Water resource assessment for the Southern Gulf catchments Australia’s National Science Agency A report from the CSIRO Southern Gulf Water Resource Assessment for the National Water Grid Editors: Ian Watson, Caroline Bruce, Seonaid Philip, Cuan Petheram and Chris Chilcott ISBN 978-1-4863-2081-3 (print) ISBN 978-1-4863-2082-0 (online) Citation Watson I, Bruce C, Philip S, Petheram C and Chilcott C (eds) (2024) Water resource assessment for the Southern Gulf catchments. A report from the CSIRO Southern Gulf Water Resource Assessment for the National Water Grid. CSIRO, Australia. Chapters should be cited in the format of the following example: Philip S, Watson I, Petheram C and Bruce C (2024) Chapter 1: Preamble. In: Watson I, Bruce C, Philip S, Petheram C, and Chilcott C (eds) (2024) Water resource assessment for the Southern Gulf catchments. A report from the CSIRO Southern Gulf Water Resource Assessment for the National Water Grid. CSIRO, Australia. Copyright © Commonwealth Scientific and Industrial Research Organisation 2024. To the extent permitted by law, all rights are reserved and no part of this publication covered by copyright may be reproduced or copied in any form or by any means except with the written permission of CSIRO. Important disclaimer CSIRO advises that the information contained in this publication comprises general statements based on scientific research. The reader is advised and needs to be aware that such information may be incomplete or unable to be used in any specific situation. No reliance or actions must therefore be made on that information without seeking prior expert professional, scientific and technical advice. To the extent permitted by law, CSIRO (including its employees and consultants) excludes all liability to any person for any consequences, including but not limited to all losses, damages, costs, expenses and any other compensation, arising directly or indirectly from using this publication (in part or in whole) and any information or material contained in it. CSIRO is committed to providing web accessible content wherever possible. If you are having difficulties with accessing this document, please contact Email CSIRO Enquiries . CSIRO Southern Gulf Water Resource Assessment acknowledgements This report was funded through the National Water Grid’s Science Program, which sits within the Australian Government’s Department of Climate Change, Energy, the Environment and Water. Aspects of the Assessment have been undertaken in conjunction with the Northern Territory (NT) and Queensland governments. The Assessment was guided by two committees: i. The Governance Committee: CRC for Northern Australia/James Cook University; CSIRO; National Water Grid (Department of Climate Change, Energy, the Environment and Water); Northern Land Council; NT Department of Environment, Parks and Water Security; NT Department of Industry, Tourism and Trade; Office of Northern Australia; Queensland Department of Agriculture and Fisheries; Queensland Department of Regional Development, Manufacturing and Water ii. The Southern Gulf catchments Steering Committee: Amateur Fishermen’s Association of the NT; Austral Fisheries; Burketown Shire; Carpentaria Land Council Aboriginal Corporation; Health and Wellbeing Queensland; National Water Grid (Department of Climate Change, Energy, the Environment and Water); Northern Prawn Fisheries; Queensland Department of Agriculture and Fisheries; NT Department of Environment, Parks and Water Security; NT Department of Industry, Tourism and Trade; Office of Northern Australia; Queensland Department of Regional Development, Manufacturing and Water; Southern Gulf NRM Responsibility for the Assessment’s content lies with CSIRO. The Assessment’s committees did not have an opportunity to review the Assessment results or outputs prior to their release. This report was reviewed by Mr Mike Grundy (Independent consultant). Individual chapters were reviewed by Dr Peter Wilson, CSIRO (Chapter 2); Dr Andrew Hoskins, CSIRO (Chapter 3); Dr Brendan Malone, CSIRO (Chapter 4); Dr James Bennett, CSIRO (Chapter 5); Dr Nikki Dumbrell, CSIRO (Chapter 6); Mr Darran King, CSIRO (Chapter 7). The material in this report draws largely from the companion technical reports, which were themselves internally and externally reviewed. For further acknowledgements, see page xxviii. Acknowledgement of Country CSIRO acknowledges the Traditional Owners of the lands, seas and waters of the area that we live and work on across Australia. We acknowledge their continuing connection to their culture and pay our respects to their Elders past and present. Photo Saltwater Arm, a tributary of the Albert River. This view typifies the tidal rivers and estuaries along the southern coast of the Gulf of Carpentaria. Source: Shutterstock Appendices Lawn Hill Gorge on Lawn Hill Creek is a popular tourist attraction Photo: Manfred Gottschalk – Alamy stock photo Assessment products More information about the Southern Gulf Water Resource Assessment can be found at https://www.csiro.au/southerngulf. The website provides readers with a communications suite including factsheets, multimedia content, FAQs, reports and links to other related sites, particularly about other research in northern Australia. In order to meet the requirements specified in the contracted ‘Timetable for the Services’, the Assessment provided the following key deliverables: • Technical reports present scientific work at a level of detail sufficient for technical and scientific experts to reproduce the work. Each of the activities of the Assessment has at least one corresponding technical report. • The catchment report (this report) synthesises key material from the technical reports, providing well-informed but non-scientific readers with the information required to make decisions about the opportunities, costs and benefits associated with water resource development. • A summary report is provided for a general public audience. • A factsheet provides key findings for a general public audience. This appendix lists all such deliverables, plus those jointly delivered for the concurrent Victoria River Water Resource Assessment. Please cite as they appear. Methods report CSIRO (2021) Proposed methods report for the Southern Gulf catchments. A report from the CSIRO Southern Gulf Water Resource Assessment for the National Water Grid Authority. CSIRO, Australia. Technical reports Devlin K (2023) Pump stations for flood harvesting or irrigation downstream of a storage dam. A technical report from the CSIRO Victoria and Southern Gulf Water Resource Assessments for the National Water Grid. CSIRO, Australia. Devlin K (2024) Conceptual arrangements and costings of hypothetical irrigation developments in the Victoria and Southern Gulf catchments. A technical report from the CSIRO Victoria and Southern Gulf Water Resource Assessments for the National Water Grid. CSIRO, Australia. Gibbs M, Hughes J and Yang A (2024) River model calibration for the Southern Gulf catchments. A technical report from the CSIRO Southern Gulf Water Resource Assessment for the National Water Grid. CSIRO, Australia. Gibbs M, Hughes J, Yang A, Wang B, Marvanek S and Petheram C (2024) River model scenario analysis for the Southern Gulf catchments. A technical report from the CSIRO Southern Gulf Water Resource Assessment for the National Water Grid. CSIRO, Australia. Hayward J (2024) Potential for farm-scale hybrid renewable energy supply options in the Victoria and Southern Gulf catchments. A technical report from the CSIRO Victoria and Southern Gulf Water Resource Assessments for the National Water Grid. CSIRO, Australia. Karim F, Kim S, Ticehurst C, Gibbs M, Hughes J, Marvanek S, Yang A, Wang B and Petheram C (2024) Floodplain inundation mapping and modelling for the Southern Gulf catchments. A technical report from the CSIRO Southern Gulf Water Resource Assessment for the National Water Grid. CSIRO, Australia. Lyons P, Barber M, Braedon P and Pert P (2024) Indigenous water values, rights, interests and development goals in the Southern Gulf Catchments: A literature review and implications for future research. A technical report from the CSIRO Southern Gulf Water Resource Assessment for the National Water Grid. CSIRO, Australia McJannet D, Yang A and Seo L (2023) Climate data characterisation for hydrological and agricultural scenario modelling across the Victoria, Roper and Southern Gulf catchments. A technical report from the CSIRO Victoria River and Southern Gulf Water Resource Assessments for the National Water Grid. CSIRO, Australia. Merrin L, Stratford D, Kenyon R, Pritchard J, Linke S, Ponce Reyes R, Buckworth R, Castellazzi