47.5 MB - The Whole Building Design Guide

ABFEs represent the best estimate of theexpected 1-percent-annual-chance flood elevations.They are provided as interim floodhazard information until more detailed floodhazard data become available. Flood RecoveryMaps depict the ABFEs, and in general,reflect additional information such as inundationlimits and surveyed high water marks (but not the 500-yearflood hazard area). For coastal areas, the Flood Recovery Maps mayalso show the inland debris line and the limit of the 1.5-foot wave(Coastal A Zone).When ABFEs and Flood Recovery Maps are produced and released,FEMA strongly encourages States and communities, aswell as private property owners and critical facility owners, to usethe information to make decisions about reconstruction untilmore definitive data become available. FEMA issues guidance tohelp the users apply the updated flood elevation information atspecific locations.After Flood Recovery Maps are released, FEMA begins the formalprocess of updating the FIRMs. The community and propertyowners are notified through public notices and meetings whenthe preliminary revised maps are available and a formal commentperiod is opened. The final maps are prepared after considerationof comments. Communities are required to adopt and use the revisedFIRMs in order to continue their participation in the NFIP.After Hurricane Katrina, FEMA expediteddevelopment of Flood Recovery Maps andABFEs for the Mississippi coast—the newmaps were delivered just 3 months afterthe storm.2.1.2 FLOOD LOADSFloodwaters can impose a variety of loads on buildings andbuilding elements. This section provides a brief overview of floodloads and factors that are important for calculating flood loads,including:m Hydrostatic loads, including buoyancy, which increase as thedepth of water increasesm Hydrodynamic loads, which result from moving waterMAKING CRITICAL FACILITIES SAFE FROM Flooding2-17