water bomb

This is often called a "water bomb", where the upstream country can temporarily hold back water and then release it suddenly, without warning, causing massive damage downstream.

“It wasn’t a water bomb, it was a tsunami,” Barbara Mayor Riccardo Pasqualini told Italian state radio, describing the sudden downpour Thursday evening that devastated his town in the Marche region near the Adriatic Sea.

Local authorities said they did not expect such a sudden “water bomb”, as around 400 millimetres of rain fell within two to three hours, inundating the streets of several towns in the Ancona and Pesaro-Urbino provinces.

In Ardennes towns like Chaudfontaine and Pepinster, life will take years to rebuild what was swept away in hours on July 14, 2021, as a “water bomb” spread misery through much of eastern Belgium and parts of western Germany.

A helicopter was brought in to "water bomb" the area as smoke drifted as far as Bournemouth.