PERMFILE48355

• Permit No: C1996083A
• IBM Index Class Name: Permit File
• Doc Date: 3/23/2004
• Doc Name: Appendix A to Appendix C - Report Dated 11/10/03
• Section_Exhibit Name: Coal Mine Waste Disposal Area No. 2
• Media Type: D
• Archive: Yes

APPENDIX B
•
BOWIE N0.2 MINE -COAL MINE WASTE DISPOSAL AREA
PROTECTION OF THE HYDROLOGIC BALANCE
STORM EVENTS
10 YEAR 24 HOUR EVENT 1.8 INCHES
25 YEAR 24 HOUR EVENT 2.1 INCHES
100 YEAR 24 HOUR EVENT 2.6 INCHES
The information presented for peak flow calculations is developed with the use of the
SEDCAD. The output data from SEDCAD follows this section.
The upland run-off areas are shown on Map No. 20 in Volume II. The run-off curve
numbers are developed based upon vegetation and soil types. Vegetation data are
presented in Volume III Exhibit 5 and shown on Map 3 in Volume II. Soils data are
presented in Volume III Exhibit 7 and shown on Map 4 in Volume II. Ditches culverts
and drainage plans are shown on Figure 2.
CURVE NUMBERS
• Disturbed
Table 2-2d-Runoff curve numbers for arid and semiarid rangelands
Cover Type -Herbaceous-mixture of grass, weeds and brush
Hydrologic Condition Fair
Soil Type -Loam C
Curve Number 87
Burned Area
1995
Vegetative Cover % 50.0 Veg Rep. Page 21
Table 2-2d-Runoff curve numbers for arid and semiarid rangelands
Cover Type -Herbaceous-mixture of grass, weeds and brush
Hydrologic Condition Fair
Soil Type -Loam C
Curve Number 81
Coal Mine Waste
Table 2-2d-Runoff curve numbers for arid and semiarid rangelands
Cover Type -Herbaceous-miMure of grass, weeds and brush
Hydrologic Condition Poor
Soil Type D
Curve Number 93
APP-B - 2 - 11/03