Paradise Dam is located on the Burnett River approximately 80km south west of Bundaberg in Queensland.  The dam was completed in 2005 and provides water to the grazing and agricultural community. Flooding in 2013 led to concern that the dam’s stability could impact downstream communities. As an interim measure, the spillway was lowered.

To better understand the flood risk in the catchment and help to inform the dam improvement actions, Water Technology were engaged by Sunwater to use the established method called Palaeoflood Hydrology.  This is an interdisciplinary science of reconstructing the timing and magnitude of past large flood events that occurred prior to historical observations and systematic measurements (i.e. gauging).  Palaeological evidence (e.g. fluvial sediments) can extend short gauge records and provide vital information of past extreme events, which are often missing or inaccurately represented. This provides the opportunity to better account for the frequency and magnitude distribution of discharge records.

The project involved acquiring evidence of past floods to extend the timeline of extreme flood events preserved in the Burnett catchment including:

• Locating and sampling preserved flood sedimentary deposits at selected sites downstream of Paradise Dam.
• Dating the collected samples and constructing a timeline of past flood events.
• Reconstructing palaeoflood discharges of these deposits.
• Providing palaeohydrologic information for Flood Frequency Analysis.