Routine Maintenance Dredging

Routine maintenance dredging refers to the removal of accumulated sediment from channel beds to maintain the design depths of existing public use facilities such as navigation channels, harbours, marinas, boat launches, port facilities, and permanent (fixed) water intakes. It does not include clean-out of channels for other purposes, such as agricultural drains or water intake installation. Routine maintenance dredging is conducted regularly (e.g., at least once every five years) and does not include any expansion of the previously dredged area. Dredging is typically conducted by mechanical methods such as clam buckets, draglines or backhoes. The greatest threats to fish habitat are from the increased amount of suspended sediments introduced to the water column during the dredging process, and the direct removal of aquatic vegetation and other habitat features in near-shore areas.

Fisheries and Oceans Canada (DFO) is responsible for protecting fish and fish habitat across Canada. Under the Fisheries Act no one may carry out a work or undertaking that will cause the harmful alteration, disruption or destruction (HADD) of fish habitat unless it has been authorized by DFO. By following the conditions and measures set out below you will be in compliance with subsection 35(1) of the Fisheries Act.

The purpose of this Operational Statement is to describe the conditions under which it is applicable to your project and the measures to incorporate into your project in order to avoid negative impacts to fish habitat. You may proceed with your routine maintenance dredging project without a DFO review when you meet the following conditions:

• if working within the Thames River, Sydenham River, Ausable River, Grand River, or Maitland River, you have contacted your Conservation Authority or local DFO Office (see Ontario DFO office list) to ensure that your project will not impact Schedule 1 mussel species at risk under the federal Species at Risk Act, before proceeding,
• the maintenance dredging is only for navigational purposes or permanent (fixed) water intakes,
• the site has been previously dredged (at least once within the previous five years), is in accordance with the results of a previous government review and no expansion of the dredged area occurs,
• the dredged material will not be used to infill the shoreline or adjacent wetlands, and
• you incorporate the Measures to Protect Fish and Fish Habitat when doing Routine Maintenance Dredging listed below in this Operational Statement.

If you cannot meet all of the conditions listed above and cannot incorporate all of the measures listed below then your project may result in a violation of subsection 35(1) of the Fisheries Act and you could be subject to enforcement action. In this case, you should contact your Conservation Authority, or the DFO office in your area (see Ontario DFO office list) or Parks Canada if the project is located within its jurisdiction, including the Trent-Severn Waterway and the Rideau Canal, if you wish to obtain an opinion on the possible options you should consider to avoid contravention of the Fisheries Act.

You are required to respect all municipal, provincial or federal legislation that applies to the work being carried out in relation to this Operational Statement. The activities undertaken in this Operational Statement must also comply with the Species at Risk Act (www.sararegistry.gc.ca). If you have questions regarding this Operational Statement, please contact one of the agencies listed above.

We ask that you notify DFO, preferably 10 working days before starting your work by filling out and sending the Ontario Operational Statement notification form (http://www.dfo-mpo.ca/regions/central/habitat/os-eo/provinces-territories-territoires/on/os-eo20-eng.htm) to the DFO office in your area. This information is requested in order to evaluate the effectiveness of the work carried out in relation to this Operational Statement.

Measures to Protect Fish and Fish Habitat when doing Routine Maintenance Dredging

1. Use existing trails, roads or cut lines wherever possible as access routes to avoid disturbance to the riparian vegetation.
2. Minimize the riparian area temporarily disturbed by access activities along the adjacent upland property, and preserve trees, shrubs and grasses near the shoreline.
3. Time routine maintenance dredging to prevent disruption to sensitive fish life stages by adhering to appropriate fisheries timing windows (see the Ontario In-Water Construction Timing Windows). Where possible, dredging should occur under winter conditions where the area to be dredged is frozen to the bottom or when the area to be dredged is dry.
4. Install effective sediment control measures around the perimeter of the work area before starting work and during dredging to prevent re-suspended sediment from spreading to adjacent areas. Inspect these measures regularly and make all necessary repairs if any damage occurs. Remove these control measures in a way that prevents the escape or re-suspension of sediments.
   • 4.1. Dredge on calm days to minimize the suspension of fine sediment particles into the water column and ensure the sediment control measures are not disturbed by wave action.
5. Minimize the amount of dredged material removed by only dredging the area and depth required for navigation or effective water intake functioning, in order to maintain as much nearshore aquatic vegetation and as many habitat features as possible.
6. Remove all dredged material to a location outside of the ordinary high water mark (see definition below) of any water body. Any dredged material that is disposed of on land should meet Conservation Authority requirements where they have jurisdiction.
7. Contaminated dredged material should be disposed of according to Ontario Ministry of Environment guidelines. It is the proponent’s responsibility to determine if the dredged material is contaminated.
8. Uncontaminated dredged material may be side-cast where the dredged material is similar to the recipient area, the final deposited profile does not impede navigation, and the dredged material is not fine silt, clay or muck (which should be disposed of on land).
9. Operate machinery on land or on water (i.e., from a barge or vessel) in a manner that minimizes disturbance to the banks or bed of the water body.
   • 9.1. Machinery is to arrive on site in a clean condition and is to be maintained free of fluid leaks.
   • 9.2. Wash, refuel and service machinery and store fuel and other materials for the machinery away from the water to prevent any deleterious substance from entering the water.
   • 9.3. Keep an emergency spill kit on site in case of fluid leaks or spills from machinery.
   • 9.4. Restore banks to original condition if any disturbance occurs.
10. Stabilize any waste materials removed from the work site to prevent them from entering the water body. This could include covering spoil piles with biodegradable mats or tarps or planting them with grass or shrubs.
11. Vegetate any disturbed areas by planting and seeding preferably with native trees, shrubs or grasses and cover such areas with mulch to prevent erosion and to help seeds germinate. If there is insufficient time remaining in the growing season, the site should be stabilized (e.g., cover exposed areas with erosion control blankets to keep the soil in place and prevent erosion) and vegetated the following spring.
    • 11.1. Maintain effective sediment and erosion control measures until re-vegetation of disturbed areas is achieved.

Definition:

Ordinary high water mark (HWM) – The usual or average level to which a body of water rises at its highest point and remains for sufficient time so as to change the characteristics of the land. In flowing waters (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 (Full Supply Level).

For the Great Lakes this refers to the 80th percentile elevation above chart datum as described in DFO’s Fish Habitat and Determining the High Water Mark on Lakes.

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