Sinking Cities

And now to Venice; City of love, rotting egg odours, and serious sea level problems:

 

I don't know - these guys look pretty happy - maybe it's like this there all the time? (The Journal, 2012)

 

In terms of water level, Venice's problems are twofold; firstly sea level is rising, and secondly the city is sinking. During the 20th century relative sea level rose by 25 cm, 13 cm of this was due to sea level rise, and the remaining 12 cm was due to subsidence of the city (Carbogin et al, 2010). This combination means that ordinary high tides, and storm surges are increasingly likely to cause flooding of the city which has an average elevation of just 90 cm above sea level (Carbogin et al, 2010).

 

 

But the big question is what are the Venetians planning on doing about it?

 



The main plan of action is the MOSE project - named after Moses who parted the sea to let the Israelites escape Eygpt (do you think there is a reason that there are no tidal barriers named after King Canute?).

The Mose Project, once completed, will be a complicated mile long barrier system across the entrances to the Venice Lagoon. When needed it can be raised to protect Venice from high tides and storms, when not needed it will be completely concealed beneath the water. I've found a little video of how the barrier will work:

But the project is not going smooothly;  construction which started in 2003 was due to finish in 2014, but the deadline has just been extended to 2016 (TheVeniceTimes, 2014). On top of this concerns have been raised about the impacts on the lagoon's ecosystem, and that raising the sam will prevent sewage from leaving the city, making it smell even worse - apparently Venice doesn't have a sewage system, it all goes into the canals (Venepedia) - not sure what the people in the first picture are thinking! And then to top it all off, the Mayor was arrested for corruption linked to the project and put under house arrest (TheVeniceTimes, 2014). But, forgetting about all that for now (!!!), the barrier will be complemented by raising pavements and walls in low lying areas, and by building a lock to at the entrance of the lagoon to allow boats to leave even when the barriers are up. 

Sounds interesting, and especially so because Venice is a very high profile city. I do really like that the barrier will be hidden when not in use - although having said that I do think that our Thames Flood Barrier is really quite beautiful. The current plans will just hold back the sea when necessary, but as we saw with the Thames Flood Barrier, all barriers have a life span. Without a way to raise the city up out of the water, there are going to be serious issues in the future - it will be interesting to see what happens.