PERMFILE114555

• Permit No: C1982057A
• IBM Index Class Name: Permit File
• Doc Date: 7/15/2005
• Doc Name: Drainage and Sediment Control Plan II-W South Extension
• Section_Exhibit Name: Tab 13 Attachment 13-5B
• Media Type: D
• Archive: Yes

2002 Senera IIW,Sautb F_ayanrian * Drainage mrd Sediment Confro! Plan 1 TOC- i
Section No.
PanvNo.
1.0 INTRODUCTION ...............................................................................................................................1
2.0 HYDROLOGIC CALCULATIONS .................................................................................................. 2
2.1 PRECIPITATION DISTRIBUTION ........................................................... ..................................... 2
2.2 STORM DURATION .................................................................................. ..................................... 2
2.3 RETURN PERIOD/PRECIPITATION ....................................................... ..................................... 2
2.4 HYDROGRAPH RESPONSE SHAPE ........................................................ ..................................... 2
2.5 DRAINAGE BASIN AREA ........................................................................ ..................................... 3
2.6 TIME OF CONCENTRATION, Tc ............................................................. ..................................... 3
2.7 MUSKINGUM ROUTING PARAMETERS, K, X ..................................... ..................................... 3
2.8 CURVE NUMBER, CN ............................................................................... ..................................... 3
3.0 SEDIMENTATION CALCULATIONS ...........................................................................................4
3.1 RAINFALL FACTOR, R ........................................................................ .......................................... 4
3.2 SOIL ERODIBILITY FACTOR, K ........................................................ .......................................... 4
3.3 LENGTH-SLOPE FACTOR, LS ............................................................ .......................................... 4
3.4 CONTROL FACTOR, C ......................................................................... .......................................... 4
3.5 PRACTICE FACTOR, P ........................................................................ .......................................... 5
3.6 SEDIMENT PARTICLE DISTRIBUTION ............................................ .......................................... 5
4.0 PONDS .................................................................................................................................................6
5.0 HAUL ROAD CHANNEL AND CULVERT DESIGNS .................................................................8
6.0 POST MINING CHANNELS ............................................................................................................ 9
7.0 REFERENCES ..................................................................................................................................12
LIST OF TABLES
Table No. Description
Page No.
1 Seneca IIW (South Expansion Axea) Curoe Number .......................................................3
2 Soil Erodibility Factor ............................................................................................................4
3 Control Factox .........................................................................................................................5
4 Practice Factor .........................................................................................................................5
5 Seneca IIW (South Expansion) Sediment Pond Summary ...............................................7
LIST OF FIGURES
Fievre No. Description Pan~~No.
1 Postmine Channel Design ..................................................................................................10
MWH * 165 S. Union Boulevard, Suite 410 * Lakemaad, Colorado 80228 * (970J 763-5140
TABLE OF CONTENTS
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