Introduction
Penrith City Council, through its Floodplain Risk Management Committee and Advisian Pty Ltd, has completed a Floodplain Risk Management Study for those sections of South Creek that fall within the Penrith local government area (LGA). The Committee includes representatives from the local community, Councilors, Council Staff, NSW Department of Planning Industry and Environment (DPIE), State Emergency Services (SES), Infrastructure NSW and neighboring Councils. The Floodplain Risk Management Study was prepared in accordance with the NSW Government’s Flood Prone Land Policy and guidelines outlined in the NSW Government’s ‘Floodplain Development Manual’ (2005).
The Floodplain Risk Management Study documents the outcomes of a detailed assessment of the viability of a range of potential floodplain risk management options. These options were identified in consultation with the Committee and the broader community and were targeted toward reducing existing and potential future flooding problems.
The Study also provides information on a range of flood characteristics critical to land use planning including peak flood levels, flood hazard, hydraulic function and the pattern of floodwater movement during floods of varying severity. This data has been used to map Flood Planning Constraints Categories (FPCC) which can be applied with other planning constraints to optimally manage future land use.
In this regard, the Study also considered the suitability of Council’s existing planning instruments and the existing State Emergency Services (SES) Sub-Plan for the study area. The Study provides guidance for changes to these plans and policies aimed at ensuring that land use controls are consistent with the predicted flood risk and flood hazard, and to ensure that the risk to life can be minimised.
The Study Area
South Creek is a tributary of the Hawkesbury-Nepean River that drains a 414 km2 catchment in western Sydney. The South Creek catchment extends from its headwaters near Narellan in the south, to its confluence with the Hawkesbury River near Windsor. South Creek generally flows from south to north through the catchment with the commercial centres of Penrith and Blacktown located to the west and east, respectively. Large areas of the catchment have been urbanised particularly in the vicinity of these commercial centres.
Ropes Creek is a major tributary of South Creek that falls within the Penrith City Council Local Government Area (LGA). Minor tributaries that also fall within the Penrith LGA include Werrington, Claremont, Blaxland, Cosgroves and Badgerys Creeks.
Stage 1 (Data Collection) and Stage 2 (Flood Study) of the NSW Floodplain Management Program were completed by Worley Parsons Pty Ltd in 2015. The document herein presents Stages 3 and 4 of the NSW State Government’s Floodplain Management Program; the South Creek Floodplain Risk Management Study and the South Creek Floodplain Risk Management Plan.
Study Objectives
The primary objective of the floodplain risk management process is for Council to formulate a Floodplain Risk Management Plan for the study area. The Plan is to be based on a range of strategies and mitigation measures that address the existing, future and continuing flood problems, in accordance with the NSW Government’s Flood Prone Land Policy. Therefore, this Floodplain Risk Management Study sets out to:
- Identify and evaluate management options for the floodplain in terms of their capacity to reduce existing and potential future flooding problems;
- Provide information on flood behaviour and flood hazard, so that community aspirations for future land use can be assessed on a consistent basis;
- Provide recommendations for emergency response management during local catchment flooding; and,
- Provide a framework for revisions to planning instruments such as Local Environmental Plans (LEPs), so that land use controls are consistent with flood risk and flood hazard.
Community consultation and public exhibition was undertaken as part of the floodplain management process. A flood questionnaire survey was sent out to more than 5,000 households within the study area to inform the community of the study, gather any additional flood information available, and assist in understanding community preferences in flood mitigation options.
