A Dutch Solution for New York's Storm Surge Woes?
Maeslant Storm Surge Barrier, the Netherlands
Hurricane Sandys storm surge did a number on New York City, flooding lower Manhattan, inundating the subway system, triggering fires and power outages, and causing other widespread damage that will take a long time to repair. As this New York Times story from September notes, the city has been only moderately proactive in prepping itself for the long-term risk posed by ocean floods, stressing how to respond when water breaches existing barriers rather than stopping floods altogether. Thats not surprising, really, because there is little political incentive to prep for something that hasnt happened, even if you know its coming at some point. Now it has. Moreover, the risks are rising inexorably: sea level rise is happening at an accelerated rate along the East Coast. Every extra inch of sea level increases the annual risk of flooding. So what was once a vanishingly rare event becomes a rare one, then a common one. Existing systems just wont cut it.
Matthew Yglesias suggests that New York (and by extension, other East Coast cities) think big and start looking at the Dutch flood protection model, which employs large-scale flood gates to repel storm surges off from the North Sea:
"The idea of essentially damning up New York Harbor sounds extreme, but thats equivalent to what the Dutch did with the Zuiderzee Works and especially the Delta Works projects undertaken after the 1953 flood. Some of the Dutch works are permanent dijks, but others are open sluices that merely shut when storms are coming to block surges. You could imagine something similar at the Arthur Kill and across the Verazano Narrows or even between Sandy Hook and Rockaway. Projects like that wouldnt immunize Staten Island or the beachfront parts of Brooklyn and Queens from storm surges but they would defend Lower Manhattan, the badly flooded Red Hook part of Brooklyn, Long Island City, LaGuardia Airport, and a big swathe of New Jersey."
Ultimately, I think something like this is exactly what well see in New York and other coastal cities. It sounds fanciful, but New York is simply too big and important not to protect, and a system of surge barriers and other structures is probably the only way to protect it long-term. Which is exactly the thinking behind the Dutch system.
As it happens, I visited the Netherlands after Hurricane Katrina to look at how Dutch flood control worked, and how its success might apply to New Orleans. (It was part of a mega-series worth rereading now that looked for lessons in how other places, from Kobe, Japan to Galveston, had recovered from disasters.) After crawling over New Orleans crappy levees and floodwalls, it was like stepping from Deadwood into Star Trek.
The single biggest insight I came away with was, its not about the type of structure you build (though thats obviously important). Its about how you estimate and choose to manage flood risks. Dutch structures are typically designed to withstand a 1-in-10,000 year flood event. Im oversimplifying this some, but if circumstances change, and risks grow more severe, then the Dutch system mandates that flood control systems be upgraded accordingly. That way the level of protection stays the same as the threat evolves.
We have nothing like this in the United States now and are unlikely to for the foreseeable future. Responsibility for flood protection is spread out among local, state and federal governments. Standards and protections vary wildly, mile-by-mile, and are vastly weaker than in the Netherlands. Which is understandable, because historically floods have not posed an existential threat to places like New York City.
So if you want visually spectacular flood control barriers, it helps to have flexible, adaptable technological systems. Such systems are exactly what we need in a world beset by not only rising seas and potentially stronger storms, but by environmental threats of all kinds. Were transitioning to an era of rapid environmental change, and that means thinking about how to build those conditions into our infrastructure, and the policies and bureaucracies that maintain it. Were not doing that yet.
But that doesnt mean a Dutch-style system is totally out of reach for us. I suspect were going to start borrowing from it, in bits and pieces, in New York and elsewhere. In New Orleans, the Corps of Engineers ultimately did adapt a Dutch-style risk standard as the basis for its $14 billion in upgrades to the levee system, which include a new surge gate spanning an especially vulnerable spot. (Its standard is a 1-in-100 year flood event; in other words, its literally 100 times less safe than the Dutch system. But hey, its a big improvement over what was there before.)
Update: Harry Shearer notes that the Corps has had ongoing problems with a key node in the New Orleans system, pumps that expel rainwater from the city while canal surge barriers are closed; this raises questions on whether our existing institutions can really work on an ambitious scale.
A Dutch Solution for New York's Storm Surge Woes? - Forbes
