Beaver dams causing a real jam for some in Charlotte

On a quiet fall night on the Catawba River, a beaver dam stopped a potential disaster. The dam was all that stood between a sewage leak and the river that supplies much of Charlotte’s drinking water.

“A beaver dam strategically located contained the spill,” a utilities report stated.

Beavers were the heroes on this day, and can benefit local ecosystems, but they are not always so helpful.

Beaver reintroduction began slowly in the 1930s. Now, the North American Beaver, the largest rodent in North America, is making its presence known – even in urban areas around Charlotte.

“They have rehabilitated their native territory, including here in Mecklenburg County,” said Rupert Medford, an N.C. Wildlife Resources Commission district biologist.

The potential damage

Medford said his office, which covers Mecklenburg and some surrounding counties, gets complaints about beaver damage to trees and also hears concerns about the standing water that their dams can create.

Two beaver dams are at the Dairy Branch of Upper Little Sugar Creek near Freedom Park. Even though the dams were breached in the last few months, water remains pooled up. In this case, a steep embankment kept the water from reaching the road, but other places are not so lucky.

Beaver trappers in Mecklenburg County say that the rodent can become a nuisance. One beaver dam, for example, covered up the manholes to underground pipelines, preventing repair crews from entering.

To curb their effects, the state has a beaver trapping season. A beaver is typically killed in the trap.

Charlotte-Mecklenburg Animal Care and Control does not remove beavers, but private companies and licensed trappers will. The Wildlife Resources Commission has a list of licensed trappers on its website.

The trapping season is November to the end of March. According to Wildlife Resources Commission’s website, trapping is the best option for a concerned property owner. Beavers can be used for their pelts and meat.

Under North Carolina law, unlike with some other animals, land owners can remove beavers from their property outside of the trapping season.

“The rules are relaxed for beavers because they are so destructive,” Medford said.

Beaver benefits

Some critics say trapping is not a permanent solution.

Sharon Brown, a biologist from Beavers: Wetlands and Wildlife, a national beaver advocacy group, said that once a colony of beavers is removed, a new colony typically will move in sometime in the near future.

Beavers will stay in one location for up to a decade if the food supply remains stable. One beaver trapper said that if one beaver is killed, the others will typically vacate the area.

Some towns, like Martinez, Calif., near the San Francisco Bay area, have petitioned local governments to install flow devices to curb beavers’ negative effects. These devices steal water away from the beavers, lessening their impact. But it allows the beavers to still keep their dam.

“(The city council) was kicking and screaming” because they initially didn’t want to pay, said Heidi Perryman, who runs a beaver blog in Martinez.

Christopher Newport University, in Newport, Va., released a study comparing the costs of keep or removing beavers. The study looked at 14 dam sites, and compared the costs before and after flow devices were installed.

It found that before the devices, it costs around $300,000 to remove beavers and to repair the surrounding areas. Often a new colony moved right back in.

The price over the same period of time with the devices was around $44,000 because the beavers’ damage is permanently controlled.

“People don’t realize the benefits of beavers are hidden,” Brown said.

Beaver dams filter water, which helps contain urban runoff and water pollution from spreading downstream. They also create new ecosystems, as animals come to the slower water around the dam. Beaver removal can destroy these habitats.

In Martinez, the community ended up saving their town’s beavers, even creating a yearly festival to celebrate the beavers’ continued survival.

“There has been a strong push to coexist,” Brown said.

This story was originally published July 7, 2016 at 10:42 AM with the headline "Beaver dams causing a real jam for some in Charlotte."