2008-01-28_PERMIT FILE - C1992080A

• Permit No: C1992080A
• IBM Index Class Name: Permit File
• Doc Date: 1/28/2008
• Section_Exhibit Name: APPENDIX 5-2 SEDIMENT POND CONTROL DESIGN
• Media Type: D
• Archive: Yes

C
Sedimenc Pond lil Pit Component
Method 1 - peak Flw Using Te va. CSlI Charts:
Hote: Time of concentration (Tc) may be computed using d ther travel
time or leg as shown below. (There are other methods used to
obtain to which may be preferred over the ones show below,)
A• Computation of Tc Using Travel Time
Page 2 of
Te -Length of Segment (Li) - Ll + L2 + L3 + ...Ln : 1 - Ars.
Velocity Through Segment (Vi) 01 p2 p3 Vn 3600
Li-Ft. VS-FtJSee.
$• Computation of Tc Using Lag I/
Slope Data: Watershed Aelght (z) - -
Contour Length (LC25)
Contour Length (LC50)
Contour Length (LC75)
Drainage Area (DA) - 11,
940 ft.
- 7250 -ft. ~25~ of (z)
- 5250 ft, @SOS of (;)
3550 ft. @75x of (z)
456,280
--esq. ft.
.25z(LC25 + LCSO + LC75)
Slope - x 1001 - 32.92 X
DA (sq• ft.) 8700 ft.
Hydraulic Length or Flov Length -
•
dope Y.ydraulie
Soil Cover ~
Lag Tc (hr)
~
(y) Len th
(fi)
Complex !!o.
(Equation 3.2) (1.667 x

(1)
2
(3) Col. 4)
4 5
32.92 8700 84 0.27 0.46
C. Peak Flog:
Tc

(hr)
1 Peak Discharge
cfs/in./sq.mi.)
(Ff 5-1)
2
Total Area
(s q. mi.)
(3) Stotm
requeney
(yr.)
(4)
Runoff
(in.)
5 Total Peak
Discharge {cfs)
(Col. 2x3x5)
0.46 525 0.41 10 yr. 0.89 191.57

1/ Intended for vacersheds in their natural condition. If SSgnifieant
urbah areas exist use Page G for modification.