Saturday, August 12, 2017

An Outsider's Guide to Secret Venice, Part 3: The Emergency Lagoon Drainage System

A large floating buoy attached to one of the Emergency Lagoon Drainage Plugs in the basin of San Marco

The most visible element of the 45-year-old Emergency Lagoon Drainage System floats for all to see in the middle of the Bacino di San Marco, its primary function unknown to and even unsuspected by tourists and most Venetians alike. 

If anyone, besides my son Sandro and me, gives it much thought at all, they do so only when it's being utilized in its secondary function as a mooring place for a large, important ship, such as the Italian destroyer the Luigi Durand de la Penne.

But the primary purpose of this large floating buoy (at least as far as Sandro and I are concerned), and the others like it in the waters around the city,* has to do with an elaborate anti-flood system designed and implemented in the first years after the catastrophic deluge that struck Venice in 1966. It was this "perfect storm" that called international attention to Venice's susceptibility to being abruptly submerged by the sea--rather than merely subsiding into it--and which led 10 years later to the plan for a system of flood gates situated at the three mouths of the lagoons.

As noted by Salvatore Settis in his book If Venice Dies, in 1986 then-Prime Minister Bettino Craxi announced that these submerged flood gates (known by the acronym MOSE) "will definitely be operational by 1995." Instead, 22 years after this promised date, MOSE shows no signs of being operational any time soon--if ever--and has functioned only to transfer over 6.2 billion euros of public funding into the hands of private construction companies and corrupt politicians. Of course, in Italy, as in America, this is considered a laudable achievement in itself.

But for all its fame and infamy, MOSE was the second engineering solution devised to protect the city against catastrophic flooding. The first was the now-forgotten, though still partly visible, Emergency Lagoon Drainage System.

In contrast to the no-bid contract that was gifted to the Consorzio Venezia Nuova to construct MOSE, in the immediate aftermath of the great flood of 1966 an international engineering competition was held. The winner of that competition was, to hardly anyone's surprise, considering the country's long history of hydraulic engineering, a Dutch firm.

This firm's solution to catastrophic flooding was both simpler and far more radical than the later MOSE proposal. It called for a vast drainage system to be installed beneath the lagoon, with a series of "plugs" located at the periphery of the city. The plugs themselves, situated snugly in massive drainage ports at the bottom of the lagoon, are invisible; we see only the large buoys attached to each of them and floating above them.

Each buoy, as you can see in the image at top, has a large steel ring in the center of its circular platform. In the event of extreme flooding, a fleet of massive helicopters known as "sky cranes" (with which Sandro was familiar from his then-favorite educational video series Mighty Machines), and currently stationed nearby on the mainland, would lower a hook into these rings, then haul them and their attached plugs into the sky.

A floating drainage buoy used for its secondary function by the Italian Navy
That is, just as we're in the habit of pulling a plug out of a sink or bathtub to let the water drain from it, so a fleet of massive helicopters would de-cork the lagoon.

By 1972 this Emergency Drainage System had been completed and was, according to computer analysis and a series of tests (extensive in number but necessarily limited in scope), fully functional.

Venice was saved.

Or was it?

For even as the system was being installed a multitude of scientific studies were arguing that even a single use of the system would cause massive and irreversible damage to the lagoon itself. The rapid and violent emptying of water from the lagoon would result not only in a staggering loss of animal, plant, and probably even human life, but widespread destruction of the lagoon's ecosystem.

The shallow, rough, irregular terrain of the lagoon bed itself, with all its sedimentation, sub-acquatic plant life and mudflats (barene), would be sucked down with the swirling mass of water rushing into the drains installed in the lagoon.

To save the built structures of the city, in other words, the lagoon itself would be sacrificed.

Indeed, a heated debate over the ethics of what critics described as the sacrifice of Nature for the sake of Culture appeared across a number of issues of the obscure but influential International Journal of Hydraulics in the first years of the 1970s, reaching such a pitched state of contention that a fear that the hitherto scholarly debate might break out into the broader public consciousness caused it to be purchased by an unknown buyer and promptly shut down.

Some have identified the Italian government itself as the buyer; others, the Dutch engineering firm responsible for the drainage system. Whoever it was, they did an admirable job of suppressing the content of the debate and purging all traces of the journal from libraries. To this day, single issues from this contentious period have fetched bids in the low six figures, and a multi-copy set said to contain the complete series of exchanges garnered a million dollar bid from the famous Ransom Rare Book Collection at the University of Texas Austin. But in every case the proffered publications have turned out to be fraudulent. 

Equally troubling, though, was the fact that a single use of the system would, by scouring the lagoon clean of its wave-buffering natural features, leave the city significantly more susceptible to disastrous flooding than ever before. A single use of the system was likely to turn what had long been a lagoon into what was effectively a shallow bay, through which water from the Adriatic would rush in with unimpeded force.

According to some it was this realization that ultimately led to the decision in 1976 to go ahead with the mobile flood gates.

While others more simply, and cynically, say that the decision to go forward with the MOSE project was less about impeding the flow of dangerous tides than about diverting a massive flow of public money into the "right" (ie, well-connected) private bank accounts.

Whatever the reason, Venice now has one almost 50-year-old system of flood prevention that is theoretically still functional but that it dare not use, and one "new" one (originating just 10 years after the former) which it's supposedly clamoring to use but seems unlikely to ever be functional.

And, alas, because some municipalities, like some people, never seem to learn from their mistakes, the use of the MOSE system--if ever it does function--raises as many questions about its own disastrous effects on the lagoon as the old Emergency Lagoon Drainage System.

In truth, considering the long, ineffectual history and deleterious consequences of each system side-by-side, the real MOSE one and the one imagined by Sandro and me, I can't quite ultimately decide which of them stretches credulity more.

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*There are a few such floating buoys and Sandro and I were inspired to look into the mystery of them after repeatedly passing a particular one of them that lay--like the subject of Part 2 of this series of posts--on the vaporetto path between his pre-school and our home (specifically, between the San Pietro di Castello stop and that of Bacini).

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