Vol-1C Chapter-18 Flooding-and-drainage

Previous chapter: Vol 1C Chapter 17 Contamination

Vol 1C Chapter 18 Flooding and drainage

hi-res pdf: New M5 EIS Vol 1C.pdf

Low-res pdf: New M5 EIS Vol 1C Chapter 18 Flooding and drainage.pdf

Section Pages
18 Flooding and drainage 18-1
18.1 Assessment methodology 18-1
18.2 Existing environment 18-3
18.3 Assessment of potential impacts 18-15
18.4 Environmental management measures 18-33

Appendix: Vol 2G App P Flooding

Next chapter: Vol 1C Chapter 19 Groundwater

Advertisements

Vol-2G App-P Flooding

Chapter: Vol 1C Chapter 18 Flooding and drainage

Appendix Vol 2G App P Flooding

Hi-res pdf: New M5 EIS Vol 2G App P Flooding.pdf

Low-res pdfs:

Section Pages
  EXECUTIVE SUMMARY 1
1. INTRODUCTION 1
1.1 Overview of WestConnex 1
1.2 Overview of the project 2
1.3 Project location 4
1.4 Secretary’s Environmental Assessment Requirements 4
1.5 Study area 4
1.6 Report structure 5
2. STATUTORY AND POLICY CONTEXT 7
2.1 Relevant Government policies and industry guidelines 7
2.2 Floodplain Development Manual 8
2.3 State Government planning directions and guidelines 8
2.4 State Government floodplain risk management guidelines 9
2.5 Flood related planning controls 11
3. ASSESSMENT METHODOLOGY 15
3.1 Key tasks 15
3.2 Definition of present day flooding behaviour 15
3.3 Sensitivity analyses 16
3.4 Comparison with findings of previous studies 16
3.5 Provisional flood hazard 16
3.6 Impact of the project on flooding behaviour 17
3.7 Impact of flooding on the project 17
3.8 Impact of a partial blockage of major hydraulic structures on flooding behaviour 17
3.9 Impact of future climate change on flooding behaviour 18
4. EXISTING ENVIRONMENT 19
4.1 Catchment description 19
4.1.1 Cooks River 19
4.1.2 Upper Wolli Creek 19
4.1.3 Sheas Creek / Alexandra Canal 19
4.2 Description of existing flood behaviour 19
4.2.1 Upper Wolli Creek floodplain 19
4.2.2 Lower Cooks River floodplain 21
5. FLOOD RISK ASSESSMENT 23
5.1 Overview 23
5.2 Impact of the Project on flood behaviour 23
5.2.1 Upper Wolli Creek floodplain 23
5.2.2 Lower Cooks River floodplain 24
5.3 Impact of flooding on the project 25
5.3.1 Upper Wolli Creek floodplain 25
5.3.2 Lower Cooks River floodplain 26
5.4 Impact of a partial blockage of major hydraulic structures on flood behaviour 26
5.5 Impact of future climate change on flood behaviour 26
5.5.1 Potential increase in rainfall intensities 26
5.5.2 Sea level rise 27
6. ASSESSMENT OF POTENTIAL FLOOD MITIGATION MEASURES 39
6.1 Proposed flood mitigation strategy 39
6.2 General flood mitigation requirements 39
6.3 Upper Wolli Creek floodplain 41
6.3.1 Flooding in existing residential development 41
6.3.2 Flooding in existing commercial/industrial development 41
6.4 Lower Cooks River floodplain 41
6.4.1 Flooding in existing residential development 41
6.4.2 Flooding in existing commercial/industrial development 42
6.4.3 Flooding in TransGrid’s Beaconsfield West Substation 42
7. REFERENCES 43
APPENDIX A. Background to Development of Wolli Creek Flood Models A
APPENDIX B. Background to Development of Lower Cooks River Flood Models B
APPENDIX C. Tables of Peak Flows C