Laserfiche WebLink
<br /> <br />POND DESIGN <br />A sedimentation pond has been designed to remove suspended so- <br />lids from the runoff before releasing it into existing drainage <br />patterns. The total drainage area tributary to the pond is 6.42 <br />acres. Of this total, 2.34 acres have been considered disturbed <br />for sediment storage purposes. <br />The pond must retain the total volume of storm water runoff <br />from a 10-year, 24-hour storm. It must also contain sediment <br />storage volume equal to 0.1 acre foot per acre of disturbed <br />area. The total capacity required for this storage is 41,900 <br />..- <br />cubic feet (see Appendix). The pond must also provide an <br />emergency spillway to pass runoff from the 25-year, 24-hour <br />storm with a freeboard of 1 foot. <br />Sediment should be periodically removed from the pond when 608 <br />of design capacity, or approximately 13 inches, has accumulated. <br />The 10-year storm runoff will be released through an orifice <br />sized to achieve a theoretical detention time not less than <br />24 hours. The water remaining in the area reserved for sedi- <br />ment storage will reenter the groundwater table by percolation <br />or will evaporate. <br />The emergency spillway is designed to discharge the peak dis- <br />charge from a 25-year storm at a depth of 1.3 feet, with a min- <br />imam freeboard of one foot. Calculations of the pond and dis- <br />-2- <br />