PERMFILE64499

• Permit No: C1982056
• IBM Index Class Name: Permit File
• Doc Date: 10/12/2006
• Section_Exhibit Name: Exhibit 08AA Haulroad A - Drainage Designs
• Media Type: D
• Archive: No

• Roadway Drainage Ditch 3
Design Parameters:
Precipitation:
Use I00-yeaz, 24-hour storm precipitation depth = 2.6 inches
Land Use:
Undisturbed azea = 1.2 ac with CN = 63 (Sagebrush -Hyd. Soil Gp. C)
Road surface (gravel) = 0.23 ac with CN = 89
Maximum road grade = 3.4
Ditch length = 325 feet
Ditch design =triangular ditch with 3:1 side slopes (see Figure 2)
Ditch surface material is alluvial silts colloidal
Limiting ditch velocity = 3.8 fps
Results:
Peak flow = 0.72 cfs
Peak velocity = 2.91 fps
Roadway Drainage Ditch 4
Design Parameters:
Precipitation:
Use 100-year, 24-hour storm precipitation depth = 2.6 inches
Land Use:
Undisturbed area = 3.29 ac with CN = 63 (Sagebrush -Hyd. Soil Gp. C)
Road surface (gravel) = 0.38 ac with CN = 89
Maximum road grade = 2.2
Ditch length = 698 feet
Ditch design = triangulaz ditch with 3:1 side slopes (see Figure 2)
Ditch surface material is graded silts to cobbles when colloidal
Limiting ditch velocity = 4.0 fps
Results:
Peak flow = 0.67 cfs
Peak velocity = 2.12 fps
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