Venice’s St Mark’s Square was under water on Tuesday after a newly installed system of mobile artificial dams failed to activate.
Residents — long accustomed to perennial “acqua alta” or high water events — pulled on their rubber boots once more to deal with flooding that reached a high of 1.37 metres (4.5 feet) above sea level in the afternoon.
The waters drowned St Mark’s Square — the Renaissance city’s lowest area at about one metre above sea level — and invaded the famous basilica as many shopkeepers blocked their entrances with wood panels to keep the water out.
A massive flood defence system called MOSE aimed at protecting Venice’s lagoon during high tide was finally installed in October.
The network of water-filled caissons is designed to be raised within 30 minutes to create a barrier capable of resisting a water rise of three metres above normal.
But on Tuesday the system failed to swing into action because the forecast erroneously predicted a rise of only 1.2 metres (four feet) above sea level.
“To activate MOSE a bigger forecast is necessary,” Venice Mayor Luigi Brugnaro told the Italian news agency Agi.