Interim code of practice: culvert maintenance
1 About this code of practice
This code of practice outlines national best practices for culvert maintenance. Culvert maintenance is undertaken to extend the life of the structure and to ensure that it functions as designed (this includes baffled culverts). For the purpose of this code, culvert maintenance includes the manual or mechanical removal of accumulated debris (e.g. logs, sediment, boulders, garbage, ice build-up) that prevents the efficient passage of water and fish through the structure. Culvert maintenance may also include the reinforcement of eroding inlets and outlets but does not include the replacement of damaged or destroyed bevel ends.
This code of practice provides useful information on the measures to follow to ensure that fish and fish habitat are protected. This code applies to routine culvert maintenance only and does not apply to culvert replacement or extension, installation of liners, trash rack installation or beaver dam removal.
Some potential impacts to fish and fish habitat from culvert maintenance could include but are not limited to: the sedimentation of aquatic habitat; changes in food supply; changes in flow regime and fish passage; changes to the riparian zone; and the accumulation of deleterious substances.
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, or other federal, provincial, or municipal legislation and policies.
2 You can use the 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 our aquatic species at risk maps to determine where at-risk populations occur in Canada and where their critical habitat is located.
- The work does not include realigning the watercourse, installing a culvert liner or support struts, replacing damaged or destroyed bevel ends or extending/replacing the existing culvert.
- The work does not include any dredging, infilling, (e.g., filling scour pools) or excavation of the channel upstream or downstream of the culvert.
- There is no use of explosives.
- There is no temporary or permanent increase in the existing footprint below the ordinary high water mark (see definition below).
- 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 Measures to protect fish and fish habitat
3.1 Protection of fish
- Plan in water works, undertakings or activities to respect timing windows to protect fish and fish habitat.
- Conduct in-water works, undertakings and activities during periods of low flow.
- 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).
- Employ fish exclusion netting (up and downstream) to isolate the work site if fish are observed in the vicinity of the works, undertakings and activities.
- Maintain an appropriate depth and flow (i.e. base flow and seasonal flow of water) for the protection of fish.
3.2 Protection of fish passage
- Maintain fish passage during the works, undertakings and activities.
- Avoid changing flow or water level.
- Avoid obstructing and interfering with the movement and migration of fish.
3.3 Protection of the riparian zone
- Limit access to shorelines and banks or areas adjacent to water bodies.
- Prune or top the vegetation instead of grubbing/uprooting.
- Limit grubbing on watercourse banks to the area required for the footprint of works, undertakings and activities.
- Construct roads, access points and approaches perpendicular to the watercourse or water body.
- Remove vegetation or species selectively and in phases.
- Re-vegetate the disturbed areas with native species suitable for the site.
- Restore the stream banks and riparian vegetation affected by the works, undertakings and activities to their natural state (substrate granularity, profile, vegetation, etc.).
3.4 Protection of fish habitat from sedimentation
- Use only clean materials (e.g., rock, coarse gravel, wood, steal, snow) for works, undertakings and activities.
- Install effective erosion and sediment control measures prior to beginning works, undertakings and activities in order to stabilize all erodible and exposed areas.
- Develop and implement an erosion and sediment control plan to avoid 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.
- 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.
- Keep the erosion and sediment control measures in place until all disturbed ground has been permanently stabilized.
- Remove all sediment control materials once site has been stabilized.
- Dispose of, and stabilize, all excavated material above the ordinary high water mark or top of bank of nearby waterbodies and ensure sediment re-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 to prevent entry into the water body.
3.6 Additional measures for culvert maintenance
- Limit the removal of accumulated material and debris (e.g., branches, stumps, other woody materials, garbage, etc.) to the area within the culvert and immediately upstream and downstream of the culvert.
- Remove accumulated materials and debris slowly to allow clean water to pass, to prevent downstream flooding and to reduce the amount of sediment-laden water going downstream.
- If maintenance activities reduce the water level within the culvert, take appropriate measures to restore previous streambed elevation/conditions.
- If replacement rock reinforcement/armouring is required to stabilize eroding inlets and outlets, the following measures should be implemented:
- Place appropriately-sized, clean rocks into the eroding area.
- Do not obtain rocks from below the ordinary high water mark of any water body.
- Ensure that acid generating rock is not used.
- Avoid the use of rock that fractures and breaks down quickly when exposed to the elements.
- Install rock at a similar slope to maintain a uniform stream bank and natural stream alignment.
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.
You must download and save this PDF form to your computer before filling it out.
How to download and open a PDF form
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 Contact us
If you have questions regarding this code of practice contact the Fish and Fish Habitat Protection Program located in your region.
- 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.
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