2008-01-16_PERMIT FILE - C1994082A ‎(2)‎

• Permit No: C1994082A
• IBM Index Class Name: Permit File
• Doc Date: 1/16/2008
• Doc Name: Sediment Ponds SEDCAD4 Results
• Section_Exhibit Name: Tab 13 Attachment 13-12 Appendix 13-12.1
• Media Type: D
• Archive: Yes

Yoast Mine
Pond 12A Design
HYDROLOGIC INPUT PARAMETERS
SEDCAD 4
Channel YPM-1-2
Watershed ID -Structure 3 - SWS1
Watershed Area: 3.1
West side subwatershed
Curve Number:
HYDROLOGIC CURVE AREA
WATERSHED TYPE VEGETATION COVER SOIL GROUP NUMBER (acres)
Reclaimed Fair (30% - 70%) B 71 2.6
Aspen/Mountain Shrub Good (>70%) C 41 0.6
Total 3.1
CURVE NUMBER 66

SEDCAD 4
Channel YPM-1-2
Watershed ID -Structure 3 - SWS2
Watershed Area: 7.8
East side subwatershed
Curve Number:
HYDROLOGIC CURVE AREA
WATERSHED TYPE VEGETATION COVER SOIL GROUP NUMBER (acres)
Reclaimed Fair (30% - 70%) B 71 5.8
Reclaimed Topsoiled, no vegetation B 86 1.4
Aspen/Mountain Shrub Good (>70%) C 41 0.6
Total 7.8
CURVE NUMBER 72
Approved Yoast Mine curve numbers are presented in Appendix 13-12, Postmining Drainage and Sediment
Control ,Table 13-12.1. Values were adapted from Urban Hydrology for Small Watersheds, Technical
Release No. 55, Soil Conservation Service, 1986.
•
TR-36
13-12.1-65
Revised 08/07