Beaver Situations & Solutions
Both humans and beavers change their surrounding to suit their needs (see Beaver Dams), and from time to time, these needs may come into conflict. Property owners, in particular, may experience unwanted flooding. Since beavers are largely beneficial, it’s in our interest to find the least draconian solutions to beaver problems.
Relocating wildlife is illegal in Massachusetts. It's also illegal in Massachusetts to disturb beaver dams or other structures without permits (the same applies to muskrat structures).
To get a permit, you must take the following steps:
1. Contact your local Board of Health to apply for a 10-day emergency permit that will allow you to take specific actions to resolve the problem. You must be able to show that beavers are causing the problem, and that the situation constitutes a threat to public health and/or safety.
2. If the Board of Health approves your application for the 10-day emergency permit, you must then get an emergency certification from your local Conservation Commission for permission to breach the dam or install a Water Level Control Device (WLCD).
Removal or Breaching of a Dam
Breaching a dam can cause severe flooding downstream, and draining a wetland affects many species—not just beavers. If a dam must be breached, it’s best to create a small notch to control the slow release water. Large breaches allow water to rush through, creating too much water pressure. This can result in the entire dam giving way.
The sound and movement of water stimulate beavers to rebuild and repair their dams, sometimes as quickly as overnight, so consider breaching a dam only as a short-term solution to flooding. Because beavers are nocturnal, it’s best to breach a dam early in the morning to allow water to flow all day.
Water Flow Devices
Many property owners find success with water flow devices, which prevent issues from flooding caused by beaver dams. Pipe system devices control the water level in a beaver pond—offering a long-term solution for homeowners while allowing beavers to continue maintaining precious wetlands.
A wide variety of devices exist on the market, with various ways to install them. The best products muffle the sound of moving water and minimize the sensation of flow—preventing industrious beavers from rebuilding.
When conflicts arise, it’s better to seek long-range solutions. Destroying beavers just creates vacant territory for new beavers to move in. If you must turn to lethal options, you will need to get a permit from your local Board of Health. You must be able to show that beavers are causing the problem and that the situation constitutes a threat to public health and/or safety. Beaver elimination should occur only at the end of summer, to avoid orphaning dependent kits. Only licensed trappers and Problem Animal Control agents (PACs) can trap beavers.
To prevent beavers from chewing on individual trees, surround the trunk with 4-foot galvanized garden fencing (2" x 4" mesh), making sure the mesh is flush with the ground. For groups of trees, standard fencing works well. Beavers are poor climbers, rarely burrow under fences, and generally do not chew fencing unless it’s wrapped tightly around the tree.
Beavers and Disease
Caused by the flagellate protozoan Giardia lamblia, Giardiasis (sometimes called “ beaver fever”) is a common cause of gastroenteritis in humans. Humans and other mammals, including beavers, can carry the disease, which can be transmitted via contaminated water.
While beavers are occasionally blamed for waterborne outbreaks, studies show higher levels of the Giardia cysts in water near high-use human recreational areas. Most contamination cases in Massachusetts derive from human origin—such as washed-out septic systems, untreated human sewage discharged into waterways, cabin toilets, and contaminated feces from campers and backpackers in rivers and streams.
Resources to Learn More
Beaver Solutions, Southampton, MA 413-527-6472
MSPCA, Boston, 617-522-7400