P, Costin B, Deng R, Gannon R, Gao S, Gilbey S, Lachish S, McGinness H and Waltham N (2024) Ecological assets of the Southern Gulf catchments to inform water resource assessments. A technical report from the CSIRO Southern Gulf Water Resource Assessment for the National Water Grid. CSIRO, Australia. Motson K, Mishra A and Waltham N (2024) A review of water quality studies relevant to northern Australia. A technical report from the CSIRO Victoria and Southern Gulf Water Resource Assessments for the National Water Grid. CSIRO, Australia. Ponce Reyes R, Stratford D, Linke S, Merrin L, Kenyon R, Buckworth R, Deng RA, Hughes J, McGinness H, Pritchard J, Seo L and Waltham N (2024) Assessment of the potential ecological outcomes of water resource development in the Southern Gulf catchments. A technical report from the CSIRO Southern Gulf Water Resource Assessment for the National Water Grid. CSIRO, Australia. Raiber M, Taylor AR, Dupuy M, Priestley S, Barry K, Crosbie RS, Knapton A and Hodgson G (2024) Characterising groundwater resources of the Gilbert River Formation, Camooweal Dolostone and Thorntonia Limestone in the Southern Gulf catchments, Queensland and Northern Territory. A technical report from the CSIRO Southern Gulf Water Resource Assessment for the National Water Grid. CSIRO, Australia. Rider Levett Bucknall (2024) Water infrastructure-related costs for the Victoria and Southern Gulf catchments. A technical report from the CSIRO Victoria River and Southern Gulf Water Resource Assessments for the National Water Grid. CSIRO Australia Speed R and Vanderbyl T (2024) Regulatory requirements for land and water development in the Northern Territory and Queensland. A technical report from the CSIRO Victoria and Southern Gulf Water Resource Assessments for the National Water Grid. CSIRO, Australia. Thomas M, Philip S, Zund P, Stockmann U, Hill J, Gregory L, Watson I and Thomas E (2024) Soils and land suitability for the Southern Gulf catchments. A technical report from the CSIRO Southern Gulf Water Resource Assessment for the National Water Grid. CSIRO, Australia. Vanderbyl T (2021) Southern Gulf: Queensland water plans and settings. A technical report from the CSIRO Southern Gulf Water Resource Assessment for the National Water Grid. CSIRO, Australia. Waschka M and Macintosh A (2024) CSIRO Water Resource Assessments: Indigenous rights and interests in Queensland and the Northern Territory. A report from Barraband Consulting to CSIRO to inform the CSIRO Victoria, Roper and Southern Gulf Water Resource Assessments. CSIRO, Australia. Webster A, Jarvis D, Jalilov S, Philip S, Oliver Y, Watson I, Rhebergen T, Bruce C, Prestwidge D, McFallan S, Curnock M and Stokes C (2024) Financial and socio-economic viability of irrigated agricultural development in the Southern Gulf catchments. A technical report from the CSIRO Southern Gulf Water Resource Assessment for the National Water Grid. CSIRO, Australia. Yang A, Petheram C, Marvanek S, Baynes F, Rogers L, Ponce Reyes R, Zund P, Seo L, Hughes J, Gibbs M, Wilson PR, Philip S and Barber M (2024) Assessment of surface water storage options in the Victoria and Southern Gulf catchments. A technical report from the CSIRO Victoria River and Southern Gulf Water Resource Assessments for the National Water Grid. CSIRO Australia. Catchment report Watson I, Bruce C, Philip S, Petheram C and Chilcott C (eds) (2024) Water resource assessment for the Southern Gulf catchments. A report from the CSIRO Southern Gulf Water Resource Assessment for the National Water Grid. CSIRO, Australia. Summary report CSIRO (2024) The Southern Gulf Water Resource Assessment. A summary report from the CSIRO Southern Gulf Water Resource Assessment for the National Water Grid. CSIRO, Australia. Factsheet on key findings CSIRO (2024) The Southern Gulf Water Resource Assessment. Key messages of reports to the CSIRO Southern Gulf Water Resource Assessment for the National Water Grid. CSIRO, Australia. Shortened forms SHORT FORM FULL FORM ABS Australian Bureau of Statistics ACARA Australian Curriculum, Assessment and Reporting Authority AE adult equivalent AEP annual exceedance probability AHD Australian Height Datum ALA Aboriginal Land Act 1991 (Qld) ALRA Aboriginal Land Rights (Northern Territory) Act 1976 (Cth) AMTD adopted middle thread distance ANZECC Australian and New Zealand Environment and Conservation Council APSIM Agricultural Production Systems sIMulator ARMCANZ Agriculture and Resource Management Council of Australia and New Zealand ASC Australian Soil Classification AWC available water capacity AWRC Australian Water Resources Council BCR benefit-to-cost ratio BOM Bureau of Meteorology CBA cost–benefit analysis CBR cost-to-benefit ratio CLA Cambrian Limestone Aquifer CLCAC Carpentaria Land Council Aboriginal Corporation CMB chloride mass balance CMIP Coupled Model Intercomparison Project CV coefficient of variation DENR Department of Environment and Natural Resources (NT) DIDO drive-in drive-out DIWA Directory of Important Wetlands in Australia DN Nominal Diameter DNRME Department of Natural Resources, Mines and Energy (Queensland) DOGIT deeds of grant in trust EBITDA earnings before interest, taxes, depreciation and amortisation EGM96 Earth Gravitational Model 1996 SHORT FORM FULL FORM EIS Environmental Impact Statement ENSO El Niño–Southern Oscillation EOS end of system EPBC Act Environment Protection and Biodiversity Conservation Act 1999 (Cth) FIFO fly-in fly-out FSL full supply level FTE full-time equivalent GAB Great Artesian Basin GABORA Great Artesian Basin and Other Regional Aquifers GCM global climate model GCM-PS global climate model – pattern scaled GDE groundwater-dependent ecosystem GGNTAC Gangalidda and Garawa Native Title Aboriginal Corporation GM gross margin GRA Gilbert River Aquifer GRF Gilbert River Formation GVAP gross value of agricultural production GVIAP gross value of irrigated agricultural production HSD health service district IEO Index of Education and Occupation IER Index of Economic Resources ILUA Indigenous Land Use Agreement IPA Indigenous Protected Area IPCC Intergovernmental Panel on Climate Change IRR internal rate of return IRSD Index of Relative Socio-Economic Disadvantage IUCN International Union for Conservation of Nature JORC Joint Ore Reserves Committee LGA local government area MAR managed aquifer recharge MODIS Moderate Resolution Imaging Spectroradiometer NAWRA Northern Australia Water Resource Assessment n.d. not dated NEM National Electricity Market NGMA Nicholson Groundwater Management Area NPF Northern Prawn Fishery NPV net present value SHORT FORM FULL FORM NRM Natural Resource Management NT Northern Territory NWPS North West Power System O&M annual operation and maintenance PAW plant available water PAWC plant available water capacity PBC Prescribed Body Corporate PE potential evaporation PET potential evapotranspiration PHN primary health network QSNTS Queensland South Native Title Services RCC roller compacted concrete RNTBC Registered Native Title Body Corporate RoNA rest of northern Australia SA South Australia SA2 Statistical Area Level 2 SEIFA Socio-Economic Indexes for Areas SGG soil generic group SILO Scientific Information for Land Owners SOI Southern Oscillation Index SSP Shared Socio-economic Pathway SWAN Surface Water Ambient Water Quality Network SWL standing water level TDS total dissolved solids TraNSIT Transport Network Strategic Investment Tool UNESCO United Nations Educational, Scientific and Cultural Organization WA Western Australia Units UNIT DESCRIPTION $ dollars % per cent c cents cm centimetre d day dS decisiemens DS dry season GL gigalitre ha hectare kg kilogram km kilometre km2 square kilometre kPa kilopascal kV kilovolt kW kilowatt L litre m metre m3 cubic metre mASL metres above sea level mBGL metres below ground level mEGM86 metres (Earth Gravitational Model 1986) mEGM96 metres (Earth Gravitational Model 1996) mg milligram ML megalitre mm millimetre MWh megawatt hour s second t metric tonne y year °C degrees Celsius List of figures Figure 1-1 Map of Australia showing Assessment area (Southern Gulf catchments) and other recent or ongoing CSIRO Assessments ........................................................................................... 3 Figure 1-2 Number of large dams constructed in Australia and northern Australia over time ..... 8 Figure 1-3 Schematic of key components and concepts in the establishment of a greenfield irrigation development ................................................................................................................. 10 Figure 1-4 The Southern Gulf catchments .................................................................................... 