Venice, Italy consists of 400 man made islands built on wooden pilings in a marsh around 1,500 years ago. The entire city has been subsiding since then and flooding is routine, so routine in fact that it has a name; the acqua alta. The Wikipedia article about the acqua alta features a photograph from inside the city council building that shows engraved lines with dates next to them on a marble wall from previous floods over the years. I guess it’s time to hire a stone carver to put another one on there. The worst flood since the accurate recording of water levels was begun in the 1920s occurred in 1966.