PERMFILE131983

• Permit No: C1982057A
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Doc Name: As-Built Report Sedimentation Structure Pond 005
• Section_Exhibit Name: Tab 13 Attachment 13-3C
• Media Type: D
• Archive: Yes

Land Flow
Condition Vertical
Dist (ft) Horizontal
Dist (ft) Slope
(X) Velocity
(fps) Time •
(hrZ
2 382 2300 16.61 2.04 0.314
5 130 1280 10.16 3.19 0.112
6 30 720 4.17 3.06 0.065
Total Time of Concentraii orL SWS-1 0.490
?
- ~~
2 315 1800 17.50
-• 2.09 0.239
5 250 2040 12.25 3.50 0.162
Total Time of Concentration SWS-2 0.401
2 380 2200 17.27 2.08 0.294
6 160 1720 9.30 4.57 0.104
Tot el Time of Concentration SWS-3 0.399
Sedimentoloav. The SEDCAD computer program was utilized to calculate the sedimenC
flowing into and through the principal spillway using the DEPOSITS portion of the program.
The results show there was no sediment flowing out of the pond es a result of the 10-year,
24-hour storm (100X Basin Trap Efficiency).
To determine the sediment l
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to quantify the sediment storage. The amount of sediment storage is determined for a
defined length of time and is based on the design storm R, design storm sediment load,
average Annual R, and the number of years of sediment storage desired. R is the rainfall
erosivity factor. The equation utilized for Required Sediment Storage is:
Required Storage = (Annual R) (#Years) (Storm Sediment Load}
Storm R
Annual R end the number of years are input. Storm R end Storm Sediment Load ere
calculated for the design storm by Sedcad+.
A value of 30 for the average Annual R value and a period of one year was used. Sedced+
determined the required Sediment Storage for the one year period to be 1.1 ec-ft. The
amount of available sediment storage is 2.5 ac-ft (elevation 6864.4). Therefore, when 60
percent of the sediment storage capacity has been consummed (1.5 ac-ft), the pond will be
cleaned out.
~~
i
13-3-8 Revised 08/11/92