The Italian city of Venice is perhaps most famous for its hundreds of canals. Located at the mouth of the Adriatic Sea, the city was built virtually right at sea level. With the city consisting of over 100 small islands, the canals and subsequent bridges were built to connect the city together. There are no roads in Venice, just footpaths and the canals.
Despite being built right at sea level, for centuries flooding in Venice (locally called acqua alta) would occur only a few days each year. To be sure, historical records indicate the city dealt with many devastating floods. However, these occurred sparingly, perhaps several times each century.
In comparison, since the 1950s there’s been a remarkable increase in the number of days of flooding in Venice. There are two primary reasons for the dramatic increase: climate change and poor city management.
The Disastrous Results of Flooding in Venice
Climate change is an obvious reason. With glacial ice at the poles melting at a rapid pace, it’s been documented that sea levels around the globe have been rising in recent decades. Sea levels in some places have risen more than others, and the Adriatic Sea is one that’s been particularly affected. With nowhere else for the water to go, Venice has been majorly impacted as it was built virtually at sea level. Storms have also gotten worse, bringing with them higher tides.
Another reason for the additional flooding in Venice is due to mismanagement of the city. In the 20th century the city has suffered from human blunders which has actually led to the city sinking further into the ground, a process called subsidence. It’s estimated in the last century the city has sunk 9 inches into the ground. For a city right at sea level, this is a major detriment.
In the 20th century industrial projects such as offshore piers for cruise ships and bridges to the mainland altered the sea floor and tidal cycles in ways that exacerbated the flooding. Other projects for industry pumped out massive amounts of groundwater from the aquifer below the city for decades which also contributed to the city sinking further.
In recent decades the city has taken measures to combat the increase flooding. The MOSE project to install a series of underwater gates began in 2003, though has been plagued by corruption, delays and technical challenges. It is debatable whether the ~$6.5 billion spent will yield an effective product.