MOSE Project

The MOSE Project (acronym for Modulo Sperimentale Elettromeccanico — in English, Experimental Electromechanical Module) is a project intended to protect the city of Venice, Italy. Is an integrated defence system consisting of rows of mobile gates able to isolate the Venetian Lagoon from the Adriatic Sea when the tide reaches above an established level (110 cm) and up to a maximum of 3 m. Together with other complementary measures such as coastal reinforcement, the raising of quaysides and paving and improvement of the lagoon environment, these barriers will protect the city of Venice from extreme events such as the floods and from morphological degradation. Work on the project has been underway since 2003 at the three lagoon inlets of Lido, Malamocco and Chioggia, the gaps connecting the lagoon with the sea and through which the tide ebbs and flows. The name MOSE is also a play on the Italian name for Moses, Mosè. The project is being executed by engineers at FIAT.Fact|date=January 2008

In 2006, the incoming government of Romano Prodi announced that the project was "under review" for budgetary reasons. [ [http://www.msnbc.msn.com/id/14304546/ MSNBC - Italian cuts leave planned bridge to Sicily in doubt] ] However, the project was reinstated the following year.

Origin of the name

Before the acronym was used to describe the entire flood protection system, it indicated the 1:1 scale prototype of a gate tested between 1988 and 1992 at the Lido di Venezia inlet.

Context

MOSE does not exist in isolation. It is part of a General Plan of Interventions to safeguard Venice and the lagoon commenced in 1987 by the Ministry of Infrastructure through the Venice Water Authority (the Ministry's operational arm in the lagoon) and the concessionary, the Consorzio Venezia Nuova. The measures already completed or underway along the coastline and in the lagoon are the most important environmental defence, restoration and improvement programme ever implemented by the Italian State.

In parallel with work to construct MOSE, the Venice Water Authority and the Venice Local Authority are raising quaysides and paving in the city to protect built-up areas in the lagoon from medium high tides below 110 cm, the height at which the mobile barriers will come into operation. These measures are extremely complex, particularly in urban contexts such as Venice and Chioggia where the raising must take account of the delicate architectural and monumental context.

The measures to improve the lagoon environment are aimed at slowing down degradation of the morphological structures caused by subsidence, eustatism and erosion resulting from wave motion and wash. Work is being carried out throughout the lagoon basin to protect, reconstruct and renaturalise salt marshes, mudflats and shallows, restore the environment of the smaller islands and dredge lagoon canals and channels.

Important activities are also underway in the industrial area of Porto Marghera at the edge of the central lagoon to oppose pollution by securing islands formerly used as dumps, consolidating and sealing the industrial canals and removing polluted sediments.

Aim

The aim of the MOSE project is to solve the problem of high waters which has afflicted Venice and other towns and villages in the lagoon since ancient times in autumn, winter and spring. Although the tide in the lagoon basin is lower than in other areas of the world where it may reach as high as 20 m, the phenomenon may become significant if associated with atmospheric and meteorological factors such as pressure and the action of the bora (a north-easterly wind coming from Trieste) or Sirocco (a hot south-easterly wind) which push the waves into the gulf of Venice. The phenomenon is also worsened by rain and freshwater flowing into the lagoon from the drainage basin at 36 inflow points represented by small rivers and canals.

The increase in the frequency and intensity of high waters is also associated with other natural and artificial causes which have altered the hydraulic and morphological structure of the lagoon, such as subsidence and eustatism (during the 20th century land in the lagoon dropped by 23 cm with respect to mean sea level [2] ); the greater erosive action of the sea as a result of some of the measures taken by man to facilitate port activities (jetties, artificial canals) and establishment of the industrial area of Porto Marghera and the increase in wash caused by motor vessels which helps erode morphological structures and the foundations of quaysides and buildings.

