ROME - Italian authorities plan to expand Venice's port into a bustling shipping hub, further endangering the fragile lagoon and contributing to the sinking of the treasured city built on water, a conservation group said Monday.

Venice in Peril, a British fund that works to preserve Venice, said a report it obtained from the local port authority showed plans to accommodate more and bigger ships in a bid to compete with other European harbors.

The Venice port authority confirmed it had written the report, but insisted the works will respect the environment and are necessary to deal with the growing flow of tourists and goods.



The debate illustrates the complex and often controversial balancing act between protecting the UNESCO world heritage site and exploiting a sea port that gives easy access to prosperous areas of northern Italy and central Europe, as well as rapidly developing markets in the Balkans.

The report drawn up for the Italian Senate outlines ongoing and future works including the continued dredging of passages in the shallow lagoon to allow larger vessels in and the construction of a new shipping terminal in the long-declining mainland industrial zone of Porto Marghera.

The port authority is spending at least $370 million to dredge inlets and navigation channels to allow the passage of ships of up to 1,300 feet in length.

This is particularly concerning for conservationists because dredging and heavy ship traffic are seen as one of the causes of the rising sea level in the lagoon, which threatens the low-lying islands on which the historic city is built.

"The fact that big ships have access to the lagoon has important consequences for its health," said Jane da Mosto, a researcher for Venice in Peril. "Apart from environmental concerns ... the problem of high tide is accentuated, so it means more flooding for Venice."

Rising sea level causes problems
Under the combined effect of rising water levels and settling of the land, Venice has sunk nine inches in the last century.

Most experts agree that the waves generated by large ships and the currents that run through the deep passageways play a big part, displacing and dragging out to sea the sandbanks and other sediments that help keep water out.

In winter, Venice periodically goes through bouts of "acqua alta" (high water), when strong winds and high tides conspire to push the sea into streets and piazzas, forcing tourists and locals alike to don rubber boots and teeter along impromptu bridges.

The rising sea level has increased the frequency of the floods, and in December, Venice suffered its worst deluge in 22 years. Experts warn the problem could further worsen in the coming decades as climate change causes sea levels to rise globally.

‘Moses’ system to prevent flooding
The port authority report dismisses environmental concerns by declaring them solved thanks to a project to build towering movable barriers designed to rise from the seabed and prevent flooding.

The $6.13 billion system, named Moses after the Old Testament figure who parted the Red Sea, is expected to be operational by 2014.

"The problem of the hydraulic equilibrium is solved because it will be manageable through judicious use of the Moses system," the report says.

Not so, some experts said.

The Moses barriers block shipping so they would only be raised when an exceptionally high tide is expected. That would not lower the average sea level and stop the waters from slowly eating away at Venice's bricks and stones, said Luigi D'Alpaos, professor of hydrodynamics at the University of Padua.

"Moses will, at best, manage the acqua alta," he said in a telephone interview. "But the other problems are not at all addressed by the barriers."

Officials at the Venice port authority said the dredging is needed to restore the navigation channels, which are filling up with silt, to their original depth. They said the digging will not go beyond the depth allowed by law and any expansions on land will be done within the existing port zone.

But Venice in Peril said work should be done instead to reduce the depth of the channels, where possible, or at least reconstruct the natural lagoon features that protected the city for centuries

September 20, 2009
The construction of mobile floodgates aims to safeguard the 1,300-year-old island city of Venice. It's an ambitious engineering project, but some scientists say it may not be sufficient to protect Venice from rising sea levels due to climate change.

Venice rose from mudflats in the middle of a lagoon which forms the largest wetland in the Mediterranean. One of the world's most endangered cities, it has been subject to increasing flooding due to sinking land — but also to rising sea levels.

It's known as "aqua alta" — high water — and it brings city life to a standstill for several hours. Big boats can't go under low-hanging bridges, and water seeps into buildings through the sewage system. Venetians have not lived on the ground floor for decades.

Enlarge Graziano Arici/New Venice Consortium/APA mobile barrier is under construction at the Malamocco inlet to the lagoon of Venice in this November 2008 photo from the New Venice Consortium.

Graziano Arici/New Venice Consortium/APA mobile barrier is under construction at the Malamocco inlet to the lagoon of Venice in this November 2008 photo from the New Venice Consortium.
Moses To The Rescue

Sophisticated technology is now being used for what has become a full-scale emergency. At one of the three inlets that lead from the sea into the lagoon, a massive mechanical hammer is driving a steel and concrete piling into the lagoon bed. Elena Zambardi works for the consortium safeguarding Venice and says the use of pilings was invented by the visionaries who founded the city 1,300 years ago.

"Under the Salute bridge or Rialto Bridge," for example, "there are piles, wooden piles to consolidate the subsoil," she says.

Enlarge Graziano Arici/New Venice Consortium/APAn artist's rendering of how the mobile barriers around Venice would work.

Graziano Arici/New Venice Consortium/APAn artist's rendering of how the mobile barriers around Venice would work.
The project acronym is MOSE, which is also the Italian word for Moses, recalling the biblical parting of the sea.

Once completed in 2014, there will be 78 large, mobile flood gates at the three inlets. When not in use, they will sit on the lagoon bed. When a high tide is forecast, Zambardi says, the gates will rise and shut off the sea from the lagoon.

But the project, which is 54 percent completed, has been hounded by controversy and, critics say, may already be outdated.

The IPCC — the Intergovernmental Panel on Climate Change — has forecast a sea level rise by the end of this century of between 18 and 59 centimeters. But scientists caution it could be even higher.

An Ecosystem In Danger

Marine scientist Laura Carbognin has been studying the Venetian lagoon for decades. Like many scientists, she fears rising sea levels could mean the floodgates will be closed often and for long periods. That would upset the vital exchange between the sea and the lagoon, suffocating its delicate ecosystem.

Carbognin co-authored a report that suggests another radical solution: "To complement the Moses solution, it is necessary that all the city is uplifted."

She says research already suggests the feasibility of raising Venice.

"Based on hydrological and geochemical data, the preliminary simulation shows that fluid injection into deep formation can uniformly raise Venice up to 30 centimeters over 10 years," Carbognin says.

Carbognin hypothesizes the injections of salt water or even carbon dioxide at a depth of 600 to 800 meters below the lagoon, but she concedes much more research is needed.

That would mean huge investments at a time when delays in state funding for the more-than-$6-billion MOSE has already substantially delayed the project's completion.