Climate change means future floods are hard to predict

The frequency and size of riverine flooding is expected to grow in future. However, the influence of climate change on flood risks is uncertain due to Queensland’s short history of collected flood data. For example, gauge records in the Lockyer Valley indicated that the 2011 peak was predicted to recur on average once every 2,000 years or more. After 2011, this reduced to 75 years. If emissions continue to rise, the probability of major flood events occurring essentially doubles, meaning a 1% AEP event in 2050 will be equivalent to a current day 0.5% AEP event. 

The Big Flood (2016) The big flood: Will it happen again? Final Report 

QFES (2022) Queensland 2021/2022 State Disaster Risk Report

Image: Melbourne Street, South Brisbane, 1974. Credit: Christa Gerard.