13 Figure 2-1 Schematic diagram of key natural components and concepts in the establishment of a greenfield irrigation development ............................................................................................. 19 Figure 2-2 Surface geology of the Southern Gulf catchments ...................................................... 23 Figure 2-3 Physiographic units of the Southern Gulf catchments ................................................ 25 Figure 2-4 Major geological provinces of the Southern Gulf catchments .................................... 29 Figure 2-5 The soil generic groups (SGGs) of the Southern Gulf catchments produced by digital soil mapping .................................................................................................................................. 32 Figure 2-6 Cracking clay (brown Vertosol; SGG 9) Mitchell grass (Astrebla spp.) downs with whitewood (Elaeocarpus sp.) and gutta percha (Palaquium spp.) on the Armraynald Plain physiographic unit, east of the Leichhardt River .......................................................................... 36 Figure 2-7 Brown Dermosol (SGG 2) buffel grass (Cenchrus ciliaris) open woodland with silver leaf box (Eucalyptus pruinosa) on the Armraynald Plain physiographic unit in the middle reaches of the Leichhardt River .................................................................................................................. 36 Figure 2-8 Red sandy soil (SGG 6.1) open woodland of Darwin box (Eucalyptus tectifica), bauhinia (Bauhinia spp.) and Cooktown ironwood (Erythrophleum chlorostachys) near Doomadgee on the Armraynald Plain physiographic unit north of the Nicholson River ............. 37 Figure 2-9 Level to gently undulating cracking clay soils of the Armraynald Plain suitable for broadacre irrigation ...................................................................................................................... 38 Figure 2-10 Soil profile of the brown Vertosol (SGG 9) sampled on the Armraynald Plain physiographic unit east of the Leichhardt River ........................................................................... 39 Figure 2-11 (a) Surface soil pH (top 10 cm) of the Southern Gulf catchments as predicted by digital soil mapping and (b) reliability of the prediction .............................................................. 40 Figure 2-12 (a) Soil thickness of the Southern Gulf catchments as predicted by digital soil mapping and (b) reliability of the prediction ................................................................................ 41 Figure 2-13 (a) Soil surface texture of the Southern Gulf catchments as predicted by digital soil mapping and (b) reliability of the prediction ................................................................................ 42 Figure 2-14 (a) Soil permeability of the Southern Gulf catchments as predicted by digital soil mapping and (b) reliability of the prediction ................................................................................ 43 Figure 2-15 (a) Available water capacity in the upper 100 cm of the soil profile (AWC 100) of the Southern Gulf catchments as predicted by digital soil mapping and (b) reliability of the prediction ...................................................................................................................................... 44 Figure 2-16 (a) Surface rockiness in soils of the Southern Gulf catchments represented by presence or absence as predicted by digital soil mapping and (b) reliability of the prediction .. 45 Figure 2-17 Historical rainfall, potential evaporation and rainfall deficit .................................... 47 Figure 2-18 Historical monthly rainfall (left) and time series of annual rainfall (right) in the Southern Gulf catchments at Mount Isa, Doomadgee, Gregory and Burketown ........................ 50 Figure 2-19 Historical monthly potential evaporation (PE) (left) and time series of annual PE (right) in the Southern Gulf catchments at Mount Isa, Doomadgee, Gregory and Burketown ... 51 Figure 2-20 (a) Coefficient of variation (CV) of annual rainfall and (b) the CV of annual rainfall plotted against mean annual rainfall for 99 rainfall stations around Australia ........................... 52 Figure 2-21 Runs of wet and dry years at Mount Isa, Doomadgee, Gregory and Burketown ..... 54 Figure 2-22 Percentage change in rainfall and potential evaporation per degree of global warming for the 32 Scenario C simulations relative to Scenario A values for the Southern Gulf catchments .................................................................................................................................... 56 Figure 2-23 Spatial distribution of mean annual rainfall across the Southern Gulf catchments under scenarios (a) Cwet, (b) Cmid and (c) Cdry .......................................................................... 56 Figure 2-24 (a) Monthly rainfall and (b) potential evaporation for the Southern Gulf catchments under scenarios A and C ................................................................................................................. 57 Figure 2-25 Simplified schematic diagram of terrestrial water balance in the Southern Gulf catchments .................................................................................................................................... 60 Figure 2-26 Simplified regional hydrogeology of the Southern Gulf catchments ........................ 62 Figure 2-27 Two-dimensional conceptual schematic of the interconnected aquifer system and its variability .................................................................................................................................. 64 Figure 2-28 Gregory River at Riversleigh Road ............................................................................. 65 Figure 2-29 Lawn Hill Gorge .......................................................................................................... 66 Figure 2-30 The Gregory River receives groundwater discharge from the Cambrian Limestone Aquifer ........................................................................................................................................... 67 Figure 2-31 Full extent of the Georgina Basin and Carpentaria Sub-basin of the Great Artesian Basin. Inset map shows full extent of Great Artesian Basin ......................................................... 68 Figure 2-32 Groundwater bore yields for major aquifers across the Southern Gulf catchments 69 Figure 2-33 Groundwater salinity for major aquifers in the Southern Gulf catchments ............. 70 Figure 2-34 Annual recharge estimates for the Southern Gulf catchments ................................. 72 Figure 2-35 Summary of recharge statistics to outcropping areas of key hydrogeological units across the Southern Gulf catchments ........................................................................................... 73 Figure 2-36 Spatial distribution of groundwater discharge classes including surface water – groundwater connectivity across the Southern Gulf catchments ................................................ 75 Figure 2-37 Modelled streamflow under natural conditions ....................................................... 76 Figure 2-38 Streamflow observation data availability in the Southern Gulf catchments ............ 78 Figure 2-39 Median annual streamflow (50% exceedance) in the Southern Gulf catchments under Scenario A ........................................................................................................................... 79 Figure 2-40 (a) 20% and (b) 80% exceedance of annual streamflow in the Southern Gulf catchments under Scenario A ....................................................................................................... 80 Figure 2-41 Catchment area and elevation profile from the upper tributaries in each catchment to the mouth along the (a) Gregory–Nicholson River and (b) Leichhardt River ........................... 80 Figure 2-42 Mean annual (a) rainfall and (b) runoff across the Southern Gulf catchments under Scenario A ..................................................................................................................................... 81 Figure 2-43 Annual runoff at (a) 20%, (b) 50% and (c) 80% exceedance across the Southern Gulf catchments under Scenario A ....................................................................................................... 82 Figure 2-44 Total runoff across the Southern Gulf catchments under Scenario A showing (a) time series of annual runoff and (b) monthly runoff averaged across the catchments .............. 