Acqua Alta or High Water: Venice comes straight to mind. But what is it in reality? When does it happen? What are the causes? And most importantly what should we do when it happens? Here is some information that can be useful so that you aren’t left “soaking” during your Venetian stay.
Venice is sinking?
It hasn’t happened yet thankfully. Even if the level of water of all seas are rising and Venice in particular, in part due to natural causes and in part due to mankind’s lack of future planning, “lowers” every year a little. The high water phenomenon has always hit the city. But that doesn’t mean something shouldn’t be done to help avoid worsening the situation.
When does high water happen?
The moment you will find yourself in front of flooded alleyway or Campielli in autumn and winter, but there can be some episodes even “out of season”. The factors are two: the astronomic tides (or really the influx of the moon on the sea) and the meteorological contribution (that is particularly tied to the Sirocco and Bora winds).
The city submerged in water: here’s how and where
the first area to finish under water in these circumstances is also the most well-known: St. Mark’s Square. Like a big artificial lake, the piazza floods enough to reflect the marvelous facades of the surrounding palaces. Generally, with 100 cm of high tide, 5% of the city is submerged by water; with 130 cm almost half of the city is flooded by water.
Foreseeing High Water
Every time High Water is announced it doesn’t mean it will have the same intensity. There are lower tides that are high enough to flood some parts of the city (more frequent) while there are higher more dangerous tides; overall there are three levels: high (up to 109 cm) very high (up to 139 cm) and exceptionally high (above 140 cm). If you unexpectedly hear a siren similar to the air raid sirens while walking along the city or placidly sleeping in your apartment, don’t worry Venice isn’t under attack. Instead it is probable that in three hours or so you will encounter high water of a certain measure (even here based on the sounds the siren emits 1,2, or 3, you can decipher the level of the high tide). In any case, you can visit the Centro Maree or Tide Center site or download the APP Hi!Tide Venezia to always be updated.