Mud in the Street, What are the Solutions?
This is the fourth in a continuing series of articles provided by the City of Lincoln, Watershed Management Division to address sediment and erosion control issues. In the previous article the use of compost was discussed as a Best Management Practice for erosion control. In this issue we will focus on the use of silt fence as a way to keep sediment out of the public right of way and out of local streams. This is a popular practical measure that can be installed on individual building sites.
Where to start? Walk around your job site and surrounding land to check for potentially sensitive areas like streams, creeks and other water bodies. Note the direction water drains across the property and where it leaves the property.
Installing a silt fence around the entire perimeter of a site is very seldom necessary. Silt fence is likely to be needed only on the low end of the lot, or at the locations along the perimeter where sediment is most likely to leave the lot.
Poor Installation - posts spaced too far apart
Good Installation - "J hook type"
What kind of silt fence do I need? Silt fence can be obtained and placed by a professional contractor experienced in sediment and erosion control or can be purchased at a home improvement store and installed by the general contractor or home owner. If you are not a professional installer there are a few things to be aware of. Installation of posts (wood or steel) can cause damage to underground utilities or personal injury to the installer. Always call the Diggers Hotline before driving stakes.
If you are going to hire a professional, they will take care of the placement and installation, but not the maintenance, unless you contract them to do so. Sediment and erosion control measures must be cleaned of silt over time as they are not designed to withstand the force of one to two feet of silt over an extended duration of time. Removing excess sediment after a rain event will make the silt fence last longer and function better. Installing silt fence yourself is an inexpensive option, but it must be done correctly to be cost effective. Incorrectly installed silt fence will not function as intended and it may fail entirely.
Things that can go wrong with do-it-yourself installations include not properly trenching in the toe of the silt fence, posts spaced too far apart, not placed in a "smile" or "J hook" configuration to detain and settle out sediment behind the fence. If buying silt fence with posts already attached, it is highly advised that additional posts be placed between each span (post spacing should be no more than six feet apart).
If you have questions about this subject please contact Gary Lacy of Public Works and Utilities at 441-4957 or contact HBAL for a listing of professional silt fence installers in our area.
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