Laserfiche WebLink
Florida Erosion and Sediment Control Inspector's Manual <br /> Trap Capacity <br /> The sediment trap must have an initial storage volume of 134 cubic yards, or 3600 cubic feet <br /> per acre ( 252 m3/ha) of drainage area , measured from the low point of the ground to the crest <br /> of the gravel outlet. Sediment should be removed from the basin when the volume is reduced <br /> by one-half. <br /> For a natural basin , the volume may be approximated as follows : <br /> V = 0 .4xAxD <br /> where : V = the storage volume in ft. 3 <br /> A = the surface area of the flood area at the crest of the outlet, in ft.2 <br /> D = the maximum depth , measured from low point in trap to crest of outlet, <br /> in ft. <br /> Excavation <br /> If excavation is necessary to attain the required storage volume , side slopes should be no <br /> steeper than 2 : 1 . <br /> Embankment Cross-Section <br /> The maximum height of the sediment trap embankment shall be 5 feet ( 1 . 5 m) as measured • <br /> from the low point . Minimum top widths (W) and outlet heights (Ho) for various embankment <br /> heights (H ) are shown in Table 4 . 25a . Side slopes of the embankment shall be 2 : 1 or flatter. <br /> wo <br /> Table 4.25a <br /> MINIMUM TOP WIDTH (W) AND OUTLET HEIGHT (Ho) REQUIRED FOR <br /> SEDIMENT TRAP EMBANKMENT ACCORDING TO HEIGHT OF EMBANKMENT (feet) <br /> H Ho W .w <br /> 2 . 0 1 . 0 2 .0 <br /> 2 . 5 1 . 5 2. 5 <br /> 3 . 0 2 . 0 2 .5 to <br /> 3 . 5 2 . 5 3 .0 <br /> 4 . 0 3 . 0 3 .0 <br /> 4 . 5 3 . 5 4 .0 <br /> 5 . 0 4 . 0 4 .5 <br /> r <br /> 4-70 <br /> �r <br />