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CYCC - .Sediment Yield Demanarnrion Ecl<mnn Pnrk Area 4! • SOiL NAME K FACTOR AABer SiIN Clav 0.28 AABer -Wavbe Com lex 0.32 - 0.37 Arbor SiIN Cla Loam 0.28 Arbor-Moverson Com lex 0.32 - 0.37 Binco Si1N Cla Loam 0.32 Buckskin Loam 0.32 Bulklev SiIN Clav Loam 0.28 Cocheto a Loam 0.28 Coutis Fine Sandv Loam 0.20 Cra o Clav Loam 0.24 Routt Loam 0.24 Roxal Variant-Lvmanson-Starman Com lex 0.32 Skvlick Loam 0.28 S vav Loam 0.20 Winevada-S litro Com lex 0.17 Cvroborolls, Torriorhents-Rock Outcro Com !ex NA Unnamed-Cocheto a Com lex 0.30 The weighted average K factor is 0.22 for Eckman Park. K factor calculations c:.n be found in Appendix A, Table 2. The K factor for the Pastureland Reference Area is 0.32. As previously stated, the soils found in Eckman Park are similar to the soils found in adjacent pastureland areas; therefore, the K factors for these areas should not vary significantly when compared to the K factors for the reclaimed blocks. Representative Slope Length. The slope length is representative of the typical slope length over the subwatershed and was determined as the distance from point of origin of overland flow to the point where the slope decreases such that significant deposition occurs or until Flow enters a defined channel. For the representative one acre parcels evaluated in this model, the assumption was made that overland flow typically occurs over the entire length of the modeled area (208.71 feet) for the unmined parcels. For the mined parcels, overland flow is interrupted by the presence of contour furrows which were established during the final grading of the reclaimed parcels. To simplify the model inputs, the contour furrows were modeled to occur at 52.17 foot width increments. A review of aerial photos covering the proposed bond release blocks and an on the ground inspection of these areas in the field indicates that furrows are hpically established at between 40 and 50 feet in the areas with flatter slopes and behveen 10 and 20 feet in areas with steeper slopes. Thc representative slope length is therefore conservatively overestimated on the reclaimed sites in the SEDCAD+ model evaluations. The principle of contour furrowing as applied at CYCC was [o increase depression storage and interrupt overland flow to the extent that design event runoff from dte drainage area could be completely contained in surface depressions. Average Slope. The average slopes are entered in percent and are the hpical or representative slopes for overland flow for each block. These average slopes were measured directly from the I" = 500' scale maps • available for both areas. As previousl}• mentioned, these representative slopes were utilized in modeling runoff responses for both the mined and unmincd areas. Contro! Practice Factor. The control practice (CP) factor is defined as the ratio of sediment loss from an area with a given cover and consen-a[ion practice to that of a field in continuous fallow. CP factors as determined in • ion`enviromnmlal`eanrhondmllvr~a Ldor