In 1966, the piazza San Marco, lowest point of Venice, is flooded under 1.25 m of water. The UNESCO launches a rescue operation "Save Venice", a vast international appeal for fund raising. Associations are created all over the world to finance the restoration of deteriorated art
Without reaching these extreme levels, Venice is flooded several times every year, between October and February: it's the "acqua alta "phenomenon. Provoked by conjoint action of tides, currents, wind and soil depressions, aggravated by an inconsiderate utilisation of the phreatic pool due to the industrial installations of Porto Marghera.
Special measures have been taken since 1966. To reduce pollution, floods and sinking, a law released billions of LIT. It is now forbidden to pump underground water, and a study has been made "grandeur nature" of mobile dams, which should protect the city in case of flood. MOSE entered its final phase in 1988. Three series of clack-valves of 20 m wide would prevent, in closed position, the water from entering the lagoon. But this project launched a lot of polemics. We are not in Italy to make things simple....