2008-12-04_PERMIT FILE - C1994082 ‎(20)‎

• Permit No: C1994082
• IBM Index Class Name: Permit File
• Doc Date: 12/4/2008
• Doc Name: 10 Year, 24 Hour SEDCAD Demonstration
• Section_Exhibit Name: Tab 13 Attachment 13-20.1 Appendix 13-20.1-A
• Media Type: D
• Archive: No

Yoast M9ne
Pond 013 Permanent Fea#ur2 Demonstration
HYDROLOGIC INPUT PARAMPTERS

SEDCAD 4
YPM-17
Watershed ID -Structure 2 - SWS1
N/atershed Area: 8.7
Curve Number:
VEGETATION HYDROLOGIC CURVE AREA
WATERSHED TYPE COVER SOIL GROUP NUMBER (acres)
Reclaimed Fair (30% - 70%) B 71 8.38
Aspen/Mountain Brush Fair (30% - 70%) D 63 0.2
W. Wheatgrass/Alkali Sagebrush Fair (30% - 70%) D 89 0.2
Total 8.7
CURVE NUMBER 71
Vegetation cover conditions presented in Tab 10, Vegetation, Attachment 10-1, 1990/1992 Vegetation Baseline
Report, Yeast Study Area (ESCO Associates, 1993). Approved Yeast Mine curve numbers are presented in
Attachment 13-12, Postmining Drainage and Sediment Control ,Table 13-12.1. Values were adapted from Urban
Hydrology for Smolt Watersheds, Technical Release No. 55, Soil Conservation Service, 1986.
•
YPM-17
Watershed ID -Structure 2 - SWS1
Sedimentology: k factcr

SOILS MAP UNIT/SOILS SERIES HYDROLOGIC SOIL
GROUP
k FACTOR AREA
(acres)
Reclaimed
35D/F - Aaberg clay B
D 0.32
0.19 8.38
0.33
Total 8.7
Weighted k Factor 0.32
Soils series information from Yoast Mine Permit Application Package (see Tab 9, Soil Baseline Study [Nyenhuis,
1994]). Hydrologic Soil Group values are approved Yoast values (see Attachment 13-12, Table 13-12.2). The soil
erodibility factor, "k-Factor", values are presented in Attachment 13-12, Table 13-12.2.
YPM-17
Watershed ID -Structure 2 - SWS1
Sedimentology: Control Factor
CONTROL AREA
LAND USE CONDITION COVER TYPE VEGETATION FACTOR (acres)
Undistrubed Aspen/Mtn. Brush 25% canopy, 80%
ground cover 0.042 0.15
Herbaceous 60% ground cover 0.042 0.2
Reclaimed Reclaimed 60% ground cover 0.042 8.38
Total 8.7
Weighted Control Factor 0.042
The Control Factor values are approved Yoast Mine values as presented in Attachment 13-12, Table 13-12.3. The
values were originally presented in Renard, et al. (1997) Predicting Soi! Erosion by Water.' A Guide to Converation
Planning with the Revised Universal Soil Loss Equation (RUBLE), Agricultural Handbook 703, U.S. Department of
Agriculture as reported in Warner et al. (1998) as reported in Wamer et al. (1998).
TR-37
13-20.1-A.14
Revised 02/08