Flood management in the Parramatta River Basin has been a challenge due to varying standards of protection and multiple authorities involved. In 1974, a coordinated approach was initiated to address flood problems in the entire catchment area. Detailed engineering investigations were conducted to understand the flood risk and propose mitigation measures. These measures, including structural works and planning regulations, aim to protect against a 100-year flood event. The results indicate that once these proposed measures are completed, the flood protection objective is expected to be significantly achieved.