PERMFILE54840

• Permit No: C1980007
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Section_Exhibit Name: Exhibit 47 Design Criteria for MB-5 & MB-6
• Media Type: D
• Archive: No

• zy"
event plus the estimated sediment yield over a 2-year
period.
Construction of the sediment pond will be supervised,
inspected and certified after construction by a
registered professional engineer. Certification of the
constructed pond will be forwarded to the CMLRD upon
completion of the pond.
The runoff volume and peak discharges for the laydown
area were determined using TR-55. The laydown area
consists of the following subareas with curve numbers
indicated:
Area Designation Acreave Curve Number
Disturbed area 5.5 75
Undisturbed area I.4 70
Total Area 6.9 74
Runoff volume expected from a 10 year, 24 hour event is
determined as follows:
10 year, 24 hour rainfall
Curve Number
Runoff Volume (Q)
q (10 yr., 24 hr. event}
Q
= 1.8 inches
= 74 '
= 0.26 inch
0.15 acre ft.
= 5,512 ft.3
Peak discharge from the area is determined as follows far
both the 10 year 24 hour event and the 25 year 24 hour
event:
10 year, 24 hour precipitation = 1.8 inches
25 year, 24 hour precipitation = 2.2 inches
Curve Number = 74
D-5