After dropping the news of the 15th beaver festival yesterday its nice to remind ourselves of how it all began. With this handsome gentleman and all the secretaries pushed up against the glass in the county recorders office to get a closer look. (And maybe Steve Weir too,) I never heard that but I remember our Gazette editor joked about making a calendar out of all the great photos taken of the day.
To humans it’s a culvert. But for beavers living near Todd Weiler’s Emsdale, Ont., driveway, it’s a poorly built dam with an 18″ hole, just begging to be plugged
with mud and sticks.
That’s why, on and off for almost two decades, when Todd cleared his blocked culvert, a new dam would soon appear. Trapping didn’t work, because new beavers replace the old ones. “If you’ve got the right geography,” Todd says, “beavers are going to find it.”
Rushing water is a trigger for the powerful dam-building urge in Castor canadensis, explains Glynnis Hood, a professor of environmental science at the University of Alberta and the author of The Beaver Manifesto. Plugging leaks is so instinctive, young beavers raised in captivity assemble dams near speakers broadcasting water sounds. When these compulsive putterers find a culvert, “they think we just didn’t finish the job,” Hood says.
Hood and Lisle together again, just like old times. If there’s a culvert to protect Skip is your man.
Todd ultimately fended the critters off with a homemade version of the “beaver deceiver,” invented by Skip Lisle in the 1990s for the Penobscot Nation in Maine. Similar to the “pond levellers” used by parks and transportation authorities, Todd’s version is a 4″ PVC pipe running from the mouth of the culvert to an area upstream, guarded by mesh cages at both ends. Hood recommends heavy-guage mesh—not chicken wire, which beavers can chew through—with 4″ to 6″ holes. The pipe channels water into the culvert, while the mesh keeps beavers from damming the culvert or plugging the pipe. Because the intake makes no sound, beavers don’t notice it. Meanwhile, water trickling into the culvert keeps them focused on the protective cage. “They can block up that downstream cage as much as they want, and as long as the pipe is flowing, the water goes through,” Todd says.
The Parks and Transportation Authorities in Ontario install pond levelers? Why doesn’t California? What the hell are we waiting for?
The system requires occasional maintenance, including clearing silt from the pipe and ensuring dam materials don’t crush the cage. During the culvert wars, “dam wasn’t the only expletive I used on the beavers,” Todd admits. “But now, it’s nice to see them.”
Todd seems like our kinda guy. I’m glad that Skip was able to fix your problem. He fixed ours too and it lasted for a decade.
