Fill is required to be stable under conditions of flooding, including rapid rise and rapid drawdown,prolonged inundation, and erosion and scour.ħ Compaction of structural fill is specified unlessotherwise required by the building code or in a geotechnical or engineering report. The DFE is always equal to or higher than the BFE. The Design Flood elevation (DFE) equals the base Flood elevation (BFE) in communities that regulate based on FIRMs. Ħ ASCE 24 uses Design Flood and Design Flood elevation to acknowledge that some communities adopt Flood hazard maps that depict Flood hazard areas in addition to Special Flood Hazard Areas shown on FEMA s Flood Insurance Rate Maps (FIRM). July 2015) 1 A summary of significant technical revisions from ASCE 24-05 to ASCE 24-14 is reproduced on page 6 of these HIGHLIGHTS. Elevation requirements in Zone V and Coastal A Zones areindependent of orientation of the lowest horizontal structuralmember (relative to direction of wave approach) as a factorin determining the required freeboard (ASCE 24-05 madeelevation a function of orientation of the lowest horizontalstructural member relative to the direction of waveapproach). Elevation and Freeboard (additional height above the NFIP s base Flood elevation) are specified as afunction of the Flood Design Class and the nature of theflood hazard areas (see table on page 4 of these HIGHLIGHTS ).ĥ Essential facilities ( Flood Design Class 4) must be elevatedor protected to the BFE + 2 ft or 500-year Flood elevation,whichever is higher. The 2015 International BuildingCode requires designers to identify the Flood Design Class assigned in accordance with ASCE 24-14.
Flood Design Classes replace Occupancy/Risk Categories for the purpose of establishing elevations oflowest floors, Flood - Resistant materials, equipment and floodproofing. Performance of foundations exposed to flooding isspecified in ASCE 24.Ĥ Soil characteristics and underlying strata, including soil consolidation,expansion or movement, erosion and scour, liquefaction and subsidence must be considered, asapplicable. Building Performance Flood loads and other loads and load combinations are specified in ASCE 7-10, Minimum DesignLoads for Buildings and Other Structures. HIGHLIGHTS of ASCE 24-14 that complement the NFIP minimum requirements are described below. The 2015 I-Codes reference ASCE 24-14, while the 2006 through 2012 I-Codes reference ASCE 24-05.ģ The International Residential Code requires dwellings in floodways to be designed in accordance with ASCE 24, and the 2015 edition of the IRC allows use of ASCE 24 for dwellings in any Flood hazard area (the 20 editions allow use of ASCE 24 in Coastal High Hazard Areas). Buildings and structures within the scope of the IBC and proposed to be located in any Flood hazard area must be designed in accordance with ASCE 24. ASCE 24 includes additional specificity, some additional requirements, and some limitations that are not in NFIP regulations. FEMA deems ASCE 24 to meet or exceed the minimum National Flood Insurance Program (NFIP) requirements for buildings and structures. Types of buildings and structures are described in ASCE 24-14, Table 1-1 (see page 5 of these HIGHLIGHTS ), and include commercial, residential, industrial, educational, healthcare, critical facilities, and other occupancy types.Ģ Buildings and structures designed according to ASCE 24 are better able to resist Flood loads and Flood damage. ASCE 24 states the minimum requirements and expected performance for the siting and Design and construction of buildings and structures in Flood hazard areas that are subject to building code requirements. 1 HIGHLIGHTS OF ASCE 24-14 Flood Resistant Design and construction Published by the American Society of Civil Engineers (ASCE), Flood Resistant Design and construction, ASCE 24, is a referenced standard in the International Codes (I -Codes ).