Venice city officials say 28 percent of the lagoon city has been flooded by waters rising 109 centimeters (more than 43 1/2 inches) above sea level.
The highest level (160 centimeters) reached in November 2012, according to Venice statistics. The last time levels topped 160 centimeters was in 1979.
Veneto regional governor Luca Zaia says flooding could reach the levels of the 1966 flood that inundated both Venice and Florence.