The city of canals, Venice, has raised its protective floodgates to combat heavy rains as water inundates the city, with roughly 1.7 meters (5.6 feet) of rain more than average, local authorities said Tuesday.

The highest warning levels are now in effect. Waters up to 1.4 meters are forecast for both Wednesday and Thursday.

What is protecting Venice from catastrophe?

The flood barrier system, a network of 78 yellow flood gates that block the three entrances to the Venice lagoon from the seafloor, was deployed early Tuesday morning.

It is especially common during the rainy autumn season for the city's defenses against flooding to be deployed.

The system is known as Mose, an acronym for its name in Italian.

The multi-billion dollar system was designed in 1984 and began operating in October 2020 and was subjected to cost overruns, corruption scandals and delays.

With no roads and only sidewalks and boats to get around, absent flood protections, 80% of the city's pedestrian paths would be underwater.

At current levels, the iconic Piazza San Marco, also known by its English-language name St. Mark's Square, would be flooded without the gates to hold back the waters. On Tuesday photos showed people walking across the square in the rain.

Has Venice flooded before?

Venice last flooded on November 12, 2019, when waters rose to 1.87 meters above normal.

The sea salt threatens to do great damage to the city's historic buildings.

Elsewhere in Italy, in Sardinia and Ostia, schools were closed due to the heavy rains. Fallen trees and flooding have been reported.

ar/jcg(dpa, Reuters)