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

•
SEDIMENT POND HYDROLOGY AND SEDIMENTOLOGY CALCULATIONS
SEDIMENT POND C
Drainage Area (acres) 31.0
Maximum Elevation (ft) 8,240
Minimum Elevation (ft) 8,185
Drainage Height (ft) 55
Hydraulic Length (ft) 1,520
Average Slope (%) 3.6
Slope Adjustment Factor 1.00
Sub Area Acres Curve Number
sD~ tad Zf .2 -~J'~
Undisturbed C 19.8 87
Average Curve Number 90
Average Runoff (in)
10-year, 24-hour event 0.84
25-year. 24-hour event 1.09
100-year, 24-hour event 1.53
Equivalent Area (acres) 27
Equivalent Peak Discharge (cfs/in) 31
•
Actual Peak Discharge (cfs/in) 35.6
Peak Discharge (cfs)
10-year, 24-hour event 30
25-year, 24-hour event 39
100-year, 24-hour event 54
Runoff Volume (acre-ft)
10-year, 24-hour event 2.2
25-year, 24-hour event 2.8
100-year, 24-hour event 4.0
Sediment Volume (acre-ft) 1.1
Pond Capacity (acre-ft) 3.3

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