Brisbane River catchment flood study
A flood study of the Brisbane River catchment has been completed using the best available information to assess the likelihood and impact of future floods on the Brisbane River catchment.
This is a key recommendation of the 2011 Queensland Floods Commission of Inquiry.
The study has delivered consistent and up-to-date technical flood data for local governments across the Brisbane River catchment, to help predict flood risk for individual properties.
The results were reviewed by an independent panel of experts to ensure they are robust and represent best practice. The data will also inform land use planning in South East Queensland.
The study, led by the Department of Natural Resources and Mines, was delivered in collaboration with other Queensland Government departments and the local governments of Brisbane, Ipswich, Somerset and Lockyer Valley, and Seqwater.
The Queensland Government engaged Aurecon Australia, partnering with Royal HaskoningDHV, Hydrobiology, Deltares and Don Carroll Project Management to complete a comprehensive hydrologic assessment as part of the study.
A hydraulic modelling specialist consultancy company, BMT WBM, undertook the comprehensive hydraulic assessment.
The comprehensive flood study comprises two major components i.e. hydrology and hydraulics. Both components are done with the aid of sophisticated technical models and up to date data/information for the catchment.
- Hydrology quantifies the volume of water draining from a catchment over time, taking into account the rainfall and catchment conditions.
- Hydraulics describes the physical behaviour of water as it moves over the land surface, floodplain and pipe network into the creek or river, and finally into the sea.
The results from the hydrologic assessments feed into the hydraulic assessment to determine flood parameters for the catchment including inundation depth, extent and water velocity. Together, the hydrologic and hydraulic assessments will provide important information to help better plan for and minimise the impacts of future floods in the Brisbane River Catchment.
The study area includes the Brisbane River catchment, with a focus on areas downstream of Wivenhoe Dam including Lockyer Creek, the Bremer River and major tributaries such as Oxley Creek.
Scope of investigation
The study represents a comprehensive technical investigation of Brisbane River flood behaviour and downstream effects. It will ensure that any future flood risk assessment takes into account the complex and variable nature of rainfall and flooding in the catchment.
The major output of the study is an up-to-date, consistent and agreed to set of hydrological and hydraulic models. These models were built on the existing work undertaken by the Brisbane River catchment councils, Seqwater and the State Government. These models have considered the lessons learnt from the recent floods. They have improved spatial coverage and took advantage of advances in computer modeling.
The study and its outputs are available for use by local councils and the public. The study will inform the development of a Strategic Floodplain Management Plan.
For more information about the Flood Study and Strategic Floodplain Management Plan visit the Queensland Reconstruction Authority.