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1 <br />1 <br />1 <br />1 <br />'.1 <br />1 <br />Table 11-4.2.1 Runoff Conveyance and Treatment BMPs by SWPPP <br />Element (continued) <br />Ele- <br />lement <br />Element <br />Ele- <br />r <br />Ele- <br />ment <br />#4 <br />Ele- <br />#8 Stab- <br />ment <br />Element <br />BMP or Ele- <br />#3 <br />Install <br />ment <br />ment <br />#7 Pro <br />ilize <br />Element <br />#9 Con- <br />#10 <br />#13 Protect <br />Con- <br />Sed- <br />#6 Pro- <br />Chan- <br />Control <br />Low Impact <br />ment Name <br />tect <br />trol Pol- <br />trol <br />iment <br />tect <br />nels <br />De- <br />Devel- <br />Drain <br />lutants <br />Flow <br />Con- <br />Slopes <br />and Out <br />Water- <br />opment <br />Inlets <br />Rates <br />trols <br />lets <br />ing <br />for High pH <br />Water <br />(p 412) <br />BMP C200: Interceptor Dike and Swale <br />IPurpose <br />1 <br />1 <br />1 <br />1 <br />1 <br />1 <br />1 <br />1 <br />1 <br />1 <br />Provide a ridge of compacted soil, or a ridge with an upslope swale, at the top or base of <br />a disturbed slope or along the perimeter of a disturbed construction area to convey storm - <br />water. Use the dike and/or swale to intercept the runoff from unprotected areas and direct <br />it to areas where erosion can be controlled. This can prevent storm runoff from entering <br />the work area or sediment -laden runoff from leaving the construction site. <br />Conditions of Use <br />Where the runoff from an exposed site or disturbed slope must be conveyed to an <br />erosion control facility which can safely convey the stormwater. <br />. Locate upslope of a construction site to prevent runoff from entering disturbed area. <br />. When placed horizontally across a disturbed slope, it reduces the amount and velo- <br />city of runoff flowing down the slope. <br />. Locate downslope to collect runoff from a disturbed area and direct water to a sed- <br />iment basin. <br />Design and Installation Specifications <br />Dike and/or swale and channel must be stabilized with temporary or permanent <br />vegetation or other channel protection during construction. <br />• Channel requires a positive grade for drainage; steeper grades require channel <br />protection and check dams. <br />. Review construction for areas where overtopping may occur. <br />. Can be used at top of new fill before vegetation is established. <br />2014 Stormwater Management Manual for Westem Washington <br />Volume 11 - Chapter 4 - Page 331 <br />