Swan and Helena River Flood Study (Hydraulics) and Floodplain Management Plan

A comprehensive study of the flood behaviour and flood risk of the Swan and Helena Rivers and preparation of a floodplain development strategy.


Client: Eastern Metropolitan Regional Councils

The Perth region has not experienced major flooding in recent memory, however there is potential for flooding in the city due to its coastal location at the base of a very large catchment. This study sought to develop information about flood behaviour and risk to support government, planners and the public make informed decisions in the management of flood risk.

BMT was commissioned to develop and calibrate a hydraulic model of the lower catchment, prepare flood mapping of a full range of potential flood sizes, estimate the regional flood risk, and prepare a floodplain development strategy to guide future floodplain development and risk management actions.

Outcomes and Benefits

The Perth region now has a fully calibrated hydraulic model using best-practice approaches (including ARR16), providing a high-degree of confidence in modelled flood behaviour. This model can be used for future flood assessments including infill development and infrastructure in the floodplain.

Outputs from the flood risk assessment process are being used by councils and the State Government to help understand their full range of flood risk and to inform flood management actions which will ultimately lead to a safer, more resilient community.

Services and Expertise Provided

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