2008-12-04_PERMIT FILE - C1994082 ‎(35)‎

• Permit No: C1994082
• IBM Index Class Name: Permit File
• Doc Date: 12/4/2008
• Doc Name: Sediment Ponds SEDCAD4 Results
• Section_Exhibit Name: Tab 13 Attachment 13-12 Appendix 13-12.1
• Media Type: D
• Archive: No

i
•
Yoast Mine
Pond 012A Design
HYDROLOGIC INPUT PARAMETERS
SEDCAD 4
Channel YPM-1-3
Watershed ID -Structure 5 - SWS1
West side subwatershed
Watershed Area: 9.5
Curve Number:
HYDROLOGIC CURVE AREA
WATERSHED TYPE VEGETATION COVER SOIL GROUP NUMBER (acres)
Reclaimed Fair (30% - 70%) B 71 6.28
/Mountain Shrub
A Good (>70%) B 30 3.23
spen
Total 9.51
CURVE NUMBER 57
SEDCAD 4
Channel YPM-1-3
Watershed ID - Stru WS2
East side subwatershed
Watershed Area: 11.6
Curve Number:
HYDROLOGIC CURVE AREA
WATERSHED TYFE VEGETATION COVER SOIL GROUP NUMBER (acres)
Reclaimed Fair (30% - 70%) B 71 10.50
Aspen/Mountain Shrub Good (>70%) B 30 0.30
Aspen/Mountain Shrub Good (>70%) C 41 0.40
Sagebrush Good (>70%) g 35 0.25
h
b Gocd (>70%) C 47 0.15
rus
Sage
Total 11.60
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, Fostmining Drainage and Sediment Control, Table 13-12.1. Values were
adapted from Urban Hydrology for Small Watersheds, Technical Release No. 55 ,Sail Conservation Service,
1986.
SEDCAD 4
Channel YPM-1-3
Watershed ID -Structure 5 - SWS1
Sedimentology: k factor
SOILS MAP UNIT/SOILS AREA
SERIES HYDROLOGIC SOIL GROUP k FACTOR (acres)
Reclaimed 8 0.32 6.28
m
I
d B 0.23 3.2
a
ca
53C/D/E/F - Wineva
Total 9'S
Weighted k Factor 0.29

TR-37
13-12.1-69
Revised 02108