There are a number of reasons for flooding.
After a thunderstorm,especially in areas where such thunderstorms are not expected to happen and hence high surface run off, causing flash floods.
during flood season in flood zones
summer
a black out
Floods are most common during spring and summer
a blackout
japan
Along the coastl lines
They mostly happen in south America or in Mexico where the land is dry is where the floods occur.
mostly in open areas
in your mom's bathroom
Most likely in the Americas