82 Figure 2-45 Flood inundation map of the Southern Gulf catchments .......................................... 84 Figure 2-46 Flood inundation in the Southern Gulf catchments for a flood event of 1 in 38 annual exceedance probability (AEP) in March 2023 ................................................................... 85 Figure 2-47 Peak flood discharge and annual exceedance probability (AEP) at (a) gauge 912107A (Nicholson River at Connolly’s Hole), (b) gauge 912105A (Gregory River at Riversleigh) and (c) gauge 913007B (Leichhardt River at Floraville) ............................................................................ 86 Figure 2-48 Minimum observed September streamflow at two stream gauge locations on the Gregory River ................................................................................................................................ 87 Figure 2-49 Minimum monthly flow over 132 years of simulation for the month of October .... 88 Figure 2-50 Instream waterhole evolution in a reach of the Flinders River ................................. 89 Figure 2-51 The Leichhardt River near Kajabbi looking south towards the Isa highlands. In the highly seasonal climate of the Southern Gulf catchments, springs and persistent waterholes provide important ecological refugia during the dry season ....................................................... 89 Figure 2-52 Location of river reaches containing permanent water in the Southern Gulf catchments .................................................................................................................................... 90 Figure 2-53 Accelerated erosion contributes sediment to streamflow........................................ 92 Figure 2-54 Water quality samples for selected constituents on the Gregory River at Riversleigh (A912005A), Gunpowder Creek at Gunpowder (913006A) and Leichhardt River at Floraville Homestead (913007B) .................................................................................................................. 93 Figure 3-1 Schematic diagram of key components of the living and built environment to be considered in establishing a greenfield irrigation development ................................................ 101 Figure 3-2 Conceptual diagram of selected ecological assets of the Southern Gulf catchments ..................................................................................................................................................... 106 Figure 3-3 Estuarine crocodiles inhabit fresh and saltwater environments ............................... 108 Figure 3-4 Location of protected areas and important wetlands within the Southern Gulf catchments Assessment area...................................................................................................... 109 Figure 3-5 Regional ecosystem biodiversity status in the Queensland part of the Southern Gulf catchments .................................................................................................................................. 110 Figure 3-6 Brolgas flying into the sunset at Lake Moondarra ..................................................... 117 Figure 3-7 Land subject to inundation (potential floodplain wetlands) and important wetlands in the Southern Gulf catchments .................................................................................................... 119 Figure 3-8 This saltpan area in northern Australia is typical in being located between mangrove and saltmarsh areas .................................................................................................................... 122 Figure 3-9 Australian bustards are common in grasslands and woodlands across northern Australia ...................................................................................................................................... 123 Figure 3-10 Location of saltpans in the Southern Gulf catchments marine region .................... 124 Figure 3-11 The O’Shannassy River – one of the northern Australian rivers where catfish are found ........................................................................................................................................... 126 Figure 3-12 Modelled potential species distribution for fork-tailed catfish (Neoarius graeffei) in the Southern Gulf catchments .................................................................................................... 127 Figure 3-13 Magpie goose perched on a fallen tree branch ....................................................... 129 Figure 3-14 Distribution of species listed under the Environment Protection and Biodiversity Conservation Act 1999 and by the NT and Queensland governments in the Southern Gulf catchments .................................................................................................................................. 130 Figure 3-15 Boundaries of the Australian Bureau of Statistics Statistical Area Level 2 (SA2) regions used for demographic data in this analysis.................................................................... 135 Figure 3-16 Land use classification for the Southern Gulf catchments ...................................... 139 Figure 3-17 Regions in the Northern Prawn Fishery and the North West Minerals Province ... 143 Figure 3-18 Main commodity mineral occurrences and exploration tenements in the Southern Gulf catchments .......................................................................................................................... 144 Figure 3-19 Local government areas and the Tropical North Queensland tourism region that statistics on tourism visitation are extracted from ..................................................................... 150 Figure 3-20 Road rankings and conditions in the vicinity of the Southern Gulf catchments ..... 153 Figure 3-21 Roads accessible to Type 2 vehicles in the vicinity of the Southern Gulf catchments: minor roads are not classified ..................................................................................................... 154 Figure 3-22 Common configurations of heavy freight vehicles used for transporting agricultural goods in Australia ........................................................................................................................ 155 Figure 3-23 Road conditions and distance to market impact the economics of development in the Southern Gulf catchments. ................................................................................................... 155 Figure 3-24 Mean speed achieved for freight vehicles on roads in the vicinity of the Southern Gulf catchments .......................................................................................................................... 156 Figure 3-25 Many roads are gravel in the Southern Gulf catchments, and often impassable in the wet season ............................................................................................................................ 158 Figure 3-26 Annual amounts of trucking in the Southern Gulf catchments and the locations of pastoral properties and ports ..................................................................................................... 159 Figure 3-27 Electricity generation and transmission network and pipelines in the Southern Gulf catchments .................................................................................................................................. 160 Figure 3-28 Solar photovoltaic capacity factors in the Southern Gulf catchments .................... 162 Figure 3-29 Wind capacity factors in the Southern Gulf catchments ......................................... 163 Figure 3-30 Location, type and volume of annual licensed surface water and groundwater entitlements across the Southern Gulf catchments ................................................................... 165 Figure 3-31 Exclusive Aboriginal lands and pastoral interests make up the majority of the Southern Gulf catchments .......................................................................................................... 174 Figure 3-32 The extent of native title claims and determinations over the Southern Gulf catchments .................................................................................................................................. 175 Figure 3-33 Indigenous protected areas and other protected areas in the Southern Gulf catchments as of April 2020........................................................................................................ 176 Figure 3-34 Indigenous Land Use Agreements (ILUAs) ............................................................... 