Laserfiche WebLink
<br />11 <br /> <br />analysis, Such a screening is an ideal time to involve the decision <br />makers in the analysis process, <br />It should be emphasized very strongly at this point that the <br />screening of alternatives should involve a detailed discussion <br />between the analyst and the decision makers, If the alternatives <br />are not properly formulated and screened, the analyst will be <br />required to undertake a great deal of unnecessary evaluation work, <br />With the experience available in the UDFCD, the number of alternatives <br />to be evaluated should be screened to approximately three, This will <br />normally involve a consolidation of combinations of approaches into <br />alternatives which can be evaluated as units, The analyst should <br />arrange the necessary coordination meetings to ensure that the screen- <br />ing process is completed, He should try to avoid uncertainty <br />at this stage over which alternatives are to be evaluated in detail, <br />5, Study of Variation of Co~J;s~l.i_Benefits with Design Frequency <br />within Each Decision Unit. This study is the key to finding <br />the damage reduction optimum for each Decision Unit, This optimum <br />~ill not always be the preferred choice because of other considerations <br />to be introduced in the tradeoff analysis, but it is usually of interest <br />to the decision makers to know the economic performance functions of <br />their flood control investments, <br />UDFCD policy is established with the objective of managing at <br />least the lOO-year floodplain, The design flood used to size convey- <br />ance facilities or detention storage reservoirs may under certain <br />circumstances be less than ~he lOO-year and result in portions of the <br />lOO-year flood levels falling into the non-structural measures category, <br />In some cases, the entire floodpla"in could be covered by nonstructural <br />measures and no structural measures used at all, <br />