PERMFILE51266

• Permit No: C1982057
• IBM Index Class Name: Permit File
• Doc Date: 5/5/2005
• Doc Name: Ditch Calculations
• Section_Exhibit Name: Tab 13 Attachment 13-6
• Media Type: D
• Archive: No

• General
All haul road ditches will be designed, constructed, end maintained to safely pass the
runoff from a 10-year, 24-hour precipitation event. All ditches will be constructed and
maintained to contain the minimum required cross sectional area for the designed runoff
volume. The minimum freeboard will be 0.5 feet above the normal depth. The locations of
the typitel ditch section (A, B, or C) are shown on Exhibit 13-2 and typical section
dimensions are located on Exhibit 73-10. The typitel section dimensions end type are
approximate far design telculations. The ditches in the field will be constructed end
maintained to ensure that the minimum cross sectional area is obtained for a particular
area. Listed below is a summary of the section properties for the typical ditch sections
and Tables 13-6-1 to 13•b-4 end Figure 13-6.1 contain rating curves for these ditch
sections. These ditches will be utilized on G and H roads, ramps end access roads. Table
73.6-5 contains the ditch specifications for all other ditches. Addendum 7 contains the
ditch calculations.
Section A B C
• TYPe
Side Slo
es V
3h
1 V
3h
1 V
3h
1
p :
v :
v :
v
Manning's N 0.035 0.035 0.035
Min. Flow Aree (ft~) 10.0 2.5 22.5
Normsl Depth (ft) 2.0 1.0 3.0
Max. Capacity (cf s) 57(0-2.0X) 70(0-2.5X) 755(0-1.7X)
94(2.0-5.5X) 15(2.5-S.SX> 279(1.7-5.5X)
•
13-6-1 Revised 04/24/91