed a nice volume of water flowing through the downstream end of the pipe
The materials cost about $30. We’re hoping the beavers quickly show up and repair the breach in the beaver dam. This hopefully would seal the pipe into the dam at a height that will control the water level – leaving enough water for the beavers to use the pond, but keeping the water level low enough to minimize the tendency for water to leak through the dam and flow over the ski trail.
We learned a lot from this first attempt at installing a pond leveling device. It was a nice muddy day playing in the beaver habitat, here’s hoping we can coexist.
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