(Bloomberg) -- Venice is headed for its second exceptionally high tide in a week, with water levels forecast to rise 160 centimeters (63 inches) above their benchmark, the Ansa news agency reported.

The level would track Wednesday’s 187-centimeter tide, the highest since 1966. The damage from the flooding to the historical city is already estimated at about 1 billion euros ($1.1 billion), Venice mayor Luigi Brugnaro told newspaper Il Messaggero in an interview.

Prime Minister Giuseppe Conte on Thursday declared a state of emergency for the city, releasing 20 million euros for urgent repairs. Brugnaro on Friday closed St. Mark’s Square after the 11th century basilica there flooded. The city’s water buses, known as vaporetti, were suspended because of the rising water, and schools in the area were closed.

While the frequency of flooding, known as “acqua alta,” has been increasing steadily in Venice in recent years, instances of water rising more than 150 centimeters above the benchmark are rare and usually occur about once in a decade. The water level is expected to start dropping from Monday night, Ansa said, citing the Venice tidal center forecasts.

Both Brugnaro and Environment Minister Sergio Costa called for the urgent completion of the mobile dams currently under construction to protect the Venice lagoon from exceptional tides. The project, dubbed MOSE, is way over budget at 5.5 billion euros and counting, and won’t be ready until at least 2022. The project is years behind schedule. It’s also the target of several corruption investigations by the judiciary and has been plagued by technical failures.

Read more: Rising Sea Levels Could Submerge Key Italian Ports, Highways

“Also to me it seems unacceptable that MOSE, after many years and many billions spent, has not been completed,” Costa told La Stampa in an interview. “It should be completed at the earliest. Even if it’s 93%-done, the part missing is not allowing it yet to function.”

--With assistance from Giovanni Salzano.

To contact the reporters on this story: Maria Ermakova in Milan at mermakova@bloomberg.net;Alessandro Speciale in Rome at aspeciale@bloomberg.net

To contact the editors responsible for this story: Lukas Strobl at lstrobl@bloomberg.net, ;Chad Thomas at cthomas16@bloomberg.net, James Amott, Andrew Davis

©2019 Bloomberg L.P.