How Venice’s canals were built: how was built on water?

The canals of Venice are among the world’s most romantic places, but before the atmospheric waterways we know and love today came into existence – before the grandeur of the city’s opulent palazzos and piazzas – there was only a marshy, muddy lagoon with little going for it beyond a smattering of 124 small islands. So how was this miraculous ‘floating city’ created from such humble origins? And just how deep are Venice’s canals? Keep reading to find out!

How Venice’s canals were built

To make the islands of the Venetian lagoon fit for habitation, Venice’s early settlers needed to drain areas of the lagoon, dig canals and shore up the banks to prepare them for building on. They began by digging canals and lining them by driving closely spaced wooden stakes – many of them made from water-resistant alder wood – through the sand and mud to rest on the harder clay beneath. On top of these stakes, they placed wooden platforms and then stone, and this is what the buildings of Venice are built on.

Of course, with no forest in the lagoon, this wood had to be imported by boat on a vast scale from forested areas that now form parts of modern Montenegro, Slovenia and Croatia. It may seem surprising that the wood on which Venice is built has withstood the test of time, but this is because it’s submerged in oxygen-poor water that doesn’t create the conditions needed for microorganisms to flourish and decay the wood. Not only that, but because it’s saltwater, salt and other minerals have, over time, seeped into the wood and hardened it to an almost stone-like state.

How deep are Venice’s canals?

There’s no single answer to this, because the depth of the canals varies greatly, and also depends on factors such as dredging work and the level of the tide. On average, though, most of the canals in Venice are only around 1.5 to 2 metres deep. The Grand Canal – the big canal that runs through the heart of Venice – is deeper, at an average of 5 metres, while the Canale della Giudecca – which separates the main part of Venice from the island of Giudecca – is around 12 to 17 metres deep.

How are the canals maintained?

Want to find out more about how Venice works? Then take a look at this fascinating video to see how the canals are built and maintained, and get an insight into the work that goes into keeping this incredible city ‘afloat’.

Venice Backstage. How does Venice work? from Insula spa on Vimeo.