Rising Tide - Business Facilities Magazine - Area Economic Development, Site Selection & Workforce Solutions

The debate about whether to build huge sea barriers around New York City -- and where to put them -- has begun. Nov 14, 2012 @ 3:25 PM

The debate about whether to build huge sea barriers around New York City -- and where to put them -- has begun. Nov 14, 2012 @ 3:25 PM

Rising Tide

Rising Tide - Business Facilities Magazine - Area Economic Development, Site Selection & Workforce Solutions









Two weeks ago, the nation’s top scientific research group gathered in Washington, D.C. to brief federal officials on the results of the group’s high-level study assessing the impending impact of climate change.

The National Research Council was prepared to tell our leaders that climate change is accelerating, and the phenomenon already is spawning disruptive events around the world that will create more frequent but unpredictable crises in global water supplies, food markets, energy supply chains and public health systems.

But the briefing had to be postponed due to Hurricane Sandy. That should tell you all you need to know about how prepared we all are to deal with this looming catastrophe.

The superstorm that arrived like a Halloween ghoul and ripped across the Northeast caused at least $50 billion in damage, officials estimate. But perhaps its most enduring legacy will be the consensus that is emerging in its wake.

Almost overnight, it seems, we’re coming to grips with what the pundits have dubbed the New Normal: Sandy is not an anomaly — what we quaintly used to call a Storm of the Century — it most likely is the shape of things to come on an annual basis as we reap the bitter harvest of decades of denial over the damage we’ve been doing to the planet’s atmosphere.

The sobering realization that the impact of climate change may already be upon us is prompting officials in low-lying regions to dust off proposals which previously could generate serious discussion only in a place like the Netherlands. The debate about whether to build sea barriers around New York City — and where to put them — has begun.

New York City Council Speaker Christine Quinn, who is expected to be a candidate to succeed Mayor Michael Bloomberg in next year’s election, on Tuesday put forward a proposal of flood-prevention measures including the construction of a storm surge barrier that could cost more than $20 billion. Quinn described flood prevention as the “single most important infrastructure challenge of our time.” She said Mayor Bloomberg’s administration has agreed to accelerate two studies to identify risks faced by different sections of the city and develop the best strategies for protecting those areas.

An analysis in The New York Times last week detailed the quandary confronting city planners as they consider measures to counter rising sea levels. The most commonly discussed solutions — including the erection of huge sea walls in the Verrazano Narrows between Brooklyn and Staten Island — could have the collateral effect of directing flood waters to other low-lying areas of the region.

The technology of humongous moveable sea walls already has been implemented to protect Rotterdam, Europe’s busiest port. Prior to the Dutch project, a mammoth 10-gate system was developed for the River Thames in London. A much more modest barrier, a 17-foot-tall “flap gate” protecting Stamford, CT, recently was deployed to seal off 600 acres of the city’s downtown at a cost of $14.5 million.

In 2009, New York City hired Jeroen Aerts, a researcher with the University of Amsterdam in the Netherlands, to assess flood risks and protections. Initially, Aerts was instructed to focus on less-intrusive options like flood-proofing buildings and expanding wetlands to absorb more water. The prevailing assumption in 2009 was that unlike New Orleans, New York was far enough above sea level that construction of a sea barrier was not required.

This thinking changed last year after Tropical Storm Irene skirted the city but pummeled coastal areas, the Times reports. After Irene, the city asked Aerts to compare the costs and benefits of barriers with those of smaller-scale measures like building levees around sewage treatment plants and elevating subway stations.

Aerts is scheduled to present a draft of his findings in January. According to the Times, he has concluded that any barrier system sufficient to protect lower Manhattan will cost up to $17 billion and require an additional $12 billion to shore up areas on the sides of the barriers. Aerts is expected to recommend that New York consider building the barriers; the next step in the process, a feasibility study by the Army Corps of Engineers, would require authorization from Congress.

The primary concern that has been raised about the sea barrier proposal — aside from the disruption construction of the barriers would create in one of the nation’s busiest ports — is what might happen to the water displaced by the barriers.

Brian A. Colle, a professor of atmospheric science and a member of the Storm Surge Research Group at Stony Brook University, told the Times that a barrier that blocks the surge would cause water levels on the other side of the barrier to rise by close to a foot. “You could have about 20 percent more water on the other side of the barrier,” he said, adding that pollution from the runoff of storm water mixed with sewage would be trapped behind a barrier, with nowhere to go while the sea gate was closed.

Environmental groups also have expressed concern about the impact of disrupting tidal flows (and salinity levels for aquatic life) by building permanent infrastructure in New York Harbor and adjacent rivers.

“The harbor, the Hudson, the Hackensack and Raritan Rivers and Arthur Kill all have thriving ecosystems that benefit us economically and in terms of recreation,” said Paul Gallay, president of Riverkeepers, an environmental advocacy group. “We understand everything needs to be on the table dealing with the new normal, but storm surge barriers may end up doing more harm than good.”

Philip Orton, a storm surge scientist with the Stevens Institute of Technology in Hoboken, told the Times that it will probably take a bigger disaster than Sandy to make sea barriers an urgent priority.

“People won’t accept these dramatic changes to the environment,” he said. “I don’t think we’ve had [a big enough] disaster yet to make this palatable. But it certainly will change the debate.”

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