2011-07-01_PERMIT FILE - C1982057 ‎(6)‎

• Permit No: C1982057
• IBM Index Class Name: Permit File
• Doc Date: 7/1/2011
• Section_Exhibit Name: Tab 20 Attachment 20-1 Part 2
• Media Type: D
• Archive: No

SENECA II-W
Channel PM-1 System
HYDROLOGIC INPUT PARAMETERS
SEDCAD 4
Channel PM-1A
Watershed ID -Structure 1 - SWS1
Watershed Area:
32.9
Curve Number: Postmine Conditions
HYDROLOGIC CURVE AREA
WATERSHED TYPE VEGETATION COVER SOIL GROUP NUMBER (acres)
Aspen/Mountain Shrub Good (>70%) C 41 4.4
Sagebrush Good (>70%) C 47 0.3
Reclaimed Good (>70%) C 71 28.2
Total 32.9
CURVE NUMBER 67
Approved II-W Mine curve numbers are presented in Appendix 13-56, Postmining Drainage and Sediment
Control, Table 1, Seneca II-W (South Expansion Area) Curve Numbers. Values were adapted from Urban
Hydrology for Small Watersheds, Technical Release No. 55, Soil Conservation Service, 1986.
•
•

TR-59 20-1.141 Revised 05/07