Appendix VII: Sediment Control

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Background

In addition to the natural sediment control function that vegetated buffer strips provide, a number of sediment control best practices and devices are commonly used to reduce sedimentation and erosion associated with construction in and around watercourses.

Objectives

Sediment control best practices will help to meet the standards of the Water Act with respect to water quality and protection of instream species and habitat.

Operational or Construction-related Best Practices

To ensure your works meet the requirements of applicable legislation:

Sediment Control

• Ensure fill or other materials used for this project on areas adjacent to the stream are inert, free of contaminants and will be placed so that they will not gain entry into the watercourse.
   
• Ensure material, such as rock, riprap, or other materials that are to be placed on the banks or within the active channel or floodplain of the watercourse are inert and free of silt, overburden, debris or other substances deleterious to aquatic life.
   
• Ensure machinery works from the bank of the stream and not in the stream channel to minimize impacts and to better enable mitigation of sedimentation.
   
• Place sediment control measures before starting any works which may result in sediment mobilization.
   
• Construct any ditches, water bars or water diversions within the work area so they do not directly discharge sediment-laden surface flows to the stream. Divert such flows to a vegetated area where flows can slowly infiltrate.
   
• Minimize the disturbance to existing vegetation on and adjacent to the stream banks.
   
• Remove excavated material and debris from the site or place it in a stable area above the high water mark or active floodplain of the stream, as far as possible from the channel.
   
• Protect this material from erosion and reintroduction to the watercourse by using mitigating measures including, but not limited to covering the material with erosion blankets or seeding/planting with native vegetation.
   
• When material is moved off-site, dispose of it in such a manner as to prevent its entry into any watercourse, floodplain, ravine, or storm sewer system.

In addition to these best practices, each project should have in place a written contingency plan to deal with sediment control during instream projects in the event there is:

• An increase in stream flow due to increased precipitation, or
• An increase in local overland runoff, or
• Saturation of the work area

Suggested Methods or Techniques for Sediment Control

Information on various sediment control techniques and their applicability to your project can be found in many documents, including the following documents and websites:

Land Development Guidelines for the Protection of Aquatic Habitat, Barry Chilibeck et al, 1992.
http://www-heb.pac.dfo-mpo.gc.ca/
publications/pdf/guidelines/ldg_e.pdf

Water Quality Best Management Practices
http://www.env.gov.bc.ca/wat/wq/
NPS_web_page/BMP_Compendium/
BMP_Introduction/BMP_Home.htm

Appendix VI: Salvage of Fish and/or Wildlife | Appendix VIII: Vegetation Management

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