As well as tackling these contingent problems, the MOSE Project (and the other defence measures) has also been designed to take into account the expected rise in sea level as a result of global warming. The mobile barriers can protect the lagoon effectively even if the most pessimistic hypotheses come true, such as a rise in sea level of up to 60 cm. [1]

Exceptional high waters have struck the city during the 20th century: the flood of November 1966 (194 cm), 1979 (166 cm), 1986 (158 cm), 1951 (151 cm), 1936 and 2002 (147 cm), 1960 (145 cm), 1968 and 2000 (144 cm), 1992 (142 cm), 1979 (140 cm). All values were recorded at the Punta della Salute (Venice) station and refer to the 1897 tidal datum point. [2]

Chronology

The need to provide Venice and other built-up areas in the lagoon with an effective sea defence system follows the devastating flood of 4 November 1966. That day, driven by a strong sirocco wind, the tide reached a height of 194 cm above the tidal datum, the highest ever recorded in the history of Venice. The tidal event began on the night of 3 November. That morning, instead of withdrawing as it should have done under normal tidal ebb and flow conditions, the water continued to rise throughout the day of 4 November until it flooded the whole city. That evening the wind dropped and the water started to flow away. At the same time, a violent sea storm devastated the beaches and broke through the seawall protecting the coast in a number of points, obliging Pellestrina to be evacuated. After this, with the Special Law of 1973, the Italian State declared the problem of Venice to be of "priority national interest".

In the early 1970s, the CNR promoted a first competition of ideas and subsequently the Ministry of Public Works issued a call for tender, in 1980 acquiring the projects presented. The six projects proposed were passed for evaluation to a commission of seven hydraulic engineers who were asked to draw up a feasibility study. Known as the "Progettone" and presented in 1981, the study proposed a combination of fixed barriers at the inlets and mobile defence structures. This triggered a long debate involving the institutions, the scientific, political and cultural world, the media and local inhabitants.

The strategies and criteria to be adopted for the safeguarding project were defined by the second Special Law on Venice in 1984. This set up a Committee for Policy, Coordination and Control (known as the "Comitatone", chaired by the President of the Council and consisting of the relevant institutions at national and local level) and authorised the Ministry of Public Works to proceed with granting of a single concession to be agreed by private negotiation. The need, reiterated also in 1982 in a document from Venice Local Authority, was for speed, but above all to adopt a unitary and organic approach to the safeguarding measures given the complex and delicate context of the lagoon basin by entrusting the work to a single body with the right qualifications. Design and implementation of the measures for the physical safeguarding of the city were entrusted by the Water Authority to the Consorzio Venezia Nuova, a pool of about fifty companies set up in 1982.

After four years of surveys, studies and analyses of the numerous systems of mobile barriers, in 1989 the Consorzio Venezia Nuova presented a complex proposal of measures to safeguard Venice known as the REA Project (Riequilibrio E Ambiente, "Rebalancing and the Environment"). This included the Conceptual Design for the Mobile Barriers at the Lagoon Inlets, the birth of MOSE. After experiments on the prototype and a number of modifications, in 1994 the new preliminary design for the mobile barriers was approved by the Higher Council of Public Works. After also examining other flood defence projects, the body approved the MOSE system.

In 1997, the Water Authority and Consorzio Venezia Nuova presented the environmental impact study (EIS) which in 1998 was given a positive assessment by a commission of five international experts appointed by the President of the Council of Ministers, Romano Prodi. In the same year, the design for mobile barriers was given a negative opinion by the Ministry of the Environment Environmental Assessment Commission. On the request of the Committee for Policy, Coordination and Control, MOSE was developed further. In 2001, at the end of the Environmental Impact Assessment procedure, the Council of Ministers, chaired by the President of the Council of Ministers, Giuliano Amato, gave the go-ahead for development of the final design, defining a number of conditions. In 2002, the Consorzio Venezia Nuova presented the final design which took the requests of the Ministry of Transport and Port Authority on board, in other words, for curved breakwaters in front of the lagoon inlets and a lock for large shipping at the Malamocco inlet. In 2002, the CIPE (Interministerial Committee for Economic Programming) financed the first tranche of work on the MOSE system covering the three-year period 2002-2004, amounting to €453 million.

