Land and water: the historic
centre of Venice is formed by 118 islands connected by 160 canals.
Life goes on: when the waters
rise, the temporary footbridges are brought out.
Venice was a utopia: the world’s
most fragile city, but powerful enough to rule a far-flung empire.
The city’s delicate equilibrium
was upset by the digging of a canal deep enough to allow oil tankers to berth at
the industrial port of Marghera.
At exceptionally high tide,
a hydraulic system fills the chests with air. They lift and turn into gates that
cut the lagoon off from the sea.
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Insula and the
canal clean-up
Any city can be compared with a big machine
that needs to be overhauled and repaired on a regular basis.
This analogy is especially apt for Venice, with its fifty-something kilometres of
canals that accumulate nearly half a million cubic metres of waste and mud each year,
its 454 bridges and its 100 kilometres of banks lined by the cellars of palaces,
churches, monasteries and convents, pictures of which are reproduced in art books
around the world.
Although the city’s regular maintenance would seem an obvious necessity, it took
years of discussions to come about. The result is called Insula, a mixed company
(52 per cent of the shares are owned by the municipality and 48 per cent by four
private companies) set up in July 1997 to manage the urban machine of Venice. In
slightly less than three years, Insula, basing its work on a huge mass of studies
conducted by UNESCO in Venice, has dredged over 22 kilometres of canals,
extracted 123,000 cubic metres of mud and restored 79 bridges. Soon it will start
laying fibre optic cables, because to survive, Venice must also be on the cutting
edge of science and research.
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No other city in the world
has been studied in such detail. None has been so painstakingly dissected to determine
the reasons for its rise and fall. |
How can the ecological balance
of Venice be reconciled with the demands of industry? Is the highly controversial
construction of mobile floodgates the solution? The decision will be made by 2001
 The traveller to Venice should arrive at
the end of a summer’s afternoon to see the sun turn into a huge red disk and swell
until it casts the lagoon’s furthest islands in a fiery glow before sinking into
the sea. Then, when the last tourist has left Saint Mark’s Square, Venice once again
becomes magical. In streets that are empty at last, the inhabitants of the world’s
most beautiful city open their doors, letting the few lingering visitors catch a
glimpse of a time-worn, history-laden monumental staircase, or a hidden, tree-shaded
garden where Giacomo Casanova may have awaited one of his mistresses two and a half
centuries ago. It is the moment when the souvenir shop signs go dark and the Venetians’
windows light up.
Each day, they are fewer and older. In 1951, about 175,000 people lived on one of
the 118 islands connected by 160 canals which form the historic centre of Venice.
In 1998, a mere 68,000 remained, and that figure will likely drop to 40,000 by 2005.
If students are not counted—they are lodged by landlords who do not declare them
to avoid paying taxes—
residents under the age of 19 make up a tiny percentage of the population. The average
age, already 50 in 1998, continues
to rise.
The Venetians are leaving, and they are taking their institutions with them: the
Assicurazioni Generali insurance company, the daily newspaper Il Gazzettino, the
local Rai station (the State radio and television network) and the banks. Tourists,
who arrive en masse, fill the void: 10 million debarked in 1994 and 15 million are
expected in 2005. The city of theatres, churches, convents, monasteries, palaces
and bordellos is turning into a huge eating place. From 1976 to 1991, the number
of pizzerias, restaurants and hotels increased by 144 per cent.
Confronting
the sea with picks and shovels
Will Venice grow old and
die like its inhabitants? That is anybody’s guess: the truth is hard to come by in
this labyrinthine city. Venice is the city of “perhaps,” as unstable as the lagoon’s
ecological balance. It is impossible to imagine the city without its lagoon, an uncertain
space, neither land nor sea, whose very name expresses absence: lacuna is Latin for
“lack.” This precarious and provisional place emerged little by little as the rivers,
torrents and streams that flow across the plains on their way to the Adriatic deposited
millions of cubic metres of silt.
The lagoon is not part of the sea; it is separated from the Adriatic by 50 kilometres
of sandbars that end with the mouths of the Lido, Malamocco and Chioggia ports. Every
six hours, the tides run through the bars, flowing in as salt water and receding
as briny water. Like a gigantic lung made up of thousands of bronchial tubes, the
lagoon breathes. It is not only formed by islands high enough to stand up to the
sea’s equinox tides. Barene, the sandbars that emerge at low tide, are complex ecosystems,
home to plants and animals which have adapted to this environment oscillating between
air and water. Velme are the mud-flats visible at low tide while ghebi are channels
that are green with mire and seaweed through which the water leaves the lagoon at
low tide.
The lagoon was bound to disappear until, one day, a group of bold men decided to
make something solid out of an unstable mass. Then, from one generation the next,
the Venetians battled the elements like funambulists walking a tight-rope. Prepared
with shovels and picks to confront the sea’s efforts to upset the delicate equilibrium,
they had only one thing in mind: to preserve the existence and richness of Venice,
the city of stone and marble that they built on spongy marshland, as if it were on
terra firma. Venice was a utopia: the world’s most fragile city, but powerful enough
to rule a far-flung empire.
