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1 <br />' 6.2 Network and Configuration <br />6.2.1 Pre-Mining State <br />No large scale mapping or small contour interval mapping is available of the area that <br />portrays pre-mined conditions. Topography for the pre-mining state is taken as equal to <br />' present land forms. From the small scale mapping available (USGS Chimney Rock 7.5 <br />Minute Quadrangle), a dirt road may have extended across the slope, from the vicinity of <br />the North Flat to the vicinity of Sedimentation Pond 003. This road is omitted from this <br />analysis, but is compensated by a segment of road to be left in place, located parallel to <br />Ditches 3Sc and d. In this demonstration, the vegetative cover of the reference area is <br />considered as representative of the pre-mining cover over undisturbed ground. Runoff from <br />' the pre-mined East Slope Area flowed east across a small alluvial valley terrace into <br />Stollsteimer Creek and Deep Creek (an intermittent tributary of Stollsteimer Creek). <br />Vegetation on this alluvial area likely acted as a grass filter for runoff from the slopes above, <br />' thus a filter is included in this demonstration. Ditch systems are employed in this <br />demonstration to collect runoff for comparison to reclaimed conditions. <br />6.2.2 Reclaimed State <br />Ditches 3Sb and c and 3Nb and c are to be retained, other ditches and Sedimentation Pond <br />' 003 to be removed. The existing road parallel to Ditches 3Sc and d is to be retained. <br />Existing ditches are used in this demonstration to collect runoff for comparison topre-mining <br />' conditions. Pre-mining drainage patterns will be re-established after the reclamation work. <br />As runoff would still cross a vegetated alluvial valley terrace prior to discharging into local <br />drainages, a grass filter is included in this demonstration. Vegetative cover information was <br />' obtained from the 1996 Vegetation Survey (East Slope, South Slope, and Top Slope areas <br />as these areas coincide with the watershed). <br />' 6.3 Soils <br />The entire watershed is located on Carracas Loam. <br />6.4 Land Use Condition (LUC) <br />Reference is made to Paragraph 2.4. <br />6.5 Curve Number (CN) <br />6.x.1 Pre-Mined State <br />' A CN value of 37 over Carracas Loam is developed in Paragraph 2.7 for the Rangeland <br />Reference Area (1996 Vegetation Survey). <br />1 <br />Page 21 of 34, 7 Oct 96 <br />1 <br />