Limit of Moderate Wave Action (LiMWA) Updates in VA and the Impact to Communities

Heather Zhao, PE, CFM,PMP, Project Manager/Coastal Engineer, AECOM

Benjamin Kaiser, Project Manager, AECOM

The Limit of Moderate Wave Action (LiMWA) has been established by FEMA to acknowledge that structures outside the Coastal High Hazard Areas (CHHAs), also known as VE Zones, may still be at significant risk of damage from wave impacts during a severe storm event.  Many communities have special building codes that pertain to structures in Coastal A Zones, the zone between the limit of VE zone and LiMWA.  Communities that participate in FEMA’s Community Rating System can receive credit for incorporating these standards into their floodplain management ordinances. Most of the effective LiMWA in VA counties and city were delineated per the outdated FEMA guidance. FEMA had initiated an effort to re-delineate the LiMWA per the latest 2013 Operating Guidance (OG) for FEMA Region III and the revision for the LiMWA in all the coastal communities of Region III has completed.  The outreach to the VA coastal communities is about to start. Due to the new rules in the latest OG and the development of our GIS technology, the LiMWA changed significantly in some areas. This presentation will give a general overview of the LiMWA and a few examples in VA on comparison between the effective and the updated LiMWA.


Author Bio

Presenter Bio: Heather Zhao is a senior coastal engineer/PM with AECOM. She has experience in conducting hydrologic and hydraulic analysis for riverine and coastal hazard areas for FEMA Flood Insurance Studies (FIS). She has worked on the FEMA Region III coastal Flood Insurance Studies, which are on the effective maps, as a task manager and a technical reviewer. She is currently leading the effort to update the LiMWAs in Region III.
Presenter Bio: Ben Kaiser is a water resources engineer with AECOM and had 15 years of experience working in support of the National Flood Insurance Program. His primary focus is FEMA flood studies and Letters of Map Change and he currently manages LOMR and CLOMR reviews on behalf of FEMA. He has been a Certified Floodplain Manager since 2006.