FEMA Flood Map Challenges

Rebecca Maxwell


In October of 2012, Hurricane Sandy wreaked havoc on the East Coast of the United States. The storm hit the entire eastern seaboard from Maine all the way down to Florida and did the most severe damage to New York and New Jersey.

Damages from Hurricane Sandy

Estimates for damages from Sandy were approximately $65 billion. Thousands of residents are still trying to rebuild their homes and their lives in the aftermath.

However, a new kind of storm is once again wreaking havoc on them. This time it comes in the forms of flood maps from the Federal Emergency Management Agency (FEMA). While being in the process of being redone, these flood maps are creating all sorts of difficulties for homeowners.

Flood Hazard Mapping Program

In order to provide ongoing flood risk assessments for individual communities, FEMA has been constantly updating and maintaining its Flood Hazard Mapping Program. The goals of these maps are to identify flood hazards and provide accurate risk data.

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These maps also are used to set building code requirements and inform flood insurance rates. These flood maps are compiled using data for such things as river flow, rainfall, topography, and storm surges.

The ultimate purpose of these maps is to help states take preventative actions that will hopefully reduce damage done to homes in the event of major flooding like that caused by Hurricane Sandy.  In the aftermath of Sandy, FEMA set out to update these maps which hadn’t been done since the 1980s.

A FEMA flood map showing the area in teal where flooding might occur against a black and white aerial image.

Unfinished and changing flood maps

The problem, however, is that the unfinished flood maps are causing all sorts of new problems for homeowners needing to rebuild. The maps designate different areas depending on how high the flood risk is.

The highest risk zones are called velocity zones, or V zones, and the less hazardous zones are known as A zones. Those homes that are in V zones are not only seeing their flood insurance rates skyrocket but are having to make costly repairs in order to meet building codes.

In response to these flood maps, George Kasimos, a New Jersey resident, has had to elevate his home four feet with expensive pilings and see his flood insurance go from $1,000 to $15,000 per year.

Another issue with FEMA’s flood maps is that they are continually being redone so that residents are getting mixed messages. The maps take about three to five years to finish, and during that time, homeowners are left wondering what will happen to their homes in terms of flood risks and insurances rates.

After Sandy, FEMA decided to release advisory maps, or rough drafts of sorts, to give people an idea of what they can expect. However, when the finished flood maps were released in June 2013, they showed that FEMA had actually scaled back a large amount of V zones and included others not previously designated as such.

Thousands of homeowners who had already planned for costly repairs or spent money on them now find they might not be needed after all. Other homeowners are finding higher insurance rates and stricter building codes, meaning thousands of more dollars out of their pockets.

Then there are communities that are do not even show up on FEMA’s flood maps and should. Residents in Vermont have suffered severe flooding in recent years, not only from fast-rising rivers and streams but from storms like Tropical Storm Irene that hit back in 2011.

However, FEMA cannot update the old flood maps due to other priorities and a lack of funding. Consequently, residents in those areas of Vermont cannot apply for FEMA programs in which flood-damaged property is bought because they are not designated as flood hazards areas on the maps.

FEMA’s flood maps have come under fire from a large variety of groups. Many of these are grassroots organizations from fed up homeowners. Other criticisms are being directed at FEMA from those who think the agency is not doing enough to prepare for rising sea levels because of global warming. While it seems that FEMA is trying to do the best to reduce the impact of flood damage in the future, many believe that are only making the situation worse in the process.

GIS Data and Services from FEMA

FEMA offers several options for accessing its flood hazard map data.  The GIS Web Services for the FEMA National Flood Hazard Layer (NFHL) offers instructions on accessing the flood hazard map data through several GIS services such as ArcGIS REST Service and OGC Web Mapping Service (WMS).  

The FEMA GeoPlatform also provides access to FEMA’s GIS services.  The NFHL is also available in KMZ format.  FEMA also offers two GIS tutorials on how to use GIS to create DFIRMs.


National Flood Insurance Program: Flood Hazard Mapping.” http://www.fema.gov/national-flood-insurance-program-flood-hazard-mapping

“Unfinished FEMA Flood Maps Put Sandy Victims in Limbo.”  http://www.npr.org/2013/04/28/179568786/new-jersey-homeowners-say-flood-maps-will-add-huge-costs

“Vermont to FEMA: Put Our Flooding on Your Maps.” http://www.npr.org/2013/04/28/1795


“New FEMA Maps Shrink N.J. Flood Zones.” http://www.usatoday.com/story/news/nation/2013/06/17/fema-maps-shrink-flood-zones/2433005/

“NYC Flood Zones: After Sandy, FEMA Revises Maps and Adds 35,000 Buildings.” http://www.huffingtonpost.com/2013/01/28/nyc-flood-zone-areas-add-_n_2567447.html

“FEMA Coastal Analysis and Mapping.” http://www.region2coastal.com/sandy/table


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About the author
Rebecca Maxwell
Rebecca Maxwell is a freelance writer who loves to write about a variety of subjects. She holds a B.A. in History from Boise State University. Rebecca has also been a contributing writer on GISLounge.com