What is the history of Brisbane's floods?

Answer 1

Four major floods have occurred in Brisbane.

The first was on 14 January 1841. This was the biggest flood of the Brisbane River since records began with the river being approximately 8.6 metres above the high tide mark. There was limited destruction to property as the town was still very young and undeveloped.

The next major flood began on 5 February 1893. These floods came within 7cm of the 1841 levels.

The worst floods in terms of death and loss of property occurred in January 1974 when tropical Cyclone Wanda developed into a rain depression that dumped hundreds of millimetres of rain on an already saturated southeast Queensland. This flood reached a height of 5.5 m. Since the construction of Wivenhoe Dam on the Brisbane River within a few years of this flood, Brisbane was believed to be flood-proof.

The most recent major floods to hit Brisbane occurred on 11 January 2011. On this date, the Brisbane River again broke its banks. The flood was the result of a La Nina weather pattern, together with the state being saturated by the rainfall resulting from a cyclone system that hit in the north on Christmas Day 2010. Wivenhoe Dam, which was designed to prevent any further floods, exceeded 160% capacity, requiring the release of a massive amount of water, comparable to the volume of Sydney harbour.