Venice was on red alert for more floods and fierce winds on Saturday after an exceptionally high tide swamped the city of canals, where authorities have declared a state of emergency.
Mayor Luigi Brugnaro ordered the iconic St Mark's Square closed on Friday as the latest sea surge struck with strong storms and winds battering the region.
The square was open again on Saturday, but the city forecast a high water of 160 centimetres (over five feet) for Sunday, lower than Tuesday's high of 187 centimetres but still dangerous.
Civil protection authorities issued a weather "red alert" for the Venice region, warning of violent winds which can whip up the sea, although Saturday's midday high was forecast to be a manageable 105 centimetres.
Churches, shops and homes in the city, a Unesco World Heritage site, have been inundated by unusually intense "acqua alta", or high water, which on Tuesday hit their highest level in half a century.
"We've destroyed Venice, we're talking about one billion (euros) in damage and that's just from the other day, not today," Brugnaro said.
The crisis has prompted the government to release 20 million euros ($22 million) in funds to tackle the devastation.
Surveying the damage, Culture Minister Dario Franceschini warned the task of repairing the city would be huge. More than 50 churches had suffered damage, he said.