PERMFILE138126

• Permit No: C1991078A
• 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: Yes

• Sediment Pond D
RIPRAP SIZING - Spillway Channel Across Top of Embankment
D50 = Size of Riprap
D50 = 1(V X S".17)/7.58))"2
D50 = Diameter in feet
V = Velocity
S = Slope
D50 = 0.052 feet 0.627 inches
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DETERMINE VELOCITY OF FLOW DOWN 5:1 EMBANKMENT
ENTER DEPTH D 0.320 FEET
ENTER WIDTH W 6.000 FEET
ENTER SLOPE 5:1 S 0.200 EXPRESS AS DECIMAL
ENTER "N" N 0.040 EXPRESS AS DECIMAL
ENTER SIDE SLOPE X 2.000 SLOPE = Y:1
AREA=(W*D)+(X*D"2)=
WETTED PERIMETER=(W)+2((XD"2+D"2)1".5
R=AREA/WETTED PERMITER
V=(1.49/NI*(R".667)*(S".5)=
Q = A X V =
Q REQUIRED
RIPRAP SIZING - Spillway 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 = 0.526 feet 6.317 inches
2.12 FEET"2
7.43 FEET
0.29
7.23 FT/SEC
15.36 CFS
14.88 CFS
The spillway for sediment pond D will be a trapezoidal
channel 6.0 feet wide snd 0.62 feet deep
with a freeboard of 12" for a total depth of 1.620
feet. Rip rap, 6" minus, will be placed in the spillway
channel across the top of the embankment, in the spillway
channel down the face of the embankment and in the inlet
that feeds the pond.
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