2012-05-11_PERMIT FILE - C1981033 ‎(4)‎

• Permit No: C1981033
• IBM Index Class Name: Permit File
• Doc Date: 5/11/2012
• Section_Exhibit Name: EXHIBIT 11 DRAINAGE AND SEDIMENT CONTROL PLAN
• Media Type: D
• Archive: No

• SEDIMENT POND EMERGENCY SPILLWAY
MANNING'S EQUATION
FLOW IN A TRAPEZOIDAL CHANNEL
DEPTH 0.600 FEET
BOTTOM WIDTH 8.500 FEET
SLOPE OF CHANNEL 0.010 EXPRESS AS DECIMAL
MANNINGS "N" 0.030 EXPRESS AS DECIMAL
SIDE SLOPE 3.000 SLOPE = X:1
AREA=(W*D)+(X*D)= 6.18 FEET^2
WETTED PERIMETER=(W)+2((XD^2+D^2))^.5 12.29 FEET
R=AREA/WETTED PERMITER 0.50
V=(1.49/N)*(R^.667)*(S^,5)= 3.14 FT/SEC
Q = A X V = 19.40 CFS
Q REQUIRED 17.64 CFS
The spillwax for the sediment pond will be a trapazoidal channel 8.5
feet wide with a flow depth of .6 feet and a freeboad of 12 inches.
Rip rap, 6" minus, will be laced in the channel to prevent erosion
where the flow enters the river.
• D50 = ((V X S^,17)/7.58))^2
D50 = Diameter in feet
V = Velocity
S = Slope
D50 = 0.036 feet 0.430 inches
DITCH "B"
FLOW IN A TRIANGULAR CHANNEL
DEPTH 1.100 FEET 1.4' W/Freeboard
SLOPE OF DITCH 0.020 EXPRESS AS DECIMAL
MANNINGS "N" 0.030 EXPRESS AS DECIMAL
SIDE SLOPE 2.000 SLOPE = X:1
AREA=(W*D)+(X*D)=
WETTED PERIMETER=(W)+2((XD^2+D^2))^.5
R=AREA/WETTED PERMITER
V=(1.49/N)*(R^.667)*(S^,5)=
Q = A X V =
Q REQUIRED AREAS 1, 2, 3, 4 & 5
•
2.42 FEET^2
4.92 FEET
0.49
4.38 FEET/SEC
10.59 CFS
9.16
11-4 Rev. 02-15-94