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

• Collection Ditches
Collection Ditch CD-lE
Flow In a Triangular Channel
DEPTH D 1.400 FEET
SLOPE S 0.020 EXPRESS AS DECIMAL
Mannings "N" N 0.035 EXPRESS AS DECIMAL
SIDE SLOPE X 2.000 SLOPE = X:1
AREA=(W*D)+(X*D^2)= 3.92 FEET^2
WETTED PERIMETER=(W)+2((XD^2+D^2))^.5 6.26 FEET
R=AREA/WETTED PERMITER 0.63
V=(1.49/N)*(R^.667)*(S^.5)= 4.41 FEET/SEC
Q = A X V = 17.27 CFS
Q REQUIRED 16.99 CFS
Collection Ditch CD-lE will be a triangular channel 1.400
feet deep with 2h:ly side slopes. With a freeboard of 0.3'
the total depth of the collection ditch is 1.700 feet.
The flow velocity is slow enough that erosion will not be a
problem.
Collection Ditch CD-2E
Flow In a Triangular Channel
DEPTH D 1.000 FEET
SLOPE S 0.020 EXPRESS AS DECIMAL
Mannings "N" N 0.035 EXPRESS AS DECIMAL
• SIDE SLOPE X 2.000 SLOPE = X:1
AREA=(W*D)+(X*D^2)= 2.00 FEET^2
WETTED PERIMETER=(W)+2((XD^2+D^2))^.5 4.47 FEET
R=AREA/WETTED PERMITER 0.45
V=(1.49/N)*(R^.667)*(S^.5)= 3.52 FEET/SEC
Q = A X V = 7.04 CFS
Q REQUIRED 6.78 CFS
Collection Ditch CD-2E will be a triangular channel 1.000
feet deep with 2h:ly side slopes. With a freeboard of 0.3'
the total depth of the collection ditch is 1.300 feet.
The flow velocity is slow enough that erosion will not be a
problem.
Collection Ditch CD-3E
Flow In a Triangular Channel
DEPTH D 0.800 FEET
SLOPE S 0.020 EXPRESS AS DECIMAL
Mannings "N" N 0.035 EXPRESS AS DECIMAL
SIDE SLOPE X 2.000 SLOPE = X:1
AREA=(W*D)+(X*D^2)= 1.28 FEET^2
WETTED PERIMETER=(W)+2((XD^2+D^2))^.5 3.58 FEET
R=AREA/WETTED PERMITER 0.36
V=(1.49/N)*(R^.667)*(S^.5)= 3.03 FEET/SEC
• Q = A X V = 3.88 CFS
Q REQUIRED 3.84
9-31 July 1992