2009-10-13_PERMIT FILE - C1991078A ‎(3)‎

• Permit No: C1991078A
• IBM Index Class Name: Permit File
• Doc Date: 10/13/2009
• Section_Exhibit Name: 2.05 Operation and Reclamation Plan
• Media Type: D
• Archive: Yes

•
use and treatment. Soils having the highest K value are the most erodible. The K
value used for this calculation is picked from the U.S. Department of Agriculture Soil
Survey, San Miguel Area, and is based on the soils classification; Barx. The K factor of 0.24
is the same for both the reclaimed slope and the adjacent natural slope.
LS (length and percent slope) factors account for the length and percent slope. These
factors are taken from Table 1. Length of slope begins at the top of the micro
watershed. This is usually at the top of a hill, ridge, terrace or diversion. The length of
slope is considered to end for a given field at one of the following places: (1) the point
where the slope decreases to the extent that deposition occurs, (2) the point where
runoff enters a well-defined channel, gully, terrace or diversion, or (3) where water
leaves the field. The LS for the reclaimed slope was measured near the southern end of the
re-seeded area, where the disturbed area length is about 1200-feet and the slope is about 3%.
Reclaimed
Length Percent Slope (S)
of Slope
2.0% 2.8% 3.0%
1200 0.420 0.732 0.810
1217 'YS" Factor 0.734
1300 0.430 0.742 0.820
The LS factor for the adjacent area was measured east of Mining Area No. 1, and parallel to the
re-seeded area LS, where the disturbed area length is about 1200 feet and the slope is 2.5%.
• Adjacent
Length Percent Slope (S)
of Slope
2.0% 2.5% 3.0%
1200 0.420 0.615 0.810
1217 "LS" Factor 0.617
1300 0.430 0.625 0.820
C (cropping - management) factors are the ratios of soil losses from lands cropped
under specified conditions to the corresponding losses from tilled, continuos fallow. C
factors for land uses other than cropland are included on Figures 7,8, and 9. The
percent ground cover is the primary item to consider because a slight change in the
percent ground cover will result in a significant change in the erosion prediction.
Figure 7 - "C" Factors for Permanent Pasture and Rangeland
ADJACENT AREA - "C" FACTOR
No appreciable canopy. Canopy is assumed to be the combined cover contributed by trees and shrubs.
Based on the 2009 vegetation study the combined tree and shrub cover totals 8.7%. The percent
ground cover for the adjacent area shown on the preceding page is 48.8%. Use figure 7 identified
above and interpolate to determine the C factor for 48.8% cover.
•
TR-/D
19WIDY0
13.OCf'2W9
TR-10 2.05-8v
08/09