The 1974 Brisbane flood occurred in January 1974 in Brisbane

Brisbane

Brisbane is the capital and most populous city in the Australian state of Queensland and the third most populous city in Australia. Brisbane's metropolitan area has a population of over 2 million, and the South East Queensland urban conurbation, centred around Brisbane, encompasses a population of...

, Queensland

Queensland

Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...

, Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

, when waterways in the city experienced significant flood

Flood

A flood is an overflow of an expanse of water that submerges land. The EU Floods directive defines a flood as a temporary covering by water of land not normally covered by water...

ing. The Brisbane River

Brisbane River

The Brisbane River is the longest river in south east Queensland, Australia, and flows through the city of Brisbane, before emptying into Moreton Bay. John Oxley was the first European to explore the river who named it after the Governor of New South Wales, Thomas Brisbane in 1823...

, which runs through the heart of the city, broke its banks and flooded the surrounding areas.
It had been an exceptionally wet spring, and by the end of October most of southern Queensland's river systems were nearing capacity. Cyclone Wanda pushed the systems to the limit, and drew the monsoonal trough

Monsoon trough

The monsoon trough is that portion of the Intertropical Convergence Zone which extends into or through a monsoon circulation, as depicted by a line on a weather map showing the locations of minimum sea level pressure, and as such, is a convergence zone between the wind patterns of the southern and...

 southward, providing the additional rainfall to the Brisbane River

Brisbane River

The Brisbane River is the longest river in south east Queensland, Australia, and flows through the city of Brisbane, before emptying into Moreton Bay. John Oxley was the first European to explore the river who named it after the Governor of New South Wales, Thomas Brisbane in 1823...

, Bremer River and Stanley River

Stanley River (Queensland)

The Stanley River in Queensland is the main tributary of the Brisbane River. The Stanley River valley extends roughly 35 km westwards from the area south of Maleny to Kilcoy before veering southwards....

 catchments to produce widespread and severe flooding.