Willis Re Damage Survey Identifies Sandy’s Storm Surge Impact on Buildings

November 13, 2012

Damage from storm surge and flooding caused by Superstorm Sandy is widespread and extensive, but there is only minor damage to buildings from direct wind, according to a report released by Willis Re, the reinsurance arm of Willis Group Holdings, the global insurance broker.

After Sandy’s landfall, representatives of Willis Re’s Catastrophe Management Services team spent four days in affected areas assessing the damage caused by wind, storm surge and flooding. Here is a snapshot of their key findings:

  • Significant structural damage to buildings, ranging from moderate to complete collapse, from the storm surge and related flooding
  • Widespread and extensive damage to boats and automobiles due to storm surge. Many cars and boats were piled up or pushed on to the streets by the storm surge and smashed into neighboring buildings causing additional damage
  • Minor to moderate wind damage to buildings in a few localized areas as well as much more widely spread damage to buildings from tree fall
  • A massive amount of ocean sand (up to two feet on many streets) was moved on shore by the storm surge indicating huge amounts of wave energy
  • Flood depths, as indicated by watermarks, up to four feet above the first floor were observed for almost all properties less than 0.2 miles from the coast. Elevated structures experienced less damage.
  • Structural damage due to flooded crawl spaces and foundations should be expected in the future for many properties.

The damage survey was conducted on properties in Ocean City, Atlantic City, Spring Lake, Belmar and Avon-by-the-Sea in New Jersey and Staten Island, Coney Island and Rockaway Beach in New York, with the objective of researching and collecting examples of property damage due to wind and storm surge.

Prasad Gunturi, senior vice president, Willis Re, and author of the Damage Survey Report commented: “We observed many examples of significant structural damage to buildings from the storm surge and related flooding, but I was surprised to see damage to buildings from the wind component of the storm was minor to none in the surveyed areas. However, moderate to minor wind damage was observed in a few highly localized areas. This pattern is a clear sign of the complex nature of Superstorm Sandy’s windfield.”

Sandy’s complexity increased due to its interaction with another weather system to the west which created a large ‘Superstorm’, compounded by the impact of a high spring tide. The Willis Re team observed ocean sand up to two feet deep on many streets and inside many properties as far as 0.15 to 0.25 miles from the coast, indicating huge amounts of wave energy generated by Superstorm Sandy.

The Willis Re Catastrophe Management Services team hopes to perform another damage survey to cover more severely damaged areas, like Hoboken, N.J., Long Island, N.Y., and downtown Manhattan once these areas became accessible to the general public.

“We will evaluate all the scientific data, observations from our field surveys and other information available for this event and are confident that the results of this detailed study, in conjunction with insurers’ actual experience from Superstorm Sandy, will be useful in helping our clients better assess future risk management decisions,” Gunturi said.

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