2008-12-04_PERMIT FILE - C1994082 ‎(15)‎

• Permit No: C1994082
• IBM Index Class Name: Permit File
• Doc Date: 12/4/2008
• Doc Name: 10 Year 24 Hour SEDCAD Demonstration
• Section_Exhibit Name: Tab 13 Attachment 13-19.1 Appendix 13-19.1-A
• Media Type: D
• Archive: No

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.'7
TR-37
Yoast Mine
Pond 011A Storage Capacity Demonstration
HYDROLOGIC INPUT PARAMETERS
SEDCAD 4
Channel YPM-13
Watershed ID -Structure 2 - SWS1
Watershed Area: 26.3
Curve Number:
VEGETATION HYDROLOGIC CURVE AREA
WATERSHED TYPE COVER SOIL GROUP NUMBER (acres)
Reclaimed Fair (30% - 70%) B 71 26.1
Aspen/Mountain Brush Fair (30% - 70%) D 63 0.2
Total 26.3
CURVE NUMBER 71
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.
SEDCAD 4
Channel YPM-13
Watershed ID -Structure 2 - SWS1
Sedimentology: k factor
HYDROLOGIC SOIL AREA
SOILS MAP UNIT/SOILS SERIES GROUP k FACTOR (acres)
Reclaimed B 0.32 26.1
103 - Ustorthents-Cryoborolls complex D 0.20 0.2
Total 26.3
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.
13-19.1-A.12
Revised 08/08