Dec. 2 (Bloomberg) -- Venice, the lagoon city composed of hundreds of small islands linked by historic bridges, was flooded by the highest tides in 22 years, prompting authorities to warn residents and tourists to stay indoors.

The city’s Tide Center, which monitors levels, said the water climbed by 156 centimeters (61 inches). Officials issued warnings by loudspeaker at around 11 a.m. yesterday. Ferry services, the main form of public transportation along the Grand Canal that snakes through the city center, were temporarily suspended. Heavy showers are forecast for today.

“These are exceptionally high waters,” Mayor Massimo Cacciari said yesterday. “Don’t go out unless you absolutely have to.”

The historic city, which attracts about 16 million visitors annually, has recorded periodic floods ever since the 13th century, according to the book The Science of Saving Venice.

The town that inspired Canaletto’s meticulous paintings of docks and buildings has become even more vulnerable because the buildings have sunk, sea levels are higher, and storms sweep water over the town’s streets more easily because of land-use changes, wrote authors, Caroline Fletcher and Jane Da Mosto.

November traditionally has the most flooding, according to a city survey of levels from 1923-2003, with the twice-a-day tides exceeding the 110-centimeter mark about 65 times in that month on average. It hit 159 centimeters in 1986.

Floodgates

Water levels reached a record 194 centimeters in 1966, pushing about 5,000 Venetians from their homes. High tides now flood the city several times a year, damaging historic buildings and disrupting transportation.

Italy’s previous government under Prime Minister Romano Prodi in 2006 approved a 4.6 billion-euro ($5.8 billion) project to build a system of adjustable dikes to protect the city. That project would include 78 floodgates that can be raised 110 centimeters to keep water out of the lagoon. The plan has encountered criticism from environmentalists and funding shortfalls.

To contact the reporter on this story: Flavia Krause-Jackson in Rome at fjackson@bloomberg.net

Last Updated: December 1, 2008 20:09 EST