Anyone interested in seeing what an acqua alta looks like, there's one going on now (07:00 PDT, 10/28/18). Here's a link to a webcam.
For those who didn't know (like me), "Acqua alta, or “high water” is a natural seasonal phenomenal in Venice, Italy during which the high tide partially floods the city." See https://veneziaautentica.com/acqua-alta-venice/
And another webcam from a different spot:
https://www.skylinewebcams.com/en/webcam/italia/veneto/venezia/riva-schiavoni.html