Beavers are busy, and dam problems multiply

Robert Dahl was driving down a road in Carlton County when he received a call from an excavator operator. The operator was going to leave two beaver dams alone and told Dahl about new ones popping up at other sites the county monitors.

It was not an unusual call for the county’s department of transportation maintenance supervisor.

“Once a week [we] have the excavator out opening all these sites,” Dahl said. “Looking at them, monitoring them, making that decision: Do we need to open it up? Is it going to cause a problem for the weekend? Is it going to flood the road? What are we looking at?”

After two years of drought, the county has had an unusually wet spring and early summer, bringing with it an increase in beaver activity.

Nature’s engineers, with their innate drive to plug up flowing water, have collided with county infrastructure in flooding roads in townships such as Barnum and Thomson, leaving humans with the task of figuring out how to manage.

“The road bed to them is a dam, and the culvert pipe is a hole in it. With a little bit of work, they can plug that pipe and turn the entire roadbed into a dam,” said Beaver Institute founder and president Michael Callahan. The Beaver Institute, based in Southhampton, Massachusetts, is a non-profit founded to spread awareness of non-lethal means of beaver management nationwide.

While flooding is an obvious result of beaver handiwork, dams can also oversaturate a roadbed, compromising its structural integrity. Beaver management includes a range of options, including trapping, building fences to block access to culvert pipes, and removing problem dams.

“I actually don’t enjoy seeing beavers in traps,” Dahl said.

He and his team are taking steps to get more fences installed while considering the time and maintenance needed for them.

“You prioritize what needs to be done, and it starts with the safety of the road, and then you move on from there,” he said.

The county transportation office traps beavers at about 10 sites, monitors several others for activity and has a list of about 21 dams that potentially need to be removed. The county also assists townships when beavers threaten those roads.

Township troubles

While these government entities have authority to trap and control for beavers on public roadways and waters, it can get tricky when private property is part of the equation.

In Thomson Township, a beaver dam adjoining private property has caused flooding on Sunnarborg Road. Thomson public works employees tried getting permission to come onto the land with an excavator to remove the offending dam, but one of multiple landowners refused to sign.

At Thomson Township’s June 20 meeting, public works equipment operator Josh Ritchie told the board that the final landowner seemed ready to give the township permission, but another family member strongly opposed and Ritchie left the property, worried about a potential altercation.

The township is getting involved now because of the effect on the road, but problems beyond the roadway have concerned some landowners for over a year.

“I spoke with the homeowners to the north and she said the waters in her yard are approaching her sewer,” Ritchie told the township board. “She’s concerned about her sewer functioning. So, I don’t know what our next step is.”

Township attorney Dave Pritchett laid out the possibility of using emergency powers to get the public works access to the site if they could not secure the final signature.

Barnum township chairman Keith Rasmussen said he hasn’t been faced with such a drastic measure. While Rasmussen said Barnum Township tries its best to take care of beaver issues, many of the township’s homeowners live elsewhere and are up only on weekends, making coordination difficult. He wishes private landowners would do more to take care of the issue themselves.

“A lot of people don’t like to shoot things, and that’s understandable,” he said. “But then they’re the same ones complaining about the roads being bad, and it’s the beavers causing it.”

Chris Balzer, a Minnesota Department of Natural Resources area wildlife manager based in Cloquet, said as long as there’s damage to their property, property owners have “wide latitude to remove those beavers” with the caveat that one can’t shoot at night with spotlights or follow beavers off their property.

“If you have a lake lot and you have a relatively finite number of trees and you’re trying to protect them, we always encourage people to just protect the trees with fencing,” Balzer said.

No-kill solutions

Will Bomier, a former assistant maintenance supervisor for Carlton County transportation, said beavers keep coming back because it’s good habitat, so working with the beavers can be a better approach.

“Rather than try and fight what turns out to be, oftentimes, a very expensive, frustrating battle, you can try some of these nonlethal ways to kind of work in harmony with them,” he said.

Bomier was the driving force behind the county’s more preventive, nonlethal focus of the past several years. Many of those ideas came from the Beaver Institute, which Bomier touts as a useful resource for both public agencies and landowners to manage beaver in a way that promotes their ecological benefits.

Beaver Institute president Callahan listed several benefits the busy creatures provide for the ecosystem and humans. Their dams can filter toxic runoff and prevent erosion. The ponds they create raise the water table to support vegetation and have even been shown to mitigate the spread of wildfires.

“Our infrastructure is gonna come first. That’s gonna be the top priority,” said Callahan, who also runs a beaver management company in Massachusetts. “But we have to be thoughtful about knowing that when we design things we want, the less we create potential conflicts, the better.”

There is a cost savings too. Rasmussen said it costs Barnum Township $75 per beaver trapped, plus the township has to spend money to re-gravel damaged roads.

Dahl said a county contract with a trapper costs $400 per site. On the other hand, Dahl said materials for a keystone fence, which widens water flow when a beaver tries to block it, cost $115 four years ago, which is how long one particular fence the county installed has lasted.

Beaver benefits

Another benefit of beavers is the habitat they create for other wildlife, including waterfowl.

“It seems like the ducks seem to move to a little bit bigger water as the fall goes on,” Balzer said. “But early in the fall, they use the beaver ponds a lot, as well as other aquatic furbearers: muskrats, otters, mink, raccoons. Those all frequent beaver dams, beaver ponds.”

Dahl is part of a hunting group with a shack on a neighbor’s property that benefits from beaver activity.

“We have a shack together (near water) that the beavers occupy and there are otters that come through. And obviously the ducks and waterfall use it, and we see swans there and it’s great,” he said.

If beaver dams are in the right places and not affecting roads, Dahl likes to leave them alone.

“Beavers will cause people problems just doing what they do, but in most cases we can manage those problems, resolve them in a way where we can keep the beavers around,” Callahan said. “I think that’s an important role for humans — to be as thoughtful about how we live on this planet as possible. So, living with beavers is an important part of that.”