Those stubborn people started by drying out the land, digging canals and deviating
rivers. For example, as part of a huge project begun in 1501 and completed two centuries
later, they changed the course of the lagoon’s three main waterways: the Sile, the
Piere and the Brenta. Then, and with increasing frequency, they launched major public
and private building projects to further the civil and military development of the
“most serene republic.” These projects enabled merchant vessels and warships boasting
the biggest drafts of their time to enter the harbour or the Arsenal.
“Although with each project the technology became more aggressive than the simple
shovels and picks of the early days, these interventions have always given the lagoon
enough time to develop a new balance,” says Stefano Boato, professor of city planning
at the University of Venice. The same was true during the operations carried out
in the second half of the 19th century, when Venice was definitively integrated into
the Kingdom of Italy (1866) after changing hands several times between France and
Austria.
It was not until much later, between 1952 and 1969, that the city was dealt its harshest
blow. A straight, 15-metre deep canal was dug so that oil tankers could berth at
the industrial port of Marghera. At the same time, highly polluting chemical and
petrochemical plants were built across the lagoon, pumping more and more water out
of the aquifers and pouring more and more poison into the water. “At that time, the
delicate balance that had always existed, and that Venetians had always managed to
maintain over19 centuries of interacting with nature, was broken. The situation is
becoming alarming,” says Boato.
Aquatic
highways for tankers and tourists
The lagoon, a unique ecosystem
formed of fresh water, brine and salt water, is inexorably turning into an arm of
the sea in its central portion and a swamp around the edges. During the time of the
republic, it was forbidden to dig canals more than four metres deep.Today, there
are veritable aquatic highways over 20 metres deep. Oil tankers, freighters and powerful
speedboats that can carry hundreds of tourists create waves that destroy the sandbars
and mud-flats, and cancel out the natural movements that once slowed down the advancement
of the tides.
All these disruptions increase the erosion that is ruining the depths of the lagoon
and eating away at the foundations of buildings. The Venezia Nuova Consortium, a
group of public and private companies which the Italian Public Works Ministry and
Venice’s Water Department have put in charge of carrying out preservation work in
the lagoon, says that 1.2 million cubic metres of soil are washed away each year,
while the province of Venice puts the figure at four million. The mussel fishermen
who “work” the floor of the lagoon using a fishing method that is outlawed but tolerated
also contribute to the erosion.
To make matters worse, fishing zones surrounded by dikes limit the tides’ area of
expansion. Twenty years (1950-1970) of pumping subterranean water lowered the city’s
ground level by 10 centimetres. Lastly, the Adriatic is rising, worsening the floods
to which the city and the surrounding area fall victim.
As a result, in 1990 Venice was 23 centimetres lower than in 1908. Furthermore, between
1965 and 1995, the Venetians “forgot” to clean the city’s canals, a practice that
their ancestors considered indispensable for reasons both physical (to improve the
circulation of tidewater) and hygienic (to wash out accumulated waste).
The neglect has proven costly. On the one hand, Venice is beleaguered by over 50
days a year of acqua alta (“high water”), which floods many of the streets and squares.
On the other, with increasing frequency the tides are so low that vessels can no
longer sail on the canals.
Hard work
for meagre results
On November 4, 1966, a
gigantic acqua alta entirely submerged Venice and the lagoon’s islands for 24 hours,
causing tremendous damage to the city’s economy and art works, and sending a wave
of panic around the world. If the water had risen a little higher, the world’s most
beautiful city might have been lost. And the flooding could reoccur at any time!
The shock triggered countless initiatives: Italian and international commissions
were set up, studies conducted, laws passed and projects proposed. Major international
bodies went on the alert, UNESCO chief among them. The organization moved
its office for science and technology in Europe to Venice and undertook the grandiose
“Project Venice,” an initiative that has given rise to a profusion of studies and
meetings to pore over all the problems of the city and its lagoon: geology and morphology,
the water’s dynamics, chemical and biological processes, contamination, demographics,
traffic and cleaning up the canals.
No other city in the world has been studied in such detail. None has been so painstakingly
dissected to determine the reasons for its rise and fall. And, it must be added,
never has so much hard work produced such meagre results.
All things considered, and at the risk of oversimplifying, this complicated business
can be summed up in two sentences. They are written in bureaucratic jargon in law
798, the most important piece of legislation concerning Venice passed since the 1966
flood. The first sentence says that the work to save Venice must “restore the hydrogeological
equilibrium of the lagoon, slow down and reverse the process of degradation and eliminate
its causes.”
In other words, everything must be done to clean up the canals and to restore their
depth to acceptable levels (other laws specify 12 metres), to re-open the fishing
lagoons, and to recreate the sandbars and mud-flats. But a harmless-sounding sentence
in the same law specifies that all these operations must be carried out while “preserving
the area’s productive and economic interests.”