In 2003, after approval by the Committee for Policy, Coordination and Control, President of the Council Silvio Berlusconi officially opened the first MOSE work sites by laying the first stone.By March 2008, 40% of the work underway in parallel at all three inlets had been completed and €2,443 million had been attributed out of a total cost for the MOSE system of €4,272 million.

On 31 January 2008, the CIPE approved financing of the fifth tranche of €400 million and construction of the caissons, the most important and final part of the project, could begin.

If funding continues to arrive regularly, the work is expected to be completed in 2012.

Work sites and complementary structures

Work on Mose is proceeding in parallel at all three inlets where 700 people are currently employed. These will be joined by a further 700 when the sites to construct the caissons on which the gates will rest are opened. Work to construct the mobile barriers was preceded by implementation of a series of measures to protect the coasts (Jesolo, Cavallino, Lido, Pellestrina, Sottomarina and Isola Verde) from the violence of sea storms, with widening and reconstruction of 45 km of beach, restoration of 8 km of dunes and reinforcement of 11 km of jetty and 20 km of the Istrian stone seawall (the "Murazzi") which protects the most fragile parts of Venice's beaches. Outside the inlets of Malamocco and Chioggia, two "crescents" (curved breakwaters) have also been constructed to attenuate the levels of tides and protect the locks.

Operation of the gates

MOSE consists of a system of retracting oscillating buoyancy flap gates which respects the indications given in 1982 by vote no. 209 of the Higher Council of Public Works [3] , namely that the barriers must not modify water exchange between the sea and the lagoon to avoid damaging lagoon morphology and water quality, must not obstruct navigation, thus interfering with port activities and fishing, and must not alter the landscape. In normal conditions, the gates, large metal box type structures 20 m wide, between 20 and 30 m long and about 5 m thick, are full of water and rest in prefabricated concrete caissons on the reinforced seabed. When a tide higher than 110 cm is forecast, the gates are emptied of water by introducing compressed air. They therefore rise, rotating around the axis of the hinges until they emerge from the water, temporarily isolating the lagoon from the sea and stopping the tidal flow. The gates reach in the raised position in about 30 minutes and will then take about 15 minutes to retract.

The level of 110 cm above which the barriers will enter into operation has been agreed by the responsible bodies as the optimum level with respect to current sea level. However, the MOSE System is flexible enough to also be used for high waters below that level. According to the winds, pressure and level of the tide, the system can also be managed in different ways, with differentiated closure of the inlets or partial closure of each inlet.

A total of 78 gates divided into four rows will be installed to protect the three inlets: two rows of 21 and 20 gates at the Lido-San Nicolò inlet, the widest, connected by an artificial island; one row of 19 gates at the Malamocco inlet and one row of 18 gates at the Chioggia inlet. To guarantee navigation while the mobile barriers are in operation, three locks are being constructed to allow the transit of vessels (large ships at Malamocco, pleasure, emergency and fishing boats at Lido and Chioggia).

At the end of work, the consortium which has designed and constructed MOSE will be in charge of management and maintenance of the system for four years, then for a further 10 years it will be responsible for its operation and for all the other public works.

Usage

The project consists of a system of 79 mobile barriers designed to protect the three entrances to the Venetian Lagoon. The barriers will stay on the seabed until high tides and storms are forecast. They will then be inflated, blocking the sea from the lagoon and effectively reducing high water levels.

