'Moses' project to defend Venice by turning back sea gets under way

More than 36 years after catastrophic floods inundated Venice to a depth of almost two metres, the Italian government promised yesterday that Venetians would soon be able to put their wellington boots back in the attic.

Decades of research, political wrangling, false hopes and hand-wringing are over. The date has finally been named for work to begin on a colossal, and vastly expensive, scheme to protect Italy's living museum from floods that have been getting worse year by year.

Budgeted at €6bn (£4.1bn), and with annual maintenance and operational costs estimated at €9m, it is expected to take eight years to complete. On 29 April, Silvio Berlusconi, the Prime Minister, will lay down the first piece of the flood- defence project and work will begin almost immediately.

A series of 78 massive sea gates, each measuring 28 metres wide and 18 metres long, will be built on the floor of the sea, at the three sea inlets into Venice's artificial lagoon. In normal times the hollow gates will be filled with sea water, lying invisible on the seabed. But when exceptional tides occur, at least 110 centimetres higher than normal, air will be pumped into the hinged gates, causing them to swing upwards and block the ingress of the sea.

"Moses" as the project is known in Italy – the acronym translates Experimental Eletromechanical Module – has been in development since 1995, but from the outset was beset by protests from environmentalists, who feared it would turn the lagoon into a stagnant pond, and others who said it might solve the problem of the highest tides but not the more frequent menace of moderately high ones.

Only with the election of Mr Berlusconi's centre-right coalition government nearly two years ago, committed to big infrastructural projects, did the political commitment to begin the work emerge. Moses broke free from what the correspondent of La Stampa newspaper yesterday called "eternal immobilising compromises, postponements and attempts at subtle sabotage".

On Monday, Venice City Council's advisory committee on the project laid down a list of 11 conditions on which it would insist before approving the gates. The government had the legal right to press ahead regardless of the conditions, but instead on Thursday announced that it had accepted all of them.

The conditions addressworries over the preservation of the essential qualities of the lagoon, and the need to protect the lowest parts of the city – including parts most popular with visitors, such as St Mark's Square – from moderate flooding, by such stratagems as raising the height of the pavements.

With the government's assent, peace has broken out between the city's centre-left Mayor, Paolo Costa, and the government; back-slapping and mutual congratulation are general. "Patience and determination, thanks to these virtues Venice has today won its battle to guarantee the city a future equal to the grandeur of its past," said Giancarlo Galan, president of the Veneto region.

The central government, reeling under anti-war protests and internal feuding, seized the opportunity to cheer. "We've won a great wager," crowed Maurizio Lupi, minister responsible for infrastructure. "We have set in motion again great projects for our country."

Outside observers, driven to distraction by endless delays, heaved a sigh of relief.

"Venice needs the mobile barriers," said Jane de Mosto, a research scholar with Venice in Peril's Cambridge University research project in the city. "It's the only way Venice can be protected against extreme flooding events."

And that, according to many in Venice, is when the trouble will really start – because the building of the gates is bound to cause short-term disruption to the delicate ecology of the lagoon. "The sediment on the sea bed is full of heavy metals," said one local expert.

"Who knows what this huge project will churn up, or the effect on the lagoon's water?" said the architect Massimiliano Fuksas, director of the Venice Biennale from 1998 to 2000. "These eight years are going to bring plenty of risks."