Travel to beautiful Venice this winter and chances are you may hear the screeching of the 16 city sirens that signal the return of the "acque alte", or flood waters.

Especially felt during the winter seasons between November and April these waters engulf several low-lying areas of the city including the magnificent St Mark's Square, rise up over the canal borders and bubble up through the drains.

The city's best defense for pedestrians thus far has been the erection of

1.5 metre high elevated walkways which themselves offer little assistance in the event of a very serious flood.

Proper defensive action, it seems, is not far away. After a lengthy debate over the effectiveness of large mobile flood barriers at the lagoons entrance, plans to expedite them into place are at last under way. The first to benefit will be the main shipping entrance at the Malamocco lagoon mouth. It will have installed a semi- circular breakwater to knock back the high Adriatic seas from southerly winds and a ship's lock to hold ships whilst the movable barriers are in place.

The other big issue is that the canal water is so filthy. Before the 1960s the natural flow of the Adriatic tidal current saw to it that the waste was flushed quickly out of these narrow canalways. However, after this time the canal was dredged as part of a large operation to allow tanker access resulted in a 14-m deep canal that effectively reversed the currents, trapping the waste of the city within the lagoons now very murky waters.

More problems abound as a result of the high level of salt in these waters which is constantly eroding the city from its foundations, and despite the public outcry of several prominent figures little is being done about this looming problem.

As a result of subsidience and rising sea levels worldwide Venice has sunk by 23cms since 1900. The most alarming aspect is that by 2100 sea levels are expected to rise by a whopping 60cms which would leave Venice almost completely submerged. Unless more action is taken by the central government in Rome to combat all these problems, Venice could end up another lost Italian beauty of the likes of Pompeii.