PERMFILE105841

• Permit No: C1981048
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Section_Exhibit Name: EXHIBIT V-3
• Media Type: D
• Archive: No

• Revised Ditch Design
1. Ditch 22-D2
2. Description: Diversion ditch around pit
3. Ditch Grade: 3.3%
4. Area drained: 23 acres
5. Peak discharge: 31(1.12)(1.25) = 43 cfs
6. Ditch Design:
* The peak discharge was assumed to be correct for the purposes
of the revised ditch design.
n = .030
Use ditch w/"V" walls 2:1 slope See chart 1031.2-2 fi
From chart: 2' FB DT D = 1.28
~•
* Depth for "V" DT w/2:1 S1
* D = 1.71 feet
Add .5 feet freeboard
Use 2.21 feet deep
Calculations below
A=2D+2D2 V=7.4 fps
= 2.56 + 3.28
= 5.84
D = -~
2
= 5.84
2
= 1.71