Venice is famous for its canals, but flooding poses serious threat to the future of the Italian city.
Engineers hope they have found the solution to protect the World Heritage site from rising sea levels.
When completed in 2016, 78 of the new flood barriers will be raised from the bottom of the lagoon to stop tides as high as three metres from reaching the city.
Al Jazeera's Claudio Lavanga reports from Venice.
Source: Al Jazeera