2012-07-10_PERMIT FILE - C1981041 (5)

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PR -5 LS (length and percent slope) factors account for the length and percent slope. These factors are taken from Figure 4. 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. Greasewood Reference Area - LS Factor The LS factor for the Greasewood Reference Area is based on an average 10.6HAV Slope and an average vertical height of 10.1 feet and average length of slope is 107 feet based on eight flow lines located in the reference area. The length of slope of run -off from the reference area was increased to a length of 356.3 feet to make it comparable to the Cameo Borrow Area #2. Average Length 356.3 Feet Average Slope 9.4% Percent Slope (S) 8.0% 9.4% 10.0% 300 1.800 2.220 2.400 356.3 1 -LS -Factor 2.411 400 2.000 2.560 2.800 Cameo Borrow Area #2 - LS Factor The LS factor for the Cameo Borrow Area #2 is based on an average 11.9H:1 V slope at an average vertical height of 30.0 feet and an average length of slope of 356.3 feet based on three flow lines cut across the reclaimed landscape. Average Length 356.3 Feet Average Slope 8.4% Percent Slope (S) 8.0% 8.4% 10.0% 300 1.800 1.920 2.400 356.3 "LS" Factor 2.055 400 2.000 2.160 2.800 C (cropping - management) factors are the ratios of soil losses from lands cropped under specified conditions to the corresponding losses from tilled, continuous 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 Greasewood Reference Area No appreciable canopy. Canopy is assumed to be the cover contributed by trees and shrubs. Based on the 2010 Vegetation Evaluation the combined tree and shrub cover totals 11.25 %. The percent ground cover for the reference area shown above is 50.1 %. Use figure 7 identified above and interpolate to determine the C factor for 50.1 % cover. CANOPY NO APPRECIABLE CANOPY PERCENT GROUND COVER 40.0% 50.1% 60.0% No G 0.100 0.071 0.042 appreciable Adacent "C" Factor 0.071 canopy A14 -13 -9 02/12