THE BASIN PLAN IMPLEMENTATION Lachlan Alluvium Groundwater Resource Description GW10 Water Resource Plan Area NSW Department of Planning, Industry and Environment | dpie.nsw.gov.au Published by NSW Department of Planning, Industry and Environment dpie.nsw.gov.au Title: Lachlan Alluvium Groundwater Resource Description Subtitle: GW10 Water Resource Plan area First published: August 2019 Department reference number: INT17/225627 More information Kenneth Kolstad, NSW Department of Planning, Industry and Environment, Wagga Wagga © State of New South Wales through Department of Planning, Industry and Environment 2019. You may copy, distribute, display, download and otherwise freely deal with this publication for any purpose, provided that you attribute the Department of Planning, Industry and Environment as the owner. However, you must obtain permission if you wish to charge others for access to the publication (other than at cost); include the publication in advertising or a product for sale; modify the publication; or republish the publication on a website. You may freely link to the publication on a departmental website. Disclaimer: The information contained in this publication is based on knowledge and understanding at the time of writing (August 2019) and may not be accurate, current or complete. The State of New South Wales (including the NSW Department of Planning, Industry and Environment), the author and the publisher take no responsibility, and will accept no liability, for the accuracy, currency, reliability or correctness of any information included in the document (including material provided by third parties). Readers should make their own inquiries and rely on their own advice when making decisions related to material contained in this publication. Lachlan Alluvium—Groundwater Resource Description Contents 1 Introduction .......................................................................................................................... 1 2 History of groundwater management ................................................................................... 2 2.1 Early groundwater management ................................................................................... 2 2.2 NSW water reforms ....................................................................................................... 4 2.3 Belubula and Upper Lachlan Alluvium ........................................................................... 5 2.4 Lower Lachlan Alluvium ................................................................................................ 5 3 Regional setting ................................................................................................................... 6 3.1 Topography ................................................................................................................... 6 3.2 Climate.......................................................................................................................... 9 3.3 Land use ..................................................................................................................... 14 4 Geology ............................................................................................................................. 17 5 Hydrogeology ..................................................................................................................... 19 5.1 Regional context ......................................................................................................... 19 5.2 Belubula Alluvium ....................................................................................................... 19 5.3 Upper Lachlan Alluvium .............................................................................................. 22 5.4 Lower Lachlan Alluvium .............................................................................................. 27 5.5 Connection with surface water .................................................................................... 34 6 Groundwater-Dependent Ecosystems ................................................................................ 35 7 Groundwater Quality .......................................................................................................... 38 7.1 Belubula and Upper Lachlan Alluvium ......................................................................... 38 7.2 Lower Lachlan Alluvium .............................................................................................. 38 8 Groundwater Management................................................................................................. 40 8.1 Access rights............................................................................................................... 40 8.2 Extraction limits ........................................................................................................... 41 8.3 Available water determinations ................................................................................... 43 8.4 Groundwater accounts ................................................................................................ 44 8.5 Groundwater take ....................................................................................................... 46 8.6 Groundwater dealings ................................................................................................. 53 8.6.1 Temporary ........................................................................................................... 53 8.6.2 Permanent ........................................................................................................... 55 9 Groundwater Monitoring ..................................................................................................... 57 10 Groundwater Behaviour in the Lachlan Alluvium ............................................................ 62 10.1 Introduction ................................................................................................................. 62 10.2 Hydrographs ............................................................................................................... 62 10.3 Review of groundwater levels ..................................................................................... 63 NSW Department of Planning, Industry and Environment | INT18/94341 | i Lachlan Alluvium—Groundwater Resource Description 10.4 Groundwater contour maps ......................................................................................... 69 10.5 Long-term changes ..................................................................................................... 79 11 Groundwater Model ........................................................................................................ 82 References................................................................................................................................ 84 Figures Figure 1 Location of the Lachlan Alluvium water resource plan Area and SDL Resource Units ... 3 Figure 2 Topography and elevation map of the Lachlan catchment (Gallant et al, 2009) ............. 7 Figure 3 Surface water map of the Lachlan catchment ................................................................ 8 Figure 4 Average annual rainfall map of the Lachlan catchment (Bureau of Meteorology—BOM, 2008)......................................................................................................................................... 10 Figure 5 Average monthly rainfall for Hillston and Forbes 1972–2016 (BOM). This period corresponds to the period of record for groundwater monitoring within the Lachlan Alluvium. ... 11 Figure 6 Average annual evaporation map of the Lachlan catchment (BOM, 2008) .................. 12 Figure 7 Average monthly evaporation for Hillston and Forbes 1972–2016 (BOM) ................... 13 Figure 8 Hillston and Forbes Airport rainfall residual mass graph 1972–2016 (BOM) ................ 13 Figure 9 Land use map of the Lachlan catchment (Smart, 2016) .............................................. 15 Figure 10 Geology of the Lachlan catchment ............................................................................ 18 Figure 11 Location map of the Belubula Alluvium showing groundwater flow direction .............. 20 Figure 12 Cross-section location map of the Belubula Alluvium ................................................ 21 Figure 13 East-west long section through the Belubula Alluvium - Section A ............................ 22 Figure 14 Location map of the Upper Lachlan Alluvium showing groundwater flow direction (deep aquifer) ............................................................................................................................ 24 Figure 15 Cross section location map of the Upper Lachlan Alluvium ....................................... 25 Figure 16 East-west section (Section B) and north-south section (Section C) through Upper Lachlan Alluvium ....................................................................................................................... 26 Figure 17 East-west section (Section D) and north-south section (Section E) through Upper Lachlan Alluvium ....................................................................................................................... 27 Figure 18 Location map Lower Lachlan Alluvium showing groundwater flow direction (deep aquifer) ...................................................................................................................................... 28 Figure