2017-08-15_PERMIT FILE - C1980007A ‎(3)‎

• Permit No: C1980007A
• IBM Index Class Name: Permit File
• Doc Date: 8/15/2017
• Section_Exhibit Name: Exhibit 66 Mine Water Control Plan
• Media Type: D
• Archive: Yes

West Elk Mine - Mine Water Control Plan Mountain Coal Company
TABLE OF CONTENTS
1.0 INTRODUCTION..................................................................................................................1
1.1 Project Description....................................................................................................1
1.2 Analysis Methods......................................................................................................1
1.3 Design Criteria..........................................................................................................1
2.0 SEDCAD+ INPUT PARAMETERS APPLICABLE TO ENTIRE PROJECT ..........................2
2.1 Storm Type...............................................................................................................2
2.2 Rainfall Depth............................................................................................................2
2.3 Structure Naming Convention...................................................................................2
3.0 SEDCAD+ INPUT PARAMETERS FOR SUBWATERSHEDS.............................................3
3.1 Subwatershed Boundary ........................................................................................... 3
3.2 Soil Type & Land Cover............................................................................................3
3.3 Subwatershed Hydrologic Parameters......................................................................4
3.3.1 Hydrologic Soil Group ..................... ...........................................................................4
3.3.2 Curve Number............................................................................................................4
3.3.3 Time of Concentration................................................................................................4
3.3.4 Muskingum Routing Parameters................................................................................4
3.3.5 Hydrograph Response Shape....................................................................................5
3.4 Subwatershed Sediment Parameters........................................................................5
3.4.1 Soil Erodibility Factor, K.............................................................................................5
3.4.2 Length -Slope Factor, LS............................................................................................5
3.4.3 Control Practice Factor, CP.......................................................................................5
3.4.4 Particle Size Distribution............................................................................................ 6
4.0 SEDCAD+ INPUT PARAMETERS FOR STRUCTURES......................................................7
4.1 Ditches......................................................................................................................7
4.2 Culverts.....................................................................................................................7
4.3 Muskingum Routing...................................................................................................7
4.4 Ponds........................................................................................................................7
5.0 SEDCAD+ OUTPUT / RESULTS.........................................................................................8
5.1 Ponds........................................................................................................................8
5.2 Subwatersheds.........................................................................................................8
5.3 Ditches and Culverts................................................................................................. 8
5.4 Small Area Exceptions and Other Exemptions.......................................................... 8
APPENDIX A: OUTPUT SUMMARY TABLES
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