Cooks River Catchment Flood Study

BMT WBM was commissioned by Bankstown City Council to prepare a Flood Study for the Cooks\r\nRiver stormwater catchment. Similar studies were simultaneously commissioned for the Punchbowl,\r\nthe Georges Hall, the Lansdowne and the Miller Road stormwater catchments. The location of the\r\nCooks River stormwater catchment is shown in Figure 1-1.\r\n\r\nThe study has been undertaken under the direction of Bankstown City Council and their Floodplain\r\nManagement Committee. The Committee includes Councillors and Council staff, officers from the\r\nOffice of Environment & Heritage (OEH), the State Emergency Service and community\r\nrepresentatives.\r\nThe study investigates flood behaviour throughout the Cooks River stormwater catchment for existing\r\ncatchment conditions as at 2012. This includes the analysis of:\r\n\r\n* Flows within the underground pipe drainage network; and\r\n* Surface runoff across the catchment.\r\n\r\nA two-dimensional computer model was established for the catchment to analyse stormwater flood\r\nbehaviour under existing catchment conditions. The model provides information on the extent of flood\r\ninundation, flood depths and flood velocities throughout the catchment for design floods ranging from\r\nrelatively frequent events to more extreme floods. Full details are outlined in the Cooks River\r\nCatchment Flood Modelling Report, which is included as Appendix C.\r\n\r\nResults from this study will form the technical basis for the Floodplain Risk Management Study. The\r\nFloodplain Risk Management Study will identify areas of high flood risk and investigate options to\r\nmanage and reduce this risk. Assistance will be sought from the community to help identify these\r\nareas and to derive appropriate solutions during the subsequent study.\r\n\r\nThe flood model developed during this study will provide Council with a valuable tool to assess the\r\nfuture development in the catchment.\r\n\r\nThe main outcomes from this study include:\r\n\r\n* A database of all public drainage assets within the study area;\r\n* Establishment of a computer model capable of assessing flood behaviour;\r\n* Information on flood behaviour under existing catchment conditions;\r\n* Indicative information on drainage asset performance for various storm events;\r\n* A property database including surveyed floor levels, flood levels and the resulting floor level\r\nimmunity, expressed in the magnitude of a storm event;\r\n* Predicted change in flood behaviour due to the potential impacts of climate change; and\r\n* A model that can be used to assess flood mitigation options and future development proposals.\r\n