Much of the historic Italian city of Venice, including St. Mark's Square, was underwater Monday following a meteorological depression combined with natural tide waters, officials said.
The tide monitoring centre said 45 percent of the Renaissance city was swamped when the lagoon rose 131 centimetres (more than four feet).
Venice was flooded 50 times between 1993 and 2002, with the worst 'acqua alta' on November 4, 1966, when the city was submerged by 1.94 metres of water amid catastrophic flooding throughout the country.
In February 1986, levels reached 1.58 metres above normal, and in December 2008 waters surged 1.56 metres.
The city has for years been wrestling with the problems posed by the threat of rising sea levels. Last year local authorities confirmed they were looking at a scheme to raise the city's buildings to meet the problem.
Under Operation "Rialto", local officials and engineers were looking at using piston-supported-poles placed at the bottom of each structure to lift buildings by up to a metre.
In April 2007, the United Nations cultural organisation UNESCO warned that Venice was one of its designated World Heritage sites that was threatened by climate change.
(c) 2009 AFP
Explore further: Switzerland 1st country to submit pledge for UN climate pact