What is a 1 in 100 year flood?
A 1 in 100 year flood (commonly known as a 100 year flood) is a large flood that has a 1% chance of occurring in any year. If an area has experienced a 1 in 100 year flood in a certain year, it does not mean that there is no chance of another 1 in 100 year flood occurring in the next 99 years. In fact, some parts of NSW have had more than one of these floods in a single decade.
