PERMFILE70936

• Permit No: C1982056
• IBM Index Class Name: Permit File
• Doc Date: 9/10/2004
• Section_Exhibit Name: Exhibit 08t 18 Right Ventilation Shaft Ditch & Culvert Design & SAE Demonstration
• Media Type: D
• Archive: No

• Diameter required = 18-inch CMP minimum, with a minimum of 2 feet
compacted cover, and riprap protection at [he inlet and outlet
Road Drainage Ditch 4
Design Parameters:
Precipitation:
Use 10-year, 24-hour storm precipitation depth = 1.8 in
Land Use:
Undisturbed area = 23.11 ac with CN = 63 (Sagebrush -Hyd. Soil Gp. C)
Road surface (gravel) = 0.97 ac with CN = 89
Maximum road grade = 8.0
Ditch length = 1,696 feet
Ditch design = triangulaz ditch with 3:1 side slopes (see Figure 2)
Ditch surface material is alluvial silts colloidal
Limiting ditch velocity = 3.75 fps
Results:
Peak flow = 0.89 cfs
Peak velocity = 3.69 fps
Culvert 4
Use same design parameters as Road Drainage Ditch 4
Peak flow = 0.89 cfs
Diameter required = 18-inch CMP minimum, with a minimum of 2 feet
• compacted cover, and riprap protection at the inlet and outlet
Road Drainage Ditch 5
Design Parameters:
Precipitation:
Use 10-year, 24-hour storm precipitation depth = 1.8 in
Land Use:
Undisturbed area = 23.78 ac with CN = 63 (Sagebrush -Hyd. Soil Gp. C)
Road surface (gravel) = 0.32 ac with CN = 89
Maximum road grade = 6.5
Ditch length = 552 feet
Ditch design = triangulaz ditch with 3:1 side slopes (see Figure 2)
Ditch surface material is alluvial silts colloidal
Limiting ditch velocity = 3.'15 fps
Results:
Peak flow = 0.30 cfs
Peak velocity = 2.59 fps
Culvert 5
Use same design pazameters as Road Drainage Ditch 5
Peak flow = 0.30 cfs
Diameter required = 18-inch CMP minimum, with a minimum of 2 feet
compacted cover, and riprap protection at the inlet and outlet