scope:

Purpose and scope

This Standard is intended to guide engineers and technicians in the planning, design, layout, construction and maintenance of water and sediment control basins (WASCOBs). These basins consist of an earth embankment with a level top section constructed across a watercourse or gulley to form a sediment trap and a water detention basin.

This Standard applies where gully erosion is a problem or there is a need to manage runoff leaving a site. The soils and site conditions must be suitable to build an earth embankment and the topography must provide adequate detention storage. The site must provide an adequate outlet either through an underground outlet or by infiltration into the soil.

Water and sediment control basins differ from terraces in that they do not necessarily follow the contour of the land, and they do not necessarily reduce slope length as defined in the Revised Universal Soil Loss Equation 2. The reduction in sheet and rill erosion may be slight with the use of WASCOBs. However, they may be used in conjunction with terrace systems.