Associazione Piazza San Marco

The flood of November 4, 1966: Saint Mark’s Square submerged

At 10 p.m. on November 3, 1966, high water flooded Venice with unusual force. At 5 p.m. on the following day, the water level should have receded based on the tidal rule of ‘flow and flowing back’. This didn’t happen and, around noon, the flood increased further and interrupted electricity, gas and telephone lines. The entire region was also disrupted by flooded rivers. The Cavallino peninsula and island of Sant’Erasmo were submerged and overcome by waves and water broke through the cracks of the ‘murazzi’, the defensive old stone water barriers, and onto the island of Pellestrina. As a result, sea water flooded built-up areas and then flowed back into the lagoon. Images of Saint Mark’s Square submerged and beaten by waves were shown around the world. At 6 p.m. on November 4, the flood water was supposed to recede but, again, this didn’t happen. At around 9 p.m., because of a change in the wind, flood water started to flow violently back into Venice, reaching a height of one metre, ninety four centimeters above average sea level: a level never seen before. Only a few more centimetres of water and the city with all its historical and architectural beauties would have been destroyed. Here is the broadcast from the RAI (Italian Radio and Television) about the flooding which opens with dramatic images of Saint Mark’s Square submerged in water: