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 and Culvert Design Parameters and Results
Roadway Drainage Ditch 1
Design Parameters:
Precipitation:
Use 100-year, 24-hour storm precipitation depth = 2.6 inches
Land Use:
Road surface (gravel) = 0.37 ac with CN = 89
Maximum road grade = 2.0
Ditch length = 260 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 = 0.58 cfs
Peak velocity = 2.26 fps
Roadway Drainage Ditch 2
Design Parameters:
Precipitation:
Use 100-year, 24-hour storm precipitation depth = 2.6 inches
Land Use:
• Road surface (gravel) = 0.21 ac with CN = 89
Maximum road grade = 8.5
Ditch length = 343 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 = 0.33 cfs
Peak velocity = 3.36 fps
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