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2.5 Practice Factor, P <br />The practice factor is used to account for conservation practices for the watershed. As indicated <br />m previous he following values were utilized (Renard era[, 1996)(Schwab and Warner, 1987): <br />TABLE 4 <br />PRACTICE FACTOR <br />SURFACE SURFACE TYPE. PRACTICE CONTROL FACTOR <br />Undisturbed Mountain Shrub None 0.90 <br /> Oak-Aspen None 0.90 <br /> Sagebrush (good) None 0.90 <br /> Sagebrush (fair) None ~ 0.90 <br />. Disturbed Topsoil Stripped None ~ ~ 0.40 <br />Reclaimed Topsoiled aad Seeded Contour Furrowed ~ 0.38 <br /> 1 to 2 Year Growth ~ Contour Furrowed 0.38 <br /> 3+ Year Growth Contour Furrowed ~ 0.38 <br />2.6 Sediment Particle Distribution <br />• A sediment particle size distribution was input into the SEDCAD+ computer model based on <br />a weighted average of the chemical and physical data for the mine site. The following <br />distribution was agreed upon between the DMG and Colowyo: <br />Sand 27°!0 <br />S11C 40% <br />Clay 33°Jo <br />A sediment distribution was created based.on the above- data and input into the SEDCAD+ <br />program. The resulting sediment distribution is shown on the SEDCAD+ printouts and on <br />the attached graphical representation. <br />3.0 Pond Geometry Input Parameters <br />Pond dimensions and input pazameters were obtained from the pond proposed plan maps. The <br />input parameters are shown on the SEDCAD+ printouts and summarized in Table 5. <br />4.0 RESULTS <br />The results of the analyses are summarized in Table 5. The supporting SEDCAD+ analyses <br />and watershed maps aze presented in Appendices A-J. <br />• Some of the SEDCAD+ printouts, for the sedimentation ponds, indicate chat the stage of the <br />principle spillway may cause bed scour. The caution message indicates that the observed <br />S <br />~:191~rnnha4.Ea <br />iVV/N LS~PN REVISED 11/98 <br />