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 B
RIPRAP SIZING - Spillway Cannel Across Top of Embankment
D50 = Size of Riprap
D50 = ((V Y S".171/7.58))"2
D50 = Diameter in feet
V = Velocity
S = Slope
D50 = 0.133 feet 1.595 inches
DETERMINE VELOCITY OF FLOW DOWN 5:1 EMBANKMENT
ENTER DEPTH D 0.630 FEET
ENTER WIDTH W 12.000 FEET
ENTER SLOPE 5:1 S 0.200 EXPRESS AS DECIMAL
ENTER "N" N 0.040 EXPRESS AS DECIMAL
ENTER SIDE SLOPE t 2.000 SLOPE = X:1
AREA=IW*D)+(X*D"2)= 8.35 FEET"2
WETTED PERIMETER=(W)+2((XD"2 +D"2))".5 14.82 FEET
R=AREA/WETTED PERMITER 0.56
V=(1.49/N)*(R".667)*(S".5)= 11.37 FT/SEC
•
Q = A X V = 94.97 CFS
Q REQUIRED 94.28 CFS
RIPRAP SIZING - Spillway Channel Down Face of Embankment
D50 = Size of Riprap
D50 = ((V K S".17)/7.58))"2
D50 = Diameter in feet
V = Velocity
S = Slope
D50 = 1.301 feet 15.618 inches
The spillway for sediment pond B will be a trapezoidal
channel 12.0 feet wide and 1.25 feet deep
with a freeboard of 12" for a total depth of 2.250
feet. Riprap, 6" minus, caill be placed in the spillway
channel across the top of the embankment and riprap,
16" minus, will be placed in the spillway channel down
the face of the embankment and in the inlet channels
that feed the pond.
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