Water

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Water Sediment Control Basin (WASCOB) Mike
Cox State Conservation Engineer
Contractor Certification Training March 2008
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Water Sediment Control Basin (638)

• Purpose 1) Reduce gully erosion
• 2) Trap Sediment
• 3) Reduce and manage downstream
  runoff

• WASCOBs are typically used when drainage areas
  are smaller.
• WASCOB Spacing is to reduce slope length and
  accommodate equipment width

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• Farmed - WASCOB
• Slopes are flatter (51 to 101)
• More yardage must be used during construction
• Harder to fit into steep areas

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• Grassed - WASCOB
• Slopes are steeper (31 to 51)
• Less yardage used during construction
• Fits better into steep areas
• Slopes steeper than 51 must be grassed

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• Compaction of Earth Fill
• Use 6-9 Lifts
• Dozer or Loaded Pan on Each Lift 2 passes
• Sheepsfoot Roller 1 pass

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• Borrow Areas
• Dont get borrow at the channel
• Unless plans call for the channel to be excavated
• Borrow should come from field above
• Remember to stockpile topsoil

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• Outlets for WASCOBs
• Underground Outlet (620)
• Outlet tile is sized per orifice diameter
• Orifice plates must be installed

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• Risers
• Must be minimum of 2.5 in height

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Installation Report http//www.in.nrcs.usda.gov/t
echnical/engineering/engineering.html Look Under
Contractor Certification Section
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