In other words, the bottoms of the canals must be raised but oil tankers must not
be prevented from travelling through them, the size of the lagoon’s harbours must
be reduced but the current level of traffic must be maintained, the tidal swells
must be contained but vessels must be allowed to continue carrying swarms of tourists
to the islands of Torcello and Murano. The law’s authors seem to be the direct heirs
to the playwright Carlo Goldoni and his Harlequin who served two masters.
The system of mobile dikes and floodgates planned as a solution has been a bone of
contention for nearly 20 years, setting off many debates and discussions between
engineers and politicians. It is called Mose, the Italian name for Moses and an acronym
that stands for Modulo Sperimentale Elettromeccanico, a prototype floodgate that
was tested in the Treporti canal between 1988 and 1992. After years of studies and
numerous variations, Project Moses was adopted by the Venezia Nuova Consortium. The
plan is to equip the entrances of the Lido, Chioggia and Malamocco ports with a system
of mobile floodgates: chests that are 20 metres wide, 20 to 30 metres high and four
to five metres deep.
In normal conditions and as long as the tide’s amplitude does not exceed one metre,
the water-filled chests will lie on the floor of the canal. When the tide is dubbed
“exceptional” (an average of seven a year and 20 in 1996), a hydraulic system will
fill the chests with air to raise them. Since the chests are connected to the canal’s
floor with stakes driven into the mud, they work by rising like a gate that closes,
becoming dikes that cut the lagoon off from the sea. Under the plan, 18 floodgates
will be set up at the entrance to the port of Chioggia, 20 at Malamocco and two sets
of 20 and 21 separated by an intermediate harbour basin at the entrance to the Lido.
Furor over
floodgates
According to estimates,
this enormous task will require eight years, 6,000 workers and 3,700 billion lire
(approximately $1.8 billion). The city of Venice puts the project’s total cost at
5,334 billion lire (in 1992 prices), or some $2.6 billion—not including maintenance.
“These mobile dikes must be built,” affirms Philippe Bourdeau, a professor at Brussels’
Free University and chairman of the international committee of experts named by the
Italian government to evaluate the project. “The mobile floodgates,” he says, “are,
along with raising the ground level and the other planned measures, the best way
to save Venice for the next 100 years.”
“These mobile dikes must be absolutely avoided,” replies Stefano Boato, along with
the Green Party, the Italia Nostra environmental group, Greenpeace, the World Wildlife
Fund for Nature (WWF) and other environmental organizations, which say that the project
would have a disastrous effect on the fragile ecosystem. But the municipality of
Venice, together with the Environment and Cultural Heritage ministries, are leading
the camp of those invoking the precautionary principle. They argue that the lagoon’s
geomorphological, hydraulic and biological balance must be restored—for example,
by cleaning up the canals, which began in 1998 (see box), and raising the ground
level—before any decisions about the mobile dikes are made.
In addition to this controversy, other questions have arisen. For example, the city’s
autonomy is at stake. The Department of Water, which depends on the Public Works
Ministry in Rome, and the companies that make up the Consortium, which include major
public and private corporations (such as Fiat), have few or no ties with Venice,
whose population has been accustomed to solving its problems alone for 2,000 years.
Fear of
oil spills
And then there is the economic
aspect: $2.6 billion, a sum that rises with each passing day, is a tremendous amount
of money. If all of it is allocated to a single project, what will be left for other
initiatives and for the small Venetian companies that could carry them out? When
all is said and done, the big corporations in Milan, Turin and Rome would reap the
benefits and Venice would have to settle for the crumbs.
The debate has been raging for a long time. In November 1998, the project’s environmental
impact commission, appointed by the Environment Ministry and chaired by Maria Rosa
Vittadini, an architecture professor at the University of Venice, issued a negative
assessment and requested the Consortium to review the entire project. One month later,
a ministerial commission published a similar review, which was annulled in June 2000
by the regional administrative tribunal of the Veneto. The latest news is that, during
a meeting of experts held in Rome in July 2000, Prime Minister Giuliano Amato said
the final decision would lie with his office and that it would be made at a cabinet
meeting by the end of the year.
But what if Venice’s real problems is not the exceptional tide, such as the one that
struck the city in 1966? And what if the next disaster comes not from the lagoon
but from the sea? Each year, 25 million tons of freight is shipped on the lagoon,
half of which is oil and petroleum products. A single oil tanker accident would be
enough to cause incalculable damage to the ecosystem, cover the canals with a thick
coat of petroleum and leave greasy, viscous streaks on the foundations of palaces
and churches forever. On November 29, 1995, five tons of light fuel spilled into
the lagoon, forming a huge slick that drifted for four days. Was that a warning?
In the city of masks, the fiery glow of the beautiful red sunsets over the city’s
palaces and churches, which enchant tourists the year round, may not be solely the
gift of nature. That extra shade of red may well come from air pollution arising
from Marghera’s petrochemical facilities.
Pierre Lasserre and Angelo
Mazollo (eds.), The Venice Lagoon Ecosystem, UNESCO Publishing/Parthenon,
2000.
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