Acqua alta or high water is a phenomenon which generally takes place in Venice in automn or winter time and is due to a combination of tidal water and strong winds from the south.
If you visit Venice during automn or winter the safest option is to choose a hotel in the upper part of town, close to the railway station or Piazzale Roma, and to avoid the areas close to Piazza San Marco.
When I visited in October 2012 I saw visitors struggling with luggage walking up to their thighs in water, and they did not seem to find it funny......
During acqua alta they sell plastic boots everywhere for a cheap price, and these boots can be pretty helpful if you have to walk through inundated areas of the town.
Venetians are used to carrying on their lives during times of Aqua Alta (High Water). Although most common between October and early March, It isn't unknown for it to occur at other times.
Raised platforms (passerelle) (pic 2) are placed at points most affected by the high waters, and are efficiently laid out by special teams of council workers (pic 5)
When using these, the idea is to keep to the right side of the platform, and keep walking.
Last Christmas (2010), the waters were especially high, and I endured the platforms along Lista de Spagna, which was quite nerve racking as people trundled along with their suitcases/rucksacks, some stopping to take photos!
Some hotels will loan out rubber boots, or you can purchase them quite easily - around 11 Euros for plain colours, to upto 50 Euros and above for the funkier designs. Street vendors sell plastic bags to fit over your shoes, but these aren't very useful.
As San Marco Piazza is one of the lowest parts of the island, it is one of the first places to experience 'flooding' especially around the main doorway of the Basilica (pics 1-3).
Water seeps up through the Squares pavement first - I've visited in June and September and have seen some flooding here.
On a plus side, you can take some interesting photos of the reflections of the buildings and lights.
There are also many places that you can walk and enjoy Venice that aren't affected by the Aqua Alta.
From December 7th 2007, a new digital sound transmitter system came into operation, to warn of imminent 'High Water' or Aqua Alta.
So, first a siren is used to alert everyone of the high tide alarm.
Next, a signal indicates the expected level of high tide - this signal has between 1 and 4 notes.
1 long sound (8 seconds) on the same note = 110cm level of high tide
2 sounds in an upward scale (4 + 8 seconds) = 120cm " " " "
3 sounds in an upward scale (4+4+8 seconds) = 130cm " " " "
4 sounds in an upward scale (4+4+4+8 seconds) = 140cm and above
So, you need to count the sounds, to know the expected level.
These signals are repeated several times.
Apparently these alerts can be sent by text message - I was wondering how those with hearing difficulties managed, now I know.
After the recent exceptional high waters I heard poor tourists scared by (probably very unprofessional) news coverage.
1) I heard of the flood... will be venice still be flooded next month?
2) I heard vaporetto doesn't work since the last flood 15 days ago, is it true?
Those are totally stupid questions IF you know more about the "acqua alta".
So, the municipality set up a Venice high tide FAQ.
These are the questions that are answered there
What's "acqua alta" (high water)?
When does an exceptional tide occur?
How long does an aqua alta last?
How often does "acqua alta" occur?
But how high can high water be?
Does Venice completely go under water when "acqua alta" occurs?
How many times in a year can a high water of + 110 cm occur?
What happens in Venice when there's a high tide?
How does water rise and fall in Venice?
What to do in Venice when there is "acqua alta"?
Follow the link below, learn how it REALLY is, and stop worrying... for a tourist 3 hours of high tide are more a fun than a problem.
You will have seen how an important part of Venice is covered with water often above 1 m high, with a maximum of 136 cm, in these first days of December 2010.
Tourists might think that Aqua Alta only happens in the winter. Not necessarily, it can even happen in the summer.
In the nineties we experienced high water in August, 5 -10 cm!
There had been strong raining for some days and one noon at the time of high tide we saw the water coming out of the pavement at the Piazza San Marco. Some streets were also under water just enough to get wet feet.
One expects the water to flow over from the canals but it gushes out of the spaces between the pavings.
When the tide turned to low all the water went back into the ground.
