Gladstone Regional Council commissioned WMS to update existing hydrologic and hydraulic models for Auckland Creek in accordance with the latest ARR requirements and undertake a new flood study of Auckland Creek. The most recent flood study was based on uncalibrated models and outdated industry guidance.
WMS collected bathymetric survey of Auckland Creek to improve the channel and wetland representation of the hydraulic (TUFLOW) model and extended the model domain further upstream. Once the hydraulic model was updated, two recent historical flood events were identified and the hydrologic and hydraulic models were jointly calibrated.
Following calibration, new design flows were derived using the latest ARR data and guidelines. The flows were validated to Regional Flood Frequency Analysis and Quantile Regression Technique. During this process it was identified that several technical deficiencies exist with the new guidance. WMS took extra time to investigate these issues and applied engineering judgement to ensure flood risks were not underestimated.