2001-12-11_PERMIT FILE - C1991078

• Permit No: C1991078
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Section_Exhibit Name: Exhibit 09 Protection of the Hydrologic Balance
• Media Type: D
• Archive: No

• Sediment Pond A
RIPRAP SIZING - Spillcaay Channel Down Face of Embankment
D50 = Size of Riprap
D50 = ((V X S".17)/7.58))"2
D50 = Diameter in feet
V = Velocity
S = Slope
D50 = 0.748 feet 8.981 inches
The spillway for sediment pond A will be a trapezoidal
channel 6.0 feet wide and 0.83 feet deep
with a freeboard of 12" for a total depth of 1.830
feet. Riprap, 6" minus, will be placed in the spillway
channel across the top of the embankment and riprap,
9 inch minus, will be placed in the spillway channel down
the face of the embankment and in the inlet channel that
feeds the pond.
COLLECTION DITCH CDA-1
FLOW IN A TRIANGULAR CHANNEL
• ENTER DEPTH D 0.460 FEET
ENTER SLOPE S 0.005 EXPRESS AS DECIMAL
ENTER "N" N 0.030 EXPRESS AS DECIMAL
ENTER SIDE SLOPE X 3.000 SLOPE = X:1
AREA=(W#DI+(X#D"2)= 0.63 FEET"2
WETTED PERIMETER=(WI+2((XD"2+D"2))".5 2.91 FEET
R=AREA/WETTED PERMITER 0.22
V=(1.49/N)#(R".667)#(S".5)= 1.27 FEET/SEC
Q = A X V = 0.81 CFS
Q REQUIRED 0.78
Collection Ditch CDA-1 will be a triangular channel 0.460
feet deep with 3h:ly side slopes. with a freeboard of 0.3'
the total depth of collection ditch CDA-1 is 0.760 feet.
The flow velocity is slow enough that erosion will not be a
problem.
L~
9-4