Protecting NYC“Soft infrastructure” as storm surge defense alternatives

Published 20 November 2012

The flooding in New York and New Jersey caused by Superstorm Sandy prompted calls from Governor Andrew Cuomo and other officials to consider building storm surge barriers to protect Lower Manhattan from future catastrophes. Such a strategy, however, could make things even worse for outlying areas that were hit hard by the hurricane, such as Staten Island, the New Jersey Shore, and Long Island’s South Shore, a City College of New York landscape architecture professor warns; landscapers and engineers say that environmentally friendly “soft infrastructure” would mitigate flood damage without sending harm elsewhere

The flooding in New York and New Jersey caused by Superstorm Sandy prompted calls from Governor Andrew Cuomo and other officials to consider building storm surge barriers to protect Lower Manhattan from future catastrophes. Such a strategy, however, could make things even worse for outlying areas that were hit hard by the hurricane, such as Staten Island, the New Jersey Shore, and Long Island’s South Shore, a City College of New York landscape architecture professor warns.

“If you mitigate to protect Lower Manhattan, you increase the impact in other areas,” says Catherine Seavitt Nordenson, associate professor of landscape architecture in CCNY’s Spitzer School of Architecture. “Everyone outside of the surge protection zone would be in jeopardy because the water doesn’t get reduced, it just goes somewhere else. It’s an environmental justice issue. You can’t just save Wall Street.”

A City College of New York release reports that Seavitt calls, instead, for deploying a storm defense strategy that combines elements of soft infrastructure with the hardening of existing infrastructure such as the subway system, highways and power plants.

“Techniques from nature and ecology”
“The idea of soft infrastructure is to use techniques from nature and ecology to improve resiliency,” she explains. “Environments that are more resilient bounce back faster after storms, and greater resiliency reduces the velocity of and damage caused by the water’s surge.”

Additionally, it would be much less expensive than building storm surge barriers, with costs running to hundreds of millions of dollars instead of billions.

She first proposed development of soft infrastructure in On the Water/Palisade Bay, a report published in 2010 in collaboration with structural engineer Guy Nordenson and architect Adam Yarinsky, and funded by the Fellows of the American Institute of Architects’ biannual Latrobe Prize. Mr. Nordenson is Professor Seavitt’s husband.

The team’s research focused on New York’s Upper Bay, which is bounded by Manhattan, Brooklyn, Staten Island, and New Jersey. Its proposal consisted of strategies to adapt to and mitigate the effects of rising sea levels caused by climate change, including increased potential storm surges from hurricanes and nor’easters.

“We wanted to show how soft infrastructure could be used to transform the coastal edge in order to create a healthier ecology and reduce the extent of storm damage,” she says. “There are things we can do besides building higher and higher seawalls everywhere. For example, if we replace a wall with a gradient edge that slopes into the