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Parting the Sea


Author Joe Keohane

WHEN THE SEA COMES FOR VENICE, which happens mostly in the fall and winter, the following occurs: First, the local authority activates a siren located at Punta della Salute, across from the Piazza San Marco. It sounds like an air raid siren. Moments later, secondary alarms begin chirping along the Grand Canal, where the motorboats and gondolas are moored. City workers drag out a bunch of rickety two-foot-tall wooden walkways and place them around the most at-risk areas. Shopkeepers, hoteliers and homeowners barricade their doors against the tide, as they have countless times before, with sandbags or built-in metal gates. Then, well, it floods. The locals call it acqua alta, or high water.

Before long, there are great pools of vaguely oily, off-smelling water in the city’s low-lying areas—picturesque, timeless spots like Rialto and the Piazza San Marco. Within minutes, tourists in rubber boots on loan from their hotels materialize around the fetid pools mugging and snapping photos, documenting for the folks back home the slow death of Venice. By 2014, however, if all goes according to plan, things will work differently when the sea rises up.

By then, a body called the Consorzio Venezia Nuova—the Consortium for a New Venice—will have predicted a major storm surge days earlier using its own forecasting technology and alerted the city government. As the surge approaches, ships headed for the industrial ports around Venice will be held or diverted, and the population will be notified by video screens placed throughout the city. As the waters begin to rise within the 212-square- mile lagoon in which Venice sits, 78 steel gates resting along the bottom of the inlets leading to the lagoon at depths ranging from about 60 feet to nearly 100, will fill with compressed air. They’ll rise about 45 degrees on their hinges and meet the sea. The surge will heave against the gates and then eventually lose its force and start rolling back. When equilibrium between the water level in the lagoon and the sea is reached, which should happen after a few hours, the gates will refill with water and sink back down to the giant concrete caissons to which they’re attached. Tourists, for their part, will have to content themselves with gondola photos.

The Consorzio calls this system MOSE. The name came from an outmoded 1990s prototype, the Modulo Sperimentale Elettromeccanico, or Experimental Electromechanical Module, but they kept it for a simple reason: It’s Italian for Moses.

VENICE IS A PLACE IN WHICH TO get lost. Sometimes, thinking you know where you’re headed, you’ll turn into a narrow alleyway and the sidewalk will just run out at your feet. You’ll stand there as the water quietly laps against the stone quaysides, trying to get your bearings. Continue through the city, and you’ll encounter other surprises. One moment you walk across the Rialto Bridge, and there’s nothing out of the ordinary. Come back an hour later, and it’s underwater and everyone’s wearing rain boots. Later that day, it’s dry and they’re wearing shoes. That is just the way it has always been, which may account for a general lack of urgency felt by locals toward the MOSE project.

MOSE, like its namesake, spent about 40 years in the wilderness. The idea of building mobile barriers first surfaced in the wake of the catastrophic 1966 flood of Venice, in which the water level rose a record 76.4 inches. When it hit, MIT oceanographer Paola Malanotte-Rizzoli, who now works as an independent consultant for the MOSE project, was a high-schooler. Prior to the big flood, she says, Venice seriously flooded only a couple of times a year, “which was great because we didn’t have to go to school.” But the ’66 flood was different. “We were on the third floor when the water came up. Usually the water went right back down, but that time it just stayed there.” The Venetians have an old phrase to describe their city’s precarious relationship with the sea: “Sempre crolla ma non cade,” or, roughly, “Always collapsing but never falls.” The ’66 flood made real the possibility of a fall.

In 1972, gates were proposed by a handful of scientists. One of them, Walter Munk, one of the great oceanographers of his generation, believed it was the obvious solution. Yet he and his colleagues encountered stiff resistance from the locals, a proud bunch keenly aware that their city had been the most powerful state in the world before being toppled by a twentysomething Napoleon in 1797 and meddled with by foreigners ever since. “It’s fair to say the old Venetian families were not overly enthusiastic about Americans and English people telling them what to do with their city,” recalls Munk.

Which isn’t to say the idea wasn’t debated. It was, heatedly, along with a slew of other ideas of varying scope and plausibility. But the gates just never got off the ground. Venetians were, and are, distrustful of outsiders, and the Venetian bureaucracy was impossible to deal with. Moreover, a project of this magnitude would require help from Rome, but for years the central government was notoriously unstable. “From the sixties until the nineties, the government collapsed every six months,” says Malanotte-Rizzoli, “and every government formed a new commission to study the problem of Venice. It just went on forever.”

Meanwhile, the flooding was getting worse. Changes to the lagoon during the 20th century had made Venice more vulnerable to the sea’s predations. Industrial plants built nearby on the mainland in the 1920s had extracted groundwater from under Venice, causing the city to sink at an accelerated rate—about nine inches total in the 20th century (the sinking slowed when the extractions were halted in the 1970s). The deep channels cut into the lagoon to accommodate large ships made the city more susceptible to the wild tidal swings of the northern Adriatic, as well as the storm surges that shoot up the sea’s narrow corridor or come laterally, propelled by winds from the east, and essentially pile up on the cul-de-sac that is the Venice lagoon. The marshes and mudflats—natural bulwarks against flooding—began to disappear under the assault. When the city flooded, as it did with greater frequency, the salty water ate away at canal walls and buildings with a growing rapacity.

