2008-12-04_PERMIT FILE - C1994082 ‎(2)‎

• Permit No: C1994082
• IBM Index Class Name: Permit File
• Doc Date: 12/4/2008
• Doc Name: 10 Year, 24 Hour Postmine SEDCAD Demonstration
• Section_Exhibit Name: Tab 13 Attachment 13-3A.1 Appendix 13-3A.1-A
• Media Type: D
• Archive: No

•

TR-37
YOAST MINE
Pond 10 -Watershed W-10
HYDROLOGIC INPUT PARAMETERS
SEDCAD 4
Structure 3 - SWS1
Watershed N/-10 (YPM-10)
Watershed Area: 61.9
Curve Number:
HYDROLOGIC CURVE
WATERSHED TYPE VEGETATION COVER SOIL GROUP NUMBER AREA (acres)
Aspen/Mountain Brush Good (>70%) D 48 0.4
Steep Mountain Brush Good (>70%) C 65 0.77
Steep Mountain Brush Goad (>70%) D 73 1.18
Sagebrush Fair (30%<x<70%) C 63 0.37
imed
l
R Fair (30%<x<70%) C 71 .59.2
ec
a Total 61.9
CURVE NUMBER 71
Vegetation cover conditions presented in Tab 10, Vegetation, Attachment 10-1, 1990/i992 Vegetation Baseline Report,
Yoast Study Area (ESCO Associates, 1993). Approved Yoast Mine curve numbers are presented in Attachment 13-12,
Fostmining 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.
SEDCAD 4
Structure 3 - SWS1
Watershed W-10 (YPM-10)
Sedimentology: k factor
HYDROLOGIC SOIL
SOILS MAP UNIT/SOILS SERIES GROUP k FACTOR ARFr4 (acres)
Reclaimed B 0.32 59.20
2D/E/F - Routt loam C 0.24 1.1
lex
borolls com
C
t
h D 0.20 1.6
p
ryo
en
s-
103 - Ustort
Total 61.9
Weighted k Factor 0.32
Soils series information from Yoast Mine Permit Application Package (see Tab 9, Soil Baseline Study [Nyenhuis,
1994]). Hydrologic Soil Group values are approved Yoast values (see Attachment 13-12, Table 13-12.2). The soil
erodibility factor, "k-Factor", values are presented in Attachment 13-12, Table 13-12.2.
13-3A.1-A.26
Revised 02/08