Interim code of practice: beaver dam removal

1.0 About this code of practice

This code of practice outlines national best practices for the removal of beaver dams. Beaver dams need to be removed or breached periodically to protect, maintain or construct infrastructure or to avoid the flooding of private or public land. Dam removal is normally accomplished using hand tools, or mechanical equipment such as backhoes. Be aware that the removal of a beaver dam may not necessarily prevent future beaver activity in the area.

Potential impacts to fish and fish habitat from the removal of beaver dams could include, but are not limited to, direct damage to substrates, release of accumulated sediments, loss of riparian habitat and stranding of fish. It is therefore important to exercise caution when proceeding with dam removal due to the possibility of downstream flooding and damage and the re-entry of dam material into the water body.

This code of practice allows for the removal of a beaver dam which is impounding water that may cause imminent threat of damage to nearby infrastructure, or is obstructing fish passage.

A project review by DFO is not required when the conditions and measures set out in this code of practice and all applicable measures to protect fish and fish habitat are applied.

This code does not remove or replace the obligation to comply with all applicable statutory and regulatory requirements of the Fisheries Act, Species at Risk Act, or other federal, provincial, or municipal legislation and policies.

2.0 You can use this code of practice if

• There are no shellfish listed under the Species at Risk Act, or critical habitat or residences of endangered or threatened aquatic species present in the work zone or the vicinity of the works, undertakings and activities. Consult the aquatic species at risk maps to determine where at-risk populations occur in Canada and where their critical habitat is located.
• The removal activities are limited to removing or breaching the beaver dam itself and do not involve channel or shoreline modification straightening, ditching, etc..
• Explosives are not used to remove the dam.
• You follow the measures in this code of practice and all other applicable Measures to Protect Fish and Fish Habitat.

Request a project near water review when the works, undertakings and activities do not meet all of the criteria listed in this section.

3.0 Measures to protect fish and fish habitat

3.1 Protection of fish

• Plan in-water works, undertakings and activities to respect timing windows to protect fish and fish habitat.
  • Limit the duration of in-water works, undertakings and activities so that it does not diminish the ability of fish to carry out one or more of their life processes (e.g. , spawning, rearing, feeding, migrating).

3.2 Protection of the riparian zone

• Use existing trails, roads, access points or cut lines wherever possible.
• Avoid tree, shrub removal whenever possible.
• Use methods to prevent substrate compaction (e.g., swamp mats, pads).
• Avoid stockpiling of material on stream banks and in riparian zones.
• Do not grade streambanks or approaches.
• Limit access to shorelines and banks or areas adjacent to water bodies.
• Construct roads, access points and approaches perpendicular to the watercourse or water body.
• Prune or top the vegetation instead of grubbing/uprooting.
• Limit grubbing on watercourse banks to the area required for the footprint of the works, undertakings and activities.
• Remove vegetation species selectively and in phases.
• Re-vegetate the disturbed areas with native species suitable for the site.
• Restore stream banks and riparian vegetation affected by the works, undertakings and activities to their natural state (substrate granularity, profile, vegetation, etc.).

3.3 Protection of aquatic habitat

• Operate machinery in a manner that minimizes disturbance to the banks of the watercourse.
• Conduct in-water works, undertakings and activities during periods of low flow or at low tide.
• Maintain an appropriate depth and flow (i.e., base flow and seasonal flow of water) for the protection of fish habitat.
• Replace/restore any other disturbed habitat features and remediate any areas impacted by the works, undertakings and activities.

3.4 Protection of fish habitat from sedimentation

• Install effective erosion and sediment control measures prior to beginning works, undertakings and activities.
  • Develop and implement an erosion and sediment control plan to prevent the introduction of sediment into any water body during all phases of the works, undertakings and activities.
  • Schedule work to avoid wet, windy and rainy periods (and heed weather advisories) that may result in high flow volumes and/ or increase erosion and sedimentation.
  • Regularly inspect and maintain the erosion and sediment control measures and structures during all phases of the works, undertakings and activities.
  • Regularly monitor the watercourse for signs of sedimentation during all phases of the works, undertakings and activities and take corrective action if required.
  • Use biodegradable erosion and sediment control materials whenever possible.
  • Operate machinery on land in stable dry areas.
  • Keep the erosion and sediment control measures in place until all disturbed ground has been permanently stabilized.
  • Remove all sediment control materials once the site has been stabilized.
  • Dispose of and stabilize all excavated material above the ordinary high water mark or top of bank of nearby water bodies and ensure sediment entry to the watercourse is prevented.

