PERMFILE111152

• Permit No: C1996083A
• IBM Index Class Name: Permit File
• Doc Date: 5/12/2003
• Doc Name: pages 8-1 through 8-80i
• Section_Exhibit Name: Exhibit 08 Protection of the Hydrologic Balance
• Media Type: D
• Archive: Yes

•
Trapezoidal Channel in C-Gulch
Riprap Sizing -Trapezoidal Channel C2 & C4
D50 =Size of Riprap
D50 = ((V X S^.17)/7.58))^2
D50 = Diameter in feet
V =Velocity
S =Slope
D50 =
2.1 feet 25 inches
Drainage channels C2, & C4 will be constructed at least 3-feet wide at the bottom with 2H:1V side slopes,
2-feet deep including freeboard with D50 riprap of 24-inches.
Drainage Ditches C6, C9, C10 & C14
Mannings Equation
Flow In a Trapezoidal Channel -Minimum Slope
DEPTH D 0.800 FEET
WIDTH W 6.000 FEET
Slope S 0.050 EXPRESS AS DECIMAL
Mannings "N" N 0.040 EXPRESS AS DECIMAL
SIDE SLOPE X 2.000 SLOPE = X:1
I •
AREA=(W'D)+(X'D^2 )=
WETTED PERIMETER=(W)+2'[((X'D)^2+D^2)^0.5]
R=AREA/WETTED PERIMETER
V=(1.49/N)'(R^.667)*(S^.5)=
O=AXV=
O REQUIRED -Peak Discharge - C14
6.08 FEET^2
9.58 FEET
0.63
6.15 FT/SEC
37.41 CFS
34.89 CFS
Drainage Ditches C6, C9, C10 & C14
Mannings Equation
Flow In a Trapezoidal Channel -Maximum Slope
DEPTH D 0.400 FEET
WIDTH W 6.000 FEET
Slope S 0.500 EXPRESS AS DECIMAL
Mannings "N" N 0.040 EXPRESS AS DECIMAL
SIDE SLOPE X 2.000 SLOPE = X:1
AREA=(W'D)+(X'D^2)= 2.72 FEET^2
WETTED PERIMETER=(W)+2*[(( X"D)^2+D^2)^0.5] 7.79 FEET
R=AREANVETTED PERIMETER 0.35
V=(1.49/N)"(R^.667)'(S^.5)= 13.06 FT/SEC
O=AXV= 35.53 CFS
Q REQUIRED -Peak Discharge - C14 34.89 CFS
PR-07 ~ EXH-8-15
2/03