Floods bring to mind destruction, but the ecosystems of floodplains and estuaries depend on the occasional deluge, so each year the U.S. Army Corps of Engineers times the release of large volumes of water.
The MOSE Project, meant to protect Venice from floods, consists of a series of gates raised and lowered by caissons, isolating the lagoon from the sea and stopping the tidal flow.
A man using a mechanical digger involuntarily unearthed a Neolithic tomb. Unfortunately he had already dug up one end of the tomb in discovering it, and now the site is flooded.