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-19- <br />The bypass culvert will discharge into a riprap-lined temporary diversion <br />which will convey the flow into the natural drainage. Because of the high <br />slope of the channel, flow velocities during the 10-year, 24-hour event could <br />be as high as 16 feet per second. The applicant has committed to the <br />installation of adequate channel lining to inhibit erosion of the diversion <br />and appropriate measures to dissipate flow energy prior to discharge into the <br />receiving drainage. <br />The collection ditches and culverts conveying runoff from the disturbed area <br />at the mine bench will adequately carry the flow resulting from the 10-year, <br />24-hour event. Ditches collecting disturbed flow and diverting undisturbed <br />flow at the underground development waste disposal site will also be stable <br />under the 10-year, 24-hour peak flow conditions. <br />Central Facilities Area Collection Ditches, Culverts and Diversions <br />The collection ditches and culverts conveying runoff from the disturbed areas <br />at the central facilities area will adequately carry the flow resulting from <br />the 10-year, 24-hour event. The ditch collecting disturbed flow and diverting <br />undisturbed flow at the coal processing waste disposal site will also be <br />stable under the 10-year, 24-hour peakflow conditions. <br />Munger Creek Permanent Stream Channel Relocation <br />The combination channel, bank, and floodplain configuration of the relocated <br />stream channel will safely pass the peak runoff of a 100-year, 24-hour <br />precipitation event. The capacity of the reconstructed channel will be at <br />least equal to the capacity of the unmodified channel immediately upstream and <br />downstream of the reconstructed channel. <br />These components of the surface drainage system are in compliance with the <br />rules and Regulations. <br />VI. Hydrologic Balance: Ground Water - Rules 2.04.5, 2.045.7, 2.05.6(3) <br />an .0 <br />Information provided by the applicant with respect to ground water in the <br />permit area can be found in Sections 2.3.2, 2.6, and 4.4 in Volume I and <br />Sections ~~,~ 2.4.4, and 4.2 bf Volume VI of the application. Based on an <br />analysis of these data and information, the following determinations have been <br />made by the ivision. <br />-1r <br />Drilling in the area indicates the presence of a saturated zone within the <br />Cameo seam (figure 4.4-1). This saturated zone occurs outside of the permit <br />area within the Munger Canyon Mine plan area and will not be encountered by <br />projected mining within the Munger Canyon Mine. Data indicates that the <br />Carbonera seam, which overlies the Cameo seam, also becomes progressively <br />saturated to the northeast of the five-year permit area. The zone of <br />saturation in the Cameo seam is probably recharged at the point where the <br />