During 1998, the acqua alta lapped over St Mark's Square on 76 days and Venetians fear the disastrous 1996 flooding may become a recurring nightmare. But this month the ambitious Moses project to build dikes between the Venetian lagoon and the Adriatic, supported by an international commission of academics earlier this year, was vetoed on ecological grounds by a second, Italian, commission that included five university lecturers.
Gherardo Ortalli, pro-rector of Venice University, said there are three accepted causes for the flooding. "First, there is the huge channel opened up to let giant tankers reach the port of Marghera, absurdly right on the outskirts of Venice. The tankers' wash has caused dramatic erosion. All agree the port should be closed. But this clashes with the petrochemical industry's interests. Second, the three main openings of the lagoon should be brought back to their original depths of 12, eight and six metres. Today they are about 25 metres with trenches 50 metres deep.
"Third, the fishing areas that used to be limited by wooden gratings I have been sealed off, limiting the area over which high tides can expand.
"The project would have produced a completely artificial lagoon. A softer approach I to restore the lagoon to the equilibrium that worked for centuries, would be far better. When the Italian state created 'Venezia Nuova', a consortium of engineering firms that came up with Moses, attention and economic interests were inevitably focused on a single spectacular, project."
Edmund Penning-Rowsell, professor of geography at Middlesex University and an expert on flood control, said: "In the past 90 years Venice has subsided by 23 centimetres because the Venetians have pumped the groundwater out of the sediments underneath. There is also a projected 30 centimetre sea-level rise by 2050. The dikes were wildly extravagant and would last for just 50 years - by that time they would have to be kept permanently raised, not once a month. And that means pollution build-up." The port should be moved away from Venice, he said.