Stores and museums in Venice were mostly closed on Sunday in the hardest-hit area around St. Mark's Square, but tourists donning high rubber boots or even hip waders still came to witness and photograph the spectacle.

Most were disappointed when officials closed down the historic square as winds ripple across the rising waters.

The doors of the famed St. Mark's Basilica were securely shut to the public, while officials took precautions - stacking sandbags in canal-side windows - to prevent water from entering the crypt again.

Venice's Tide Office said the peak tide of 1.5 metres hit just after 1pm local time, as a weather front off the coast blocked southerly winds from the Adriatic Sea from pushing the tide to the predicted level of 1.6 metres.

It marked the third time since Tuesday night's 1.87-metre flood - the worst in 53 years - that water levels in Venice had topped 1.5 metres.

Since records began in 1872, that level had never been reached even twice in one year, let alone three times in one week.

Many store owners in the swanky area around St. Mark's completely emptied their shops, while others raised wares as high as possible and counted on automatic pumping systems to keep the water at bay.

Venice's mayor has put the flooding damage at hundreds of millions of euros and Italian officials have declared a state of emergency for the area.

They say Venice is both sinking into the mud and facing rising sea levels due to climate change.

The flooding has raised renewed debates about the city's Moses flood defence project, a corruption-riddled underwater barrier system that is still not operational after more than 16 years of construction and at least 5 billion euros of public funding. It was supposed to be working by 2011.

Floods were also hitting other parts of Italy on Sunday.

In Pisa, workers sandbagged the road along the rising Arno River, which was also surging through the heart of Florence, reaching a level near the Uffizi Galleries that was described as the highest in some 20 years.

A popular Florence tourist attraction, the Boboli Gardens, was closed as a precaution while near the Tuscan town of Cecina, 500 people were evacuated when a local river swelled to the top of its banks.

In Italy's mountainous Alto Adige, or South Tyrol region, a mid-autumn snowstorm triggered power outages and blocked roads in several Alpine valleys.

Meanwhile, in Val Martello, the local mayor told state TV an avalanche had damaged two houses but caused no injuries, and other homes were evacuated as a precaution.

High winds in the Rome area also caused damage, authorities said.

Australian Associated Press