Projections

The MOSE project has a budget of € 3 billion and it is planned to be completed by 2011. As of January 2008, The project is reported as 37% complete and projected to open on schedule in 2012. [ [http://www.npr.org/templates/story/story.php?storyId=17855145 NPR story on MOSE project] ]

Controversy

The project has met resistance from environmentalist and conservationist groups such as Italia Nostra. The World Wide Fund for Nature has commented negatively on the project. [http://www.unesco.org/courier/2000_09/uk/planet.htm]

The main criticisms of the MOSE project, opposed since the beginning by environmentalists and certain political forces, are related to the costs to the Italian State of construction, management and maintenance, said to be much higher than alternative systems which other countries (the Netherlands and England) have employed to resolve similar problems.In addition, according to those opposing MOSE, the system with its monolithic integrated conception is not "gradual, experimental and reversible" in line with the criteria specified by the Special Law for the Safeguarding of Venice.There have also been criticisms of the environmental impact of the barriers, not just at the inlets where complex levelling will be carried out (as the part of the seabed where the barriers will be installed must be flat) and the lagoon bed will be reinforced to accommodate the gates (which will rest on thousands of concrete piles driven into the bottom for metres underground), but also on the hydrogeological balance and delicate ecosystem of the lagoon.The NO MOSE front also emphasises what could be a number of critical points in the structure of the system and its ineffectiveness to cope with the forecast increase in sea level.

Appeals

During the years, nine appeals have been presented. Eight have been rejected by the TAR and the Council of State. The ninth, currently being examined by the Administrative Tribunal, was presented by Venice Local Authority and contests the favourable opinion of the Safeguard Venice Commission on the commencement of work in the Pellestrina site at the Malamocco inlet where part of the MOSE gate housing caissons will be made using processes which, according to the Local Authority, could damage a site of particular natural interest.

As regards the environmental damage caused by work currently underway, environmental associations have also requested the intervention of the European Union, as the activities affect sites protected by the Nature 2000 Network and by the European Directive on birds. Following the report of 5 March 2004 by the Venetian MP Luana Zanella, on 19 December 2005 the European Commission opened an infraction procedure against Italy for "pollution of the habitat" of the lagoon, given that the European Environmental Commission Directorate General considers that as it has "neither identified nor adopted — in relation to the impacts on the area ‘IBA 064-Venice Lagoon’ resulting from construction of the MOSE project — appropriate measures to prevent pollution and deterioration of the habitat, together with harmful disturbance of birds with significant consequences in the light of the objectives of article 4 of EEC Directive 79/409, the Italian Republic has not fulfilled the obligations deriving from article 4, paragraph 4, of EEC Directive 79/409 of the Council of 2 April 1979 on the conservation of wild birds". [5] Specifying that the aim of the initiative is not to stop MOSE, the European Environmental Commission has called on the Italian Government to produce new information on the impact of the sites and the environmental mitigation structures. The Water Authority and Consorzio Venezia Nuova confirm that the work sites are temporary and will be completely restored at the end of the work.

Alternative proposals

Over the years, various proposals have been presented as an alternative to MOSE. Some propose quite different technological systems, others suggest technologies to improve the efficiency of the system of mobile gates. On the request of the Mayor of Venice, Massimo Cacciari, some ten or so of these projects were examined in 2006 by various round tables of experts appointed by the individual responsible bodies, including the Higher Council of Public Works. In November 2006, the negative opinions expressed by the experts led the Government to give the definitive go-ahead for the MOSE project as the alternative proposals presented were found to be ineffective or inappropriate for guaranteeing the defence of Venice.

References

* "Venice Against the Sea: A City Besieged" By John Keahey (Thomas Dunne Books, St. Martin's Press, March 2002)
* [http://www.techcentralstation.com/042903M.html Techcentralstation.com]
* [http://portal.unesco.org/en/ev.php-URL_ID=11987&URL_DO=DO_TOPIC&URL_SECTION=201.html Unesco]
* [http://transcripts.cnn.com/TRANSCRIPTS/0511/28/ywt.01.html CNN.com]
* NOVA Sinking City of Venice [http://www.pbs.org/wgbh/nova/venice/]

Notes