What Is The Acqua Alta in Venice?
The Acqua Alta in Venice is the name given to the flooding caused by the high tides throughout the winter season. Very high tides usually happen during the months of October through to January. Venice floods because it is extremely low lying. It was essentially built on marshland and is made up of 118 islands. I’ll give you a brief overview. Yes, I will try my best to keep it brief.
History of Venice
Venice has a really interesting history, which I didn’t actually read about until after my trip, but if you’ve got a few minutes I recommend doing some reading before you go!
When Was Venice Built, and Why?
In the 5th Century AD barbarian conquerers ravaged Italy and civilians were forced to flee. They escaped to the marshland and took refuge amongst groups of poor fishermen living out there. As more and more people escaped a need grew to build substantial homes. They needed more space and a stronger foundation to live on. They needed something permanent to raise families.
How Was Venice Built?
The settlers needed to find a way to strengthen the land they were living on, to install drainage and to protect them from the environment. Their solution was to dig hundreds of canals and secure the banks with wood pilings. The same wood pilings were then used to make the foundations of the buildings. Thousands of these wooden pilings were set into the earth and solid platforms were laid on top. Because the wood was underwater it didn’t rot and it remains there to this day. Crazy to think the majority of Venice is still stood on 1000 year old piles of wood!
So I think we can all agree Venice doesn’t have the most solid of foundations, and what does that mean?
Is Venice Sinking?
Venice started sinking the moment it was built. All those buildings and all that weight are causing the dirt underneath to compact. People say slightly different things when it comes to how quickly Venice is sinking. One record says Venice has sunk 9 inches in the last 100 years, other records say it’s sinking at a rate of 1mm per year. Whichever is correct it is safe to say Venice is sinking, slowly but surely.
How Are Rising Sea Levels Affecting Venice?
The bigger problem is the speed at which sea levels are rising. Sea levels are rising at just over 3mm per year, that’s three times as fast as Venice is sinking. These rising sea levels means the tides are coming in higher and higher, causing worse flooding and more damage to Venice’s most iconic buildings.
Should I Visit Venice During Acqua Alta Season?
If you want to visit Venice off peak during the winter months then chances are you’re running the risk of experiencing the Acqua Alta. I visited in November and although we saw some flooding it didn’t affect our trip at all. However, I’ve got to say we were lucky with that. Just two weeks before our trip Venice was hit by the worst flooding in 50 years.
There are massive perks to visiting during the winter months – the lack of tourists, the cheap accommodation and beauty of the quiet winter mornings to name a few. But if you are visiting during the months of the Acqua Alta it’s important to plan.
How To Plan For the Acqua Alta
The Acqua Alta is worst during the full moon or half moon. This is because the tides are in line with the moon. You can look at these dates in advance and I’d recommend you avoid them. Choose dates either a week before or week after a full moon or new moon.
The high tides can also be predicted several days in advance so if worst came to worst you could cancel or rearrange your trip. A normal tide is up to 80cm. Anything over that Venice may flood. The table below shows the percentage of Venice that floods at each tidal range.
| Level of tide | Percentage of Venice flooded |
| Up to 80 cm | Normal tide |
| 100 cm | 4% |
| 110 cm | 12% |
| 120 cm | 35% |
| 130 cm | 70% |
| 140 cm | 90% |
Flooding at the top end of this scale is very rare so even if a high tide is predicted it’s likely you won’t have too many problems. In November we experienced a high tide of about 106cm and it just got a bit puddly. I live in the UK. I’m used to puddles. It really won’t affect your trip.
How To Prepare
Venetians are well used to the Acqua Alta so don’t expect to visit a city that’s completely unprepared. During the Acqua Alta in Venice boardwalks are laid out around the city in the areas that flood the worst. You can find maps online and around the city which show where these boardwalks are. This means you can still navigate your way around without too much trouble, even if the water is thigh high.
And don’t forget, not all of Venice will be underwater. The worst hit areas are St Mark’s Square, the Doge’s Palace and the lowest lying parts of San Marco. Much of Venice doesn’t really flood at all.
If you are expecting flooding during your stay then I recommend taking wellies with you. Alternatively you are able to buy plastic boot covers in Venice but some places are very overpriced. You also might struggle to find a pair that fit if you have larger feet.
Is the Acqua Alta in Venice Dangerous?
The Acqua Alta in Venice isn’t a danger. The flooding is slow. It comes through the drains and cracks in the pavement. No one has drowned even during the worst floods. At most it’ll be an inconvenience to your trip.
Summary of the Acqua Alta in Venice
Venice is still definitely worth visiting during the season for the Acqua Alta. Don’t let the new stories and the scaremongering put you off. The high tides are predictable so Venice will be prepared. As long as you are too, you won’t have a problem.
Are you planning a trip to Venice in the winter? Have you been and experienced the Acqua Alta for yourself? Let me know!
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This is a fascinating read. I didn’t realise that it was such a thing. It might almost be more interesting to visit Venice again just to see how they deal with this.
I agree, well worth another visit to see what’s changed!
Wow, I didn’t realize it was normal for things to flood (and that last year was just a really bad version of a yearly flood)
I do love Venice, if I go back in November I’ll be sure to bring wellies.
It’s really sad. We can only hope the flood defences they are building work and can preserve the city.
Wow! So the most recent flooding was just exceptionally worse than other years. How scary. I have never been Venice before. Maybe I’ll avoid the Acqua Alta season, just in case. 😛
Yes exactly! I didn’t know much about it before this year too! Probably best to avoid if you don’t want to run the risk.
Great post! I was lucky enough to visit Venice in May, so I avoided all the flooding last year.
Krystianna @ Volumes and Voyages
I bet that’s a great time to visit! Hope you had a great trip!
Oh, now I know, about the flooding and high tides. Wonderful article. Keep it up!
Thank you!
This is good advice. I went to Venice a few years back in mid-June but would love to return in the off season. But flooding has concerned me. I didn’t realize that much of the city is not as prone to the high waters. Good to know!
Glad to have helped! I hope you have a great time if you do visit off peak!