2013-10-07_PERMIT FILE - C1981025A ‎(6)‎

• Permit No: C1981025A
• IBM Index Class Name: Permit File
• Doc Date: 10/7/2013
• Doc Name: Final Engineering Calculations
• Section_Exhibit Name: 4.0 Appendix 4-B
• Media Type: D
• Archive: Yes

r1
LJ
Diversion Ditches
UPPER DIVERSION DITCH D-6
FLOW IN A TRIANGULAR CHANNEL
DEPTH D 1.100 FEET
SLOPE S 0.050 EXPRESS AS DECIMAL
Mannings "N" N 0.030 EXPRESS AS DECIMAL
SIDE SLOPE X 1.500 SLOPE = X:1
AREA=(W*D)+(X*D^2)= 1.82 FEET^2
WETTED PERIMETER=(W)+2((XD^ 2+D^2))^.5 3.97 FEET
R=AREA/WETTED PERMITER 0.46
V=(1.49/N)*(R^.667)*(S^.5)=
Q = A X V =
Q REQUIRED
The diversion ditch will be a triangular channel 1.1
feet deep with 1.5h:1v side slopes. With a freeboard of 0.3'
the total depth of the upper diversion ditch is 1.4 feet.
The flow velocity is high enough that energy dissipaters
will be required.
UPPER DIVERSION DITCH D-2A
n
U
n
FLOW IN A TRIANGULAR CHANNEL
DEPTH D 0.850 FEET
SLOPE S 0.050 EXPRESS AS DECIMAL
Mannings "N" N 0.030 EXPRESS AS DECIMAL
SIDE SLOPE X 1.500 SLOPE = X:1
AREA=(W*D)+(X*D^2)=
WETTED PERIMETER=(W)+2((XD^2+D^2))^.5
R=AREA/WETTED PERMITER
6.60 FEET/SEC
11.97 CFS
9.82
1.08 FEET^2
3.06 FEET
0.35
V=(1.49/N)*(R^.667)*(S^.5)= 5.55 FEET/SEC
~Q = A X V = 6.02 CFS
Q REQUIRED 5.82
The diversion ditch will be a triangular channel 0.9
feet deep with 1.5h:1v side slopes. With a freeboard of 0.3'
the total depth of the upper diversion ditch is 1.2 feet.
The flow velocity is potentially erosive. However, the
ditch channel in this area is comprised of competent
gravels so erosion should not be a factor.
4-B:7
October 1994