2010-10-07_PERMIT FILE - C1994082

• Permit No: C1994082
• IBM Index Class Name: Permit File
• Doc Date: 10/7/2010
• Doc Name: Post Mining Channels SEDCAD Results/Channel YPM-1 to YPM-8
• Section_Exhibit Name: Tab 13 Attachment 13-12 Appendix 13-12.3
• Media Type: D
• Archive: No

•
Yoast Miine
Postmine Channel Design
f-iYDROLOGIC I~iFUT FARAI~IETi=RS
SEDCAD 4
Pcnd 012A
OPTION 2
V~latershed ID -Structure 11 - SWS1
~Natershed Area: 3.8
Curve Number:
HYDROLOGIC
CURVE
AREA
WATERSHED TYPE VEGETATION COVER SOIL GROUP NUMBER (acres)
Reclaimed Fair (30% - 70%) B 71 3.2
Good (>70%) B 30 0.6
Aspen/Mountain Shrub
Total 3.8
CURVE NUMBER 65
SEDCAD 4
Pond 012A
OPTION 2
Watershed ID -Structure 11 - SWS2
Pond surface
Watershed Area: 1.5
Curve Number:
HYDROLOGIC CURVE
AREA
WATERSHED TYPE VEGETATION COVER SOIL GROUP NUMBER (acres)
Pond Water surface N!A 99 1.5
1.5
Total
CURVE NUMBER 99
Vegetation cover canditions presented in Tab 10, Vegetation, Attachment 10-1, 1990/1992 Vegetaticn
Baseline Report, Yoast Study Area (ESCO Associates, 1993). Approved Yoast Mine curve numbers are
presented in Attachment 13-12, Postmining Drainage and Sediment Control ,Table 13-12.1. Values were
adapted from Urban Hydrelogy for Small Watersheds, Technical Releasa Mo. 55, Soil Conservation Service,
1988.
•
TR-37
13-12.3-26
Revised 02/08