The Last Line of De-Fence!

When it comes to sediment control, silt fence is a major factor when trying to retain soil on site. We’ve all seen it, Its everywhere! So, what does it do or help prevent?

The purpose of silt fence is to retain soil on site, it is indeed a sediment control device or BMP (Best Management Practice). When soil is exposed during construction or other activities, it is prone to erosion when it rains. Erosion can have major impacts on roadways, wetlands, ponds, rivers, and streams. It can also lead to very expensive problems when dealing with piping or underground utility work. If the pipe drainage systems are clogged and filled with mud/sediment, there is a smaller capacity to carry off stormwater. This can cause major flooding issues in populated cities or urban areas. The cost of installing silt fence on a construction site is likely to be less expensive than trying to clean out municipal storm sewers (MS4).

Silt Fence, a temporary barrier used to retain sediment and control erosion, come in different varieties each of which serves an individualized purpose. For example, Type A and Type B Silt Fences are similar in material and purpose. Type A however, has a 36-inch-wide filter fabric, better for longer construction projects (6 months or greater), while Type B has 22-inch-wide filter fabric sufficient to use on shorter projects (less than 6 months). A more fortified silt fence, Type C, are 36 inches wide and have an added wire reinforcement which permits 3 X’s greater water run off that that of Type A.  Making it more appropriate for downhill slopes greater than 10ft.

Some sites may contain bright orange safety fences made of mesh and are more suitable for high visibility and support and act as both a perimeter and warning for dangerous job site or work area.  When a stronger barrier is needed, Smart Fence and or Super Silt Fence (S/Fence), can be used. The Smart Fence eliminates the need for reinforced wire fenced backing. It is considered cost effective because it exceeds the strength of a chain-linked fence and allows for heavy-duty containment of sediment-laden runoff. S/Fence, known as super silt fencing, combines chain-linked and synthetic woven filtration fabric. With its double-duty tensile abilities, it is appropriate for controlling extreme erosion, sloping land areas, protections from waterways, and minimizes impact during construction.


Silt fence types serve many purposes and come in a variety of designs and performance levels. It can be important to know why different sites have different types of fence and that their application is based on site needs and containment goals. For more on what kind of perimeter controls would best work with your site, be sure to contact the professionals at KCI for a consultation!

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