Anna Somers-Cocks: Can Venice be saved from drowning?

Why should this miraculous and ancientcity not take a leap into the future and become a Silicon Serenissima?

The statistics cannot be ignored any more; the flooding in Venice is getting worse and worse, largely due to climate change. In the first decade of the 20th century, St Mark's Square was flooded an average of nine times a year. In the Eighties, it was 40 times, and now, since September alone, there have been over 40 tides of more than 80cm above mean sea level (St Mark's Square, the lowest-lying part of Venice, floods at 80cm).

The statistics cannot be ignored any more; the flooding in Venice is getting worse and worse, largely due to climate change. In the first decade of the 20th century, St Mark's Square was flooded an average of nine times a year. In the Eighties, it was 40 times, and now, since September alone, there have been over 40 tides of more than 80cm above mean sea level (St Mark's Square, the lowest-lying part of Venice, floods at 80cm).

The raised walkways have been constantly out in the alleys and squares, and twice, on 6 November and 21 November, even these were floating away. The 144cm flood of 6 November was the third worst since 1900, with 93 per cent of the city under water.

The indifference of the Venetians has at last been shaken. The previous mayor's advice just to go out and buy some galoshes has a Marie-Antoinettish ring to it now, and there has been a protest march in St Mark's Square by shopkeepers.

Some of the consequences of the flooding are obvious: the tidemarks in shops and bars; the damp staining exterior walls up to the first floor windows. The long-term damage to foundations and ancient brickwork is less obvious, nor can you tell at once how many people have decided that enough is enough, and they would rather go and live on the mainland now, where life is cheaper and more convenient.

We do know, however, that the population of Venice was 150,000 in the Fifties and is now 64,000. This leads to a vicious circle of fewer schools, doctors, cinemas, real shops (as opposed to ones selling carnival masks and souvenirs); more expensive food, goods and services, and so on. Down and down, until the only business worth conducting in Venice will be the tourist industry, with its quick return on investment.

The mayor, Paolo Costa, says that, already, if his planning committee were less vigilant, every building falling vacant would become a hotel. He appealed last autumn to the private committees for the safeguarding of Venice, such as Venice in Peril, to bring high-technology companies to the city.

And why not? The fibre-optic cables are being laid in the canals; the vast former dockyard, the Arsenal, and other large buildings formerly occupied by the state and town council, are available. Why should this miraculously beautiful and ancient city not take a leap into the future and become a Silicon Serenissima? It is still a wonderful place in which to live: the right size to cross on foot, a town made up of meeting places, where no one need feel lonely or alienated; a town with a negligible rate of serious crime, where no woman need fear walking home alone at night, or mother fear to let her child out to play; a town where the social and economic classes live comfortably next to each other and everybody knows their neighbour; a town without the pollution, danger and noise of cars, just the glorious ringing of the bells throughout the day, and the great bell of St Mark's, the Maragona, that sounds right across the lagoon, to close the day.

A revived Venice could become the living Utopia, a reminder of what civil, urban living can be.

But who will invest long-term in a city that is being flooded, and not just to the levels of the last few months, but which is at risk of a storm surge? In 1966, a low-pressure system combined with a violent scirocco banked up the waters in the Adriatic to two metres above mean sea level and totally overwhelmed the town for a whole day. And it could have been worse, says Roberto Frassetto, one of Italy's leading oceanographers: "It was a neap tide that day, just as it was this 6 November; in both cases, had it been a spring tide it would have been at least 20cm more."

He is quite clear in his mind as to the solution. He was part of the team appointed by the government after the 1966 flood to devise a flood protection system and he believes that their scheme for mobile barriers is the answer. These consist of 79 hinged metal flaps attached to the seabed at the three entrances from the Adriatic to the lagoon. Provisional estimates are that they would cost £1.4bn. When the meteorologists give the warning, compressed air forces the water out of the flaps, and they rise to hold back the sea. When the tide subsides, water is pumped in and they descend on to the seabed once more.

A working prototype for this exists, and as long ago as 1994 it was approved by the ministry of public works. Since then, however, the whole project has become so bogged down in the political system, with the decision-making now referred right up to prime ministerial level, that the real issue, the survival of Venice, seems to have been forgotten.

Opposition to the barriers developed because ecologists, and in particular, the Green activists, say, quite rightly, that the lagoon has been grossly mistreated in modern times. A vast channel was cut to allow patrol tankers through to the refineries on the other side. Fish farms were created that prevent the water from spreading out as it rushes through from the sea. The industries around the lagoon allow polluted waters to flow into it, and the rivers feeding it wash down fertilisers and pesticides. Closing the mobile barriers would allow pollution to build up dangerously in the lagoon; go back to looking after the lagoon as tenderly as when the Doges ruled Venice, and the flooding will be solved, say the Greens. Not true, say the oceanographers such as Frassetto, and the few international experts who have been called in to advise: opening up the fish farms, for example, would make a difference to the water levels of a negligible two or three centimetres. The barriers would need to be closed only 100-300 hours a year, and there are 8,600 hours in a year. A notional golden age cannot be brought back. Venice is 23cm lower down in the water than in 1900 due to soil subsidence and sea level rise, and have the Greens not noticed?

World climate systems have changed, and there is no chance of a diminution in the frequency and intensity of atmospheric perturbation. But the Greens are part of the fragile centre-left coalitions at national and city level, and for them this is a matter that can bring down governments.

What is the way out of this tangle? Scepticism about the pronouncements of scientists is not confined to Venice. The best solution in such circumstances is to open up the contentious area to scrutiny by other qualified people who are known to be impartial, so that even the most sceptical - and the politicians - can be reassured. So far, this has happened to a very limited extent in the case of Venice.

What is urgently needed now, therefore, is for the existing studies to be translated into English and the international scientific community to work with their Italian colleagues as quickly as possible on the material. And when they have reached agreement, to publish their findings in plain English and Italian so that no one in future will be able to take refuge in mere prejudice or say they did not know that the most beautiful city in the world is at mortal risk.

The writer is executive chairman of Venice in Peril