VENICE SUB MARE A CITY THAT IS SUBSIDING BENEATH ITS OWN CANALS

Press, Volume CIX, Issue 32166, 9 December 1969, Page 16

VENICE SUB MARE A CITY THAT IS SUBSIDING BENEATH ITS OWN CANALS

(Reprinted jrom the "Economist' 1 by arrangement)

The Venetian crisis is deepening. The crisis, as is well known, is water: Venice is subsiding beneath its own canals at the rate of 6.2 to 6.6 minimetres a year. No-one knows why but one possible reason is industrial development. Industry is poised to dredge part of the lagoon and start another major phase of land reclamation. This would create factory space for a new industrial area, so possibly undermining further the foundations of the old section. Industry could use the existing land on the mainland, but that would be more costly.

In the meantime most Venetians are content to do nothing. The gondoliers staged brief strikes this year at the decision to ban them from the Grand Canal. But most Venetians argue that Venice has stood for 1000 years and refuse to believe one day it might stop doing so. In any case they have been deserting old Venice in increasing numbers in favour of Mestre, just across the lagoon, a hideous industrial town, which gives them jobs and cheap houses that are not tumbling down. The Venetians themselves are abandoning their city in favour of progress. Tourists Wade Meanwhile the waters rise. On November 4, 1966, there erupted the most disastrous flooding the city had had, not merely involving' the now routine spectacle of tourists wading across the Piazza San Marco in water over their ankles, but residents fleeing to the upper storeys of their houses in fear of drowning. Flooding recurred, in scarcely less menacing shape, on November 5, 1967, and again on November 3, 1968. Last month too it returned: indeed there has been no month this year without flooding of some sort Besides, it is only half the story. While water—and increasingly contaminated water —is sloshing and sucking away at the city from below, polluted air is corroding its palaces, churches and monumental statuary from above. This can be seen by anyone who compares the stones of Venice with Florence or Rome. If subsidence continues as at present, Venice will lose 20 centimetres in as many years. Within 70 years, and possibly much less, the historic centre- would become uninhabitable.

Recently U.N.E.S.C.O. prepared a 350-page study summarising possible reasons why Venice is sinking. Out of a mass of candidates, U.N.E.S.C.O. isolated three principal causes. Two of them at least are within man’s control, though one of these is the subject of fierce controversy. This is the exis-

tence of Porto Marghera, the new industrial and commercial centre on the mainland, created by dredging and filling processes that must have had some effect on toe delicate equilibrium of the lagoon. Less controversial but also associated with Porto Margbera is the cumulative im-

pact of drilling wells for fresh water in this and other areas. The Porto Marghera region pumps 40,000 cubic metres a day. This extraction from the underground reservoir reduces the buoyancy of the subsoil, which compacts, causing subsidence at the surface.

The third cause is the constantly rising level of the sea in the cul-de-sac of the Adriatic, the indirect product of the melting of polar ice caps; this progressively lifts the high water mark of the tides in the lagoon.

“Outsize Committee” Responsibility for doing something about Venice lies, if anywhere, in the hands of what is called the Committee for the Study of the Measures for the Defence of Venice and for Safeguarding its Environmental and Monumental Characteristics. It is known more briefly as the Comitatone, which in this context may be translated as the “Outsize Committee,” with six sub-committees and a membership of 70. It is the chosen instrument of the government to implement the master plan for Venice’s salvation. It is committed to numerous programmes, but implementation is another matter. It is certainly a cumbersome machine, and at times has been frustrated by lack of funds. Only since the disaster of November, 1966, has Rome given it any real encouragement. With any luck this extra support will speed up the researches now being carried out by the subcommittees.

The key question these researches ought to answer is the extent to which the Porto Marghera is contributing to the problems of the industrial area. Opinion has polarised into two quarrelling schools: (1) The Venezia Viva organisation and its supporters, who argue that the only worthwhile future for Venetians lies in the industrialisation of the mainland. (2) Italia Nostra and its supporters led by the redoubtable Contessa Anna Maria Cicogna Volpi, and Contessa Teresa Foscari Roscolo, who demand industry be subordinated to the need to preserve the historical centre, which, with its cultural treasures, should be regarded as part of the inheritance of the whole world.

