Laserfiche WebLink
• <br />Chapter 4-Site-Specific Industrial Storm water BMps <br />work area completely. In addition, a silt fence is effective where sheet and rill erosion may be a <br />problem. Silt fences should not be constructed in streams or swales. <br />I What to Consider <br />• <br />A silt fence is not appropriate for a large area or where the flow rate is greater than 0.5 cfs. This <br />type of fence can be more effective than a straw bale barrier if properly installed and maintained. <br />It may be used in combination with other erosion and sediment practices. <br />The effective life span for a silt fence is approximately 6 months. During this period, the fence <br />requires frequent inspection and prompt maintenance to maintain its effectiveness. Inspect the <br />fence after each rainfall. Check for areas where runoff eroded a channel beneath the fence, or <br />where the fence was caused to sag or collapse by runoff flowing over the top. Remove and <br />properly dispose of sediment when it is one-third to one-half the height of the fence or after each <br />storm. <br />Advantages of a Filter Fence <br />• Removes sediments and prevents downstream damage from sediment deposits <br />• Reduces the speed of runoff flow <br />• Minimal clearing and grubbing required for installation <br />• Inexpensive <br />Disadvantages of a Filter Fence <br />• May result in failure from improper choice of pore size in the filter fabric or improper <br />installation <br />• Should not be used in streams <br />• Is only appropriate for small drainage areas with overland flow <br />• Frequent inspection and maintenance is necessary to ensure effectiveness <br />4-77