2008-12-04_PERMIT FILE - C1994082A ‎(16)‎

• Permit No: C1994082A
• IBM Index Class Name: Permit File
• Doc Date: 12/4/2008
• 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: Yes

i

TR-37
YOAST POSTMINE CHANNEL 12
HYDROLOGIC INPUT PARAMETERS
SEDCAD 4
WATERSHED ID
Structure 2 - SWS1
Channel YPM-12 Watershed
Watershed Area: 91.2
Curve Number:
HYDROLOGIC SOIL CURVE
WATERSHED TYPE VEGETATION COVER GROUP NUMBER AREA (acres)
Aspen/Mountain Brush Fair (30% - 70%) B 48 57.9
AspenlMountain Brush Fair (30% - 70%) D 63 13.1
Steep Mtn. Brush Fair (0% - 70%) D 83 3.3
Sagebrush Fair (30% - 70%) B 51 3.9
Sagebrush Fair (30% - 70%) D 70 7.2
W. Wheatgrass/Alkali Sagebrush Fair (30% - 70%) D 89 2.2
Reclaimed Fair (30% - 70%) B 71 3.6
Total 91.2
CURVE NUMBER 55
Vegetation cover conditions for undisturbed areas presented in Tab 10, Vegetation, Attachment 10-1, 1990/1992
Vegefation Baseline Report Yoast Study Area (ESCO Associates, 1993). Approved Yost 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
13-12.3-142K
Conservation Service, 1986.
Revised 08/OS