177 Figure 4-1 Schematic of agriculture and aquaculture enterprises as well as crop and/or forage integration with existing beef enterprises to be considered in the establishment of a greenfield irrigation development ............................................................................................................... 206 Figure 4-2 Area (ha) of the Southern Gulf catchments mapped in each of the land suitability classes for 14 selected land use combinations (crop group × season × irrigation type) ............ 214 Figure 4-3 Agricultural versatility index map for the Southern Gulf catchments....................... 215 Figure 4-4 Climate comparisons of Southern Gulf catchments’ sites with established irrigation areas at Kununurra (WA) and Mareeba (Queensland) ............................................................... 219 Figure 4-5 Annual cropping calendar for irrigated agricultural options in the Southern Gulf catchments .................................................................................................................................. 221 Figure 4-6 Soil wetness indices that indicate when seasonal trafficability constraints are likely to occur on sands, Kandosols (loamy sands) and Vertosols (high clay) with a Gregory climate for two thresholds (a) 80% and (b) 70% of the maximum plant available water capacity .............. 222 Figure 4-7 Influence of planting date on rainfed grain sorghum yield at Gregory for a (a) Kandosol and (b) Vertosol ........................................................................................................... 224 Figure 4-8 Influence of available irrigation water on grain sorghum yields for planting dates of (a) 1 February and (b) 1 August, for a Vertosol with a Gregory climate .................................... 225 Figure 4-9 Fluctuations in seedless watermelon prices at Melbourne wholesale markets from April 2020 to February 2023 ....................................................................................................... 234 Figure 4-10 Modelled land suitability for Crop Group 7 (e.g. sorghum (grain) or maize) using furrow irrigation in the (a) wet season and (b) dry season ........................................................ 246 Figure 4-11 Sorghum (grain) ....................................................................................................... 248 Figure 4-12 Modelled land suitability for mungbean (Crop Group 10) in the dry season using (a) furrow irrigation and (b) spray irrigation .................................................................................... 250 Figure 4-13 Mungbean ................................................................................................................ 250 Figure 4-14 Modelled land suitability for soybean (Crop Group 10) in the dry season using (a) furrow irrigation and (b) spray irrigation .................................................................................... 253 Figure 4-15 Soybean.................................................................................................................... 253 Figure 4-16 Modelled land suitability for peanut (Crop Group 6) using spray irrigation in the (a) wet season and (b) dry season ................................................................................................... 256 Figure 4-17 Peanut ...................................................................................................................... 256 Figure 4-18 Modelled land suitability for cotton (Crop Group 7) using furrow irrigation in the (a) wet season and (b) dry season ................................................................................................... 260 Figure 4-19 Cotton ...................................................................................................................... 260 Figure 4-20 Modelled land suitability for Rhodes grass (Crop Group 14) using (a) spray irrigation and (b) furrow irrigation ............................................................................................................. 263 Figure 4-21 Rhodes grass ............................................................................................................ 264 Figure 4-22 Modelled land suitability for Cavalcade (Crop Group 13) in the wet season using (a) spray irrigation and (b) furrow irrigation .................................................................................... 266 Figure 4-23 Lablab ....................................................................................................................... 268 Figure 4-24 Modelled land suitability for (a) cucurbits (e.g. rockmelon, Crop Group 3) using trickle irrigation in the dry season and (b) root crops such as onion (Crop Group 6) using spray irrigation in the wet season ........................................................................................................ 270 Figure 4-25 Rockmelon ............................................................................................................... 270 Figure 4-26 Modelled land suitability for (a) mango (Crop Group 1) and (b) lime (Crop Group 2), both grown using trickle irrigation.............................................................................................. 273 Figure 4-27 Mango ...................................................................................................................... 273 Figure 4-28 Modelled land suitability for Indian sandalwood (Crop Group 15) grown using (a) trickle or (b) furrow irrigation ..................................................................................................... 276 Figure 4-29 Indian sandalwood and host plants ......................................................................... 276 Figure 4-30 Black tiger prawns .................................................................................................... 280 Figure 4-31 Barramundi .............................................................................................................. 280 Figure 4-32 Schematic of marine aquaculture farm ................................................................... 282 Figure 4-33 Land suitability in the Southern Gulf catchments for marine species aquaculture in (a) lined ponds and (b) earthen ponds ....................................................................................... 286 Figure 4-34 Land suitability in the Southern Gulf catchments for freshwater species aquaculture in (a) lined ponds and (b) earthen ponds ................................................................................... 287 Figure 5-1 Schematic of key engineering and agricultural components to be considered in the establishment of a water resource and greenfield irrigation development .............................. 296 Figure 5-2 Hydrogeological units with potential for future groundwater resource development ..................................................................................................................................................... 306 Figure 5-3 Groundwater dependent ecosystems along Lawn Hill Creek ................................... 308 Figure 5-4 Thickness of the Georgina Basin in the Southern Gulf catchments .......................... 309 Figure 5-5 Hydrogeological cross-section through the Cambrian Limestone Aquifer in the Georgina Basin and south-west of the Southern Gulf catchments ............................................ 310 Figure 5-6 Depth to standing water level (SWL) of the Cambrian Limestone Aquifer (CLA)...... 311 Figure 5-7 Location of the Undilla Sub-basin groundwater flow model in relation to the Southern Gulf catchments and portions of the model that coincide with the Lawn Hill Creek and Gregory subcatchments and Nicholson Groundwater Management Area ................................ 312 Figure 5-8 Depth to the top of the Gilbert River Aquifer (GRA) ................................................. 314 Figure 5-9 South-west to north-east cross-section traversing the Great Artesian Basin in the Southern Gulf catchments. ......................................................................................................... 315 Figure 5-10 Depth to standing water level of the Gilbert River Aquifer (GRA) .......................... 316 Figure 5-11 Uncontrolled artesian flow from the Gilbert River Aquifer at the Burketown groundwater bore ....................................................................................................................... 318 Figure 5-12 Types of managed aquifer recharge ........................................................................ 