Resilient design is the first line of defense against natural disasters. Civil engineers want to cover all the bases, and a new standard aims to prepare structures for one of nature’s most destructive events: flooding.
Flood Resistant Design and Construction, ASCE/SEI 24-24, establishes minimum requirements for building structures in high-risk flood areas. This comprehensive guide specifies minimum construction standards in flood hazard areas, lists materials for building flood-resistant structures, and incorporates requirements of the National Flood Insurance Program and FEMA.
The ASCE Structural Engineering Institute ASCE 24 Flood Resistant Design and Construction Standards Committee took on the challenge of creating the new standard, an updated version of ASCE/SEI 24-14. Jessica Mandrick, P.E., S.E., M.ASCE, vice chair of the ASCE 24 Committee, discussed the standard and how it will impact the construction of flood-resistant infrastructure with Civil Engineering Source.
Civil Engineering Source: What inspired the creation of ASCE/SEI 24-24? Were there any specific events that brought the need for this standard to light?
Jessica Mandrick: The standard had not been updated since ASCE 24-14 came out in 2014. ASCE 24-24 became urgently needed when ASCE 7-22 Supplement 2 was published in 2023. ASCE 7-22 Supplement 2 raised the mean recurrence interval for the flood level that is used to determine flood loads, with the average building now designed to resist the loads imposed by the 500-year flood.
To reduce the loads imposed on a structure and also reduce damage to its contents, it was critical to raise the elevation of buildings correspondingly. The standard now specifies building elevation based on a mean recurrence interval determined by the buildings Flood Design Class, which is similar to its Risk Category. We also moved elevation requirements that were spread throughout the standard to one consistent location. There were also many updates in FEMA Technical Bulletins and the standardization of ANSI/FM 2510 in the past 10 years that the standard was able to pick up.
Source: What did the process of creating this new standard look like?
Mandrick: We were fortunate to have the support of FEMA in this effort. Their data analysis helped to distill varying elevations all over the country into formulas that could appropriately approximate the flood elevation for different MRIs. They were joined by academics, industry representatives, practitioners, and building officials in this study to refine the formulas and methods as well as estimate costs and loss reduction. Industry representatives gave feedback on flood vent and barrier products currently on the market and testing available through ANSI/FM 2510. The committee used this data along with the availability of certified products in the market to identify where such testing is required.
Source: Which changes do you think will have the most significant impact on flood-resistant infrastructure?
Mandrick: For building type-projects, raising the elevation of the lowest floor will reduce flood risk and protect investment in a structure. This will result in reduced damage to the structure and its contents.
Learn more about ASCE/SEI 24-24.
Learn more about how you can join a standards committee.
