The lower the city goes and the more clogged the lagoon gets, the more floods Venice suffers. When the mouth of the lagoon is blocked - as happens when the Adriatic on the Lido shore is stirred by wind - tidal waters are forced back onto Venice. This happened rarely in the 18th and even 19th centuries. A flood in those days brought Venetians flocking to the Piazza and a party atmosphere swept in with the waters. The fact that their houses were getting water logged did not appear to bother them at all.
Today's floods, including the disaster of November 1966 when the Piazza San Marco disappeared under four feet of water, force Venetians to bring out planks and trestles so that instead of partying in the water, they are able to cross the Piazza. And come the waters do, often more than once during the winter months. In some areas, the water may rise two or three feet above the pavement.
In November 1988, the Consorzio Venezia Nuova - a consortium of Italian public and private bodies - embarked on an experiment to test the feasibility of moveable barriers at the lagoon's three entrances. These are aimed at preventing floods. If the experiment is successful, about 20 similar barriers will be put up over the next 10 years. The Consorzio is also dealing with other problems in the lagoon, including restoring the ecological balance.