Ãë²¥

Lota Creek Catchment Flood Study Update

After a major flood event, Brisbane City Council undertook a review of flood studies in their local government area (LGA). They engaged our team to update the Lota Creek Catchment Flood Study in line with Australian Rainfall and Runoff (ARR) 2019 Guidelines, and Council¡¯s Flood Study Procedure Manual.

We performed hydrological model development and calibration using up-to-date software to replace the model from the old study. This helped us simulate ultimate catchment conditions within the model based on the City Plan, calibrated to five historical flooding events.

Next, our team created a new hydraulic model development and calibration using newly built TUFLOW modeling, which includes a sub-grid sampling feature. Using outputs from the old model, we jointly calibrated the new model to the same historical events and undertook consistency checks between the models to produce comparable results. We also conducted a design even analysis using a variety of frequent, intermediate, rare, very rare, and extreme events.

Based on results from the event modeling, we generated a variety of outputs that included detailed mapping of processed results and tabulated data for multiple events. This covered peak flood levels and hydraulic structure flows. Our team also produced hydraulic structure reference sheets detailing results for individual structures within the catchment.

With an updated study, Brisbane City Council are now better prepared to address and respond to future flooding events.