PERMFILE118993

• Permit No: C1980006A
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Doc Name: DRAINAGE & SEDIMENT CONTROL PLAN
• Section_Exhibit Name: EXHIBIT 42
• Media Type: D
• Archive: Yes

•
DITCH HYDROLOGY CALCULATIONS
DITCH B1
Ditch B1 Ditch 62 Total
Drainage Area (acres) 46.3 65.4 111,7
Maximum Elevation (ft0 8,362 8,462
Minimum Elevation (ft) 8,230 8,210
Drainage Height (ft) 132 192
Hydraulic Length (ft) 1,600 1,500
Average Slope (%) 8.3 12.8
Slope Adjustment Factor 0.84 0.95
Sub Area Acres Curve No.
Di tc}i~-
Disturbed 30.7 96
Undisturbed B 0.8 78
Undisturbed C 14.8 87
Ditch B2
Disturbed 16.1 96
Undisturbed B 23.8 78
Undisturbed C 25.5 87
Average Curve Number 93 86
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Average Runoff (in)
10-year, 24-hour 1.04 0.63
25-year, 24-hour event 1.31 0.85
100-year, 24-hour event 1.78 1.24
Equivalent Area (acres)
Equivalent Peak Dischargee (cfs/1n)
Actual Deak discharge (cfs/in)
Peak Discharge (cfs)
10-year, 24-hour event
25-year. 24-hour event
100-year, 24-hour event
•
29.8 26.7
67 75
81.4 174.5
91 110 201
115 148 263
I56 216 372
23-28