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TABLE 6 (Cont.) <br /> Design Storage Capacity Summary <br /> Sedimentation Pond 007 <br /> Elevation Stage Capacity <br /> (msl) (Ft.) (Ac-ft) Description <br /> 5651.2 11.2 26.23 10-year, 24-hour Peak Stage <br /> 5652.5 12.5 31.26 Elevation of Emergency Spillway <br /> 5654.4 14.4 40.12 25-year, 24-hour Peak Stage <br /> 5656.0 16.0 48.33 100-year, 24-hour Peak Stage <br /> 5657.0 17.0 54.10 Top of Embankment Elevation <br /> The conservation storage is the estimated water required by the State Engineer's Office <br /> for water rights (see Tab 16). This equivalent volume of water would be made available by <br /> Peabody if a senior water right holder made a "call" for the water. The water would be <br /> dewatered by pumping the water downstream in compliance with Peabody's water discharge <br /> permits. Peabody does not anticipate any additional pit pumpage or, other additional <br /> inflow to the pond at this time. <br /> Spillway <br /> Sedimentation Pond 007 provides for a combination of principal-emergency spillway to <br /> safely discharge the runoff from a 25-year, 24-hour storm. The principal spillway inlet <br /> will also be used as the nonclogging dewatering device and is located at an elevation <br /> higher than the maximum sediment storage volume. The principal spillway inlet is located <br /> in a position on the embankment so as to prevent short-circuiting as much as possible. <br /> The stage-discharge relationship of the emergency spillway inlet was calculated using <br /> SEDIMOT II , while the stage-discharge relationship of the principal spillway inlet was <br /> calculated using the orifice flow equation. <br /> Q = C Ao 2gH <br /> Q = discharge (cfs) <br /> C = coefficient of discharge = 0.6 <br /> Ao = area = 0.267 sq. ft. (7" dia.) <br /> g = 32.2 ft/secz <br /> H = 0 to 10 ft (above the opening) <br /> 10 <br />