319 Figure 5-13 Managed aquifer recharge (MAR) opportunities for the Southern Gulf catchments independent of distance from a water source for recharge ...................................................... 321 Figure 5-14 (a) Managed aquifer recharge (MAR) opportunities in the Southern Gulf catchments within 5 km of major rivers and (b) aquifer underlying the MAR opportunity classes .............. 322 Figure 5-15 Potential storage sites in the Southern Gulf catchments based on minimum cost per megalitre storage capacity .......................................................................................................... 326 Figure 5-16 Potential storage sites in the Southern Gulf catchments based on minimum cost per megalitre yield at the dam wall .................................................................................................. 328 Figure 5-17 Julius Dam on the Leichhardt River ......................................................................... 329 Figure 5-18 Southern Gulf catchments hydro-electric power generation opportunity map ..... 330 Figure 5-19 Cumulative yield at 85% annual time reliability versus cumulative cost of water in $/ML and change in the end-of-system (EOS) volume in the Southern Gulf catchments ......... 335 Figure 5-20 Location of listed species, water-dependent assets and aggregated modelled habitat in the vicinity of the potential dam site on Gunpowder Creek dam AMTD 66 km and reservoir extent ........................................................................................................................... 337 Figure 5-21 Potential dam site on Gunpowder Creek AMTD 66 km: cost and yield at the dam wall .............................................................................................................................................. 338 Figure 5-22 Location of listed species, water-dependent assets and aggregated modelled habitat in the vicinity of the potential dam site on the Gregory River AMTD 174 km ............... 340 Figure 5-23 Potential dam site on Gregory River AMTD 174 km: cost and yield at the dam wall ..................................................................................................................................................... 341 Figure 5-24 Schematic cross-section of sheet piling weir ........................................................... 343 Figure 5-25 Rectangular ringtank and 500 ha of cotton in the Flinders catchment (Queensland) ..................................................................................................................................................... 345 Figure 5-26 Suitability of land for large farm-scale ringtanks in the Southern Gulf catchments 346 Figure 5-27 Annual reliability of diverting annual system and reach target volumes for varying pump start thresholds ................................................................................................................. 348 Figure 5-28 Annual reliability of diverting annual system and reach target volumes for varying pump start thresholds with annual diversion commencement flow requirement of 150 GL ... 350 Figure 5-29 Annual reliability of diverting annual system and reach target volumes for varying pump start thresholds assuming pumping capacity of 10 days ................................................. 351 Figure 5-30 Annual reliability of diverting annual system and reach target volumes for varying pump rates assuming a pump start threshold of 600 ML/day ................................................... 352 Figure 5-31 50% annual exceedance (median) streamflow relative to Scenario A in the Southern Gulf catchments for a pump start threshold of 600 ML/day and a pump capacity of 20 days .. 353 Figure 5-32 80% annual exceedance streamflow relative to Scenario A in the Southern Gulf catchments for a pump start threshold of 600 ML/day and a pump capacity of 20 days ......... 354 Figure 5-33 Most economically suitable locations for large farm-scale gully dams in the Southern Gulf catchments .......................................................................................................... 360 Figure 5-34 Suitability of soils for construction of gully dams in the Southern Gulf catchments ..................................................................................................................................................... 361 Figure 5-35 Reported conveyance losses from irrigation systems across Australia .................. 369 Figure 5-36 Efficiency of different types of irrigation system .................................................... 370 Figure 6-1 Schematic diagram of key components affecting the commercial viability of a potential greenfield irrigation development .............................................................................. 379 Figure 6-2 Locations of the five dams used in this review .......................................................... 400 Figure 6-3 Trends in gross value of agricultural production (GVAP) in (a) Australia and (b) Queensland over 40 years (1981–2021) ..................................................................................... 403 Figure 6-4 National trends for increasing gross value of irrigated agricultural production (GVIAP) as available water supplies have increased for (a) fruits, (b) vegetables, (c) fruits and vegetables combined, and (d) total agriculture ............................................................................................ 404 Figure 6-5 Queensland’s north-west region used in the input–output (I–O) analyses relative to the Southern Gulf catchments Assessment area ........................................................................ 410 Figure 7-1 Schematic diagram of the components where key risks can manifest when considering the establishment of a greenfield irrigation or aquaculture development ............ 417 Figure 7-2 Locations of the river system modelling nodes at which flow–ecology dependencies were assessed (numbered) and the locations of hypothetical water resource developments in the Southern Gulf catchments .................................................................................................... 429 Figure 7-3 Riparian vegetation along the Leichhardt River – riparian zones are often more fertile and productive than surrounding terrestrial vegetation ............................................................ 436 Figure 7-4 Spatial heatmap of habitat-weighted changes in flow for sawfish, considering the assets important locations across the catchment ...................................................................... 437 Figure 7-5 Habitat-weighted change in sawfish flow dependencies by scenario across model nodes ........................................................................................................................................... 438 Figure 7-6 Habitat-weighted change in swimming, diving and grazing waterbirds flow dependencies by scenario across model nodes ......................................................................... 441 Figure 7-7 Habitat-weighted change in floodplain wetlands flow dependencies by scenario across model nodes .................................................................................................................... 444 Figure 7-8 Lake Moondarra near Mount Isa is used for urban water supply and is a popular water and recreational reserve................................................................................................... 449 Figure 7-9 Mean change associated with each asset’s important metrics across water harvesting increments of system target and pump-start threshold with no annual diversion commencement flow requirement and pump rate of 30 days .................................................. 450 Figure 7-10 The invasion curve with biosecurity actions taken at various stages ..................... 461 Figure 7-11 Farm biosecurity signage available through www.farmbiosecurity.com.au ........... 462 Figure 7-12 An extratidal flat on the Karumba Plain near Burketown, with white salt crystals either side of a shallow natural drainage line. Salt-tolerant samphire and mangrove species can be seen in the background. ......................................................................................................... 475 Figure 7-13 Example of salt-affected areas on the northern part of the Armraynald Plain ...... 476 List of tables Table 2-1 Soil generic groups (SGGs), descriptions, management considerations and correlations to Australian Soil Classification (ASC) for the Southern Gulf catchments .................................... 