How To Save New York

The $15-billion Dutch-style storm surge control system that could prevent America’s biggest city from flooding next time.

Flooding in downtown New York's Financial District on Monday night.
Flooding in downtown New York’s Financial District on Monday night

Photograph by Andrew Burton/Getty Images.

Growing up in New York City, I never had much consciousness of it as a coastal city. The beaches are in the farthest-off parts of the outer boroughs, and the population centers in Manhattan and Brooklyn are oriented inward rather than toward the waterfronts. But the devastating flooding of Hurricane Sandy is a powerful reminder that the reason New York was built where it is was take advantage of a good harbor and extensive coastline. And while the city continues to be a relatively unlikely place for a hurricane to make landfall, the combination of more frequent storms and higher baseline sea levels that we can expect thanks to climate change means New Yorkers need to prepare for these kind of storms to arrive multiple times in the course of any given person’s lifetime. Beyond hoping that the rest of the country embraces liberal policies on greenhouse gas emissions, the city ought to look to its former colonial overlords in the Netherlands for some ideas.

Whether by coincidence or by design, the former Dutch colony of New Amsterdam turns out to have a lot in common, geographically speaking, with the old Amsterdam.

New York, like Holland, became a shipping center in an era of shallower boats—a period when extensive water frontage against a not-very-deep harbor was a key economic edge. A result of that in both places was acute land shortage. The urban growth process forced extensive development on low-lying terrain reclaimed from the sea. When a storm hits, that’s a deadly combination. The shallow harbor means a proportionately larger storm surge, and the reclaimed land is prone to flooding. Worst of all, the very extensive irregular waterfront is difficult to defend with seawalls and flood barriers.

The Dutch have responded to this problem with an impressively elegant solution: Make the coast shorter. In the wake of a 1916 flood, they erected the Zuiderzee Works to turn a former inlet of the North Sea into a nice tame lake. Today, the Afsluitdijk—a causeway 32 kilometers long, 90 meters wide, and 7.25 meters high—separates the North Sea from two freshwater lakes known as the IJsselmeer and the Markermeer, in the process protecting a huge swath of Holland, including Amsterdam itself, from storm surges.

An even more relevant precedent is the massive Delta Works series of dams and flood control devices in the southwestern Netherlands. These works protect, among other things, the enormous port of Rotterdam, meaning that they can’t completely sever the mainland from the sea the way Afsluitdijk did.

Consequently, key elements of the Works including the Maeslantkering and the Oosterscheldekering have moving parts. They remain open most of the time, preserving the sea route to Rotterdam and the saline quality of the Oostershelde inlet. Those are the kind of barriers New York would need to seriously reduce flood risk without devastating the local ecology or unduly disrupting the important working port in Elizabeth, N.J. and other waterfront activity in the region.

A 2009 seminar hosted at the Polytechnic Institute of New York University considered several options for major infrastructure upgrades to combat storm surges—a barrier at the south end of the Arthur Kill that divides Staten Island from New Jersey, an East River barrier to prevent surges up that narrow waterway, a barrier perpendicular to the Verrazano Narrows Bridge between Staten Island and Brooklyn, and most ambitiously a “Gateway Barrier System” stretching from Sandy Hook to the Rockaways. Engineers don’t believe it would be feasible for the Gateway system to entirely block storm surges, but it could weaken and deflect them—significantly reducing the flood risks to the entire New York Harbor.

Even in full combination, this system would hardly eliminate storm-related problems. The Rockaways and the farther-east barrier islands off the coast of Long Island would still be subjected to potentially devastating impacts, as would the Jersey Shore communities. But this is an inherent risk of oceanside living. You can enjoy the waves and the view, but the geography won’t support robust anti-storm engineering. The system would, however, substantially reduce the exposure of southern Brooklyn, eastern Staten Island, and Raritan Bay communities in New Jersey. Better, it would essentially immunize Manhattan, Red Hook, Dumbo, Green Point, Long Island City, LaGuardia Airport, Hoboken, and other parts of Hudson County, N.J. from storm surges.

It would, of course, be expensive. The estimates presented at the seminar suggest a ballpark figure of $15 billion. But even if that turns out to be a substantial underestimate, it’s a bargain compared to the cost of widespread flooding. A 2011 study of a catastrophic hurricane scenario suggested the tab for rebuilding transportation infrastructure alone could run as high as $55 billion. That’s to say nothing of the indirect economic cost of having the New York City Subway, three commuter rail networks, and the PATH train under the Hudson out of commission for days. And while power outages due to downed power lines are a constant of any storm anywhere, downtown Manhattan is currently blacked out despite buried lines because flooding destroyed a power station located right by the East River. The direct and indirect costs of this would, again, be enormous. And that’s all before considering the damage to private property.

Something to note is that despite its misfortune in Hurricane Sandy, the New York Harbor region is almost uniquely lucky in being a place that can feasibly contemplate these kind of costly defenses. Manhattan, Brooklyn, Hudson County, and the northern coasts of Queens and Staten Island are some of the most densely populated and capital-rich terrain in the entire United States, meaning that the per capita cost of tens of billions in flood control infrastructure is tolerable. Rising sea levels are going to mean flooding problems for many other coastal American cities, but your Savannahs, and Charlestons and Wilmingtons—to say nothing of rural communities on the Delmarva Peninsula and elsewhere—will have a much harder time finding the means to pay for adequate defenses. Here, too, the Dutch precedent is relevant. As the most densely populated part of Europe, it’s the part that can afford these kinds of investments. Greater New York, similarly, is by far the densest agglomeration of people and economic activity in North America. The interstate nature of the project and the fact that both termini of the Gateway system would be on land controlled by the National Park Service means there’s room for a federal role in safeguarding the city. But it would be pennywise and pound-foolish for New York and New Jersey to wait around for some kind of federal handout. The bill for defending the area against a recurrence of Sandy or the likelihood that sooner or later an even bigger storm will hit is large, but the price is worth paying. New York and its neighbors can and should find a way to raise the money and get it done.