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FEMA Releases New Base Flood Elevation Maps

June 19, 2013 | No Comments
Posted by Steven Gouin

On June 17, 2013, the Federal Emergency Management Agency (“FEMA”) released new base flood elevation maps (“BFEs”) – providing much-needed guidance to homeowners still debating how to address flood-related damage suffered during Superstorm Sandy.  The new BFEs substantially revise the advisory base flood elevation maps (“ABFEs”) released by FEMA in December 2012.  Most importantly, the new BFEs remove thousands of coastal New Jersey homes from FEMA’s dreaded “V” (or “Velocity”) Flood Zone.

The “V”-Zone is otherwise known as the “Coastal High Hazard Area.”  These are areas that are subject to high-velocity wave action from storms or seismic sources. According to FEMA, the hazards in “V”-zones include not only inundation by flood waters, but also the impact of waves and waterborne debris and the effects of severe scour and erosion.  By contrast, “A”-Zones are flood hazard areas not within a high hazard area.  Though both “A” and “V”-Zones risk flooding, the severity of the flood hazard is less in “A”-Zones primarily because high-velocity wave action is either not pres­ent or is less significant than in “V”-zones.

Communities, including many in New Jersey, that participate in FEMA’s National Flood Insurance Program (“NFIP”), must regulate three types of building construction in flood hazard areas (including both “A” and “V”-Zones:  (1) new construction, (2) substantial improvements to existing buildings, and (3) repairs of substantially damaged buildings.    Any building falling in one of these three categories must be elevated above the “base flood elevation” as determined by FEMA.  Under the NFIP, the elevation techniques that may be used depend on whether the building is located in the the “A” or “V”-Zone.

In the “V”-Zone, the buildings must be elevated on an open foundation (e.g., pilings, posts, piers) and the bottom of the lowest horizontal structural member (e.g., floor support beam) must be at or above the base flood elevation.  So a building in a “V”-Zone may not be supported by continu­ous walls that are below the base flood elevation.  The rationale is that continuous walls (e.g., concrete block walls) are more susceptible to dam­age from the additional hazards present in “V”-Zones such as wave impact, waterborne debris impact, scour, and erosion.  Comparatively, in “A”-Zones, where flood hazards are less severe, buildings may be elevated either on an open foundation or on continuous foundation with walls below the base flood elevation.

Under the ABFEs, some 5,003 acres of Monmouth County and another 38,012 acres of Ocean County were included in “V”-Zones.  This meant that many thousands of homes built on continuous wall foundations would have to be raised on pilings.  Depending on the size and location of a home, the costs of this renovation could be in excess of $100,000.

Now, under the BFEs, Monmouth County acreage in “V”-Zones was reduced by 46% (to 2,698 acres).  In Ocean, the acreage was reduced by 45%, to 20,808 acres.  In Atlantic County, 80% of the 46,749 acres initially included in “V”-Zones under the ABFEs was revised to be included in “A”-Zones.

Still, “A”-Zone homeowners who suffered damage as a result of Sandy should not be too quick to raise on continuous wall construction, without at least considering raising on piles.   Many believe that the permitted “A”-Zone building techniques (e.g., raising on block foundation walls with flood vents) are inadequate to protect a home against the dangers presented by the next Superstorm Sandy.  And according to FEMA’s guidance documents, “Because Coastal A Zones may be subject to the types of hazards present in Zone V, such as wave effects, velocity flows, erosion, scour, and high winds, [it is] recommend[ed] that buildings in Coastal A Zones meet the NFIP regulatory requirements for Zone V buildings.”

An easy-to-use interactive map showing the comparison between the ABFEs and BFEs can be found here:  http://www.nj.com/monmouth/index.ssf/2013/06/fema_flood_maps_1.html.

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