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requires that the lowest horizontal structural member of all new construction be at or above an elevation of 10 feet NGVD. Therefore, the lowest floor elevation would be approximately 11.5 feet NGVD or higher. The A-Zone BFE ranges from a minimum of 6 feet NGVD to a maximum of 10 feet NGVD. Therefore, the SRIA's requirement results in lowest floor elevations up to 5.5 feet higher than what would otherwise be obtained. During Hurricane Opal, flooding occurred in V- Zone and A-Zone areas shown on the city's FIRM. Recent post-FIRM A-Zone construction generally performed well, as evidenced by the survival of elevated structures in A-Zones and the destruction of nearby pre-FlRM, at-grade structures. The BPAT believes that the higher elevations of lowest floors, coupled with the requirement for construction on piles, helped to significantly reduce the extent of damage in the city's barrier island A-Zones. Communities that are considering adopting more restrictive requirements in their coastal A- Zones, such as V-Zone construction requirements or freeboard requirements, may want to contact the FEMA Region IV Office or the State ofF1orida Department of Community Affairs for technical assistance. Communities should also consider that by adopting these more restrictive requirements, they can earn community-wide reductions in flood insurance premiums under the NFIP's Community Rating System. In addition,lower flood insurance premiums can be obtained for individual structures when the structures are built to provide freeboard above the BFE. Such structures, if designed and constructed in accordance with the NFIP requirements, ,,~ll receive lower premiums in I-foot increments for up to 4 feet of freeboard above the BFE. Communities are encouraged to reexamine foundation design requirements for structures in areas near the Gulf of Mexico shoreline in light of damage caused by Hurricane Opal. Structures in these areas should be designed to withstand all anticipated flood, erosion, debris, and wind forces. Foundation designs for structures in A-Zones, B-Zones, CZones, and X-Zones should be considered carefully to ensure that the designs reflect actual risks. Therefore, the BPAT recommends that communities and individuals consider the following: . For all areas subject to high-velocity wave action, strong currents, erosion, or combinations thereof - regardless of flood zone designation - the embedment depths specified for pile foundations should be sufficient to ensure that the foundation will ,,~thstand anticipated erosion, conical scour, and storm forces. . Foundations for masonry columns should be designed to withstand all anticipated flood, erosion, conical scour, debris, and wind forces. Shallow footings should not be used to support masonry columns where the risk of undermining exists. . In areas known to be subject to storm-induced scour and erosion, any slabs serving as floors for habitable spaces should be designed and constructed to withstand all anticipated erosion, scour, and storm forces. Therefore, if the potential for undermining exists, slabs should be designed and constructed as structural slabs and attached to sufficient foundation systems that do not rely on underlying soil for support. . In areas known to be subject to storm-induced scour and erosion, slabs used solely for parking should not be attached to structural members and should be designed and constructed to break into small pieces in the event of undermining, thereby minimizing potential transfer of flood loads to the structure. 3-2 RECOMMENDATIONS