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roughened condition prevalent on the reclaimed lands as compared to undisturbed areas. An adjustment <br />factor for the tabular C values of 0.65 was applied to reflect "moderate" surface roughness conditions on <br />the reclamation. Several reclamation practices account for the development of this roughness. To the <br />extent practicable, all farming operations associated with reclamation activities are performed along the <br />contour. Specifically, seedbed preparation and seeding activities are intentionally conducted along the <br />contour. The seeding process itself incorporates a tillage practice which results in a roughened soil <br />surface exhibiting a series of furrows oriented perpendicular to the slope. These practices result in a <br />roughened surface on the reclamation particularly as compared to undisturbed areas. In addition, the <br />documented higher effective cover values established on reclamation also act to roughen the reclaimed <br />surface by necessitating more tortuous flow paths. As a further consideration, Trapper's reclamation <br />procedures routinely include the use of contour ditches and small depressions (i.e. livestock water tanks) <br />to enhance slope stability and reduce erosion. Contour ditches are typically removed after vegetation has <br />become well established, however, the livestock water tanks, which are typically situated in drainages, <br />remain as permanent features. The contour ditches act to shorten overland flow lengths and rill erosion <br />flow paths while vegetation is becoming established and thereby serve to protect the integrity of the initially <br />roughened reclaimed surface until vegetation is established. <br />In all instances, the SEDCAD 4 models demonstrate the total sediment generated from the reclaimed <br />blocks is less than or approximately equal to the total sediment generated from the same blocks under <br />pre -mining conditions. These results are primarily attributable to the excellent cover values documented <br />to occur on the reclaimed lands. <br />1.4.3 CONCLUSIONS <br />Both the USLE and SEDCAD 4 evaluations demonstrate that existing conditions will result in equivalent or <br />lesser sediment contributions to surface runoff when compared with pre -mining levels as determined by <br />baseline data. Both methodologies possess certain strengths and limitations and each offers a distinct <br />and different view of the test required to meet Phase II criteria. The herbaceous cover and C -factor <br />variables are critical to both approaches. Both methods account for and reflect the outstanding cover <br />percentages established on the Trapper reclamation in the areas being evaluated. In a similar previous <br />analysis conducted by CDRMS (SL -1 application), these methodologies were in effect validated and found <br />to be conservative by comparing their results to direct measurements of sediment accumulations <br />occurring in downgradient catchments at Trapper. For this particular application, the same type of <br />verification exercise is not feasible as extensive disturbed areas also contribute runoff and sediment to the <br />downgradient catchments. Trapper, however, does note that the currently pending application addresses <br />areas with strong similarities to those previously evaluated and verified by CDRMS. The vegetative cover, <br />cover type, topographic setting, and reclamation methodologies employed are all comparable. Given <br />these similarities, Trapper believes it is reasonable to conclude that equivalent conditions, in terms of <br />erosion and sediment transport, prevail on the reclaimed blocks addressed by this application. <br />15 <br />