Laserfiche WebLink
Table 6.8.2-3 CP Value for Subwatersheds 1112, 2112, 3112, 3231, 3232 <br /> No appreciable canopy <br />% Ground Cover ~ <br />In Contact With <br />Ground Surface 40 56 60 <br />100% grass' 0.10 0.042 <br />73% grassz 0.114 0.067 0.055 <br />100% weeds <br />(fortis)' 0.15 0.090 <br />' Table S.Sc SEDCAD+ documentation. <br />= Includes grasses, litter and rocks, 1996 Vegetation Survey. <br />6.9 Grass Filter <br />The width of the alluvial valley terrace would act as a grass filter for runoff prior to such <br />runoff reaching the natural stream in the area (Stollsteimer and Deep Creek). In this <br />analysis, the first 100 feet is considered as a grass tilter. The grasses are equated to a fescue <br />in the SEDCAD+ selection tables, with a stem to stem spacing of 2 inches. The height of <br />grass was selected as 7 inches, Manning's n of 0.014, infiltration of 0.03, and a stiffness factor <br />of 20. The size of the representative filter is 100 feet long, 100 feet wide, at a slope of 3%. <br />6.10 Comparisons of Water Quality <br />SEDCAD+ demonstration results are presented in Table 6.10-1. <br />Table 6.10-1 Summary of SEDCAD+ Demonstrations <br />Parameter Pre-Mining j Reclaimed <br /> Rangeland Permit Description 1996 Vegetation <br /> Reference ~ Survey <br />Peak Sediment 274' 1422' 433' <br />Concentration <br />(SCp) (mg/l) <br />' SEDCAD+ Demonstration File Name: <br />Appendix J <br />- SEDCAD+ Demonstration File Name: <br />Appendix K <br />' SEDCAD+ Demonstration File Name: <br />Appendix L <br />C:\SEDCAD3\CR\ES, 09-12-1996, 13:42:53, <br />C:\SEDCAD3\CR\ES2, 10-04-1996, 16:08:50, <br />C:\SEDCAD3\CR\ESr, 09-12-1996, 13:54:37, <br />Page 23 of 34, 7 Oct 96 <br />