Background

Narromine Shire Council, through its Floodplain Management Committee is undertaking a Floodplain Risk Management Study and Plan for the town in accordance with the New South Wales Government's flood prone lands policy and using procedures set out in the Floodplain Development Manual, 2005. The results of the Study and the draft Plan are presented in this report.

The Floodplain Risk Management Study used the data from the recent Narromine Flood Study (LACE, 2006) to undertake a review of the physical, social and economic aspects of flooding on the Macquarie River floodplain at Narromine in order to prepare the draft Floodplain Risk Management Plan.

The Floodplain Risk Management Study summarised present day flooding conditions as determined by the LACE, 2006 investigation and identified and assessed potential measures aimed at reducing the impact of flooding on both existing and future development. This process allowed the formulation of a draft Floodplain Risk Management Plan for Narromine having regard to both existing flooding problems and to potential future development.

Overview of Report

The Floodplain Risk Management Study and draft Plan are set out in this report. Contents of each section of the report are briefly described below:

• Section 2, Baseline Flooding Conditions. This section includes a general description of the Macquarie River catchment and a review of land use on the floodplain at Narromine. Social, economic, physical and ecological aspects of existing flood behaviour are described. The section reviews existing flood management measures, including flood warning and evacuation practices.
• Section 3, Potential Floodplain Management Measures. Possible floodplain management options for Narromine are outlined and assessed.
• Section 4, Selection of Floodplain Management Measures. Floodplain management strategies comprising combinations of options are assessed in detail and a preferred strategy is outlined.
• Section 5, Draft Floodplain Risk Management Plan. The contents of the draft Floodplain Risk Management Plan are summarised.

The report is supported by four Appendices, which provide further details of the investigations leading to the preparation of the draft Floodplain Management Plan.

Appendix A sets out the results of a detailed investigation of damages likely to be experienced to residential, commercial and industrial property in Narromine in the event of major flooding.

Appendix B reviews the operation of Burrendong Dam as a flood mitigation storage during flood periods and its impact on downstream flooding.

Appendix C sets out the draft Flood Policy for Narromine.

Appendix D contains several exhibits derived from the Narromine Flood Study, 2006 which have been included to assist the reader in understanding flooding patterns in Narromine.