Water Sediment Control Basin WASCOB Mike Cox State

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/engine ering. html Look Under Contractor Certification Section

Construction Tolerances-WASCOB Orifice Elevation: +0. 1 foot Levee Width: Planned width or wider Top of Levee: Grade or above Planned slope or flatter Side Slopes:

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