6.8 Million U.S. Homes at Risk of Hurricane Storm Surge Damage in 2016
Total Reconstruction Cost Value for All Homes Over $1.5 Trillion
According to CoreLogic's 2016 Storm Surge Report
, more than 6.8 million homes on the Atlantic and Gulf coasts are at potential risk of damage from hurricane storm surge inundation with a total reconstruction cost value of more than $1.5 trillion.
In addition to the number of homes at risk, the analysis also provides the reconstruction cost value (RCV), which is the cost to completely rebuild a property in case of damage, including labor and materials by geographic location, assuming a worst-case scenario at 100-percent destruction. Using more advanced and granular data than in previous years, the 2016 analysis shows an increase from 2015 in the overall number of homes at risk of storm surge as well as an increase in the reconstruction value of these homes. Despite the overall increases, the 2016 analysis shows a decrease in the most extreme category for both the number and value of homes at risk.
The CoreLogic analysis examines risk from hurricane-driven storm surge for homes along the Atlantic and Gulf coastlines across 19 states and the District of Columbia, as well as for 88 metro areas. Homes are categorized among five risk levels, including Low, Moderate, High, Very High and Extreme.
"Using more granular-level data has given us an even clearer picture of which homes are at risk of storm surge damage," said Dr. Tom Jeffery, senior hazard risk scientist for CoreLogic. "Despite the overall increases in risk, we were glad to see that the number and value of homes in the most extreme, and dangerous, category actually declined. It just goes to show the power of how advanced data can improve risk assessment at the property level."
At the regional level, the Atlantic Coast has just under 3.9 million homes at risk of storm surge with an RCV of $953 billion, and the Gulf Coast has just over 2.9 million homes at risk with $592 billion in potential exposure to total destruction damage (Table 2).
At the state level, Texas and Florida, which have the longest coastal areas, consistently have more homes at risk than other states. Florida ranks first with 2.7 million at-risk homes across the five risk categories and Texas ranks third with 531,169 at-risk homes (Table 3). Since the number of homes at risk strongly correlates with the accompanying RCV, these two states rank first and fifth, respectively for having the largest RCV (Table 4). States with less coastal exposure but lower-lying elevations that extend farther inland, such as Louisiana (ranked second at 800,521 at-risk homes) and New Jersey (ranked fourth at 468,823 at-risk homes), tend to have more total homes at risk because of the potential for surge water to travel farther inland. Louisiana and New Jersey are also near the top of the list for RCV, with Louisiana totaling $184 billion (ranked second) and New Jersey totaling $139 billion (ranked fourth).
At the local level, 15 Core Based Statistical Areas (CBSAs) account for 67.3 percent of the 6.8 million total at-risk homes and 68.3 percent of the total $1.54 trillion RCV (Table 5). This disproportionate distribution of homes suggests that the location of hurricanes that hit land is often a more important factor than the number of storms that may occur during the year. The Miami CBSA, which includes Fort Lauderdale and West Palm Beach, has the most homes at risk totaling 780,482 with an RCV of just under $144 billion. By comparison, the New York City CBSA has slightly fewer homes at risk at 719,373, but a significantly higher total RCV totaling $260 billion.
The CoreLogic storm surge analysis also complements Federal Emergency Management Agency (FEMA) flood zone information to provide a snapshot of potential damage exposure at the property level since many properties located outside designated FEMA flood zones are still at risk for storm surge damage. Standard FEMA flood zones are designed to identify areas at risk for both freshwater flooding, as well as storm surge, based on the likelihood of either a 100-year or 500-year flood event. They do not differentiate risk based on storm severity, and as a result, do not accurately reflect the total extent of potential risk along coastal areas. Homeowners who live outside designated FEMA flood zones often do not carry flood insurance, given that there is no mandate to do so, and therefore may not be aware of the potential risk that storm surge poses to their properties.