3.5 Protection of fish and fish habitat from deleterious substances (including suspended sediment)

• Develop and immediately implement a response plan to prevent deleterious substances from entering a water body.
  • Stop works, undertakings and activities in the event of a spill of a deleterious substance.
  • Immediately report any spills (e.g., sewage, oil, fuel or other deleterious material), whether near or directly into a water body.
  • Keep an emergency spill kit on site during all phases of the works, undertakings and activities.
  • Contain any water with deleterious substances.
  • Ensure clean-up measures are suitably applied so as not to result in further alteration of the bed and/or banks of the watercourse.
  • Clean-up and appropriately dispose of water contaminated with deleterious substances.
  • Maintain all machinery on site in a clean condition and free of fluid leaks.
  • Wash, refuel and service machinery and store fuel and other materials for the machinery in such a way as to prevent any deleterious substances from entering the water.
  • Dispose of all waste materials (e.g., construction, demolition, commercial logging) above the ordinary high-water mark of nearby water bodies to prevent entry into the watercourse.

3.6 Additional measures for beaver dam removal

• Remove beavers prior to undertaking the removal of the beaver dam. Their removal must be undertaken in compliance with all relevant Acts and Regulations.
• When a series of dams is to be removed, this should be done from downstream to upstream in order to avoid severe flooding and damage to fish habitat.
• Removing a beaver dam by non-mechanical methods (by hand) is preferred over using industrial equipment.
• When dewatering beaver impoundments:
  • Remove the dam gradually to prevent sediment at the bottom of the pond from being released downstream.
  • Ensure the width of the breach opening of the beaver dam does not exceed the width of the original stream channel.
  • As the water levels drop in the upstream pond, increase the size of the opening to drain the pond to the desired water level.
  • The original watercourse bed and bank material and/or the beaver lodge(s) may not be removed or disturbed.
• Relocate any fish that become trapped in isolated pools or stranded in newly flooded areas to the main channel of the watercourse.
  • Relocate any fish as per applicable permits for capturing and relocating fish.

4.0 Notification

When making use of this code of practice, please submit a Notification Form (PDF, 50 KB) to your regional DFO office to help us improve this fish and fish habitat protection guidance over time.

It is your Duty to Notify DFO if you have caused, or are about to cause, the unauthorized death of fish by means other than fishing and/or the harmful alteration, disruption or destruction of fish habitat. Such notifications should be directed to the Fish and Fish Habitat Protection Program.

5.0 Contact us

If you have questions regarding this code of practice contact the Fish and Fish Habitat Protection Program located in your region.

6.0 Glossary

Deleterious substance

Any substance that, if added to any water, would degrade or alter or form part of a process of degradation or alteration of the quality of that water so that it is rendered or is likely to be rendered deleterious to fish or fish habitat or to the human use of fish that frequent that water.

Ordinary high-water mark

The usual or average level to which a body of water rises at its highest point and remains for sufficient time to change the characteristics of the land. In flowing waters (e.g., rivers, streams) this refers to the "active channel/bank-full level" which is often the 1:2 year flood flow return level. In inland lakes, wetlands or marine environments it refers to those parts of the water body, bed and banks that are frequently flooded by water so as to leave a mark on the land and where the natural vegetation changes from predominately aquatic vegetation to terrestrial vegetation (excepting water tolerant species). For reservoirs this refers to normal high operating levels (i.e. full supply level).

Riparian zone

Area adjacent to streams, lakes, and wetlands that support a unique mixture of water tolerant vegetation from trees and shrubs to aquatic and herbaceous plants.