Wearing colorful, disposable boots, tourists last fall slogged to outdoor cafés in Piazza San Marco (St. Mark’s Square) in Venice—even as waters were receding from one of the city’s worst floods since 1872. The saltwater damaged St. Mark’s Basilica’s marble columns and mosaic floors. Other buildings and landmarks are in danger of being ruined or lost to the sea. What’s being done to save the City of Water?
Venice, Italy, sits on 118 small islands at the northern tip of the Adriatic Sea. A tidal lagoon and several barrier islands surround the city. Instead of streets, Venice has a network of canals. The city’s iconic gondolas take the place of cars.
Venetian engineers have dealt with flooding since the 1100s. The city’s acqua alta, or high-water season, takes place from October through January. High tides often overlap with a strong, warm wind called sirocco. The combo wreaks havoc on low-lying areas of Venice. The Piazza San Marco is chief among them.
Diverting water, upgrading stone dams, constructing embankments, and raising walkways—Venetians have tried many measures to stem the tide of, well, the tide.
In 2003, scientists proposed MOSE. MOSE stands for MOdulo Sperimentale Elettromeccanico (Experimental Electromechanical Module). The project’s nickname has biblical significance: Mosè is Italian for Moses, the Old Testament figure who parted the Red Sea under God’s direction.
The Venetian Moses is a string of 78 moveable metal flood barriers. Engineers installed the barriers at three inlets around the lagoon. Pumping air into the hollow barriers causes them to rise out of the lagoon. The barriers, or gates, would separate the lagoon from the sea during especially high tides, about four times a year.
Scientists hope Moses will protect Venice from disastrous flooding. But overspending and corruption scandals have long delayed the project.
This year’s acqua alta caused severe flooding in Venice and elsewhere—partly because of poor upkeep of Italy’s many river beds. Would the barriers have prevented damage? No one knows for sure.
Engineer Pierpaolo Campostrini cares for the 1,000-year-old St. Mark’s Basilica. He says salt in the water is damaging the church’s marble-covered columns and tiles. He believes one 2018 flood aged the structure more than 20 years.
Moses is supposed to be completed by 2022. Meanwhile, Venetian residents and businesses are reinforcing their doors with metal or wooden panels to prevent water from entering bottom floors. Some even pumped out excess water. But the tide keeps rising.