When did the Australian flash floods begin?

Answer 1

Only one major flash flood has occurred in Australia. This was the flash flood that began in Toowoomba on 10 January 2011, and made its way down the Toowoomba Range, swamping the towns at the base of the range, resulting in at least 12 deaths.

The remainder of the state has experienced a slow-onset flood, although there have been some fast-onset floods in some regional centres. Slow-onset floods last for weeks.