After closing the iconic central square on Friday amid safety concerns, Venice authorities reopened St Mark's Square on Saturday.
However, water levels were still high, peaking at 1.1 meters (3 feet six inches) on Saturday
City authorities have also issued a "red alert," their highest possible warning for weather conditions on Sunday.
A state of emergency was declared on Thursday. Flooding began on Tuesday when waters reached a height of 1.87 meters (6 feet 1 inch), the highest since 1966.