HIGH TIDE IN VENICE
Acqua alta, or “high water,” can make Venice feel like Atlantis.
On Tuesday, November 12, the island of Venice was hit by severe flooding (the second highest ever recorded). Venice Marco Polo Airport remained open, but vaporetto services and regular public transportation by sea were interrupted. Tourist attractions were closed on the day of the event.
This blog is about what happens during Acqua alta, and reassure you that it was an exceptional event, due to the coincidence of many factors.
Let me explain what happens during high tide.
Why (and when) acqua alta floods the city:
Acqua alta occurs when certain events coincide, such as:
- Una marea molto alta (di solito durante la luna piena o nuova).
- Low atmospheric pressure.
- A sirocco wind blowing across the narrow, shallow Adriatic Sea, pushing water into the Venice Lagoon.
- By official definition, acqua alta occurs when the tide is 90 cm (35.4 inches) above normal high tide. Always remember that the lowest point in Venice is not below the water level, it is about 80 cm above the water level.
- The phenomenon is most likely to occur between late September and April, and especially in the months of November, December and October, in that order. However, thanks to global warming, it can now occur at any time of year.
- Not all areas of the city are equally exposed to flooding, as the following graph from the Municipality of Venice indicates. Furthermore, the actual depth of water in the streets is much lower than the “tide level” might suggest. (See the “extreme case” below, where 135 cm of flooding translated into 40 cm of water in St. Mark’s Square.)
An extreme case:
The worst flood in Venice’s history occurred in 1966, when the flood reached 194 centimeters. The second-worst was in November 2019, when the waters reached 187 centimeters. Fortunately, the city has made changes over the years to ameliorate the effects of high water. For example, electrical substations have been moved out of harm’s way, and ground-floor wiring is now installed high enough on the walls to prevent short circuits in most cases. Thanks to these changes, the 2019 floods did not cause massive power outages (which left the city without electricity for days in 1966).
What to expect during acqua alta:
In most cases, acqua alta is only a minor nuisance: you may have to avoid a pool or two in Piazza San Marco or avoid water splashing onto a fondamenta, or sidewalk, near a canal.
However, if you hear a siren, be prepared for more serious flooding, especially in low-lying areas of the historic center. A siren means that an unusually high tide will peak in three to four hours. Depending on the height of the acqua alta and where you are in the city, you may experience flooding for several hours before and after the peak tide. Such flooding can range from a few centimeters to a major inundation.
The city provides elevated wooden walkways in areas of the city that are prone to flooding; you can see a map of these pedestrian walkways at most ACTV vaporetto stops.
How to prepare:
If you plan to spend time in Venice during the fall and winter months, you may want to pack wellies, especially for visits around the full or new moon, when high water is most likely to occur. Alternatively, consider packing several plastic garbage bags and string or rubber bands to hold them in place. Garbage bags may not be fancy, but they can help keep your shoes and legs dry.
Another option is to buy wellies in Venice or purchase temporary plastic rain boots from souvenir stalls and street vendors.
Tip: For rubber or plastic rain boots, try Ratti, which offers an excellent selection of men’s and women’s wellies in a variety of sizes. The historic hardware and home goods store is just a few minutes’ walk from Piazza San Marco.
Again, high water is unlikely to be more than a minor annoyance during your stay, and it is not life-threatening and tourists usually love it for the different and incredible atmosphere.
hi!tide Venice App (Android or iOS): Download the free and official Venice tide forecast app for iPhone or Android for your smartphone.
Low tide
Low tide occurs when the water level is around half a meter.
Low tide leaves the canals of Venice almost dry, boats are beached while the water level drops dramatically.
The canals look more like mud pits and moving around by boat could become a problem.
However, low tide is a truly exceptional event.
What is the situation at this moment?
Venetians are used to high water and, despite the exceptional situation that occurred last November, business has returned to normal in a short time. Museums and institutions are all open again and the famous Venice Carnival will take place as planned, from 8 to 25 February 2020. We understand that the situation has been exaggerated by the media.
Now we are waiting to welcome you to our majestic and unique city!