33 Table 2-2 Area and proportions covered by each soil generic group (SGG) in the Southern Gulf catchments .................................................................................................................................... 35 Table 2-3 Projected sea-level rise for the coast of the Southern Gulf catchments ...................... 57 Table 2-4 Streamflow metrics at selected gauging stations in the Southern Gulf catchments ... 77 Table 2-5 Summary of water quality data for the open Southern Gulf catchments sites, with values of minimum, median and maximum for each site and each water quality parameter .... 91 Table 3-1 Categories of biodiversity status of the Queensland regional ecosystems ................ 112 Table 3-2 Freshwater, marine and terrestrial ecological assets with freshwater flow dependences in the Southern Gulf catchments ......................................................................... 116 Table 3-3 Nationally important wetlands in the Southern Gulf catchments ............................. 118 Table 3-4 Definition of threatened categories under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999, the NT wildlife classification system, and the Queensland Nature Conservation Act 1992 ................................................................................ 131 Table 3-5 Major demographic indicators for the Southern Gulf catchments ............................ 134 Table 3-6 Socio-Economic Indexes for Areas (SEIFA) scores of relative socio-economic advantage for the Southern Gulf catchments .............................................................................................. 136 Table 3-7 Key employment data for the Southern Gulf catchments .......................................... 137 Table 3-8 Value of agricultural production estimated for the Southern Gulf catchments and the value of agricultural production for Queensland for 2020–21 ................................................... 140 Table 3-9 Indicative numbers for employment in different types of mining operations in the Southern Gulf catchments .......................................................................................................... 145 Table 3-10 Resource and reserve data for several major deposits in and on the margins of the Southern Gulf catchments .......................................................................................................... 146 Table 3-11 Global water consumption in the mining and refining of selected metals .............. 148 Table 3-12 Overview of commodities (excluding livestock) annually transported into and out of the Southern Gulf catchments .................................................................................................... 157 Table 3-13 Unallocated surface water in the Queensland part of the Southern Gulf catchments ..................................................................................................................................................... 166 Table 3-14 Schools servicing the Southern Gulf catchments ..................................................... 168 Table 3-15 Number and percentage of unoccupied dwellings and population for the Southern Gulf catchments .......................................................................................................................... 169 Table 4-1 Land suitability classes based on FAO (1976, 1985) as used in the Assessment ........ 212 Table 4-2 Crop groups and individual land uses evaluated for irrigation (and rainfed) potential ..................................................................................................................................................... 213 Table 4-3 Qualitative land evaluation observations in Southern Gulf catchments areas A to F shown in Figure 4-3 ..................................................................................................................... 216 Table 4-4 Crop options for which performance was evaluated in terms of water use, yields and gross margins .............................................................................................................................. 218 Table 4-5 Soil water content at sowing, and rainfall for the 90-day period following sowing for three sowing dates, based on a Gregory climate on a Vertosol ................................................. 223 Table 4-6 Performance metrics for broadacre cropping options in the Southern Gulf catchments: applied irrigation water, crop yield and gross margin (GM) for four environments ..................................................................................................................................................... 227 Table 4-7 Breakdown of variable costs relative to revenue for broadacre crop options ........... 231 Table 4-8 Sensitivity of cotton crop gross margins ($/ha) to variation in yield, lint prices and distance to gin ............................................................................................................................. 232 Table 4-9 Sensitivity of forage (Rhodes grass) crop gross margins ($/ha) to variation in yield and hay price ...................................................................................................................................... 232 Table 4-10 Performance metrics for horticulture options in the Southern Gulf catchments: annual applied irrigation water, crop yield and gross margin .................................................... 233 Table 4-11 Sensitivity of watermelon crop gross margins ($/ha) to variation in melon prices and freight costs ................................................................................................................................. 235 Table 4-12 Performance metrics for plantation tree crop options in the Southern Gulf catchments: annual applied irrigation water, crop yield and gross margin ............................... 236 Table 4-13 Likely annual irrigated crop planting windows, suitability and viability in the Southern Gulf catchments .......................................................................................................... 239 Table 4-14 Sequential cropping options for Kandosols .............................................................. 240 Table 4-15 Production and financial outcomes from the different irrigated forage and beef production options for a representative property in the Southern Gulf catchments ................ 243 Table 4-16 Summary information relevant to the cultivation of cereals, using sorghum (grain) as an example .................................................................................................................................. 247 Table 4-17 Summary information relevant to the cultivation of pulses, using mungbean as an example ....................................................................................................................................... 251 Table 4-18 Summary information relevant to the cultivation of oilseed crops, using soybean as an example .................................................................................................................................. 254 Table 4-19 Summary information relevant to the cultivation of root crops, using peanut as an example ....................................................................................................................................... 257 Table 4-20 Summary information relevant to the cultivation of cotton .................................... 261 Table 4-21 Rhodes grass production for hay over 1 year of a 6-year cycle ................................ 264 Table 4-22 Cavalcade production over a 1-year cycle ................................................................ 267 Table 4-23 Summary information relevant to row crop horticulture production, with rockmelon as an example ............................................................................................................................. 271 Table 4-24 Summary information relevant to tree crop horticulture production, with mango as an example .................................................................................................................................. 274 Table 4-25 Summary information for Indian sandalwood production ....................................... 277 Table 4-26 Indicative capital and operating costs for a range of generic aquaculture development options .................................................................................................................. 288 Table 4-27 Gross revenue targets required to achieve target internal rates of return (IRR) for aquaculture developments with different combinations of capital costs and operating costs . 