Erosion and Sediment Control

Follow these standard best management practices that apply to all roadwork projects.

• Do phased construction, only clearing areas necessary for immediate construction and stabilizing small parcels before moving to the next phase.
• Maintain all naturally occurring native vegetation where possible.
• Minimize soil disturbance.
• Minimize how long soil is exposed.

• Install adequate erosion and sediment controls before starting work. 
• Properly install and maintain sediment fencing around the perimeter of the work area, stockpiles/soil areas, sensitive habitats, and downslope of disturbed areas.
• Maintain erosion and sediment control measures so they are effective, functioning, and stable the entire time they are in place.
• Maintain erosion and sediment controls during all phases of work, until the area is permanently stabilized and/or successfully re-vegetated.
• For in-water work, site isolation measures should be installed prior to in-water work and remain effective at all times.
• For in-water work that does not require working in the dry, a turbidity curtain can be used and maintained to isolate the work area.

• If using erosion and sediment control fencing for wildlife exclusion, install it before the species' critical activity periods (e.g., nesting) to prevent access (see Temporary Wildlife Exclusion Fencing BMP).
• n sites where there are amphibians and reptiles, ensure sediment fencing is installed following proper wildlife safe design considerations (see Temporary Wildlife Exclusion Fencing BMP).
• Use wildlife-safe materials and avoid netting that could trap small animals.
• Use coir or biodegradable materials instead of plastic mesh products.

• It’s best to inspect erosion and sediment control measures daily prior to starting work for the day.
• At a minimum, inspect erosion and sediment control measures at least once a week, as well as before any forecasted rain and immediately following any rain or extreme weather event.
• Reinforce or replace damaged controls immediately.

Monitor weather events and time activities accordingly. Only work in dry weather conditions. Stop work during periods of heavy rainfall.

• Stockpile uncontaminated topsoil from the worksite within the work area and later redistribute the topsoil as a base for seeding and planting, which maintains the local seed bank.
• Ensure the work site is revegetated following work. Mulch, seed, and stabilize exposed soils immediately after disturbance.
• Immediately following work activities beside waterbodies, stabilize waterbody banks and riparian habitat that have been disturbed. Restore them to their original condition as soon as possible.
• When permanent bank stabilization is necessary, use natural materials like native stone, vegetation, and woody materials for bank stabilization. Avoid hard engineering like stone block walls, gabions, or rock rip-rap.
• Stabilize high risk areas and areas with bare soil that will be inactive for 30 days or longer. Key
• areas to apply erosion controls are:
• • Slopes
  • Stockpiles
  • Runoff conveyance channels
  • Areas downstream of water outlets
  • Banks of detention ponds and sediment traps
  • Lay down areas for sediment bags
  • Areas where runoff flows directly to sensitive habitats
• If it’s near the end of the growing season, stabilize the site, for example, with erosion control blankets, to protect the soil over winter, then plant vegetation the following spring.

• Avoid working on slopes or in erosion-prone areas.
• On steep slopes or embankments, apply erosion control blankets or mats to help reduce erosion.
• On slopes with exposed soil, use surface roughening techniques to reduce water runoff velocity.
• Stabilize slopes up to a 3:1 gradient by applying seed and covering it 0.3 to 0.6 cm deep, or leaving a minimum of 5 cm of native topsoil with an intact natural seed bank, then mulching with straw, hydromulch, or straw/coconut fiber mats.
• Stabilize slopes steeper than 3:1 by using seed and biodegradable erosion control blankets or a flexible growth medium.

• For construction or maintenance activities that disturb soil near ditches, slopes, culverts, or drainage pathways, especially when working near watercourses or in areas with sensitive habitats, consider techniques to reduce the velocity of flowing water such as check dams or filter socks.
• In areas where runoff may flow toward watercourses, direct drainage from work areas through vegetated filter strips to slow flow, trap sediment, and reduce contaminants before water enters streams or wetlands.
• When working near waterbodies or in areas with surface flow, divert clean water around the work area to prevent it from mixing with disturbed soils or contaminants.
• When necessary, install temporary diversion channels to direct runoff around areas with exposed soil or substrate. Design swales with sufficient capacity to handle peak stormwater flows. Line swales with geotextiles or riprap if necessary to prevent erosion.

• Remove sediment accumulated behind silt fencing when it reaches half the height of the fencing, or 300mm, whichever is less. Ensure accumulated sediment is removed before removing the silt fencing.
• All accumulated debris, vegetation, or logs that are removed from the site are temporarily stored and stabilized a minimum of 30 metres away from watercourses above the highwater mark. 
• Excess material that poses a risk of contamination should be disposed of off-site. Clean surplus material should be disposed of at designated sites away from sensitive habitats and a minimum of 30 metres from waterbodies.
• If the work activity requires stock piles or other materials on the work site, ensure the stockpiles aren’t eroding and that sediment is contained. This may require installing and maintaining sediment fencing around the perimeter of the stockpile or work area.

Use erosion control materials that are clean and free of invasive species or deleterious substances.

• When permanent erosion control is necessary, combine hard and soft stabilization techniques by using rock and vegetation to stabilize shorelines while maintaining natural habitat features.
• If rock rip-rap reinforcement is necessary:
• • use clean rock, sized and placed appropriately.
  • install rock at a similar slope as the original stream bank to maintain a uniform stream bank and natural alignment
  • do not use acid generating rock where it does not already exist
  • do not obtain rock from below the ordinary high water mark
  • ensure rip-rap does not interfere with fish passage or constrict the channel width
  • use nonwoven geotextile underneath the rip-rap to separate exposed soil from rip-rap.