Environmental Law Institute - National Wetlands Awards

Keel Kemper is an award winner in the Science Research category for his contributions to wetland conservation in Maine. Kemper is an assistant regional wildlife biologist for the Maine Department of Inland Fisheries and Wildlife, assigned to resolve nuisance beaver problems.

Beaver dams impound water and permit the animals to travel on water highways to forested areas where trees and shrubs are harvested for food, darns, and lodges. However, as roads bisect wetlands and beaver populations continue to expand, more and more dams are built in road culverts, flooding public roads.

To avoid flooding, state and local highway departments destroyed dams and drained the associated wetlands. However, beavers frequently repaired the dams within 24-hours, recreating the problem, and necessitating the destruction of additional dams. Widely fluctuating water levels in beaver impoundments can be devastating to ground nesting birds and other wildlife that require relatively stable water levels, particularly during the nesting season. Continual destruction of beaver dams is both a burden to highway department budgets and a poor management practice.

To resolve this conflict, Kemper perfected an innovative water control device, called a beaver exclosure. By using a combination of drain pipes, one-inch welded wire, and metal stakes, Kemper constructs portable, easily maintained fence structures in front of road culverts. To stabilize water levels, Kemper inserts perforated drain pipes through the dam and the fence, making it unnecessary to drain the wetlands. Beavers rebuild their dams against the fence, instead of in culverts, thus preserving acres of palustrine emergent, scrub-shrub, and forested wetlands. Since 1992, beaver exclosures have been installed at 82 culverts in Maine, protecting 968 acres of wetlands. This has been a win-win situation for all parties. Towns are happy that roads are not flooded, landowners are happy that their wetlands are not drained, and the many wetland-dependent species continue to benefit from beaver dams.

One notable example of Kemper’s efforts is visible in Monmouth, Maine, where the installation of $150 worth of enclosure hardware prevented flooding and saved a 300-acre marsh. The marsh is home to 18 pairs of wood ducks, six pairs of black ducks, other waterfowl, bitterns, ospreys, harriers, rails, green-backed herons, otter, mink, muskrats, dragonflies, and many other vertebrates and invertebrates. The town of Monmouth, which routinely destroyed beaver darns, now has its highway crews install the demonstrations statewide, Kemper has shown towns like Monmouth that the installation of exclosures is more cost effective than weekly trips to unplug culverts.

Acting on the work of Kemper, partnerships have been formed between the U.S. Fish and Wildlife Service, U.S. Animal Plant Health Inspection Service, municipalities, paper companies, railroad companies, and private landowners. As a result, the techniques of this highly successful program are being applied by timber companies, railroad companies, and other private landowners.

Kemper’s commitment to wetland conservation has improved attitudes towards wetlands in Maine. Kemper’s work has been portrayed in the media as a conflict resolution technique, and as a result, it is the private landowner who is quoted in local papers about wetland conservation. Landowners discussing why wetlands should not be drained are more convincing than public employees with the same message.

The U.S. Fish and Wildlife Service and the Maine Department of Inland Fisheries and Wildlife are co-producing a 30-minute documentary on the values of beaver-created wetlands. The video includes a step by step guide to installing beaver exclosures. The program, featuring Kemper, will be aired on Maine Public Television. The video is also being distributed to other states wrestling with conflicts between humans and beaver-created wetlands.

— Ron Joseph, U.S. Fish and Wildlife Service