Erosion Prevention
Reducing Erosion:
A Quick Guide to Common Best Management Practices (BMPs)
To keep soil on-site and protect our waterways, it is essential to implement Soil Erosion and Sedimentation Control (SESC) strategies using Best Management Practices (BMPs).
The Core Principles of SESC
Before selecting specific controls, keep these fundamental strategies in mind:
❋ Minimize Disturbance
Expose the smallest area of soil for the shortest possible time.
❋ Shield the Soil
Protect bare ground with live vegetation, mulch, or erosion-resistant materials as quickly as possible.
❋ Manage Water Flow
Avoid concentrated runoff, or reduce its speed to non-erosive velocities.
❋ Trap Sediment
Use barriers and basins to capture sediment before it leaves the site.
❋ Inspect & Maintain
Regularly check all controls to ensure they are working and not overwhelmed by sediment.
Top BMPs for Erosion & Sediment Control
1. Vegetative & Soil Covers (Stabilization)
Seeding & Mulching: Seeding binds soil particles together with a dense root system and increases water infiltration. Because seeds need time to grow, mulch or straw is applied over the top to protect the soil from raindrop impact, hold in moisture, and prevent wind erosion while the seeds germinate.
Rolled Erosion Control Products (RECPs): These are temporary, degradable blankets (often made of straw, coir, or wood fiber) that are unrolled and staked over bare ground. They provide immediate erosion protection and help establish vegetation, making them ideal for steep slopes and channels.
2. Perimeter & Runoff Barriers (Trapping)
Silt Fence: A porous geotextile fabric attached to wooden posts, designed to intercept and pool sheet-flow runoff so that suspended sediment settles out before the water leaves the site. A silt fence is only effective if properly installed: it must be placed along an elevation contour and the bottom flap must be trenched at least 6 inches into the ground.
Check Dams: Small, temporary or permanent dams made of rock, stone-filled bags, or fabricated logs placed across ditches and drainage channels. They do not stop water; rather, they slow the water's velocity to prevent channel erosion and allow sediment to drop out of the flow.
3. Structural Runoff Protections
Riprap: Clean, angular stone placed over a geotextile fabric on steep slopes, drain banks, or culvert outlets. Riprap absorbs the energy of concentrated water flows, preventing scouring and lateral bank cutting.
Storm Drain Inlet Protection: Specialized filters or fabric drop-sacks placed around or inside storm sewer catch basins. These protect underground stormwater networks by filtering sediment out of runoff before it enters the drain.
4. In-Water Protections
Turbidity Curtains: When work must be performed directly in or next to a lake or stream (like seawall construction), a turbidity curtain is used. This is a flexible, floating barrier anchored in the water to isolate the work area and prevent suspended silt and sediment from spreading into the broader water body.
Pro Tips for Site Success
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Maintaining a natural, undisturbed vegetative buffer between your work area and nearby water bodies provides an excellent natural filter in case other measures fail.
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On large sites, stage excavation and construction to limit the amount of bare soil exposed at any single time.
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Silt fences and catch basin covers cannot handle massive, unmanaged storm surges or freezing weather on their own.
Always ensure proper drainage and maintain your BMPs immediately after major rain events.