Hurricane season starts June 1, and more than 4.2 million homes along the U.S. Atlantic and Gulf Coasts are located within storm-surge risk zones, totaling more than $1.1 trillion in property exposure, according the “2013 CoreLogic Storm Surge Report.” And, almost half a million of those properties are in New York City metro area alone. The report from CoreLogic, a residential property information, analytics and business services provider, contains a breakdown of residential property risk along the Atlantic and Gulf coasts at five key geographic levels: national, regional, state, metro and ZIP code.
Storm surge is triggered primarily by the high winds and low pressure associated with hurricanes, which cause water to amass inside a storm as it moves across the ocean before releasing as a powerful rush overland when the hurricane moves onshore, CoreLogic said.
The 2013 findings reflect a significant increase in both the number of total properties at risk, as well as total value. This year’s report features an enhanced methodology using CoreLogic Automated Valuation Model (AVM) data. New this year, the report also provides an estimation of the potential increase in risk based on theoretical future rises in sea level.
The report focuses heavily on the East Coast, due to last year’s Superstorm Sandy and 2011’s Hurricane Irene. Federal Emergency Management Agency (FEMA) released preliminary revised flood maps that increase the scope of designated flood zone areas in several New York City suburbs to include 35,000 additional homes and businesses not previously identified as existing within a flood zone.
Other highlights from the 2013 CoreLogic report include:
• Of the risk valued at roughly $1.1 trillion, more than $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.
• As a result of the completion of a new protective levy system in the aftermath of Hurricane Katrina, a noticeable number of properties in the New Orleans area that were previously located in an “Extreme Risk” zone have now been downgraded to the “High Risk” zone between 2012 and 2013.
• The Miami area could potentially have the highest increase in the number of homes at risk of the cities discussed in the report. Given a one-foot rise in sea level, total properties at risk would nearly double from just under 132,000 to almost 340,000, and estimated value would increase from an estimated $48 billion to more than $94 billion overall.
“One recurring question in storm-surge analysis is whether or not climate change is affecting the development of hurricanes and causing an increase in the frequency or intensity of these events,” said Howard Botts, VP and director of database development, CoreLogic Spatial Solutions. “Though the CoreLogic Storm Surge Report is not designed to address that specific question, we do consider a potential rise in sea level as a crucial contributing factor to the full extent of coastal storm-surge risk and have expanded the analysis to include projected increases in risk associated with a hypothetical one-foot, two-foot and three-foot rise. The geographic location and characteristics of an urban area along the coast will naturally contribute greatly to the level of risk resulting from a potential sea-level rise, as is the case in Miami with lower elevation and close proximity to ocean water.”
