NSW coastal salinity audit NSW coastal salinity audit Geoffrey Beale Michelle Miller Paul Barnett Gregory Summerell Rachel Gilmore David Hoey NSW Coastal Salinity Audit Acknowledgments The assistance of Susana Realica and Humphrey Milford in preparation of data is gratefully acknowledged. Thanks to Jim Armstrong, Mitch Talau, Glen Atkinson, Scott Taylor, Adam Lillicrap, Alan Cibilic and Dave Morand for reviewing the draft hazard maps and to Richard Bush for his assistance in coordinating regional meetings and site visits. Published by: Centre for Natural Resources NSW Department of Infrastructure, Planning and Natural Resources Parramatta May 2004 NSW Government ISBN 0 7347 5405 1 CNR2003.64 NSW Department of Infrastructure, Planning and Natural Resources ii NSW Coastal Salinity Audit Contents Page Executive summary ................................................................................................................................x 1. Introduction................................................................................................................................1 1.1 The Audit Process..........................................................................................................1 1.1.1. Review of available data......................................................................................1 1.1.2. Analysis of stream salinity and flow....................................................................1 1.1.3. Salinity hazard mapping ......................................................................................2 1.1.4. Analysis of groundwater salinity data .................................................................2 2. Data availability / review ...........................................................................................................4 2.1 Hydrogeology Data........................................................................................................4 2.2 Surface Hydrology Data ................................................................................................4 2.3 GIS Spatial Data ............................................................................................................5 2.4 coastal basins North of the hunter river.........................................................................5 2.4.1. Existing information ............................................................................................5 2.4.2. Water quality .......................................................................................................6 2.4.3. Hydrogeology ......................................................................................................6 2.4.4. GIS data sources ..................................................................................................7 2.5 coastal basins South of the hunter river.........................................................................7 2.5.1. Existing information ............................................................................................7 2.5.2. Water quality .......................................................................................................8 2.5.3. Groundwater ........................................................................................................9 2.5.4. GIS data sources ..................................................................................................9 3. Methodology............................................................................................................................10 3.1 Surface Water Quality Analysis ..................................................................................10 3.2 Salinity Mapping .........................................................................................................11 3.2.1. The weights-of-evidence approach....................................................................11 3.3 Groundwater Salinity Analysis....................................................................................13 4. Results......................................................................................................................................14 4.1 Surface Water Salinity.................................................................................................14 4.2 Instream Salt Load.......................................................................................................20 4.3 summary of regional groundwater salinity information ..............................................21 4.3.1. North Coast basins.............................................................................................21 4.3.2. Hunter basins .....................................................................................................23 4.3.3. Sydney South Coast basins................................................................................24 NSW Department of Infrastructure, Planning and Natural Resources iii NSW Coastal Salinity Audit 5. Discussion of coastal salinity...................................................................................................31 5.1 Salt Loads ....................................................................................................................31 5.2 Stream Salinity Impacts...............................................................................................32 5.3 Groundwater Salinity...................................................................................................32 5.4 Land Use on the Coastal Zone.....................................................................................32 5.5 SulfIde Sludges............................................................................................................33 5.6 Infrastructure Development in Hazard Zones on the Coast.........................................33 6. Conclusions and recommendations..........................................................................................34 7. References................................................................................................................................38 Appendix 1. Tweed and Brunswick river basins..................................................................................43 Appendix 2. Richmond River basin .....................................................................................................50 Appendix 3. Clarence River basin........................................................................................................56 Appendix 4. Bellinger River basin.......................................................................................................64 Appendix 5. Macleay River basin ........................................................................................................69 Appendix 6. Hastings River basin........................................................................................................74 Appendix 7. Manning River basin .......................................................................................................79 Appendix 8. Karuah River basin ..........................................................................................................84 Appendix 9. Lake Macquarie and Tuggerah Lake basin..................................................................88 Appendix 10. Hawkesbury River basin................................................................................................92 Appendix 11. Sydney basin..................................................................................................................97 Appendix 12. Wollongong basin........................................................................................................101 Appendix 13. Shoalhaven River basin ...............................................................................................105 Appendix 14. Clyde River basin ........................................................................................................110 Appendix 15. Moruya River basin .....................................................................................................114 Appendix 16. Tuross River basin.......................................................................................................118 Appendix 17. Bega River basin..........................................................................................................122 Appendix 18. Towamba River basin..................................................................................................128 NSW Department of Infrastructure, Planning and Natural Resources iv NSW Coastal Salinity Audit Appendix 19. East Gippsland basin ...................................................................................................132 Appendix 20. Snowy River basin.......................................................................................................136 Appendix 21. Slope class areas ..........................................................................................................141 Appendix 22. Discussion of hazard mapping.....................................................................................142 NSW Department of Infrastructure, Planning and Natural Resources v NSW Coastal Salinity Audit Figures Page Figure 1. Map of groundwater studies for NSW (Bradd and Gates 1995).............................................3 Figure 2. Median salinity range (EC) for stochastically modelled catchments in North Coast river basins........................................................................................................................................15