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<br />VERSION 1.0 1/12/95 <br /> <br />B-C PROGRAM: Level One Anaiysis <br /> <br />For buildings with basements, the situation can be more <br />complicated depending on the degree of flood proofing of the <br />basement. Unless there is detailed information available about <br />an individual structure, assuming that elevating N feet is 100% <br />effective to N-1 feet is a reasonable assumption for structures <br />with and without basements. This assumes that flood proofing <br />of the basement occurs along with elevation. <br /> <br />The flood depth at which elevations are 0% effective is <br />calculated automatically by the program and need not be <br />entered by the user. <br /> <br />Relocation/Buyout <br />Relocation/Buyout projects are assumed to be 100% effective at <br />all flood depths and thus effectiveness depths need not be <br />entered by the user. <br /> <br />Fiood Barriers <br />The flood depth at which flood barriers are 100% and 0% <br />effective depends on how the barrier is constructed and on <br />assumptions about freeboard. Freeboard is defined as the <br />height of a flood barrier above a flood height which is necessary <br />to insure satisfactory flood performance. For example, to <br />provide 100-year flood protection for flood insurance purposes <br />levees must be constructed 3 feet above the 1 OO-year flood <br />elevation (i.e., with 3 feet of freeboard). <br /> <br />In the absence of detailed engineering analysis, a simple <br />assumption about flood barriers is that a flood barrier of height N <br />feet is 100% effective to N-1 feet and 0% effective at N feet. <br /> <br />Other <br />Other flood hazard mitigation projects include wet flood proofing <br />and any other measures not covered by the three mitigation <br />types discussed above. <br /> <br />The depths at which "Other" flood hazard mitigation projects are <br />100% and 0% effective must be estimated on a case-by-case <br />basis. <br /> <br />The program calculates effectiveness only for the selected mitigation <br />project type. Other entries should be deleted (see Delete button, page <br />3-13) to avoid confusion; however, the program ignores any other <br />values in the table. <br /> <br />The effectiveness of flood hazard mitigation projects at every flood <br />depth is calculated by the program from the depths of 100% and 0% <br />effectiveness. To view the default Mitigation Effectiveness estimates <br />at each flood depth select Level Two Data I Mitigation Project <br />Effectiveness from the Benefit-Cost program menu; for more <br />information see page 8-17. <br /> <br />6-16 <br />