Generally speaking, a worldwide flood could have occurred at the end of the last ice age - at least in the northern hemisphere and I think it would have been about 50,000 years ago
Whoops - about 11.5 - 12000 years ago
Canadian ice sheets broke up about 13,000 to 14,000 years ago. Dogerland flooded, the Seine valley because the English channel, the Mediterranean, then the Black sea flooded. (There ruined buildings under both the Black See and the North Sea.)