American Society of Civil Engineers (ASCE) 24

American Society of Civil Engineers (ASCE) 24
Title	ASCE 24
Subject	Flood Resistant Design and Construction
Publisher	American Society of Civil Engineers
First published	1995
Latest revision	2014
Scope	Floodplain management, building design, floodproofing

American Society of Civil Engineers (ASCE) 24 ASCE 24 is a consensus standard for flood-resistant design and construction that sets minimum requirements for structures in flood-prone areas. It is used by regulatory bodies, insurance programs, and design professionals to reduce flood risk to buildings and infrastructure. The standard interacts with model codes, federal regulations, and engineering practice to guide elevation, materials, utilities, and floodproofing measures.

Overview and Scope

ASCE 24 defines minimum design and construction criteria for new and substantially improved buildings and structures in flood hazard areas. It applies to building siting, elevation of lowest floors, foundation systems, Federal Emergency Management Agency flood hazard mapping, National Flood Insurance Program, International Code Council model codes, and coastal flood hazards such as storm surge and wave action. The standard addresses types of construction recognized by the American Concrete Institute, American Institute of Steel Construction, and National Fire Protection Association for resilience against flood forces and hydrostatic pressures. ASCE 24 specifies treatment of utilities including American Water Works Association recommendations, and aligns with historic practice from United States Army Corps of Engineers floodproofing guidance and Federal Highway Administration bridge criteria.

Historical Development and Revisions

ASCE 24 originated from engineering concerns raised after major flood events including Hurricane Katrina, Midwestern floods of 1993, and earlier coastal storms. Early editions incorporated lessons from National Research Council reports and coordination with Federal Emergency Management Agency initiatives such as the Floodplain Management Bulletin. Subsequent revisions reflected research by United States Geological Survey, National Oceanic and Atmospheric Administration, and academic groups at Massachusetts Institute of Technology, University of California, Berkeley, and Texas A&M University. Editions have been cited in rulemaking by the Department of Homeland Security and incorporated into editions of the International Building Code and International Residential Code.

Key Provisions and Requirements

ASCE 24 sets requirements for minimum elevation of the lowest floor relative to the base flood elevation established by Federal Emergency Management Agency, freeboard practices advocated by American Society of Civil Engineers leadership, and foundation design compatible with load paths defined by American Institute of Steel Construction and American Concrete Institute. The standard mandates hydrostatic and hydrodynamic load considerations from Coastal Engineering Research Center findings, requires use of flood-resistant materials catalogued by Underwriters Laboratories and imposes utility and mechanical equipment elevation consistent with American Society of Heating, Refrigerating and Air-Conditioning Engineers guidance. It defines acceptable enclosures and breakaway wall performance in line with National Marine Manufacturers Association and addresses scour and erosion with methods from United States Army Corps of Engineers and Federal Highway Administration.

Floodproofing and Flood-Resistant Design

ASCE 24 details wet floodproofing, dry floodproofing, and elevation strategies informed by studies from International Association for Hydro-Environment Engineering and Research, American Society of Civil Engineers Coastal Hydraulics Laboratory, and National Institute of Standards and Technology. Dry floodproofing requirements reference tests by American Society for Testing and Materials and performance criteria used by Federal Emergency Management Agency in flood insurance determinations. The standard specifies material durability per American Concrete Institute and American Wood Council recommendations, and provides guidance on flood vents consistent with Engineers Australia and Institution of Civil Engineers best practice. It addresses coastal wave-induced loads using principles from American Shore and Beach Preservation Association and Delft Hydraulics research.

Implementation, Adoption, and Enforcement

Adoption of ASCE 24 occurs through incorporation by reference in model codes such as the International Building Code and by local ordinances administered by state offices and municipal planning departments including those influenced by New York City Department of Buildings post-Hurricane Sandy. Federal adoption occurs when Federal Emergency Management Agency references the standard in floodplain management criteria for participation in the National Flood Insurance Program. Enforcement is typically executed by building officials, plan reviewers, and inspectors trained through programs by National Society of Professional Engineers and continuing education at institutions like American Public Works Association.

Relationship to Other Codes and Standards

ASCE 24 interoperates with the International Building Code, ASCE 7, American Concrete Institute codes, American Institute of Steel Construction manuals, and National Fire Protection Association standards for mechanical and electrical systems. It complements Federal Emergency Management Agency flood maps and the National Flood Insurance Program requirements while aligning technical methods with research from United States Geological Survey, National Oceanic and Atmospheric Administration, and Coastal Engineering Research Center. The standard also interacts with state model codes such as the California Building Code and guidance from professional bodies like American Society of Plumbing Engineers and American Society of Heating, Refrigerating and Air-Conditioning Engineers.

Impact, Criticisms, and Future Directions

ASCE 24 has influenced flood risk reduction in policy and practice, shaping insurance requirements under the National Flood Insurance Program and building resilience after events like Hurricane Sandy and Hurricane Katrina. Critics cite limitations in accounting for climate-driven sea level rise documented by Intergovernmental Panel on Climate Change, uncertainties in storm surge modeling from National Oceanic and Atmospheric Administration, and implementation gaps identified by Government Accountability Office. Future revisions are likely to incorporate adaptive design approaches advanced by United Nations Office for Disaster Risk Reduction, probabilistic hazard methods from National Academies of Sciences, Engineering, and Medicine, and regional data from National Oceanic and Atmospheric Administration sea level rise scenarios, while continuing coordination with International Code Council and professional societies such as American Society of Civil Engineers and American Geophysical Union.

Category:Engineering standards