Sir

Your News Feature “Save our city!” (Nature 424, 608–609; 2003) reviews the dilemma faced in selecting a large-scale engineering project to protect Venice, to be implemented and financed by the Italian government. I can see benefits in both of the two major projects discussed: the MOSE series of moveable gates, and the scheme to separate the city from its lagoon and the sea. Unfortunately, the first option is likely to serve only as a temporary protective measure for a century or two and cause collateral problems, such as increased pollution. The second, on the other hand, will permanently alter the configuration and setting of the Venice we know, a city that is charmed and recognized by its lagoon.

Various ancient Greek coastal cities, some with canals and constructed centuries earlier than Venice, are now completely submerged, such as Herakleion off the coast of Egypt. They, too, faced problems of insufficient protection against water surges and sea-level rise, and subsidence caused by the building of monumental structures on inadequate foundations. Towards the end of their active history, when the sea level rose above the base of the buildings, structures toppled increasingly rapidly until the cities were finally submerged.

In geological terms, these cities were similar to Venice. Considering what befell them, the opposite of the geological tenet “the present is key to the past” may well apply to Venice. Perhaps a longer-term, more secure approach would be one involving comprehensive Netherlands-type 'polder' dyke constructions, with seawater being pumped out of the encircled city, water maintained in the canals, and those unique structures reinforced, where possible, by deep pilings.