It was the highest level since the record the 6 feet 4 inches set in 1966 but with rising water levels becoming a regular threat to the tourist jewel, city mayor Luigi Brugnaro was quick to blame climate change for the disaster.

"Venice is on its knees," said Brugnaro. "The damage will run into hundreds of millions of euros."

"This is the result of climate change," he said on Twitter.

The floods, accentuated by driving rains and strong winds, also ravaged areas beyond the city itself.

One man died on Pellestrina, one of the many islands that dot the Venetian lagoon, electrocuted while trying to pump water out of his house.

A water taxi carried by record high waters onto a street in Venice. Manuel Silvestri / Reuters

"Venice has been tortured, but there are also other parts of the Veneto region besides Venice. It is an apocalyptic disaster," regional governor Luca Zaia told reporters.

He said he was "horrified" by what he was seeing from numerous communities.

Venice's huge Saint Mark's Square, once described as Europe's living room, was submerged by more than one meter of water, while the adjacent Saint Mark's Basilica was flooded for the sixth time in 1,200 years — but the fourth in the last 20.

"The Basilica is suffering structural damage because the water has risen and so it's causing irreparable damage," said Venice Archbishop Francesco Moraglia, warning that ancient mosaics and tiling might have been badly degraded.

"I have never seen anything like it. Venice is a wounded city, but it can't keep on being wounded every year in the same way," he said.

More than 80 percent of Venice was under water when the tide was at its highest and although levels had receded by daybreak further bad weather was expected later in the week, with a series of storms lining up to batter Italy.