In 1987, the Italian government commissioned the Consorzio, formed that year by some of Italy’s biggest construction and engineering firms, to build MOSE. When the commission was granted, nepotism and corruption were rampant in Italy, so the idea of a group of powerful corporations gaining a no-bid monopoly on an experimental public works project now employing 3,000 people and expected to cost nearly five billion euros, was met with skepticism. Nevertheless, the gears were in motion. After that it was a simple matter of everyone squabbling over it for an additional 20 years, and construction was underway.

Gated Community

The MOSE gates are being built at the three inlets leading to the Venetian lagoon, which sits in a precarious watery cul-de-sac at the northern end of the Adriatic Sea.

How it works

1 When the sea is at a manageable level, the water-filled steel gates stay in their caissons, out of view.

2 As the sea rises, hydraulic pumps expel the water from the gates and fill them with compressed air, caus- ing them to float up.

3 Once deployed, the gates repel the storm surge. When the water level returns to normal, they refill with water and sink back down.

ELENA ZAMBARDI, WHO WORKS for the Consorzio and lives in town, sits in the cabin of one of Venice’s inimitably stylish wooden water taxis early one cool autumn morning. She’s wearing rubber boots, the one item found in every single Venetian household. In 2009, she says, there were 10 serious floods, a record. “It was a horrible year for acqua alta,” she says. By November 2010 there had already been 10. “It will be the worst year in history,” she says. While she talks, the taxi motors through a dense fog toward the Lido inlet, one of three along the dune bar that separates the lagoon from the sea. En route, we pass a pontoon boat transporting two cement trucks to the other major MOSE worksite—by the Malamocco inlet— then we tie up on the north side of the Lido. Here, the Consorzio is building some of the caissons: huge, hollow concrete structures that will hold the gates when the project is complete. Each one is 197 feet long, 28.5 to 37 feet tall, and weighs up to 22 tons—nearly the size of a 20-story building laid on its side. When the time comes to install them, the bed will be flooded, and the caissons will float up with the tide. They will then be tugged over to the inlet itself, filled with cement and carefully lowered, using sonar and GPS, onto steel pilings already pounded into the sea floor. Once they’re in place, the gates will be bolted on and hooked up to a series of water and compressed air pumps built into the caissons.

The Consorzio will operate the barriers for the life of the equipment, which the group expects to last for a century. It claims the gates will be able to handle floods up to 10 feet, and as long as the average sea level rises no more than two feet in the next 100 years, MOSE will work as intended. After that, the hope is that nature and man will be able to work cooperatively to solve the problem of flooding (the Consorzio is also restoring the salt marshes, beaches and other natural defenses of the lagoon), rather than simply damming off the sea.

None of which is to say MOSE is popular among the locals. The gates have been, and remain, a source of controversy in Venice. Arguments against them fall into a few overlapping categories: No. 1: The Consorzio members are crooks (unsubstantiated). No. 2: The Consorzio’s projections of sea level increase are off, which could render the gates less eff ective than claimed (debate is ongoing). No. 3: MOSE will be an ecological disaster, because if the gates stay closed for a prolonged period, say, in the case of a sudden, permanent increase in the global sea level, the tides won’t be able to flush out the lagoon, and Venice, which has no municipal sewer system, will become a toxic sump (time will tell, but unlikely). No. 4: There are better, cheaper ways to save the city, like a proposed scheme to forcibly re-inject groundwater 2,300 feet under the city to push it back up.

The opposition to the project, which for a time included the previous mayor of Venice, succeeded for years in delaying the project using these and other lines of argument. Ultimately, though, for all their passion, they fell short. The project is now two-thirds done. The present mayor, Giorgio Orsoni, is on board, Prime Minister Berlusconi is on board, and most of the funding is secured. “There was a war,” says Giovanni Cecconi, the Consorzio’s head of engineering. “In case of war, it’s not important that you win. What’s important is that you survive. We survived. And we’re doing the barrier.”

Nevertheless, the sheer cost, scale and complexity of the effort has left many here convinced that the only real outcome of MOSE is farce. Signs reading “NO MOSE” are still visible around town. The argument, though futile, is still ongoing. But the project’s supporters argue that the detractors suffer from a failure of vision. “The local people think the gates are useless,” says Malanotte-Rizzoli. “They say it’s a pharaonic work. Well, the pharaohs built the pyramids. If it’s a pharaonic work, let us just hope we’re up to the job.”

2 Responses to “Parting the Sea”

  1. Amanda Werhane Says:
    March 7th, 2011 at 10:47 am

    Who wrote this article? I couldn’t find the author’s name anywhere.

  2. layla Says:
    March 7th, 2011 at 12:02 pm

    It was Joe Keohane, our executive editor.

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