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Diversion Dike (DD) is used at the top, mid or bottom of <br />a slope to divert overland runoff prior to reaching <br />velocities that may cause erosion. These diversions shall <br />transport sediment laden runoff to an area where the <br />stormwater can effectively be treated prior to leaving the <br />site. A diversion dike can be constructed out of earthen <br />materials consisting of a berm and swale combination. <br />Synthetic materials may also be used and installation <br />procedures shall follow manufacture=s specifications. <br />Temporary Slope Drains (TSD) are required when <br />concentrated runoff is expected to flow down a slope. These <br />drains are intended to limit scour occurrence on the slope <br />by conveying stormwater runoff to an area where it can be <br />treated prior to leaving the site in a controlled manner. <br />The drains can be constructed as a flexible pipe or a ditch <br />liner and are sized based on contributing area. <br />Straw Bale Barriers (STB) serve as temporary sediment <br />barriers that slow overland stormwater runoff and facilitate <br />sedimentation up gradient of the bale. They adequately <br />function for small drainage areas if placed with 3 Acre of <br />tributary area per 100 lineal feet on slopes less than 150 <br />feet in length with less than a 2:1 gradient. Straw bale <br />barriers shall not be used where stormwater runoff is <br />concentrated. <br />Silt Fence (SF) is used to limit sediment transport caused <br />by overland stormwater runoff. The fence is placed at the <br />toe of slopes with 3 Acre of tributary area per 100 lineal <br />feet in areas less than 150 feet in length and less than a <br />2:1 gradient. Silt fence shall not be used where stormwater <br />runoff is concentrated. <br />Check Dams (CD) are used along the borrow ditches of the <br />haul roads or where stormwater runoff is concentrated. The <br />purpose of a check dam is to effectively reduce erosive <br />velocities behind the embankments to facilitate sediment <br />deposition in a controlled manner. <br />Temporary Sedimentation Basins (SB) are required for all <br />areas of disturbance larger than 1-Acre. The purpose of the <br />sedimentation basin is to allow sediment laden stormwater <br />runoff to be released over a period of time prior to discharge <br />to the receiving waters. The basin is designed to provide <br />a minimum volume of 1800 cubic feet per contributing acre. <br />The basin embankment is designed with a maximum slope of 3: 1. <br />Release is governed by a perforated riser section, surrounded <br />by a gradation of gravel. The basin shall be cleaned of <br />deposited sediment prior to becoming half full. The inlet <br />