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 threat to fish habitat is from the increased amount of suspended sediments introduced to the water column during the dredging process.

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:

• your planned work is not located in a critical area, as identified in a NWT Community Conservation Plan, or other applicable land use plan,
• 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,
• dredging of contaminated sediments does not occur,
• hydraulic methods such as propeller washing are not used (suction dredging is acceptable),
• the dredged material will not be used to infill the shoreline or adjacent wetlands,
• this Operational Statement is posted at the work site and is readily available for reference by workers, 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 the DFO office in your area if you wish to obtain DFO’s opinion on the possible options you should consider to avoid contravention of the Fisheries Act.

You are required to respect all local, municipal, territorial 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 the DFO office in your area (see Northwest Territories DFO office list).

We ask that you notify DFO, preferably 10 working days before starting your work by filling out and sending the Northwest Territories Operational Statement notification form (http://www.dfo-mpo.ca/regions/central/habitat/os-eo/provinces-territories-territoires/nt/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 Northwest Territories
   In-Water Construction Timing Windows). Routine maintenance dredging may also occur without further DFO review when the area to be dredged is frozen to the bottom or 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.
   • 5.1. Avoid bottom stockpiling or side casting during dredging.
6. 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.
   • 6.1. Machinery is to arrive on site in a clean condition and is to be maintained free of fluid leaks.
   • 6.2. 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.
   • 6.3. Keep an emergency spill kit on site in case of fluid leaks or spills from machinery.
   • 6.4. Restore banks to original condition if any disturbance occurs.
7. 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 stockpiles with grass or shrubs.
8. 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. If re-vegetation is not possible due to climatic extremes and/or lack of appropriate seed or stock, the site should be stabilized using effective sediment and erosion control measures. In areas with permafrost, care should be exercised to ensure these measures do not cause thawing or frost heave.
   • 8.1. Maintain effective sediment and erosion control measures until re-vegetation of disturbed areas is achieved or until such areas have been permanently stabilized by other effective sediment and erosion control measures, in the event that re-vegetation is not possible.

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