How is a silt fence used on a New Brunswick site?

A silt fence is a temporary sediment control barrier installed on construction and landscaping sites to prevent disturbed soil from washing off-site into waterways, storm drains, or neighbouring properties. In New Brunswick, where heavy spring runoff, Maritime rainfall, and strict watercourse protection regulations apply, silt fencing is one of the most common and important erosion control tools you'll encounter on any grading or excavation project.

How It Works

A silt fence consists of a permeable geotextile fabric stretched between wooden or metal stakes, with the bottom edge buried 150-200mm (6-8") into the ground in a trench. When rain hits disturbed soil, it carries fine sediment particles in runoff. The fabric allows water to pass through slowly while trapping the suspended sediment on the uphill side. Over time, a small berm of captured sediment builds up against the fence — which is exactly what it's designed to do.

The buried toe is critical. Without it, water simply undercuts the fabric and carries sediment right underneath. This is one of the most common installation failures on NB sites.

Where It's Installed on a NB Site

Silt fences are placed downslope of any disturbed area — along the perimeter of a grading project, at the base of a slope, around stockpiled topsoil, or along the edge of a property near a ditch or watercourse. In New Brunswick, the Watercourse and Wetland Alteration Regulation requires that work near watercourses protect water quality, and silt fencing is a standard compliance measure inspectors expect to see. If your project is within 30 metres of a watercourse, wetland, or drainage ditch, sediment control isn't optional — it's a legal requirement.

For larger NB sites — new home construction, major regrading, commercial landscaping — you may also see silt fencing combined with other Best Management Practices (BMPs) like rock check dams, sediment basins, or erosion control blankets on steep slopes.

Practical Installation Tips

The fence must follow the contour of the slope, not run straight up and down it. Running it up-and-down a slope turns it into a channel and concentrates flow, defeating the purpose entirely. On longer runs, "J-hooks" (turning the ends of the fence uphill) prevent water from flowing around the ends. Stakes are typically spaced 1.5-2 metres apart, closer on steeper ground.

Silt fences require regular inspection and maintenance — especially after NB's heavy spring rains or any significant rainfall event. Once sediment builds up to about one-third the height of the fence, it needs to be removed or the fence replaced. A collapsed or overloaded silt fence provides almost no protection.

DIY vs. Hiring a Pro

For small residential projects — a garden bed regrading, a new patio excavation — a homeowner can install silt fencing themselves. Materials run roughly $1.50-$3.00 per linear foot at local suppliers. For larger grading projects, new construction, or anything near a watercourse, have a landscaper or site contractor handle the full erosion control plan. Improper sediment control near NB waterways can result in stop-work orders and remediation costs that far exceed the price of doing it right the first time.

If you're planning a grading or landscaping project that involves significant soil disturbance, New Brunswick Landscaping can match you with a local landscaper familiar with NB's erosion control requirements — free of charge.