Sandy’s storm surge, flooding causes most of damage: preliminary report

Major damage imposed by Superstorm Sandy relates mostly to storm surge and flooding as opposed to direct wind, Willis Re notes in a preliminary post-event damage survey.

While damage from storm surge and flooding is widespread and extensive, there is only minor damage to buildings from direct wind, Willis Re, the reinsurance arm of Willis Group Holdings, notes in a statement released Monday.

The damage survey was carried out by representatives of Willis Re’s catastrophic management services team. Immediately following Sandy’s landfall near Atlantic City on October 29, team members spent four days on several affected properties in New Jersey and New York to assess damage caused by wind, storm surge and flooding.

Key findings include the following:

• 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 as a result of storm surge;
• flood depths, as indicated by water marks, as much as four feet above the first floor for almost all properties less than 0.2 miles from the coast;
• structural damage from flooded crawl spaces and foundations should be expected in the future for many properties; and
• 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.

“I was surprised to see damage to buildings from the wind component of the storm was minor to none in the surveyed areas,” says Prasad Gunturi, a senior vice president at Willis Re and the report’s author. “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,” Gunturi notes.

“We noted that the majority of buildings damaged due to wind represented older construction. Overall, the newer construction performed well and any damage to the new construction could be attributed to poor workmanship,” the report states.

“In some cases, total loss of contents was observed due to high storm surge and related flood levels,” the report notes. “We noticed that structures elevated and on stilts experienced relative less damage compared to other structures.”

Although sea walls and sand dunes along the coast helped to reduce storm surge impact on waterfront structures in some areas, “in many cases, storm surge was able to overtop these sea walls,” the report points out.

The hope is that team members will be able to perform another damage survey covering more severely damaged areas of New Jersey and New York once these become accessible to the general public, notes a statement from Willis Re.

“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 adds.

Photos: Damage in New Jersey from Hurricane Sandy. (Credit: Office of the Governor/Tim Larsen)