47.5 MB - The Whole Building Design Guide

year, a very low probability flood occurssomewhere in the United States, often with The Saffir-Simpson Hurricane Scalecatastrophic consequences. Therefore, for categorizes hurricanes based on sustainedplanning and design of critical facilities, wind speeds (see Section 3.1.1). Stormuse of a lower probability flood (at leastsurge is not always correlated with thethe 500-year) is strongly recommended.category because other factors influenceAs noted in Section 2.1.3.3, the 500-year surge elevations, notably forward speed oflevel of protection is required if Federal the storm, tide cycle, offshore bathymetry,funds are involved in constructing facilities and land topography.that are vital for emergency response andrapid recovery, including hospitals, EOCs,emergency shelters, and other buildings that support vital services.This reinforces the importance of protecting both thefunctionality and financial investment in a critical facility withstricter standards than those applied to other buildings.2.1.1.2 Hazard Identification and Flood DataFlood hazard maps identify areas of the landscape that are subjectto flooding, usually flooding by the 1-percent-annual-chanceflood. Maps prepared by the NFIP are the minimum basis ofState and local floodplain regulatory programs. Some Statesand communities have prepared maps of a floodplain based onthe assumption that the upper watershed area is fully developedaccording to existing zoning. Some communities base their regulationson a flood of record or a historically significant flood thatexceeds the base flood shown on the NFIP maps.The flood hazard maps used by the appropriate regulatory authorityshould be consulted during planning and site selection,site design, and architectural and engineering design (whetherfor the design of new buildings or rehabilitation of existingbuildings). Regardless of the flood hazard data required for regulatorypurposes, additional research should be conducted onpast major floods and other factors that could lead to more severeflooding.The NFIP produces Flood Insurance Rate Maps (FIRMs) for morethan 20,000 communities nationwide. FIRMs are prepared for eachlocal jurisdiction that has been determined to have some degreeof flood risk. The current effective maps are typically available forMAKING CRITICAL FACILITIES SAFE FROM Flooding2-