The natural phenomenon of acqua alta (‘high water’) happens several times a year in Venice when high tides from the Adriatic Sea combine with winds and long waves to flood the city. In 2019, Venice experienced the worst acqua alta since 1966, with 1.87m-high tides flooding two-thirds of the city. The number of high tides over 1.4m has been increasing, with 14 in the last 20 years.
In 1984, a scheme to protect the historic city’s inhabitants and buildings was designed, consisting of barriers at the mouths of each of the three inlets to the Venice Lagoon.
The MOSE (Modulo Sperimentale Elettromeccanico, or Experimental Electromechanical Module) is a network of barriers located at the Malamocco, Chioggia and Lido harbours. Each barrier is a series of metal gates, which are raised when the high tide exceeds 1.1m and can protect from tidal waters of up to 3m.
There are 19 gates at the Malamocco inlet, 18 at Chioggia harbour, and the Lido harbour is separated...