My friend Lisa happened to be in Venice last December when the city was badly affected by "acqua alta", the term used in Venice to describe partial flooding caused by exceptionally high tides. So I did know about this phenomenon, but I had no idea it was so common for water to accumulate around the Piazza San Marco area. As we were walking around the piazza one evening, we noticed that there was a bit of water in front of the basilica and nothing seemed to be going down the drain. We kept on walking and taking pictures for a while, and when we turned back to leave the piazza, it was almost entirely covered with water! It was only about one inch deep, but even that was too much for the shoes I was wearing so like many other women, I hitched a ride on my husband's back to make it across the puddle. And the funny thing is that when we walked past Piazza San Marco the next day, it was as if nothing had ever happened - the water was gone and there was no trace of the previous night's microflood. I guess it must take much more than a bit of water to prevent Venitians from going about their business!
When a very high tide combines with low atmospheric pressure and strong scirocco wind, there is the risk of Acqua alta, or "high water" (+ 90 mm above normal high tide.), first of all in the months of October, November, and December.
This is only a fun if you are prepared with wellies - but sometimes the flood is so high you need thigh-high waders or else you must be prepared to stay indoors until the tide lowers. Fortunately the flooding in Venice is tidal and will go down within 12 hours.
When there is going to be an exceptionally high tide, a siren is sounded over the whole city in plenty of time to warn you to get to where you need to be.
The most extreme acqua alta in 22 years, was on December 1, 2008, when the water level reached 156 cm and flooded more than 90% of the city.
In the near future the global warming may cause a bigger threat by the rising sea level. There are some projects on the way with the intention, to turn the Lagoon into a freshwater lake by closing off it from the sea.
The water level is measured in centimetres: when it’s over 80 cm you can see it over Saint Mark Square, this happens about 20 days in one year and usually during Fall Season.
All the main streets are practicable, thanks to board walkways, until the water rises over 120 cm, but that’s very very unusual.
Remember to bring a mosquitos repellent for your kid and copy how Venetians overcome bridges with the stroller.
I'll be in Venice with my little girl too :-)
In certain seasons Venice may become flooded by what is known as Aqua Alta. Please be careful where you walk.
The waters are known to get pretty dirty, use caution and make sure to wash any flood waters off you with fresh water.
It is also important to be considerate of the locals and allow them to continue protecting and preserving their property without disruption from the tourists. Many locals want you to stay and enjoy the beauty and shopping Venice affords but they must go about protection first. For more on aqua Alta please see my Intro to Venice.
Hmm, was not sure where to write this. I guess it 's more of the warning. As we all know Venice suffers from seasonal floods. So be prepared for stepping in lots of water or walking on the tables (which you may notices always on a side on every plaza and major street). So pack some good water proof shoes.
When the Adriatic is at high tide or there has been heavy rainfall, Venice suffers from high water levels(aqua alta). Particularly prevalent in the winter months. The lowest parts of Venice get flooded. The locals just don plastic sacks on their feet, held by elastic bands.
But not to worry - those umbrella vendors appear selling rubber boots instead.
Occasionally the water level rises above the level of the squares and streets flooding them. Acqua alta, or high water is likely to happen between late september and april; especially during the months of october, november and december.
When the city is flooded you can walk on the raised platforms that are placed for that purpose or buy a pair of rubber boots.
venice is under water more than half of the year and they`re very honest about it.
there`s even a small billboard by the docks on the side of the doge`s palace saying how many days in a year ( about 200 something).
expect the worst and hope for the best before going there.
and if you`re as lucky as me that the few days i was there san marco was dry, don`t forget to say your prayer of thanks.
On occassions, during winter especially, you will get the Aqua Alta in venice.
This is where due to the high tide the water rises to the extent of flooding the squares and walk ways. This is more of an issue around the low lying areas such as St Marks square.
However the local council is very well organised and wooden walkways are erected to enable the people to keep there feet dry.
One Dec 28th 2005 we took the following pics with a little flooding in St marks Square.
The website below gives forecast of expected water levels -
A sudden storm can catch you unaware in Venice and the water level can rise rather quickly. In this picture everyone is hiding around the Doges Palace after a sudden downpour which also left St Marks Square one foot deep in water.