Discover The MOSE Flood Barriers

The system spans the lagoon's three inlets -- Lido (with two barriers either side of an artificial island), Malamocco and Chioggia -- with 78 gates in total.

Each gate is a hollow steel box roughly twenty metres wide, hinged along its bottom edge to a concrete caisson sunk into the seabed. At rest it lies flat in its housing, flooded and level with the floor of the channel.

To raise it, compressed air is pumped in and the water forced out; the gate becomes buoyant and swings up to sit at an angle above the surface. To lower it, the air is released and it sinks back.

The visible works are the service infrastructure rather than the gates themselves: locks at Malamocco for shipping, breakwaters, an artificial island at the Lido inlet, and control buildings.

The design was chosen specifically so that nothing stands permanently across the inlets -- when MOSE is not in use, the lagoon looks as it always has.