Section 1612.1/Flood Loads
IBC 1612 covers design requirements for buildings in flood hazard areas including elevation, materials, and ASCE 7/ASCE 24 compliance.
Buildings in flood hazard areas identified on FEMA Flood Insurance Rate Maps (FIRMs) must be designed and constructed per ASCE 7 Chapter 5 (Flood Loads) and ASCE 24 (Flood Resistant Design and Construction). The design flood elevation (DFE) is the base flood elevation (BFE) plus any freeboard required by the jurisdiction. In coastal high-hazard zones (V zones), buildings must be elevated on piles or columns with the lowest structural member above the DFE. In A zones (riverine flooding), the lowest floor must be at or above the DFE. Flood loads include hydrostatic pressure, hydrodynamic pressure, wave loads, and debris impact loads.
Why this section exists
Flooding causes more property damage than any other natural hazard in the United States. Buildings in flood hazard areas that are not designed for flood loads suffer foundation failure, wall collapse from hydrostatic and hydrodynamic pressure, and wave impact damage. The IBC flood provisions align with FEMA's National Flood Insurance Program requirements, ensuring buildings are elevated above expected flood levels and structurally designed to resist flood forces.
What plan reviewers look for
Plan reviewers check the FIRM for the project location to determine the flood zone and BFE. They verify the DFE on the architectural drawings matches the FIRM data plus any local freeboard. In V zones, they check the pile or column foundation design and verify the lowest structural member elevation. In A zones, they verify the lowest floor elevation. They check for flood-resistant materials below the DFE and flood vent openings in enclosed areas below the DFE.