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Interim code of practice: municipal and agricultural drain maintenance

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1.0 About this code of practice

This code of practice outlines Fisheries and Oceans Canada's (DFO) national best practices for municipal and agricultural drain maintenance, and applies only to drains with intermittent flow. Intermittent drains flow only for a short period of time in spring or during wet weather and are dry for the remainder of the year.

Municipal and agricultural drain maintenance is required to restore drains to their original design grade, to ensure proper drainage during intermittent flow (for example, drainage for agricultural fields and municipal storm drains). Maintenance activities can include:

When municipal and agricultural drains with intermittent flow are dry or frozen, these activities can be completed at any time of year. When these drains contain water, the activities must adhere to timing windows.


  1. Follow codes of practice for culvert maintenance, bridge repair and maintenance, beaver dam breaching and removal, and clear span bridges if these activities are required for your project.
  2. For the purposes of this code of practice, the words “water body” and “watercourse”, are meant to describe municipal and agricultural drains.

You can protect fish and fish habitat when proceeding with municipal and agricultural drain maintenance by following the measures listed below. When implemented correctly, these measures can manage the risk of harmful impacts associated with municipal and agricultural drain maintenance, which can include:

The purpose of this code of practice is to describe the conditions under which the code can be applied to your project and the measures you are required to implement in order to prevent harmful impacts to fish and fish habitat and avoid contravention of the Fisheries Act and the Species at Risk Act. If you cannot meet all of the conditions and implement all of the applicable measures listed below, your project may result in a violation of the Fisheries Act and the Species at Risk Act and you could be subject to enforcement action.

DFO is responsible for the conservation and protection of fish and fish habitat across Canada. Under the Fisheries Act, no one may carry out works, undertakings and activities in or near water that result in the harmful alteration, disruption or destruction (HADD) of fish habitat, or the death of fish, unless it has been authorized by DFO, and prohibitions in the Aquatic Invasive Species Regulations must be followed unless authorized under federal or provincial law. DFO’s approval under the Species at Risk Act is also required if an activity affects an aquatic species at risk, any part of its critical habitat or the residences of its individuals.

If you are uncertain about whether this code of practice is applicable to your project, it is recommended that you consult our website or a qualified environmental professional to determine if other codes of practice should also be implemented, or if further review by DFO may be necessary. For any remaining questions, please contact the Fish and Fish Habitat Protection Program office located in your area. It remains your responsibility to comply with the Fisheries Act and the Species at Risk Act.

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/harmful alteration, disruption or destruction of fish habitat. Such notifications should be directed to the Fish and Fish Habitat Protection Program office located in your area.

This code of practice does not remove nor replace the obligation to comply with the requirements of any other federal, territorial, provincial or municipal regulatory agency including guidance regarding species and habitats managed by these jurisdictions.

It is good practice to notify nearby Indigenous communities before starting the project.

A project review by DFO is not required when the project activities meet the description in section 1 and the conditions in section 2, and when the measures to protect fish and fish habitat set out in section 3 of this code of practice are applied. Request a project review if your project does not meet all of these requirements.

2.0 Conditions

The following conditions describe when this code of practice can be applied:

As a condition of this code of practice, please submit a notification form to your regional DFO office 10 working days before starting work. Notification forms will inform the continuous improvement of the codes of practice over time.

To fill out a PDF form, you must:

  1. download it to your computer
  2. use PDF software to open it (such as, Adobe Reader or Foxit PDF)

For more information: How to download and open a PDF form

3.0 Measures to protect fish and fish habitat

3.1 Protection of fish

3.2 Protection of the riparian zone

3.3 Protection of aquatic habitat

3.4 Protection of fish and fish habitat from sediment

3.5 Protection of fish and fish habitat from other deleterious substances

3.5.1 Develop a prevention plan

3.5.2 Implement a response plan

4.0 Glossary

Affected area
The area within which all of the proposed project impacts are likely to occur either directly (i.e., project footprint) or indirectly (i.e., downstream or other surrounding areas).
Aquatic invasive species
Aquatic invasive species are fish, invertebrate or plant species that have been introduced into a new aquatic environment, outside of their natural range. See more information on Aquatic invasive species.
Aquatic species at risk
Any aquatic species listed under Schedule 1 of the Species at Risk Act as endangered, threatened, or extirpated.
Bottom cleanout
Consists of removing accumulated sediment from a drain, spreading the spoil on adjacent fields and, removing vegetation from the bottom of the channel only.
The removal of vegetation along the slope of the bank. Brushing the bank slope does not disturb soil or remove the roots of any trees or shrubs.
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. For example: fuel, lubricants, paint, primers, rust, solvents, degreasers, antifreeze, uncured concrete, creosote, chlorinated water, herbicides, debris, Styrofoam, sand blasting abrasives, etc.
Full cleanout
Consists of removing accumulated sediment from a drain, spreading the spoils on adjacent fields, and removing vegetation from the bottom of the channel, the slopes of both banks, including root removal. Can also include the removal of trees and other vegetation from the top of a bank (as required).
Harmful alteration, disruption or destruction (HADD)
Any temporary or permanent change to fish habitat that directly or indirectly impairs the habitat’s capacity to support 1 or more life processes of fish.
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).
Qualified Environmental Professional (QEP)
A person who is experienced in identifying and assessing potential impacts to fish and fish habitat generated from various works, undertakings or activities conducted in or near water, and implementing management measures to avoid and mitigate them. QEPs possess a post-secondary degree or diploma in biological, geophysical or environmental sciences and are often referred to as:
  • aquatic biologist
  • fisheries biologist
  • fluvial geomorphologist
  • applied scientist
  • fisheries technician
  • environmental consultant
  • natural resource consultant
Riparian vegetation
Occurs adjacent to the watercourse and directly contributes to fish habitat by providing shade, cover and areas for spawning and food production.
Riparian zone
Area located between a water body's ordinary high water mark and upland area.
Spot cleanout
Cleanout of isolated areas of sediment build-up that is significant enough to cause erosion or flow blockage/flooding concerns in the channel. This may include a sediment trap (dug below design grade) cleanout.
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