The Eastern Australian Floods of February 2022 and Its Relationship with Climate Change

Abstract

During February 2022 major riverine flooding occurred in an area which has the fastest population growth in Australia. This extended from the Mary River in Southeast Queensland (SEQ) to the Clarence River in Northeast NSW (NENSW). Two centres within this area were devastated by floods unprecedented in living memory. One was the Brisbane Metropolitan area where all-time record daily rainfall in the suburbs flooded creeks. This creek flooding was much worse than that caused by the Brisbane River itself where Wivenhoe Dam played a role in preventing more disastrous flooding. The other was in the Northern New South Wales city of Lismore where rainfall in the Wilsons River catchment exceeded all known rainfall rates there. The structure of the weather system generating the rainfall responsible for these two floods is studied along with the climatology of such events. One event which occurred during 1954 stands out and is examined in detail. A climate shift in 1976 resulted in two decades of relatively benign weather in the region and tourism flourished there due to mild summers and warm winters. The area experienced a huge growth in population with fading memories of past disastrous weather events and huge residential development occurred in flood plain areas. During the twenty-first century these extreme events have returned although so far not as frequent as earlier decades but still result in some residents experiencing multiple flooding events. The 1954 event occurred during an extended period of devastating flood events not experienced in recent decades. With the huge increase in population in this area since the 1970s such a series of events like those in the 1950s would stretch the resources of disaster managers given the problems, they faced in 2022.