Silt socks--an effective tool for sediment control

Dirty street gutters

These are one of the common problems I seen at construction sites, especially street construction locations.

When it rains, any dirt in the gutters goes directly to the lakes.  Leaving dirt in the gutter is like just dumping it into the lakes.  You can count on it!

Filters on stormwater inlets are the common solution to prevent debris from getting into storm sewers.  But the filters don't work that well, and they require maintenance (which is usually not done).

An easy method to control sediment in gutters

• Keep gutters squeaky clean.  Good housekeeping!  A man with a broom is very effective.
• Use short segments of silt sock in the gutter where water leaves your site, to filter sediment.
• Use short segments of silt sock in the gutter above your site, to deflect incoming water away from your gutter.

Dams in gutters, like silt socks or gravel, cannot handle large volumes--if there's a lot of flow, the water will just go around or over the silt sock.  So they can't be used everywhere.

That's why you use a silt sock upstream of your site.  By deflecting incoming water (to the other side of the street, for example), you reduce the volume of water hitting the silt sock at the lower end of your site.

Silt sock used to deflect water to left

Perimeter control

Where the ground is relatively level and runoff isn't concentrated into channels, silt socks can be very effective in preventing any sediment from leaving your site.  I've watched how they work at Sequoia Commons--Phase II.

Effective 8" silt socks at Sequoia Commons.
The only mud leaking out is coming from the entrance to the left.