Dec. 12 (Bloomberg) -- Italy is being hit by extreme weather, as the heaviest rains in more than a century flood cities up and down the peninsula, drowning Venice’s St. Mark’s Square and Rome’s cobbled medieval streets.

The city of Rome declared a state of emergency today after a woman died while trapped in a car in a flooded underpass. Almost a quarter of Venice is under water amid the highest tides in 22 years. Record snowfall on Sicily’s Mount Etna, Europe’s highest active volcano, has left eight Boy Scouts stranded on the mountain.

Italy’s civil protection agency predicts another 36 hours of hail, heavy rain and snowfall after two weeks of storms pushed the country’s bridges, roads and transport systems to their limit, prompting criticism about a lack of spending on aging infrastructure. The 18-meter (59-foot) walls built to retain Rome’s Tiber River date back to the city’s 1870 flood.

The banks of the Tiber today spilled onto the city’s streets, threatening to submerge its island, and flooding created a lake around the 2,000-year-old Coliseum. Municipal workers removed debris from 4,500 drainage holes around the city and 12,000 others are “at risk,” according to the local government.

“This is like an unprecedented earthquake,” Mayor Giovanni Alemanno said yesterday. “In one night we had more rain than we usually have in all of December.”

God’s Wrath

Since antiquity, the capital has been prone to periodic violent floods with marks etched into the stone of many of the center’s houses to commemorate the worst episodes. The existing infrastructure, some of which dates all the way to the emperors of the Roman Empire, is buckling. The walls built in the aftermath of the 1870 flood can no longer cope with the extent of the damage unleashed by heavy rains.

Back then, the Church hinted the floods were God’s punishment for Italy’s crimes against its pope, who had been locked into the Vatican City after the unification of the country. Today, climate change is held responsible for an unprecedented number of natural disasters around the world ranging from hurricanes to earthquakes.

“Glaciers are melting in the Alps, the Andes, the Rockies and most ominously in the Himalayas, where there is 100 times as much ice and snow in all of the mountains here in Europe,” former U.S. Vice President Al Gore Jr. told delegates in Poznan, Poland, today at negotiations for a new global-warming treaty.

Traffic Halted

The wet weather and flooding have brought traffic on Rome’s narrow streets to a near-halt, while commuters using trains and trams have suffered through hours of delays.

“I’m three hours late for work and there’s nothing I can do,” said Francesca Pollari, a 24-year-old hairdresser. “I can’t walk, I can’t bike, maybe I can swim.”

Other parts of the country have also been pummeled by the weather, with many of Venice’s hundreds of small islands now submerged. The city’s tide center, which monitors water levels, said the sea reached 156 centimeters (61 inches), the highest since 1986.

Ferry services between the island of Sicily and the mainland have been interrupted by violent maritime storms. In Naples, civil protection phone banks were overwhelmed with hundreds of calls from alarmed citizens worried about the rain.

“I aged 10 years that night when the heavens opened,” said, Enzo Tremaglia, a 52-year-old taxi driver. “I have never seen anything like it in 20 years on the job.”

To contact the reporters on this story: Alessandra Migliaccio at amigliaccio@bloomberg.net; Flavia Krause-Jackson in Rome at fjackson@bloomberg.net

Last Updated: December 12, 2008 09:38 EST