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larger opening then the 3 inch by 3.5 inch oblong opening (approximately a 3.2 inch circular opening) <br />constructed. The orifices at 6,841.4 were input ac 2.5 inches. The retention time using these input <br />decant specifications was calwlatad at !.4 days. The maximum retention time was determined using <br />two orifices per elevation, with the diameter ofthe orifices at 6,840.G feet specified as 3.2 inches and <br />the orifices at 6,841 4 feet specifed as 2.5 inches. The maximum retention time using the <br />conservativo docent spxifications was calculated at 2.9 days. The calculated retention lime utilized <br />four orifices per elevation, with the oriflces at 6,840.6 feet specified at 2.3 inches (which equates to <br />an equivalem opening by area to the as-built orifices) and the orifices at 6,841.4 feet specified as 2.5 <br />inches. This set of decant orifice inputs resulted in a calculated retention time of ] .5 days. <br />The SFDCAD outputs are inc]uded as an attachment to this evaluation. The results indicate that the <br />retention time for runoff from the 10-year, 24-hour design storm will be between 1.4 and 2.9 days, <br />with a calwlated time of t.5 days. This retertion time is greater than 24 hours and indicates that the <br />principal spillway as constructed, with the referenced specifleations which CYCC provided to <br />TerraMatrix, will provide the nocessary retention time. <br /> <br />y. <br />Pik r~3poik~pmd_e~pro,cipJ.chk YP96 <br />