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i <br />TABLE 13-SA-7 <br />Drincipal end Emergency Spillway Deta Summery i <br />Sediment Dond 009 <br />Principal Spillway: <br />Type Drop Inlet (CMP) <br />Inlet Elevation 7086.3 ~30$(n.S <br />Length 725 feet <br />Diameter 78 inches <br />Slope 2 X 3•Z. <br />70-Yr, 24-Nr Peak Stage 7086.8 ~-o$~ <br />Emergency Spillway: <br />Type Trapezoidal Channel <br />Channel Protection Biprap and <br /> Landatrend/Vegetation <br />Bottom 4idth 15 feet <br />Length 30 feet $~ ~ <br />Side Slopes 38:tV and 2H:1V 3 ' ' <br />Outfell slope 6.5X `Y ~. • <br />Outfall Length 200 feet <br />Inlet Elevation 7089.5 ~-0 9 0 <br />25-year, 24-hour Peak Stage 7090.4 ~ o~jl <br />Summary <br />Sediment Pond 009's eapecity le ettrlbuted partially to the embankment and partially to <br />the pond excavation. During passage of the 10-year, 24-hour storm the spillway does not <br />discharge sediment downstream nor is there any flow through the emergency spillway. The <br />pond will be s temporary structure, end therefore has been designed to safely pass the <br />flow from the 25-year, 24-hour preci pitation event. The final ponding capacity will be <br />constructed to contain approximately four years of sediment storage. In addition, the <br />spillway is designed and constructed to sef sly discharge the 25-year, 24-hour storm event. <br />The embankment will be constructed to be stable and provide adequate freeboard. <br />Therefore, based on the design, this structure complies with the appropriate regulations <br />for a temporary sediment structure. Peabody Coal Campeny will periodically inspect the <br />structure }or sediment storage, atructura( integrity, end hazardous conditions. <br />Maintenance and remedial work will be performed in accordance with the approved mine • <br />permit. <br />73-SA-10 <br />