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VERSiON 1.0 1/12/95 B-C PROGRAM: Guidance 3. Group similar projects. If a large number of structures are similar (such as a housing development), then it may not be necessary to conduct individual analyses of each structure. Rather, projects with the same flood hazard risk (i.e., at the same elevation or closely similar elevations) can be grouped or averaged. A buyout or relocation of one hundred 1,000 square foot houses can be analyzed as 100,000 square feet of single family residences, or analyzed by calculating the benefits for one (average) house, multiplied by one hundred, and then compared to the total cost of the buyout. Consider projects at the same or closely similar, Zero Flood Depth Elevation with the same flood hazard risk. Flood hazard risk will be identical for structures at the same or closely similar Zero Flood Depth Elevation in the same neighborhood. Once the flood hazard information is compiled, many single analyses can be conducted using the flood hazard information, or groups of buildings at the same Zero Flood Depth Elevation can be grouped for one analysis. If a large number of similar structures at varying elevations are to be evaluated for a buyout, relocation, or for a single type of flood mitigation measure (e.g., elevation or protection by a levee) then structures may be grouped in bands (contours) of elevation. One or two feet of elevation difference can markedly change flood hazard, so it is very important to group structures only of the same or closely similar elevations: If a large group of structures varies in elevation, the structures may be grouped in one-foot elevation bands: for example, consider all structures between 6.5 and 7.5 feet of elevation to be at 7 feet. Grouping structures in wide bands of elevation (e.g., covering several feet of elevation difference) will almost certainly produce substantially inaccurate results. 4. 5-7