As a result of preliminary revisions to the Federal Emergency Management Agency's coastal flood maps, there are now more than 4.2 million homes along the U.S. Atlantic and Gulf coasts located in storm surge risk zones, creating more than $1.1 trillion in risk, according to real estate data analytics firm CoreLogic.
The revisions bring an additional 35,000 homes and businesses into FEMA-designated flood zones, according to CoreLogic's Storm Surge Report for 2013. This year, CoreLogic changed its methodology in estimating the potential risk by accounting for theoretical future rises in sea level. Also driving the increased risk is the fact that property values have increased significantly since Superstorm Sandy struck the East Coast in October 2012.
Of the $1.1 trillion in property risk, about $658 billion is concentrated in 10 major metro areas, according to the report.
Florida tops the state rankings, with nearly 1.5 million properties at risk and $386 billion in total potential exposure to damage. Louisiana ranks second, with just over 411,000 homes in storm-surge zones.
New York ranks second in total value of coastal properties exposed, at nearly $135 billion.
The New York metropolitan area, including northern New Jersey and Long Island, has not only the most homes at risk but also the highest total value of residential property exposed, at more than $200 billion, the report finds.
The Miami area is identified as being most at-risk due to rising sea levels. The report theorizes that should there be a one-foot rise in sea level, the total number of properties at risk in that area would nearly double from almost 132,000 to almost 340,000. What's more, the risk would increase from about $48 billion to more than $94 billion.
The report, however, acknowledges that there is no way to predict how far sea levels will rise in the future, or how quickly, as a result of environmental factors.
‘As Hurricane Sandy and recent history have made clear, the full extent of potential storm-surge risk is not often understood, especially in areas thought to be less common targets for hurricanes,’ said Dr. Howard Botts, vice president and director of database development for CoreLogic Spatial Solutions.         Â
The report provides a breakdown of residential property risk on a national, regional, state, metro basis, as well as by ZIP code.