High tides flooded St. Mark’s Square in Venice on Tuesday, propelled by winds that were stronger than predicted.
An experimental system of inflatable barriers to prevent water from inundating the lagoon city wasn’t activated.
The system, while still in an experimental phase, is activated when high tides are predicted to reach at least 1.3 metres (4 feet, 4 inches).
Tuesday's tide was predicted to reach 1.25 metres.
Instead, it kept rising, to a height of 1.38 metres by the late afternoon.
Some shops were flooded, and Venetians waded in water as they scrambled to set out raised walkways.
Damage to shops and other business was destined to compound the suffering already sharply felt in Venice’s economy, with tourism largely washed away by the pandemic.
In July, Venice successfully carried out a trial run of the ambitious anti-flood system, which consists of 78 barriers that can be inflated when needed to rise from the sea like a kind of dyke-on-demand.
The system is dubbed Moses after the Biblical figure, who, in the Old Testament account, parted the waters of the Red Sea.
Just over a year ago, Venice experienced its worst flooding in more than 50 years when the water reached 1.87 metres in the city.
The new moveable barrier system is designed to protect the city from tides as high as three metres (10 feet).