NEW YORK CITY — Nearly two years after Hurricane Sandy, residential buildings in Downtown Manhattan are taking a variety of measures to ensure flood prevention in the event of another big storm. Their efforts dovetail with a new report, released last week by the Department of City Planning, that offers recommendations for retrofitting residential buildings to protect against future floods.
Retrofitting for flood prevention requires building owners to face difficult choices that weigh financial costs against potential risk. What’s best for each building’s flood-prevention strategy can vary depending on a number of factors, but more owners are choosing to go beyond sandbags to keep potentially destructive floodwaters at bay — even if those flood mitigating measures aren’t legally required by the city.
"The cost of some retrofitting can be huge and not practical for a large, older building," said Anthony Notaro, the owner of condo in the 248-apartment Battery Park City building Liberty Terrace. “But we also want to feel like we’re doing what’s best for the future and our safety.”
Notaro’s condo board has been deliberating over purchasing an external flood-protection system.
One option they are considering is the Tiger Dam, which consists of massive, heavy-duty plastic orange tubes that are filled with water and surround the building in the event of a potential flood. The tubes, which vary in height, can be stacked on top of each other and replace the equivalent of about 500 sandbags, according to the U.S. Flood Control Corp., the manufacturer of the inflatable dams.
The dams haven’t been deployed in the city yet, but a growing number of large residential buildings, as well as commercial properties like Brookfield Place and those owned Con Edison, have purchased the system, said a spokeswoman for U.S. Flood Control.
"There are many external flood-prevention systems. But for us, this made sense," said Michael Gubbins, senior vice president the Albanese Organization, which already bought Tiger Dams for two of its 27-story Battery Park City buildings, the Solaire and the Verdesian.
"It’s more efficient than sandbags, and it's something we can relatively easily get out and ready to go when a storm comes," he said.
The system, however, is not cheap. For a building of Notaro’s size, the dams would cost about $80,000 — an expense the condo owners would have to cover, he said.
The other big issue with these new, external dam systems is that they don’t defray the cost of flood insurance rates.
Since Sandy, Notaro’s building insurance coverage has increased by $100,000 annually, he said. The only way to receive reduced rates is to comply with federal standards for residences in flood zones, but that’s a difficult, costly and often impractical task for urban buildings, said Rachaele Raynoff, a spokeswoman for the Department of City Planning.
“So many more people are now left with the question, 'How do we best protect ourselves from an impending storm?’" said Raynoff. "And it’s often a complicated answer.”
Because new federal regulations are aimed primarily at single-family homes rather than at apartment buildings, City Planning's report detailed how multi-unit structures can retrofit to become compliant with the new rules — but also illustrated alternative means for flood prevention that the agency believes will work efficiently for city buildings.
For example, to be in compliance with federal regulations, many buildings would have to move all their critical systems to a higher floor. They would not be able to have residences on the first or basement floor, or levels that are in many cases below delineated flood planes.
“In other parts of the country, raising a house is a practical step — but you really can’t do that with an old, solid building in the city,” said Cecilia Kushner, deputy director of strategic planning for resilience at City Planning and an author of the Retrofitting Buildings For Flood Risk report.
“We want the federal government to recognize that alternate flood mitigation, like sealing off heating and cooling systems, rather than moving them, should also be recognized as a way to defray flood insurance cost,” she said.
Residential buildings that adhere to the federal regulations for flood prevention are eligible for more affordable insurance, but they do not face a penalty if they do not comply. The only structures that must be compliant with city and federal regulations are new buildings under construction or buildings in which at least 50 percent of the space is being remodeled.
By 2017, FEMA is supposed to revise its urban flood mitigation regulations thanks to federal legislation, Kushner said. “We’re hoping our alternatives will offer a guide to buildings and residences hoping to retrofit and also, ultimately, to policy makers to change how city-flood prevention is understood."
For now, though, many buildings say trying to work toward lowered insurance rates isn't at the heart of their concern. They simply want to be better prepared in a storm.
"Our building is more than 25 years old," Notaro said. "We can't move our boiler, our other systems from the basement — but we want to do something to make sure our residents are safe."