Climate change

Is Venice really sinking?

The news about Venice sinking are all over the Internet. Everyone knew that Venice was going to sink someday, but what people didn’t realize was how quickly this is happening. That Venice still exists today is already a miracle, knowing that it is a city full of marble buildings which was built on an ancient wooden structure.

But, how true and how bad is this situation really?

Threats to Venice

Something very important is the place and the terrain on wich Venice was build on.

The city was build on hundred low-lying salt marsh islands almost two thousand years ago. These salt marsh islands are slowly dissolving, and therefore the city slowly, but periodically sinks into the lagoon.

Apart from this Issue there are some other wich also affect Venices survival:

  • Boat traffic: Big boats run by a motor, produce waves. These waves erode the canal walls and the salt islands that remain.
  • “Acqua alta”

“Acqua alta”

This specific phenomenon consists of extremely high tides wich enter the lagoon, and end up flooding the canals and the city itself. This happens when the water level is 90mm above normal. The worst case of “aqua Alta” was the one wich produced the historic flooding of 1966 when the water level went up to 194 cm. To make it easier to understand this situation, when the water rises 90cm, St marks´s square already floods.

However, these floodings were something abnormal and sporadic. But nowadays it is safe to say that at least 60 days per year are characterized by high tides and several floodings.

This is Venices biggest threat.

Tourists visiting Venice during the high-water season

The main cause behind the acqua alta is a more global concern: rising sea levels. Due to climate change, the periodicity of the aqua alta has been multiplied. Venice having floodings is nothing new, but the fact that the flooding are becoming more regular and more destructive is alarming.

Venice in the future

A question that is often asked is: How much is Venice actually sinking per year?, and according to research, the city sinks, on average, 1-2 millimeters per year!

Flood risk needs to be integrated into a city’s vision: how do we want our city to look like in 10, 20, 50 years?

Swenja Surminski
 Head of adaptation research at the Grantham Research Institute on Climate Change and the Environment in London,

There have been several project ideas, such as the ones suggesting pumping concrete into the city’s foundations or to deepen the underwater channels. Nevertheless, Venice’s authorities are putting the majority of their eggs into one basket: the soon-to-be-completed Mose (Experimental Electromechanical Module) project.

More or less, it consists of several sea-based defensive barriers made up of 78 mobile gates, each 20m wide and located at strategic locations to create a “coastal cordon” which, it is hoped, will minimize major flooding events. These barriers will remain submerged until the water level rises above 110cm. The problem is, that the construction began in 2003, and it still isn’t finished. The constructors announced that it should be ready by the end of 2023.

In addition, the Mose project will end up costing around €8bn. It is also not a long-term solution, it will maybe work for more or less 100 years, knowing that the constant opening and closing of the barriers will also eventually “doom” the lagoon. This will lead to the destruction of the lagoons ecosystem.

Therefore, taking into consideration all the data commented on the paragraph above, experts come to the following conclusion; a Dutch-style solution will have to be introduced. Moreover, this solution takes a very long time to build and is very expensive. The dam system is approximately 30km long, that is roughly 18 times the size of Mose.

Conclusion

In conclusion, we need to be seeking those ultimate solutions right now, before it is too late. In the end, Venice’s very position as such an admired and sought after city may be the key to making these protective changes happen here first.

I don´t think that the world will let Venice sink

Fabio Carrera
 Professor at Worcester Polytechnic Institute in Massachusetts and founder of Venice Project Center

Please Leave a Comment

×