Special Reports

Busy beavers muck up state's best efforts

The groundskeeper in Caddyshack grappled with a gopher. The state of North Carolina is in a battle with beavers.

The state has spent $80,000 trapping beavers and removing dams at stream and wetland restoration projects and just signed a $150,000 contract to do more. In some cases, the beavers' strongholds have been so sturdy that the state has hired people to blow them up.

A recent repair list shows beavers have caused problems at 50 of 132 completed restoration projects, in many cases multiple times. The beavers chew up newly planted trees, which are needed to hold soils together and draw nitrogen and phosphorus out of the water. Their dams cause the newly restored streams to back up and flood, increasing the potential for erosion.

Depending on where they are built, the dams can also dry up or inundate restored wetlands. A wetland, after all, is property that's too wet to be a forest and too dry to be a marsh.

Beaver dams are practically an annual occurrence at a stream restoration site at Smith and Austin creeks in Wake Forest. Five years ago, dams backed up the water and flooded the town's soccer fields; last year a dam caused the water to rise onto backyards along Trentini Avenue.

In other places, dams have appeared just as quickly as others have been removed.

"Always, those pesky beavers," one state staffer wrote in an email about yet another problem.

At times, state officials get exasperated. In 2009, they visited two sites where a contractor had already removed beavers and dams only to find more dams backing up water on the projects.

"The above example feeds my expressed concern about this becoming a bigger 'whack a mole' situation than it has to be," wrote Greg Melia, who monitors restoration projects for the state's ecosystem program.

What's unusual about the beaver-phobia is that the critters can actually enhance water quality in streams and wetlands. Beaver dams are one of nature's best filters for sediment and pollutants.

Melia and other state officials say that it pains them to remove the beavers, but that with millions of dollars at stake, they can't afford to have restoration projects delayed or damaged by these water-loving rodents.

Beavers were trapped nearly to extinction in North Carolina by the late 19th century, at a time when their pelts were big business. In 1939, the state imported 29 beavers from Pennsylvania to bring the species back.

That, of course, was before the state started its stream restoration program.