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

YOAST MINE
Pond 10 -Watershed W-16
HYDROLOGIC INPUT PARAMETERS
SEDCAD 4
WATERSHED ID
Structure 4 - SWS1
Watershed W-16 (YPM-16)
Watershed Area:
19.1 acres
Curve Number:
VEGETATION HYDROLOGIC CURVE AREA
WATERSHED TYPE COVER SOIL GROUP NUMBER acres
Aspen/Mountain Brush Good (>70%) C 41 1.10
Sagebrush Good (>70%) C 47 0.96
Reclaimed Fare (30%<x<70%) B 71 6.06
Spoil Bare C 86 11.02
Total 19.1
CURVE NUMBER 77
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-55) ,Soil Conservation
Service, 1986.

SEDCAD 4
WATERSHED ID
Structure 4 - SWS1
Watershed W-16 (YPM-16)
Watershed Area:
19.1
Sedimentology
k Factor and Control Factor:
VEGETATION HYDROLOGIC k CONTROL AREA
WATERSHED TYPE COVER SOIL GROUP FACTOR FACTOR acres
Aspen/Mountain Brush Good (>70%) D 0.37 0.042 1.10
Sagebrush Good (>70%) D 0.19 0.042 0.96
Reclaimed Fair (30%<x<70%) B 0.16 0.043 6.06
Spoil Bare C 0.16 1.0 11.02
Total 19.1
0.17 0.59
TR-35 13-3A-A.23 Revised 08107