At 3 am in the darkness of late November, the 78 acid yellow painted steel gates of the Mose rise very slowly to try to close the perfect storm out of the lagoon, the destructive tide 1.60 meters above mean sea level, the bad and humid sirocco wind and immediately after the bracing bora with freezing gusts up to 120 kilometers per hour. The weather forecasts for the morning of Tuesday 22 are the repetition of those that had flooded the whole city on the evening of 12 November 2019, from the 150 centimeters of astronomical and meteorological tide had become 187 centimeters driven by the wind to break down the doors of the houses, to crumble walls and railings, to crumble the planking of boats.
This time the Mose is waiting for the perfect storm, which was not yet there three years ago. The 78 sluice gates have to withstand the impact of the sirocco, the wind from the southeast which pushes the entire Adriatic against the lagoon, and then the gusts of the bora from the northeast which pushes the water of the lagoon against Chioggia.
In 2019, without mobile barriers, the sequence of events was similar to this year. First, ostro and sirocco had blown from the south, and the rising tide had pushed against the houses of Venice; then, after having caused millions of damages, in a few minutes the wind had turned and in the night had vented its blind fury against the inhabited centers on the other side of the lagoon, such as Pellestrina.
What is Moses
The Mose is a colossal system of four retractable dams, a work of engineering unique in the world, designed starting in the 1980s. It is made up of 78 mobile sluice gates that rest on the bottom of the three inlets, the arms of the sea that join the Adriatic with the lagoon. When the water exceeds the safety level, the sluice gates rise side by side until they close the entrance to the sea inside the lagoon.
The first stone was laid on May 14, 2003 by Silvio Berlusconi in favor of television cameras. After 19 years it’s almost over; it works but some fittings have to be completed. Total cost of the work, with the complete package, around 6 billion. Annual operating cost, including staff salaries, about 100 million. There were Pharaonic bribes and Babylonian dissipations; in 2014 an investigation had led to the arrest of 35 people: the cost of the malfeasance is still an incomplete figure, certainly many tens of millions.