Italia Nostra opposes the huge dam system proposed for Venice and its Lagoon. First, for a central principle: if the Lagoon's environmental imbalance is a cause of flooding in Venice, and this has to be addressed before considering a Pharaonic project that could aggravate the problem.

In addition to this fundamental objection, Italia Nostra has dozens of reasons for opposing this costly project, commonly called the "Mo.S.E.", that failed its environmental impact assessment. Two dozen, in fact.

Environmental impacts

1. To anchor the huge dams on the sea bed, the construction companies would excavate about five million cubic metres of sediment, including parts of the hard layer of clay on which Venice itself rests.

2. Into the huge cavities to be dug in the Lagoon, the builders would then dump over 12,000 cement piles, over eight million tons of rock (enough to build the Great Pyramids at Giza!) for the foundations of their dams. They would also sink 50,000 tons of sheet metal for the underwater dams.

3. Just for construction, a further 10 hectares (25 acres) of Lagoon would be exacavated.

4. A huge flotilla of barges and ships will be necessary to remove the excavated material and bring in the rock, cement and metal.

5. The Lido outlet would be transformed with the creation of an artificial island, 9 hectares (22 acres) in size, for buildings and workshops, as well as a 20 metre (60 foot) high smokestack.

6. The coastline would be devastated at Ca'Roman, whose beaches are protected as a natural area under EU law.

7. Before the dams actually start operation, Venetians will have to undergo at least eight years of construction with high environmental impacts (for example, the sediment released to the Lagoon's waters could devastate shellfish harvested.)

8. When the dams are completed, anodes to protect their huge metals gates will release about 10 tons of zinc into the Lagoon each year. The toxic metal could accumulate in the food chain.

Costs

9. Construction will cost an estimated 3.7 billion Euros. In comparison, restoring the Lagoon's environmental balance would cost little.

10. Maintenance and operation of the dams will cost millions more each year. For example, up to 35 kilos (75 pounds) of molluscs and other animals and plants will encrust each square metre of metal gate. These will need regular cleaning. Moreover, every five years, each gate will need to be removed. The Lagoon will be become a permanent building site.

Will it be effective?

11. The colossal dams will render permanent the Lagoon's environmental imbalance: the deep channels dredged in the last century through its outlets will become concrete. The erosion that is now eating away the Lagoon's precious wetlands would become permanent, and this rich coastal lagoon, protected by European law, would be transformed into an area of open sea.

12. The dams may not even protect Venice! In the case of significant sea-level rise - 50 cm (20 inches) or more - according to scientists such as Paolo Antonio Pirazzoli, they will not be effective.

13. The dams may not protect Venice in the case of exceptional events, such as the devastating 1966 flood. Water would steadily pass between the individual gates. Moreover, torrential rains on the mainland would also pour into the Lagoon, as in 1966.

14. Another risk is that oscillation of the individual gates in the face of heavy seas would allow through more water and may in extreme cases result in a complete breakdown of the system.

15. For smaller flooding events, on the other hand, the dams would not be used. At present, the dams would be raised only for the highest tides (those +110 cm above median sea level). In 2002, low-lying areas of Venice, in particular St. Mark's Square, were repeatedly flooded by these lesser events.

16. Italy's environmental impact commission also warned that the maintenance of this huge, underwater structure could face unexpected difficulties.

Legal issues

17. Italy's special laws for Venice call for the restoration of the Lagoon's environmental balance, the elimination of petrol tankers and the opening of the fishing valleys - before building any dam structure. Italy's cabinet reaffirmed these priorities in March 2001. None of these has happened.

18. The special laws also call for public works that are testable, reversible and gradual. The huge dam project has none of these characteristics: it will be a rigid system, cemented permanently into the Lagoon bed.

19. The national Environmental Impact Assessment Commission gave the dam project a negative assessment in 1998 (legal maneuvres invalidated the subsequent formal Minister's decree - but not the assessment itself). The dam builders are starting construction on initial, "complementary" works, approved only by a regional commission. Italia Nostra argues - in court - that only the National Commission can approve these works.

The monopoly problem

20. The dams' builders, the New Venice Consortium, hold an - essentially a form of monopoly - on studying, designing and building public works in the Lagoon of Venice. Private companies have a natural and legitimate interest to compete and make profits in the marketplace. Major public policy decisions, however, need good government and transparency to ensure that the public good is protect. For large public works, both design and construction should be open to competitive bidding (under EU and even Italian law). For complex works, design and construction may be combined - but again with open competition. In Venice, the "exclusive concessionaire" has never faced competition. Moreover, the builders were also in charge of most preliminary scientific and technical studies, which could have been used to develop and evaluate alternative approaches.

21. The builders dominate public information about flooding in Venice. Their information centre, press office and high-quality videos and materials present beautiful images of the dam project with hardly any discussion of its impacts and risks.

Missing studies

22. The national Environmental Impact Assessment Commission identified a series of important issues that need to be studied. These include: predicting exceptional tide events; assessing environmental risks; studying the sediment layers to be excavated; and reviewing the changes in the Lagoon's dynamics the dams would create.

The wrong approach

23. The Lagoon, goes an ancient saying in Venice, has a thousand names. Italy's National Environmental Impact Assessment Commission warned that Venice can not be protected without "complex management of the Lagoon system". This "system" includes the city itself, surrounding islands, salt marshes and other key ecosystems, as well as the mainland area whose waters flow into the Lagoon. It needs "an articulated union of works and actions" that are testable, reversible and gradual, according to the Commission. Instead, the dams try to address the problem of high tides with one single, huge project.

24. For centuries, Venice and Venetians have intervened in the Lagoon with extreme prudence. All works were extensively tested and discussed. Today, this prudence and the underlying respect for the complexity of an exceptional ecosystem are as indispensible as ever.

Here the original text in the site of Italia Nostra - sezione di Venezia