AT 12.25 ON July 10th, something happened that had never happened before. Venice was cut off from the Adriatic Sea it dominated for centuries. Watched by Italy’s prime minister, Giuseppe Conte, and a bevvy of ministers and officials, all 78 movable sluice gates comprising the MOSE sea barrier reared up, blocking the inlets to the lagoon that surrounds the city.
All present stressed that this was not an inauguration. MOSE, an acronym for Experimental Electromechanical Module, will not be fully functional until the end of 2021. But now that it has been operated in its entirety (only sections had been tested previously), there is a chance that the barrier can be used this winter if Venice is threatened by a sea surge like the one that swamped the city in November 2019.
As an opening—or closing?—ceremony, this one was pretty bizarre. Elisabetta Spitz, the special commissioner put in charge of the project after last year’s lethal flooding, noted its “troubled and controversial history”. The mayor of Venice, Luigi Brugnaro, said MOSE was “not an example to be copied”. Indeed not: delays have put MOSE nine years behind schedule and three times over its original budget. A bribes-for-contracts scandal in 2014 involved dozens of local politicians and executives of the consortium building it. Mr Conte was just as downbeat, saying “let’s all hope it works”.
But then caution is advisable. Whether MOSE will be as efficient in parting the seas as its biblical namesake is unclear. The latest test was carried out in ideal conditions: a far cry from the 100 kilometres per hour winds and three-metre waves (60mph and ten feet) that tore into the lagoon last November. And while its giant, box-shaped “gates” go up, not all can currently go back down into their housings on the sea floor. That is because of sand in the works—a problem that is as tricky to solve as it was seemingly easy to predict.
The other doubt is whether Italy can afford the MOSE’s astronomic running costs, estimated at around €100m ($110m) a year. Additional government borrowing to restart the economy after the covid-19 pandemic could easily push public debt above 160% of GDP, so money is tight.
But even if this entire, ill-starred scheme can be made to work, Venice will be far from safe. The sea surges and their effects are newsworthy, telegenic and easy to explain. Not so the other threat facing Venice: the inexorable rise in the everyday level of the water in the city, which is eating away at its very fabric. The proof can be seen in strips of marine vegetation that run along the brickwork above the base of canal-side houses instead of attaching to the stone of the foundations as they once did. Few but the Venetians notice it, and those who do often see it as evidence that Venice is sinking.
In fact, says Pietro Teatini, professor of hydrology at the university of Padua, many of the world’s cities are sinking because of the draining of aquifers below them. Venice too sank 10-15 centimetres in the post-war years because of industrial exploitation of the aquifer system underneath. But water is no longer being extracted in excessive quantities, and the city today is relatively stable.
The causes of the gradual rise in sea levels around Venice are nowadays global warming and the abuse of the lagoon. “Imagine a bath with a huge sponge in it,” says Jane Da Mosto, executive director of We Are Here Venice, an NGO. “Open a tap and some of the water will reach the end of the bath. But a lot of it will be absorbed by the sponge.” The sponge in her example is made of salt marshes around the lagoon; but these have been severely eroded by port activities and unmanaged boat traffic. Human intervention has also flattened the bed of the lagoon and scored it with navigation channels, allowing water to flow into the city with greater force and increasing the distance between high and low tides.
What to do? Keeping big ships, including cruise liners, out of the lagoon would certainly help. But Mr Teatini and his faculty colleagues have a more ambitious idea: raise Venice. He notes that MOSE will only come into operation when the water in the lagoon gets to 110 centimetres above its reference level. “But even at 90 centimetres, part of the city, including St Mark’s Square, is swamped.” Raising the level of the ground by just 20-30 centimetres would make a huge difference and Mr Teatini thinks it can be done by pumping sea water into the already salty network of aquifers below the city. In 2008, it was estimated that a pilot scheme would cost €11.1m to launch and €1.4m a year to run; the full project around €80m and €10m a year. That is vastly less than the €6bn that MOSE has devoured. All the professor needs is a billionaire philanthropist who wants to be remembered as the saviour of St Mark’s Square.