Venetian Lagoon

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The Venetian Lagoon

The Venetian Lagoon is a lagoon of the Adriatic Sea in which the city of Venice is situated. Its name in the Venetian language has provided the international name for an enclosed, shallow embayment of saltwater.

The Venetian Lagoon stretches from the Sile in the north to the Brenta in the south, with a surface area of around 550 km². It is around 8% land, including Venice itself and many smaller islands. About 11% is permanently water, or canal as the network of dredged channels are called, while around 80% is mud flats, tidal shallows and salt marshes.

It is connected to the Adriatic Sea by three inlets: Lido inlet, Malamocco inlet and Chioggia inlet. Being at the end of a closed sea, the lagoon is subject to high variations in water level, the most extreme being the spring tides known as the acqua alta (Italian for "high waters"), which regularly flood much of Venice.

The Lagoon of Venice is the most important survivor of a system of estuarine lagoons that in Roman times extended from Ravenna north to Trieste. In the sixth century, the Lagoon gave security to Romanised people fleeing invaders (mostly the Huns). Later, it provided the conditions for the growth of the Venetian Republic and its maritime empire. It still provides a base for a seaport, the Venetian Arsenal and for fishing, as well as a limited amount of hunting and the newer industry of fish farming.

The island of Torcello seen from the Lagoon

The Lagoon was formed about six to seven thousand years ago, when the marine transgression following the Ice Age flooded the upper Adriatic coastal plain.^[1] River sediments compensated for the sinking coastal plain, and coastwise drift from the mouth of the Po tended to close tidal inlets. Venetiuan hydraulic projects to prevent the lagoon from turning into a marsh reversed the natural evolution of the Lagoon in the fifteenth and sixteenth centuries. Pumping of aquifers since the nineteenth century has increased subsidence. Thus the present aspect of the Lagoon is due to human intervention. Originally many of the Lagoon’s islands were marshy, but a gradual programme of drainage rendered them habitable. Many of the smaller islands are entirely artificial, while some areas around the seaport of the Mestre are also reclaimed islands. The remaining islands are essentially dunes, including those of the coastal strip (Lido, Pellestrina and Treporti).