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crested weir spillway. <br /> As previously stated, the weir crest elevation for the West Pond <br /> spillway is 208.7 or 11 feet above the bottom of the pond. The <br /> maximum water surface elevation during the 25yr event is 209. 0 ft. <br /> and the top of the embankment is 210.0 ft resulting in 1 ft of <br /> freeboard. As with the East Pond the weir crest length is 8 ft (see <br /> East Pond discussion) . <br /> Low-Level Outlet <br /> Type: Circular Orifice <br /> Co = 0.7 <br /> Area = 0.048 ft2 <br /> Diameter = 3 . 0 in <br /> Invert Elev. = 198.7 ft <br /> Max. Head = 10. 3 ft <br /> Emergency Spillway <br /> Type: Rectangular Sharp Crested Weir <br /> C = 3 .27 <br /> L = 8ft <br /> Crest Elev. = 208 .7 ft <br /> Max. Head = 0. 3 ft <br /> The low level outlet is a 3 inch circular orifice sized to drain <br /> a full pond in 48 hours. The invert of the orifice is at elevation <br /> 198.7 and the maximum head on the orifice is 10. 3 ft. The orifice <br /> discharges water through a vertical drop pipe into a 12 inch <br /> diameter drain pipe which terminates in the field north of the <br /> pond. As with the East Pond the minimum allowable slope for the <br /> drain pipe is 0. 007 (0.7%) . <br /> The outlet works characteristics are summarized in the tables and <br /> are the same as those shown in figure 2 and 3 . The discharge rating <br /> curve for the orifice can be seen in the HEC-1 run entitled 'Low- <br /> Level Outlet Performance, West Pond' in the appendix 8. The <br /> combined rating curve for the orifice and the weir is seen in the <br /> HEC-1 output entitled 'Design Storm, Full West Pond and 25yr-24hr <br /> Event' (appendix 7) . <br /> 12 <br />