Coastal Floodplain Building Requirements

On the Federal Emergency Management Agency’s digital Flood Insurance Rate Maps (DFIRMs), coastal high hazard floodplains are located along the Pacific Ocean shoreline and are identified as a ‘V Zone’ (i.e., wave velocity).· These floodplains are subject to storm surges and wave impacts during coastal storms and tsunamis; often resulting in shoreline erosion and scour which can undercut building foundations.

Elevating buildings on pilings, posts, piers and columns, use of non-structural breakaway walls below the main floor, and prohibiting crawlspaces and basements are some of the special construction requirements intended to help buildings withstand wave impacts and damage during coastal high hazard floods.

More Information:

A Report –Mitigation of Flood and Erosion Damage to Residential Buildings in Coastal Areas


Free-of-Obstruction Requirements TFEMA Technical Bulletin – 5


Corrosion Protection for Metal Connections in Coastal Areas FEMA Technical Bulletin -8


Design & Construction Guidance for Breakaway Walls Below …FEMA Technical Bulletin-9