Subsidence Quickens The. rate of subsidence has accelerated since 1925, and has speeded up further since 1952. The year 1925 was when toe first industrial zone took shape, on 860 hectares (2125 acres)- Since 1952 a second zone, on 2009 hectares (4964 acres), has been added. The contessas claim that the acceleration of subsidence is attributable to these developments. The industrialists deny this. They insist that the subsidence is actually caused by melting of the ice caps and a gradual "natural” adjustment of terrain. Terrain does change: Ravenna, a Roman port, now lies some miles inland. More immediately, the argument centres on two points: the new deep water channel through the Porto MalamoccO; and the third industrial zone. This zone, for which industrialists are now lobbying vigorously, would amount to a massive 4035 hectares—bigger, in other words, than the first two zones combined. The new channel would permit the delivery of oil and dry cargo to all three zones by a route avoiding the present channel via the San Marco Basin and the Giudecca, through the heart of the historic centre. Last March all but 1000 metres of the channel’s 18 kilometres was finished, and the third industrial zone was about 25 per cent prepared. At that point work on both

projects was baited by order of the Minister of Public Works, Mr Mancini. This decision was precipitated largely by pressure from Italia Nostra, which has repeatedly denounced the latest round of dredging and filling on the grounds that it still further concentrates tide-

water, increasing both the inflow-battering and outflowsucking effects. Probably rising interest and unease in Italy and around the world played a part too. No Further Works The contessas look like losing the channel battle. A final decision is supposed to be taken before the end of the year. But they may have better fortune in the fight over the proposed third industrial zone, and the three others that are intended to follow it. It now looks likely that no further works will take place until local and international experts have compiled reliable data and made recommendations.

Porto Marghera is already Italy’s second port, an impressive complex of oil refineries and storage areas, coke and aluminium reduction plants, chemical and petrochemical facilities, grain storage facilities, and factories processing food, textiles, glass, wood and other products. But for the historic centre a few miles out in the lagoon, it might now be well on the way to becoming another Rotterdam or Hamburg.

But its proponents now recognise that some concessions must be made to the preservationists. The Porto Marghera is now forbidden to drill any more wells, maybe permanently. It therefore now plans to augment its fresh water supply by an aqueduct from the Sile river (16 kilometres away, near Treviso) which may be the first of several. There have been strenuous objections to the establishment of a major oil terminal in the third zone, supplied by the Malamocco channel. So an alternative is now under discussion. Supertankers are quite clearly never going to be allowed into the lagoon. There is therefore a case' for building a depot outside it anyway, on an artificial island for instance, and completing delivery either by smaller vessel or pipeline. This depot could also be designed to handle the smaller tankers now expected to use the Malamocco channel. Indeed, some people are already wondering if the Malamocco channel, with its maximum capacity of 65,000 tons, might not be obsolete before it opens. Air Pollution The problem of air pollution by industrial plants can be reduced as it has been already in similar situations by controls calling for filters and other devices. .To prevent it altogether in Venice, however, involves other action. From January 1 therefore in home central heating systems fuel oil will only be allowed of a type that does not contaminate the atmosphere. Controls also need to be applied to public and private motorboats, for which, so far, nobody has proposed anything.

Three suggestions have been made for dealing with the tides. Shutting entirely the three entry-exit mouths into the lagoon—at Lido, Malamocco, Chioggia coupled with sewage works and other measures to prevent it becoming a malarial swamp; narrowing the mouths: or fitting them with movable barriers that would block excessive tidewater without interfering with the normal flow. Of these three, movable barriers are the most likely solution. These alternatives are now under study by the Hydraulic Subcommittee of the Comitatone.

Advanced Studies Further studies involve the construction of a hydraulic model of the lagoon, and a “mathematical profile” of it. Corrected with existing data, and with seismic and other surveys by Gulf Italiana and Agip, these studies will transfer much of the present argument out of the realms of polemic and Into the field of informed discussion.

If they confirm that Porto Marghera is in fact disturb- ' ing the equilibrium of the ' lagoon, then it will have to stop Microaching on the ' water for future growth, by turning inland. This would be considerably more expen- ' rive than the present method of reclamation. But suitable land is readily available: and ' land development would diminish the risk of water ’ pollution. ’ In one important respect. 1 negotiation of these and other

thorny issues have been facilitated in recent years by the concentration of industry in the area. Of 240 or so individual enterprises in the area, employing close to 40,000 ■ workers, about a dozen employ 90 per cent of all the labour. Some 50 per cent of all employment is provided by one firm, Monte-catini-Edison, which dominates the industrial complex. Unfortunately, no such unifying factor exists on the other side. The unwieldy Comitatone, which is supposed to act as referee, is itself often not unanimous, with its effectiveness weakened by its bureaucratic structure. There is talk of

stream-lining it into a superauthority, with one man in firm charge—a development that would benefit everyone. Not only would it speed up the Comitatone’s researches. It would also increase the chances of effective action after the facts have been established. Meanwhile although dredging and industrial development have been frozen for the moment, nobody dares to suggest that subsidence has stopped. Even if no further dredging or reclamation er well drilling is ever allowed, and pollution is minimised, Venice will still need to be rescued sometime in the coming century.