What is the probable maximum flood PMF?

It is caused by a perfect storm generating the probable maximum precipitation.

This is the maximum theoretical physical limitation of how much water the atmosphere can dump in a given location.

Its probability:

1-10k years to One in 1 Million years

A similar order of probability to a large meteorite strike

It’s a useful tool. But the problem is that councils are increasingly pushing to use it as the base design case for developments.

Thankfully, you can push back on this. Recently, NSW Land and Environment Court Commissioner Gray went so far as to say it is the “quintessence of de minimis”.

A more suitable risk assessment max is the PMP Flood.