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

Sediment Pond lit
• T[ethod 1 - Peak Floe Daing Te vs. CSIS Charts:
Hote: Time of eoaeentration (Te) may be computed ucing either travel
time or lag as show below. (There are other methods used to
obtain Tc which mey be preferred over the ones •how below.)
A• Computation of Tc Using Travel Time
Page 2 of 4
Te .Length of Segment (Li) ~ Ll + L2 + L; + ...Ln x 1
Velocity Through Segmen[ (Vi) Vl V2 V3 Va 3600 ~ Hrs.
•
LI~Ft. Vi~Ft/See.
B• Computation of Tc Usinq Lag 1/
Slope Data: Watershed Height (z) 410 ft.
Contour Length (LC 25) .2400 -ft. X255 of (z)
Contour Length (LCSO) ~ 324~_~t. @505 of (;)
Contour Length (LC75) ~ 81 ft. @755 of (z)
Drainage Area (DA) ~ 2.018,570
--esq. ft.
.25z(LC25 + LC50 + u7S)
Slope ~ x 1005
DA (sq. ft.)
Aydraulie Length or Flov Length
Slope Y.ydraulic Soil Cover La
g Tc (hr)
(5) Length
(f t) Complex Y.o. (Equation
3.2) (1.667 x
Col. 4)
(1) 2 (3) 4 5
32.75 3330 77 0.16 0.27
C. Peak Flou

Te
(hr)
1 Peak Discharge

(FS 5 )
2
Total Area
(sq. mi.)
(3) Storm
requeney
(yr.)
(4)
P.unoff
(in.)
5 Total Peak
Discharge (cfs)
(Co1.2 x 3 x 5)
0.02 10 0.56 28.38

1/ Intended for watersheds in theiz natural condition. If SSgniflcant
urbih areas exact use Page 4 for modlfieatfon.
32.75 5
3330 ft.
•