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Water & Sediment Control Basin (WASCOB) Mike Cox State Conservation Engineer. Contractor Certification Training March 2008. Water & Sediment Control Basin (638). Purpose: 1) Reduce gully erosion 2) Trap Sediment 3) Reduce and manage downstream runoff.
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Water & Sediment Control Basin (WASCOB) Mike Cox State Conservation Engineer Contractor Certification Training March 2008
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
Farmed - WASCOB • Slopes are flatter (5:1 to 10:1) • More yardage must be used during construction • Harder to fit into steep areas
Grassed - WASCOB • Slopes are steeper (3:1 to 5:1) • Less yardage used during construction • Fits better into steep areas • Slopes steeper than 5:1 must be grassed
Compaction of Earth Fill • Use 6-9” Lifts • Dozer or Loaded Pan on Each Lift – 2 passes • Sheepsfoot Roller – 1 pass
Borrow Areas • Don’t get borrow at the channel • Unless plans call for the channel to be excavated • Borrow should come from field above • Remember to stockpile topsoil
Outlets for WASCOBs • Underground Outlet (620) • Outlet tile is sized per orifice diameter • Orifice plates must be installed
Risers • Must be minimum of 2.5’ in height
Installation Report http://www.in.nrcs.usda.gov/technical/engineering/engineering.html Look Under Contractor Certification Section