Powells Creek Flood Study
EXECUTIVE SUMMARY BACKGROUND Powells Creek is a small southern tributary of the Parramatta River and Saleyards Creek is the major tributary of Powells Creek (Figure 1). The total catchment area of Powells Creek to Homebush Bay Drive is 8.1km2 and Saleyards Creek to the confluence with Powells Creek is 3.2km2. The Powells Creek catchment is in Sydney’s Inner West region, approximately 12 kilometres west of the CBD. The catchment includes the suburbs (or parts) of Burwood, Concord West, Homebush, Homebush West, North Strathfield, Strathfield, and Rookwood (cemetery). Approximately 77% of the catchment is within the Strathfield Municipal Council (SMC) local government area (LGA), 15% is within City of Canada Bay Council LGA, 5% is within Burwood Council LGA and 3% (Rookwood cemetery) within Auburn LGA. Saleyards Creek is predominantly within the SMC LGA, apart from Rookwood cemetery. The Powells Creek catchment drains to Homebush Bay on the Parramatta River via an open channel. Sydney Water Corporation (SWC) owns the larger “trunk” drainage assets including the open concrete lined channel with the smaller pipe and pit networks owned by the various councils. The study area of this Flood Study is that part of the City of Canada Bay LGA within the Powells Creek catchment. OBJECTIVES The purpose of this Flood Study is to identify mainstream and overland flow flooding (assumed as where there is no defined channel) to define the existing flood liability within the City of Canada Bay part of the catchment. This objective is achieved through the development of a suitable hydrologic and hydraulic modelling platform that can subsequently be used as the basis for a future Floodplain Risk Management Study and Plan for the study area, and to assist Council when undertaking flood-related planning decisions for existing and future developments. This project involves conducting a flood study: •
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Which is a comprehensive investigation of flood behaviour that provides the main technical foundation for the development of a robust floodplain risk management plan. It aims to provide a better understanding of the full range of flood behaviour, risks, and consequences in the study area. It involves consideration of the local flood history, available collected flood data, and the development of hydrologic and hydraulic models that are calibrated and verified, where possible, against historic flood events and extended, where appropriate, to determine the full range of flood behaviour.
FLOODING HISTORY From the flooding history it must be noted that the drainage characteristics of this catchment have been significantly altered because of urbanisation and as such older flood extents and depths for
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