2010-10-07_PERMIT FILE - C1994082 ‎(2)‎

• Permit No: C1994082
• IBM Index Class Name: Permit File
• Doc Date: 10/7/2010
• Doc Name: YPM-9 to YPM-24, Dragline Deadhead Route Postmine Channel
• Section_Exhibit Name: Tab 13 Attachment 13-12 Appendix 13-12.3 Part 2
• Media Type: D
• Archive: No

•

YOAST MINE
Postmine Channel Designs -Channel YPM-11
HYDROLOGIC INPUT PARAMETERS
SEDCAD 4
Structure 4 - SWS1
Watershed W-16 (YPM-16)
Watershed Area: 18.1
Curve Number:
HYDROLOGIC CURVE
WATERSHED TYPE VEGETATION COVER SOIL GROUP NUMBER AREA (acres)
AspenlMountain Brush Geod (>70%) B 30 0.37
AspenlMountain Brush Goad (>70%) C 48 0.81
Sagebrush Goad (>70%) D 55 0.77
Fair (30% - 70%) B 71 16.16
Reclaimed Total 18.1
CURVE NUMBER 68
Vegetation cover conditions presented in Tab 10, Vegetation, Attachment 10-1, 1990/1992 Vegetation 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 Hydrology for Small
Watersheds, Technical Release No. 55, Soil Conservation Service, 1986.
~,
~_~

TR-37
13-12.3-141 B
Revised 02/08