2020-12-12_GENERAL DOCUMENTS - C1981010

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Table 4. USLE Variables and Basis for Selection Pre-mining Variable Trapper's Trapper's Source Division's Comment Selection R 30 SCS Map: R factors for Colorado Reasonable, as per Trapper's location on R factor map. Trapper Permit C1981010 Appendix Q Section Reasonable, as per soil types of K 0.25 XIII ,Table E3 bond release blocks delineated on map M29. LS 8.92 SCS LS Table, 748 ft, 17.5%Slope Reasonable based on the 17.5% slope and 748 ft. slope length Reasonable as per pre-mining rangeland conditions and C 0.05 SCS C factor table for specified conditions applicable C value tables 2.3-13 and 4.4-2. Reasonable as per erosion control practice factor, P 1 SCS P factor table for specified conditions consistent with premiing practice on bond release blocks. Table 4 cont. USLE Variables and Basis for Selection Post-mining Variable Trapper's Trapper's Source Division's Comment Selection R 30 SCS Map: R factors for Colorado Reasonable, as per Trapper's location on R factor map. Trapper Permit C1981010 Appendix Q Section Reasonable, as per soil types on K 0.25 XIII bond release blocks delineated on map M29. LS 8.92 SCS LS Table, 748 ft. 17.55%Slope Reasonable based on the 17.5% slope and 748 ft. slope length SCS C factor table for permanent pasture, rangeland, idle land and grazed woodland - Reasonable as per vegetation C 0.033 data submitted with SL22 no canopy, 74.1 herbaceous cover,grass type (Table 1.2-1 of bond release application. application (Table 1.2-1). P 1 SCS P factor table for specified conditions Reasonable, as no control practices were utilized. SEDCAD Comparison: Trapper utilized baseline data for selecting SEDCAD 4 parameters for modeling pre-mining conditions. Trapper utilized recent vegetative data in the bond release submittal for modeling post-mining conditions. The parameters employed in the SEDCAD model and their definitions are presented in the table below: Permit Number C1981010 SL22 Page 13 of 18