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Silt Fence

  

Code References

  • "For sites with less than 5 acres disturbed at one time, filter fences, straw bales or equivalent control measures shall be placed along all side slope and down slope sides of the site. (Reference: Section 290-7.2.e-5 of the City Code of Ordinances).
  • If a channel or area of concentrated runoff passes through the site, filter fences shall be placed along the channel edges to reduce sediment reaching the channel." (Reference: Section 290-7.2.e-5 of the City Code of Ordinances).
  • "Perimeter erosion control measures shall be placed within 24 hours of beginning excavating." (Reference: Section Comm 21.125(1)(a) of the Wisconsin Administrative Code).
  • "Erosion control measures shall be placed along down slope areas and along side slope areas as required to prevent or reduce erosion where erosion during construction will result in a loss of soil to waters of the state, public sewer inlets or off-site." (Reference: Section Comm 21.125(1)(a) of the Wisconsin Administrative Code).

Quick Tips

  • Silt fence shall be inspected weekly at minimum and within 24 hours after a precipitation event of 0.5 inches or greater.
  • Sediment deposits shall be properly disposed of when the deposits have accumulated to 1/2 the height of the fence.
  • Silt fence shall not be placed perpendicular to flow in swales, ditches, streams, or any other place where concentrated runoff exists.
  • Silt fence shall not be placed where the up slope gradient is greater than 50% (2:1 slope).
  • Silt fence ends shall extend up slope to prevent water from flowing around the fence.
  • Where two lengths of silt fence meet, the end posts shall be wrapped around each other to provide a secure joint or the lengths shall overlapped the distance between two posts.
  • Silt fence shall be anchored by burying at least 8 inches of fence fabric in either a 4-inch wide by 6-inch deep trench or a 6-inch deep V-trench on the up slope side of the fence (support posts should then be on the downhill side of the fence).
  • The maximum spacing between silt fence support posts shall be 8 feet for woven fabric fence and 3 feet for non-woven fence.
  • When installing silt fence near trees, avoid compaction and root cutting within 1.5 feet multiplied by the inch diameter of the tree (i.e., for an 8-inch tree avoid a 12-foot radius around the tree trunk).
  • Torn, degraded, trampled, or otherwise compromised silt fence shall be properly replaced immediately upon notice.

Applicable Standards

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