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RECLAIMED AREA -"C" FACTOR <br />Cameo Borrow Area #1 <br />No appreciable canopy. Canopy is assumed to be the combined cover contributed by trees and shrubs. <br />Based on the 2010 Vegetation Evaluation the combined tree and shrub cover totals 22.7 %. The percent <br />ground cover for the reclaimed area shown on the preceding page is 52.8 %. Use figure 7 identified above and <br />interpolate to determine the C factor for 52.8% cover. <br />CANOPY NO APPRECIABLE CANOPY <br />PERCENT GROUND COVER <br />40.0% 52.8% 60.0% <br />No G 0.100 0.063 0.042 <br />appreciable Adacent "C" Factor 0.063 <br />canopy <br />USING THE UNIVERSAL SOIL LOSS EQUATION <br />A= RKLSCP <br />A is the soil loss in Tons/Acre/Year <br />Grease - <br />wood <br />Adjacent <br />CBA#1 <br />Reclaimed <br />R = rainfall factor <br />20.00 <br />20.00 <br />K = soil erodibili factor - Torriorthents <br />0.37 <br />0.37 <br />LS = combined length slope factor <br />2.03 <br />1.48 <br />C = cropping management factor: <br />"C" - Crop Management - Greasewood <br />Canopy <br />11.3% <br />Cover - Grass <br />4.9% <br />Ground Cover <br />50.1% <br />0.071 <br />"C"- Crop Management - CBA#1 <br />Canopy <br />22.7% <br />Cover - Grass <br />1.2% <br />Ground Cover <br />52.8% <br />0.063 <br />P = erosion control practice <br />factor <br />1.00 <br />1.00 <br />SOIL LOSS CALCULATION <br />AREA R K I LS C P A <br />Greasewood Reference Area - Adjacent <br />20 1 0.37 2.03 0.071 1.0 1.07 <br />Cameo Borrow Area #1 - Reclaimed <br />20 1 0.37 1.48 0.063 1.0 0.69 <br />It can be seen from the above calculation that the revegetated area of the Cameo Borrow Area #1 may lose <br />about 0.69 tons per acre per year. The adjacent area may lose about 1.07 tons per acre per year to erosion. <br />The above calculation demonstrates that untreated drainage from the reclaimed area contributes fewer <br />suspended solids to streamflow or runoff outside the permit area than untreated drainage from the natural <br />surrounding premining area. CBA#1 Sump receives drainage from the Cameo Borrow Area #1. Based on <br />this demonstration, CBA#1 Sump can be reclaimed. <br />CBA#1 Sump has never discharged, therefore, no quality analysis has been performed on the runoff to or from <br />this pond. The disturbed area will not contribute additional suspended solids above natural conditions, and the <br />quality of untreated drainage from the disturbed area will meet the State and Federal water quality standard <br />requirements applicable after the sedimentation pond and treatment facilities are removed because the <br />surrounding areas are very well vegetated and there is virtually no erosion or other stability issues. It is unlikely <br />any significant runoff from the well vegetated reclaimed area will reach the Colorado River. The calculated <br />runoff from the reclaimed area for the 25 year storm (1.8 ") event for CBA#1 Sump is 0.18 AF (Appendix 13-3), <br />which is insignificant when compared to the average annual runoff generated from the entire Colorado River <br />drainage (2.8 million AF per year). <br />PR -5 A1413 -17 02/12 <br />