That sinking feeling - again

ON THURSDAY, if the decision is not delayed yet again, Edo Ronchi, the Italian Minister for the Environment, is expected to reject the plan to build mobile barriers at the three openings from the lagoon of Venice into the Adriatic.

This is despite the fact that he has before him a report (completed this summer by five eminent experts from institutions including MIT and the Institute for Environmental Studies in Amsterdam) which says that the barriers are ecologically safe and effective defences; this is despite the fact that the report was commissioned by the Italian government itself; this is despite the fact that St Mark's Square was under more than a metre of water again last week, and will be dozens of times more this year. We can be sure of that. At the beginning of the century, St Mark's Square was flooded about seven times a year; by 1989 it was 40 times in the year and in 1996 it was 99 times.

Even the politician who himself has to wade through the water, the mayor of Venice, makes sibylline statements when asked whether he is in favour of the barriers; he is not overtly against them, or for them, but says that they need to be studied further and that their financing needs to be clarified.

Why do the Italians have such difficulty in deciding how to protect the world's most beautiful city? Much of it comes down to the cat's cradle of coalitions that is Italian politics at state, regional and city levels. Thus Massimo d'Alema, the Prime Minister, upsets the Greens at his peril because he depends on their support to stay in power, and the Minister of the Environment is a Green. Mayor Cacciari of Venice is also dependent on Green support for his position.

And yet the evidence for a declining state of affairs is incontrovertible. The seaweed lines on the marble steps to the Venetian palaces show how much higher the water now laps than when they were built. This is partly because the whole of north-east Italy is subsiding, and partly because, after the Second World War, water was extracted from the subsoil by the factories on the nearby mainland (this has now ceased).

In addition, as we all know, the seas are rising. Scientists world-wide generally agree that by the middle of the next century, the waters will be about 20cm higher everywhere, including the Mediterranean. Weather patterns are also changing, leading to more low-pressure systems and storms. So quite apart from the frequent small floods, the risk of a storm surge tide (a low-pressure system coinciding with a high tide and strong wind) of the kind that put the whole of Venice under nearly two metres of water in 1966, is greater than ever. Experts say that it is not a question whether it will happen, merely when. It could be tomorrow, this being the flooding season in Venice when everyone keeps their gumboots at the ready.

Across the world - in south-east England, the Netherlands and parts of the east coast of the US, for instance - populations and politicians have accepted the global situation and are planning for the future. They are preparing to add billions to the money they have already invested in their sea defences. By contrast, Italy, which has this especially fragile and lovely creation to protect, has managed to turn the issue into a punchball for party politics and nothing has been done - nor does it look as though it will be.

Back in 1981, a scheme for mobile barriers at the three openings between the lagoon and the Adriatic was first developed and went on being improved, until in 1992 the prototype was tested successfully. It works on the principle of a series of hinged flaps that normally lie invisibly on the sea bed but are raised when needed. When down, ships and tides can move through the mouths of the lagoon as usual.

But over the last 10 years, opposition in Italy to these barriers has grown. It is of three sorts. Big business fears that if the barriers have to be closed frequently, ships and, in particular, the petrol tankers entering the lagoon to get to the refineries on the other side, will be held up, and money will be lost. The Green objection is that the lagoon has been as sinfully mistreated as the rainforests of the Amazon, by deepening the shipping channel (for the said tankers), by building fish farms, and by polluting it with phosphates washed down from the agriculture in the hinterland. If we could only return to the good old ways of the Venetians under the doges, they say, then the flooding problem would be much reduced (but they daren't predict by how much it would be reduced, nor does anyone in this camp concede that the modern world's ecology bears no relationship to what it was 200 years ago - which is paradoxical, considering that these people are ecologists).

The short-term pragmatists' objection is that, because the barriers are expensive - an estimated pounds 1.5bn spread over the eight years they would take to build - there might be less money for the other things that need doing in Venice, such as dredging the canals. This seems to be behind the apparently perverse reluctance on the part of Venice's mayor to see his city protected.

The truth is that there is a fundamental confusion in people's minds which leads them to think that it is a choice between ecological virtue or some kind of barrier, when it is not a question of either/or, but both. The lagoon must be looked after as tenderly as when the doges used to wed the waters with a ring, and yet we must also accept that conditions have changed fundamentally in the last 200 years, and new measures must be built to protect Venice. The historical Venetians themselves did not shrink from innovations, such as the great sea walls that still defend the lagoon.

It must also be accepted that no barriers will be the final solution. Just as the Thames Barrier comes to the planned end of its economic life after 50 years, in 2030, and will be succeeded by something else, so the price of keeping Venice for our grandchildren will be endless vigilance and expense.

Is Venice worth the expense? An evaluation of the risk and cost benefit involved needs to be made for the city, if only because the people who say that the barriers are too expensive have already, however unconsciously, decided that Venice is not worth the investment. With their vast Deltaplan for defending themselves from the sea, the Dutch have already brought such cost/risk evaluations down to a fine art and could give lessons in how to proceed.

All that is needed is the will to do these things. In the early Nineties, a European politician called Carlo Ripa di Meana, an Italian, suggested that the Venice should be declared independent of Italy - a sort of San Marino - so that the chaotic politics and bureaucracy would no longer get in the way of looking after it properly. Italian public opinion was deeply offended and the idea was rightly derided.

Venice is, after all, Italy's glory - but also its responsibility. It is the duty of its government to end 15 years of indecision as soon as possible. Then, when it has decided to act, the rest of Europe and the world can help with the costs, if help is needed. But until Italy does decide, the rest of us can only stand by anxiously, fearing the big flood with all the dreadful destruction and perhaps loss of life that it will bring with it.

What is almost worse is that we are already watching the gradual erosion of the social, economic and physical fabric of the city by the dozens of small acque alte, as every year, more and more young, productive people leave the city for ever, and the economy becomes more and more dependent on tourism alone.

As the highly successful manufacturer of the Aprilia motorscooter, Ivano Beggio, said at a recent symposium in Venice on how to revive its economy: "What businessman in his right mind will invest seriously in a city where his employees have to wear gumboots to work one day in three?"