Critical Updates to ASCE Flood Design Standards

The nation continues to experience severe and damaging floods, and as sea levels rise, and extreme climatic conditions worsen, the damages to the built environment from each flooding event continue to increase. The experiences of just Hurricanes Helene and Milton in September and October 2024 should be reminders to the public, and to the nation's structural engineers, that the way we approach building and infrastructure designs for flooding needs to change. As structural engineers and members of ASCE, we are charged with the protection of the health, safety, and welfare of the public and with mitigating adverse societal, environmental, and economic effects of hazard events. The unrelenting assault on our flood-prone communities brought the SEI Standards Committees of ASCE 7 and ASCE 24 to take action. The Flood Load Task Committee of ASCE 7-22 and the ASCE 24 Standards Committee have both worked to develop major revisions to the current engineering standards that address our charge from the code of ethics to reduce future flood losses and to improve the risk-based consistency of our engineering approaches to risk reduction across building types and building locations. Changes to the Minimum Design Loads and Associated Criteria for Buildings and Other Structures, ASCE 7-22, Chapter 5 (the flood chapter), were approved and published in May 2023 as Supplement 2 and are available free on ASCE's website. ASCE Standard 24-24 Flood Resistant Design and Construction passed the last ballot hurdle needed for publication in September 2024 and will be published by early 2025. Both of these documents bring the practice of engineering for floods much more in line with today's climatic reality and the more stringent standards in these documents will absolutely help to reduce losses caused by floods. In addition to the updated ASCE 7 Standard and the Commentary, FEMA has also published a guidance document on how to use the new provisions with many worked examples. The title of the document is: “Building Designer's Guide to Calculating Flood Loads Using ASCE 7-22 Supplement 2.” The document number is FEMA P-2345 and it was published in April 2024. It is available free on FEMA's website. In addition, an article was published in STRUCTURE Magazine in August 2024 titled “Major Changes to ASCE 7-22 Flood Loads.”