The MOSE Flood Barriers Historical Timeline

Origins

The catastrophic flood of 4 November 1966, which put nearly two metres of water into Venice and broke the sea walls at Pellestrina, made permanent protection a national question rather than a local one.

Turning points

Decades of study followed. Construction finally began in 2003, on a design that keeps the gates hidden on the seabed rather than standing permanently across the inlets -- a concession to the lagoon's tidal exchange and to Venice's own appearance.

Influential people

In 2014 a corruption investigation into the consortium building it produced dozens of arrests, including the sitting mayor of Venice. The project was placed under special administration.

Cultural evolution

The first full defensive closure came on 3 October 2020, when the gates held back a tide that would have flooded St Mark's Square. It has been raised regularly since.

Present-day significance

The argument now is about the future rather than the past: the running and maintenance costs are very large, the gates were designed against sea-level projections that have since been revised upward, and closing the lagoon more often has consequences for the water inside it.