Whenever a big storm comes along and wipes out a US city, the response is always the same: We need to build a wall to protect us. This was true after Hurricane Katrina hit New Orleans, after Hurricane Sandy hit New York City, and after Hurricanes Matthew and Irma washed away homes in Florida and the mid-Atlantic coast.
In New Orleans, they raised the dikes; in New York City, there are plans for an enormous wall around Lower Manhattan; in Florida, walls are going up so fast that parts of the coast are starting to look like a military fortress. And in Miami, where sea level rise is already a clear and present danger, voters just passed a $400 million “Miami Forever” bond, a portion of which will fund sea walls to help protect the city.
But walls and barriers are problematic in a number of ways. For one thing, they sever the land from the sea, destroying rich coastal ecosystems that are not only important for the health of the oceans but also provide important buffers from storm surge.
Walls and barriers also create a false sense of security; if and when they fail, the consequences can be catastrophic. Walls and barriers are also expensive, take a long time to build, and are not very adaptable to changing conditions.
It is perhaps true that with enough money and engineering knowhow, anything can be protected. It’s one thing, however, to spend $7 billion on a barrier around Lower Manhattan, the most valuable real estate on earth; it’s another to shell out similar funds to protect smaller neighborhoods. Walls and barriers are by their very nature unjust, dividing cities not just along class and racial lines but between the saved and the doomed.
When it comes to dealing with sea level rise and increasing flood risks, even the richest, most well-engineered, well-protected coastal cities are vulnerable.
Consider Rotterdam, in the Netherlands. Rotterdam is often cited as one of the cities in the world best adapted to sea level rise.
That is probably true. But it is also true that Rotterdam is an almost entirely new city. It was heavily bombed during World War II, and one of the most striking things to me about the city is the lack of any ancient architecture, any sense of the kind of history that one associates with an old Northern European city. It is all modernist towers, square and blocky. It is also a modern architect’s playground: The train station looks like a cresting wave, buildings are made of cubes and trapezoids, and I bought coffee in an enormous new marketplace that looks like an airplane hangar with flowers and cows painted on it.
Rotterdam is the largest port in Europe, strategically located on the Rhine about 30 miles from the North Sea. The city is full of old canals and wooden boats that have been transformed into hip hotels and restaurants. Flooding is a well-known threat here: The city sits on a plain that absorbs outflows from the Scheldt, Meuse, and Rhine Rivers, which makes it vulnerable to inundation from extreme rainfalls, as well as sea level rise and storm surges that move up the Rhine.
How Rotterdam has adapted to a persistent risk of dangerous flooding
Dutch engineers have come up with a lot of innovative ways to deal with flooding in Rotterdam, including pioneering the use of “water parks,” which are public squares that double as catch basins for water, essentially creating storage ponds that keep the water from draining into the streets and flooding neighborhoods. During big rainstorms, the catch basins funnel the water into the stormwater discharge system, sending it out into the river.
I visited one of those water parks in Rotterdam. It was a sunny day, so the water park was dry — it just looked like a large sunken concrete plaza between modern office and apartment towers. A sequence of concrete benches led down into the catch basin in the center of the square. As far as public spaces go, the featureless concrete square was pretty bleak, though perhaps less bleak than a flooded city.
Rotterdam’s understanding of the risks of living with water has been shaped by tragedy. In 1953, a great storm swept in from the North Sea during high tide and flooded large parts of the Netherlands, the UK, and Belgium, killing 2,000 people. In the Netherlands, a 20-foot surge broke through dikes, flooding areas that the Dutch had believed would never be flooded. In terms of psychological impact, the catastrophe was similar to the 1966 flood in Venice. As Henk Ovink, the Dutch special envoy for international water affairs, told me while I was in Rotterdam, “It was the moment we realized we weren’t so safe anymore.”
Like the people of Venice, people in the Netherlands have been living with water for a thousand years. Some of the oldest laws in the country are about controlling and sharing and protecting themselves from water.
Reclaiming land from the sea is, in some ways, the origin tale of the Netherlands. Seventy percent of the country lies below sea level, and this nation had long felt protected by walls and dikes against the attacking sea.
But the 1953 flood was a wakeup call to the risks they faced in the future. The Dutch government responded with an all-out engineering effort to defend the nation from the sea, launching the Delta Works project, which, among other things, required all infrastructure be built to 1-in-10,000-year flood standards. That meant raising dikes and levees, rerouting rivers, and, in some cases, moving villages out of harm’s way.
The centerpiece of the Delta Works is the Maeslant Barrier, about 15 miles from the center of Rotterdam, where the Rhine enters the sea. (“It’s the storm drain of Europe,” one engineer told me.)
When a storm is coming, two enormous gates swivel out from hinges on the riverbanks and close off the river from the ocean, holding back both the flow of the Rhine and the surge of the incoming ocean. The gates, held firm by 52,000 tons of concrete buried in the ground, are designed to roll with the waves, swinging on both horizontal and vertical axes like a human shoulder.
However, despite the size of the barrier, it can only stay closed for about 12 hours before the stress on the joints and the foundation becomes too much and the gates have to open.
While I was in Rotterdam, I drove out to the barrier with Richard Jorissen, managing director of the Dutch Flood Protection Program. We parked near the visitors’ center and walked out to have a look at the wide and powerful Rhine. We watched an oceangoing freighter pass out into the North Sea. It was carrying coal.
“These structures are ... about buying time until we better figure out how big the problem really is”
The Maeslant Barrier looms on the shore, showing off its huge hinges and enormous steel gates. (“When they are closed, the gates together are longer than the Eiffel Tower is tall,” Jorissen told me.) Instead of hiding away discreetly, it shows off its muscle and dares the seas to rise and test it. The barrier, which was completed in 1997, cost $450 million to build. In the 20 years it’s been in operation, it has only been used once (although it is tested every year).
“That’s a lot of money to spend on something you use only once in 10 years,” I said to Jorissen.
“We’re Dutch — we take protection seriously,” he joked. “So as long as this barrier works, Rotterdam is safe from flooding? Well, no. There are scenarios we can imagine that would still be catastrophic.”
Jorissen described his nightmare scenario: A hurricane-level storm blows in from the northeast, dropping massive rainfall on Rotterdam. At the same time, the storm drives a wall of water up the Rhine — enough to flood Rotterdam, even without the rainfall. So operators of the barrier face a kind of devil’s choice: open the gates to let the rain-swollen river out, or close the gates and risk letting the storm surge in. Either way, the city floods.
“Luckily, we haven’t faced that yet, and perhaps never will,” Jorissen told me.
The Maeslant Barrier serves the complex purpose of keeping an important city safe from the sea, while at the same time keeping the city open to the sea. It is a difficult trick, and one that, in a world of quickly rising seas, probably won’t work for long.
With 3 feet of sea level rise, the Maeslant will no longer be helpful. Unless walls and levees are raised for many miles around it, the sea will come in from other directions, making the opening and closing of the gate moot. As one engineer put it to me, “These structures are not about solving the problem — they are about buying time until we better figure out how big the problem really is.”
Ultimately, the solving the problem of sea level rise will require a fundamental shift from engineering projects designed to keep water out, to engineering projects designed to find new ways to live with water. As one Florida geologist told me not long before I left for my trip to Rotterdam, “If you’re not building a boat, then you don’t understand what’s happening here.”
Jeff Goodell is a contributing editor at Rolling Stone and the author of five books, including The Water Will Come: Rising Seas, Sinking Cities, and the Remaking of the Civilized World, from which this essay is adapted.