The Big Flood: Will It Happen Again?

The Big Flood discusses the frequency and causes of extreme flood events to be used for social and economic planning and environmental protection in southeast Queensland (SEQ). This project contributes to the improved understanding, prediction and management of extreme flood events in the Lockyer Valley and broader SEQ region. 

The project involved the following three major aims:

• The reconstruction of a time series of major flood events extending back more than 1000 years;
• The prediction of river channel and floodplain geomorphic susceptibility to floods and identification of areas of high risk;
• The incorporation of research findings into climate change predictions, water quality protection and river management in Australia. 

Model results highlight two important processes for which strategic riparian vegetation management can play an important role in flood mitigation. The report argues that the absence of a coordinated strategic approach is a missed opportunity to integrate flood risk mitigation with other elements of catchment management. 

The conclusion will hopefully encourage state governments and councils to open a new dialogue on future changes to flood management. Fact Sheets, over 30 scientific peer-reviewed papers, and the final report now form a sound basis for future change. Consistently defining floodplain types, spill out zones, locations of high stream power and aligning management actions with the right erosion process will take SEQ a long way to better flood hazard management and downstream water quality protection.