6. DREDGING INCLUDING THE REMOVAL OR RELOCATION OF LOGS, STUMPS OR ROCKS
Dredging is the removal, relocation or dislodging by digging, gathering or pulling out or otherwise, or to alter any natural or other material or object for the purpose of the following activities: commercial harvesting, creating new channels or boat slips, altering the shoreline, constructing or placing any in-water structures such as wharves or retaining walls or maintaining previously dredged areas or openings to any dredged area on private land.
The potential impacts are:
- Loss of aquatic habitat for a wide variety of aquatic organisms;
- Disturbance or destruction of cultural resources;
- Destruction of fish and fish spawn;
- Turbidity and re-suspension of sediments from the bed;
- Alteration of water circulation and exchange;
- Deposition of sediment in nearby waters.
Since dredging is highly disruptive, Parks Canada generally discourages dredging applications.
- Sunken logs, stumps and rocks may not be removed from the water. In some circumstances they may be relocated in front of the property in an area of similar water depths.
- Dredging will not be allowed if cultural resources will be destroyed.
- Dredging will not be allowed in wetlands or in areas containing rock rubble on the lake or river bed, unless shown to be environmentally beneficial.
- The size and depth of the area proposed for dredging should be minimized. No more than 25% of the shoreline length to a maximum of 15 m (50 ft.) may be dredged in front of residential property.
- A single boat channel dredged through a shallow area to deeper water may be no wider than 6 m (20 ft.); dredging of communal boat channels shared among adjacent property owners may not exceed 8 m (26 ft.) in width.
- Proponents for dredging will be required to undertake an environmental assessment to demonstrate that there will be no significant adverse environmental impacts or impacts to cultural resources; fish spawning and nursery areas must be avoided.
- Dredged material must be tested for contaminants, placed upland at least 15 m from a watercourse and above the flood plain, or in accordance with the requirements of another agency, whichever is greater, and must be stabilized to prevent the dredged material from re-entering the water.
- For open water dredging, a silt or turbidity curtain must be properly installed and maintained around the entire work area prior to the start of dredging and maintained in an effective condition.
- Vertical edges must be avoided and the final slopes of the dredged area must allow for the natural slope and stabilization of the bottom material.
- Nighttime dredging and dredging during the winter will require specific authorization.