How to Tackle Conflicts Caused by Beaver Dams
Beavers build dams to create a sufficient depth of water to protect themselves from predators but this can cause localised flooding problems and other problems, such as potentially preventing fish migration. If you need to manage a beaver, seek professional advice from the relevant regulatory authority as the work needs to be carried out without causing pollution while also considering animal welfare and, potentially, fish passage depending on the site.
Management Methods for Resolving Damming Conflicts
Dam Notching / Removal
- In some cases it may be necessary to manage or even remove a dam.
- Dam notching is the partial removal of a small section of the middle of a beaver dam, usually by hand, to increase water flow over that section, with the aim of reducing the water level behind the dam to reach a compromise level.
- Breaching a dam will immediately reduce water levels but one-off management such as causing a breach may be ineffective as beavers can repair breaches within a matter of hours if they are determined.
- Similarly dam removal may simply result in the dam being re-built by beavers within 24 to 48 hours in active beaver territories.
- Some dams are more important to beavers than others. These are likely to require more persistent management. Frequent monitoring and management is required for dam notching and removal to achieve their desired outcomes.
Flow Devices
- In some specific circumstances, where other options including making space in the riparian zone, are not feasible, a flow device is a potential, semi-permanent solution to a beaver damming conflict that involves reducing the water level behind the dam to a compromise level.
- This involves inserting artificial piping through the dam. The device’s inflow pipe is submerged away from the dam and protected from blockage with a wire-mesh cage. Submergence masks the sound and feel of water leaving the pond from the beavers.
- The outflow pipe installed in the dam allows water to pass through it, lowering the water level enough to prevent flooding of the land around it while preserving the beavers wetland habitat.
- A permit is always required for flow devices. Fish passage will need to be considered. Flow devices should not be installed where salmonid passage is required.
- Flow devices will not be effective in all landscapes as beavers can build new dams further along the watercourse
Culvert Protector
- A culvert protector prevents culverts becoming blocked by beaver activity.
- This involves building a fence out of fence posts and wire-mesh around the culvert in order to prevent beavers from accessing and damming it.
- Where it is desired that beavers and other animals need to use the culvert for passage, a T-pipe can be mounted within the fence that allows animals and beavers to pass through whilst preventing them from carrying sticks and other materials in.
- In areas where the water level fluctuates substantially, a roof can be fitted to the culvert protector to prevent beavers bypassing the fencing during periods of high water flow.
- A permit is always required for culvert protectors and fish passage will need to be considered.
Tips and Additional Considerations
- Beaver dams are a legally protected feature and removing an established dam (over 2 weeks old) requires a licence in England and Scotland. See the licensing information below.
- Dams should be left in place if possible prior to exploring some of the above options.
- Interfering with dams can increase tree felling. It is therefore worth considering whether any important trees nearby require protection.
- The purpose for which the beaver built the dam (natal or forage access) will influence the level of beaver motivation to re-dam.
- Seek professional advice before undertaking dam mitigation and consult national regulations especially regarding species protection and obstacles in the water course.
Licensing in Each Country
In Scotland
As of 1st May 2019 beavers are recognised as a European Protected Species in Scotland.
Removing, notching or installing a flow device in a beaver dam < 2 weeks old does not require a licence but removing notching or installing a flow device in a beaver dam > 2 weeks old does require a licence under the current management framework.
If you own or manage land that is affected by beaver damming visit NatureScot’s website.
In England
As of 1st October 2022 beavers are recognised as a European Protected Species in England.
Removing, notching or installing a flow device in a beaver dam < 2 weeks old does not require a licence but removing notching or installing a flow device in a beaver dam > 2 weeks old does require a licence under the current management framework.
If you own or manage land that is affected by beaver damming, visit the Government’s website.
In Wales
Beavers are not currently a protected species in Wales.
If you own or manage land that is affected by beaver damming contact the Welsh Beaver Project for support on beaver.afanc@
Other Management Techniques
Mitigate Beaver Impacts
Choose from a range of well-established mitigation and management techniques
