The changing face of Venice amid the acque alte
Just about every day I was in Venice, we had Acque Alte. That's when the lagoon backwashes into the city streets, starting with Piazza San Marco (the lowest point of Venice) and then filling in the low-lying calle around the Grand Canal.
The air raid sirens go off when the rising waters cause the first gondola moored at Piazzetta San Marco to start nudging over the embankment, usually somewhere around 5 a.m. Since this is an ancient and oft-repeated emergency, the Venetians are perennially prepared during the autumnal Acque Alte season.
Along key arteries of the city they string out a raised wood-plank walkway in long lines of picnic table–looking devices that allow pedestrians to glide over the surface of the water. Once the waters recede, these wide walkways on their stubby aluminum tube legs are stranded high and dry, dividing the streets down the middle, looking sort of like Venice is about to throw a huge outdoor feast for an army of dwarves.