2009-09-29_PERMIT FILE - C1994082

• Permit No: C1994082
• IBM Index Class Name: Permit File
• Doc Date: 9/29/2009
• Doc Name: Drainage and Sediment Control Plan
• Section_Exhibit Name: Tab 13 Attachment 13-12
• Media Type: D
• Archive: No

February 1999 Yoast Mine * 13-12 Drainage and Sediment Contml plan ? i
TABLE OF CONTENTS
Section
•
Page No.
1.0 INTRODUCTION ...............................................................................................................................1
2.0 HYDROLOGIC CALCULATIONS .............................................................................................. 1
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 ................................................................................................................. 2
2.6 Time of Concentration, Tc ....................................................................................................... 2
2.7 Muskingum Routing Parameters, K, X .................................................................................. 2
2.8 Curve Number, CN .................................................................................................................. 3
3.0 SEDIMENTATION CALCULATIONS .......................................................................................3
3.1 Rainfall Factor, R .......................................................................................................................3
3.2 Soil Erodibility Factor, K .........................................................................................................3
3.3 Length-Slope Factor, LS ...........................................................................................................3
3.4 Control Factor, C ......................................................................................................................3
3.5 Practice Factor, P ......................................................................................................................6
3.6 Sediment Particle Distribution ................................................................................................6
4.0 PONDS .....................................................................................................................................................7
0 5.0 DITCH AND CULVERT DESIGN ...............................................................................................9
6.0 POST MINING CHANNELS ........................................................................................................10
6.1 Vegetated Channel Design .................................................................................................... 10
6.2 Rock Riprap Channel Design ............................................................................................... 11
6.3 Turf Reinforcement Mat Channel Design ..........................................................................12
7.0 SMALL AREA EXEMPTION DESIGN .....................................................................................14
8.0 STOCKPOND DESIGN ...................................................................................................................14
9.0 REFERENCES ....................................................................................................................................16

Montgomery Watson Mining Group * 165 S. Union Boulevard, Suite 460 * Lukemoo4 Colorado 80228 * [phone]
TR-44 Revised 08/09