Introduction Cardno were commissioned by Shoalhaven City Council to undertake the Floodplain Risk Management Study and Plan for the Broughton Creek catchment. The catchment is approximately 518 km2 in size and surrounds the township of Berry on the NSW south coast. The study has been undertaken to define the existing flooding behaviour and associated hazards, and to investigate possible mitigation options to reduce flood damage and risk. The tasks were undertaken alongside community consultations to ensure that community concerns were addressed. In the past, flooding in the catchment has caused property damage and posed a hazard to residents. Significant flood events occurred in 2011, 2005, 2002, 1988 and 1974. A flood study was previously prepared that identified the flood behaviour in the study area (SMEC, 2008). An update has subsequently been undertaken in this study to improve the definition of the flood behaviour in the Berry Township, and in the areas immediately adjacent to the township. Details on the update and outcomes of the study are provided in Appendix B through Appendix E. Flooding was assessed for the 50% AEP, 20% AEP, 10% AEP, 5% AEP, 2% AEP and 1% AEP events, as well as the Probable Maximum Flood (PMF). Flood levels, depths and velocities were determined, as well as provisional hazard categories, and hydraulic categories. From the base case results, a number of flood mitigation options were examined to manage flooding within the Broughton Creek catchment. The identification and examination of these options was done in accordance with the NSW Government Floodplain Development Manual (NSW Government, 2005).

INTRODUCTION The Tabourie Lake Flood Study has been prepared for Shoalhaven City Council (Council) to define the existing flood behaviour in the Tabourie Lake catchment and establish the basis for subsequent floodplain management activities. This project has been conducted under the State Assisted Floodplain Management Program and received State financial support.

This report documents the Burrill Lake Floodplain Risk Management Study and Plan which investigates and presents a flood risk management strategy for the catchment. The study identifies the existing flooding characteristics and canvasses various measures to mitigate the effects of flooding. The end product is the Floodplain Management Plan, which describes how flood liable lands within the Burrill Lake catchment are to be managed in the future.

Cardno were commissioned by Shoalhaven City Council to undertake the Floodplain Risk Management Study and Plan for the Nowra and Browns Creeks catchment. The study has been undertaken to define the existing flooding behaviour and associated hazards of the study area, and to investigate possible mitigation options to reduce flood damage and risk. The tasks were undertaken alongside community consultation to ensure that community concerns were addressed. This report details the proposed implementation strategy for the flood risk management options identified in the Floodplain Risk Management Study (Cardno, 2015).

A Floodplain Risk Management Study and Plan (FRMS&P) for the Beverley Park catchment has been prepared by Cardno Lawson Treloar for Kogarah Council. The FRMS&P identify and examine options for the management of flooding within the Beverley Park catchment floodplain and is prepared in accordance with the NSW Government Floodplain Development Manual (2005). A locality plan can be found in Figure 1.1. The outline of the study area can be found in Figure 1.2. Study Context This study consists of the two stages of the multiple stages of the Floodplain Management process which includes:,

1 Introduction Cardno were commissioned by Shoalhaven City Council to undertake the Floodplain Risk Management Study and Plan for the Kangaroo Valley catchment. The study has been undertaken to define the existing flooding behaviour and associated hazards of the study area, and to investigate possible mitigation options to reduce flood damage and risk. The tasks were undertaken alongside community consultation to ensure that community concerns were addressed. This report details the flood damages assessment, the environmental, social and policy review, and the investigations undertaken into potential flood mitigation options. The findings of this report will be used to develop the Floodplain Risk Management Plan.

1.3 Overview of Report This Report (Volume 1) summarises the investigations and presents plans showing water surface profiles and the indicative extents of flooding. The Report is supported by three Appendices, which provide additional details on flooding patterns and are bound in Volume 2. Section 2 of the Report contains background information including a description of the catchments, a review of the data base available for the study and a discussion on the history of flooding in the two catchments. This led to the selection of the historic floods for calibration and testing of the RORB hydrologic model of Currambene Creek. Streamflows recorded at The Falls gauging station, together with pluviographic data recorded at the RAN Air Station at HMAS Albatross and daily rainfall data were used for this purpose. Appendix A provides further details of the calibration process. Section 3 deals with the derivation of design runoff hydrographs from the study catchments. The RORB runoff-routing program was adopted for this study. Models of the catchments of Currambene and Moona Moona Creeks were developed. This step involved the determination of design storm rainfall depths over the catchments for a range of storm durations, and conversion of the rainfall hyetographs to discharge hydrographs. Further details of this phase of the investigation are presented in Appendix B. Section 4 deals with the development of the hydraulic models of the main streams and their estuarine surrounds. The unsteady flow version of the HEC-RAS software was used for this purpose. There were no historic flood level data available for calibration of the hydraulic models. Accordingly, selection of model parameters required a detailed review of the engineering literature and previous studies of a similar nature undertaken by the Study Team, supplemented by sensitivity analysis. The results of model testing are presented in the first part of Appendix C. Section 5 details the results of the hydraulic modelling of the design floods using HEC-RAS. Results are presented as water surface profiles and plans showing indicative extents of inundation. Appendix C presents further details on the derivation of design flood information and contains diagrams showing zones of provisional high and low hazard on the floodplain for selected design floods events, categorisation of the floodplain into floodway and flood storage areas and tabulations of peak levels and flow velocities at each cross section in the hydraulic models. Section 6 summarises the flood study investigations and identifies several flood related issues on the tributaries of Currambene Creek which will require further study during the Floodplain Risk Management Study and Plan. Section 7 contains a list of References.

Middle Creek Floodplain Risk Management Study and Plan (2021)

Floodplain RIsk Management Plan to be read in conjunction with Floodplain Risk Management Study

This Floodplain Risk Management Study (FRMS) for Turo Creek, Pretty Beach, has been undertaken by Cardno Lawson Treloar for Gosford City Council to identify, assess and compare various options for the management of flood risk within the Turo Creek floodplain. The study has been undertaken in accordance with the NSW Government Floodplain Development Manual (2005). A locality plan can be found in Figure 1.1. The outline of the study area can be found in Figure 1.2. The report format follows the study methodology, which involved:,