More than 4.2 million homes along the U.S. Atlantic and Gulf coasts are within storm-surge risk zones, with a total of more than $1.1 trillion worth of property exposed, according to a new report from CoreLogic.
The new data in the annual report "reflect a significant increase in both the number of total properties at risk, as well as total value," the firm reports. For the first time, the report includes the potential risk from a "climate-related" rise in sea level.
The Miami area would have the highest increase of potential homes at risk from rising sea level during storm-surge, the report concludes. A one-foot rise in sea level would result in the volume of total properties at risk to nearly double from just under 132,000 to almost 340,000, and the estimated value would increase from an estimated $48 billion to more than $94 billion overall, the firm concludes.
"Public awareness of the risk hurricane-driven storm surge poses to coastal homeowners has never been higher coming off the heels of Hurricane Sandy last fall," said Dr. Howard Botts, vice president and director of database development for CoreLogic Spatial Solutions.
"Sandy was a harsh reminder of the potential destruction associated with storm-surge flooding, and of just how many communities are vulnerable to that risk, in areas typically assumed to be relatively safe from hurricanes along the northeastern Atlantic shoreline."
The Federal Emergency Management Agency (FEMA) revised flood maps to include 35,000 additional homes and businesses in several New York City suburbs, CoreLogic notes.
But the annual report found a noticeable number of New Orleans properties were downgraded from "Extreme Risk" to "High Risk" zone between 2012 and 2013, resulting from a new protective levy system built by the Army Corps of Engineers.
It is important to note "the total properties and structural values included in the CoreLogic analysis are based on all homes that could potentially be damaged from hurricane-driven storm surge, and are not meant to infer that a single storm or storms in a specific hurricane season will result in these damage totals," the firm added.
Key highlights of the 2013 CoreLogic analysis include:
Out of the $1.1 trillion worth of property exposed, $658 billion of that risk is concentrated in 10 major metro areas.
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 in total properties at risk 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.
At the local level, the New York metropolitan area, which encompasses northern New Jersey and Long Island as well, contains not only the highest number of homes at risk for potential storm-surge damage, but also the highest total value of residential property exposed, at more than $200 billion.