PERMFILE56724

• Permit No: C1994082
• IBM Index Class Name: Permit File
• Doc Date: 9/27/2007
• Doc Name: 10-Year, 24 Hour SEDCAD Demonstration
• Section_Exhibit Name: Tab 13 Attachment 13-3A.2 Addendum 13-3A-A
• Media Type: D
• Archive: No

C
YOAST MINE
Pond 10 -Watershed W-8
HYDROLOGIC INPUT PARAMETERS
SEDCAD 4
WATERSHED ID
Structure 6 - SWS1
Watershed W-8 (YPM-8)
Watershed Area:
27.1
Curve Number:
VEGETATION HYDROLOGIC CURVE AREA
WATERSHED TYPE COVER SOIL GROUP NUMBER (acres
Aspen/Mountain Brush Good (>70%) C 41 2.9
Reclaimed Fair (30%<x<70%) B 71 15.98
Spoil Bare C 86 8.23
Total 27.1
CURVE NUMBER 72
Curve number (CN) values used are approved Yoast Mine values (see-Table 13-12.1). Values were adapted
from Urban Hydrology for Small Watersheds, Technical Release No. 55 (TR-55J ,Soil Conservation Service,
7 986.
SEDCAD 4
WATERSHED ID
Structure 6 - SWS1
Watershed W-8 (YPM-8)
Watershed Area:
27.1
Sedimentology
k Factor and Control Factor:
VEGETATION HYDROLOGIC k CONTROL AREA
WATERSHED TYPE COVER SOIL GROUP FACTOR FACTOR acres
Aspen/Mountain Brush Good (>70%) C 0.23 0.042 2.9
Reclaimed Fair (30%<x<709'°) B 0.16 0.043 75.98
Spoil Bare C 0.76 1.0 8.23
Total 27.1
0.17 0.33
TR•35
13-3A-A.25
Revised 08/07