What is it?

Sediment barriers are used primarily as temporary structures to slow stormwater runoff into streams, filter sediment, and promote stormwater infiltration. Barriers are used in agriculture, construction, restoration, and stormwater management. The type of sediment barrier used will depend on objective, courseness of sediment, drainage area, and water velocities. Straw bales, brush barriers, and fences are efficient in areas with low sheet flow velocities, grass barriers and wattles can slow more concentrated flows, and other structures like berms are used in areas with higher concentrated flow velocities. Barriers should follow the contour of the slope.

Conservation Benefits

• Decreases sediment in streams (protects aquatic habtiat)
• Decrease water velocities before entering streams
• Promotes stormwater infiltration
• Sediment retained in riparian and upland areas

What does it include?

Barriers: Barriers are commonly made of straw bales or brush. Filter fabric is sometimes required by local regulations for brush barriers to more effectively capture fine sediment (especially at contruction or agricultural sites). Grass barriers are also effective for slowing stormwater runoff and filtering sediment in areas with steeper slopes.

Berms : Berms are constructed ridges made of materials like compost, mulch, gravel, or sand. They are typically used around site perimeters as a secondary BMPs to catch stormwater sediment and slow water velocities. Berms are also used during consturction to divert flow from erosional areas. Height of the berm will depend on drainage area and materials used to construct the berm (minimum is usually 1 foot tall).

Fascines, bundles, and wattles : Wattles are biorolls/logs that can be constructed from wood, straw, coir, burlap or other fibers. They can be used on steeper slopes to trap sediment and slow stormwater velocities, as ditch checks, and for construction site inlet protection. The natural fibers are commonly held together with biodegradable netting and the entire wattle is secured to the by site by partially burying the structure and securing with stakes. See coir fiber log for a specific example of wattle.

Silt Fences : Silt fences are temporary barriers made of geotextile fabric used to filter sediment from stormwater and reduce sheet flow velocities. The fabric is secured to metal posts and then partially burried at the bottom to prevent flow under the fence. Fences are not able to withstand high flow velocities and need to maintained to remain effective.