Glass barriers installed around St. Mark's Basilica in Venice protect its marble columns and precious mosaics from frequent floods, the Associated Press reported.

Even after the water evaporates, salt crystals remain that corrode the marble bases of the columns and floor mosaics, said Mario Piana, the architect and restoration specialist in charge of San Marco.

The new barriers are made of glass mounted on a reinforced concrete base dug under the pavement of St. Mark's Square to withstand the force of the incoming water.

Piana said the system can hold up to 1.10m of water in the square, which equates to a tide of 1.90m above sea level. 

"Let's hope there won't be any more high water reaching the base of the basilica," Piana said during a site visit, stressing the fragility of the mud brick structure.

Built on wooden stilts amid canals, Venice has struggled with flooding since its foundation 1,600 years ago.

But like other coastal areas, rising sea levels and more extreme weather that scientists attribute to climate change mean more frequent tides.

The Moses dikes saved Venice from flooding

While the basilica was built on one of the highest points in Venice at the time, it is now one of the lowest in the city due to landslides and rising sea levels. 

As a result, St. Mark's flooded more than other sites, and the basilica remains vulnerable despite the activation of protective underwater barriers around the city in 2020.

The November 2019 flood was particularly devastating as the water did not drain quickly after repeated downpours, leaving parts of the basilica submerged for up to 24 hours.

The floods that enter the basilica often happen out of season, making it even more vulnerable and forcing experts to come up with the new glass barriers as protection.

Piana said the glass and concrete barriers were part of a larger engineering project to create a series of channels below the surface of the church and the plaza of the same name to divert water from the lagoon and prevent it from flooding the plaza, BTA reported.

Italy

floods

Venice

glass partition