290 Table 5-1 Summary of capital costs, yields and costs per ML supply, including operation and maintenance ............................................................................................................................... 300 Table 5-2 Opportunity-level estimates of the potential scale of groundwater resource development opportunities in the Southern Gulf catchments .................................................. 304 Table 5-3 Summary of estimated costs for a 250 ha irrigation development using groundwater ..................................................................................................................................................... 307 Table 5-4 Mean annual groundwater balance for the Cambrian Limestone Aquifer (CLA) in the Undilla Sub-basin of the Georgina Basin for a 109-year climate sequence (1910–2019) and areas of the CLA that coincide with the Lawn Hill Creek and Gregory subcatchments and Nicholson Groundwater Management Area (NGMA) ................................................................................. 313 Table 5-5 Potential dam sites in the Southern Gulf catchments examined as part of the Assessment ................................................................................................................................. 331 Table 5-6 Summary comments for potential dams in the Southern Gulf catchments ............... 332 Table 5-7 Estimated construction cost of 3 m high sheet piling weir......................................... 343 Table 5-8 Effective volume after net evaporation and seepage for ringtanks of three mean water depths, under three seepage rates, near Century Mine in the Southern Gulf catchments ..................................................................................................................................................... 355 Table 5-9 Indicative costs for a 4000 ML ringtank ...................................................................... 357 Table 5-10 Annualised cost for the construction and operation of three ringtank configurations ..................................................................................................................................................... 357 Table 5-11 Equivalent annual cost per megalitre for two different capacity ringtanks under three seepage rates based on a climate station near the Century Zinc Mine in the Southern Gulf catchments .................................................................................................................................. 358 Table 5-12 Actual costs of four gully dams in northern Queensland ......................................... 362 Table 5-13 Cost of three hypothetical large farm-scale gully dams of capacity 4 GL ................. 363 Table 5-14 High-level breakdown of capital costs for three hypothetical large farm-scale gully dams of capacity 4 GL ................................................................................................................. 363 Table 5-15 Effective volumes and cost per megalitre for a 4 GL storage with different mean depths and seepage loss rates based on a climate station at the Century Zinc Mine in the Southern Gulf catchments .......................................................................................................... 364 Table 5-16 Cost of construction and operation of three hypothetical 4 GL gully dams............. 364 Table 5-17 Equivalent annualised cost and effective volume for three hypothetical 4 GL gully dams with various mean depths and seepage loss rates based on climate data at Victoria River Downs Station in the Victoria catchment ................................................................................... 365 Table 5-18 Summary of conveyance and application efficiencies .............................................. 367 Table 5-19 Water distribution and operational efficiency as nominated in water resource plans for four irrigation water supply schemes in Queensland ........................................................... 368 Table 5-20 Application efficiencies for surface, spray and micro irrigation systems ................. 371 Table 6-1 Types of questions that users can answer using the tools in this chapter ................. 382 Table 6-2 Indicative capital costs for developing three irrigation schemes based on the most cost-effective dam sites identified in the Southern Gulf catchments ........................................ 386 Table 6-3 Assumed indicative capital and operating costs for new off- and on-farm irrigation infrastructure .............................................................................................................................. 387 Table 6-4 Price irrigators can afford to pay for water, based on the type of farm, the farm water use and the farm annual gross margin (GM), while meeting a target 10% internal rate of return (IRR) ............................................................................................................................................. 389 Table 6-5 Farm gross margins (GMs) required in order to cover the costs of off-farm water infrastructure (at the supplier’s target internal rate of return (IRR)) ......................................... 391 Table 6-6 Water pricing required in order to cover costs of off-farm irrigation scheme development (dam, water distribution, and supporting infrastructure) at the investors target internal rate of return (IRR) ........................................................................................................ 392 Table 6-7 Farm gross margins (GMs) required in order to achieve target internal rates of return (IRR), given various capital costs of farm development (including an on-farm water source) .. 393 Table 6-8 Equivalent costs of water per ML for on-farm water sources with various capital costs of development, at the internal rate of return (IRR) targeted by the investor .......................... 394 Table 6-9 Risk adjustment factors for target farm gross margins (GMs), accounting for the effects of the reliability and severity (level of farm performance in ‘failed’ years) of the periodic risk of water reliability ................................................................................................................ 396 Table 6-10 Risk adjustment factors for target farm gross margins (GMs) accounting for the effects of reliability and the timing of periodic risks .................................................................. 397 Table 6-11 Risk adjustment factors for target farm gross margins (GMs), accounting for the effects of learning risks ............................................................................................................... 398 Table 6-12 Summary characteristics of the five dams used in this review................................. 401 Table 6-13 Summary of key issues and potential improvements arising from a review of recent dam developments ..................................................................................................................... 402 Table 6-14 Indicative costs of agricultural processing facilities .................................................. 405 Table 6-15 Indicative costs of road and electricity infrastructure .............................................. 406 Table 6-16 Indicative road transport costs between the Southern Gulf catchments and key markets and ports ....................................................................................................................... 406 Table 6-17 Indicative costs of community facilities .................................................................... 407 Table 6-18 Key 2021 data comparing the Southern Gulf catchments with the related I–O analysis region ............................................................................................................................. 410 Table 6-19 Regional economic impact estimated by I–O analysis for the total construction phase of an irrigated agricultural development based on estimated Type ll multipliers determined from the north-west Queensland I–O models ............................................................................ 411 Table 6-20 Estimated regional economic impact per year in the Southern Gulf catchments resulting from four scales of direct increase in agricultural output (rows) for the different categories of agricultural activity (columns) using the I–O model for north-west Queensland 413 Table 6-21 Estimated impact on annual household incomes and full-time equivalent (FTE) jobs within the Southern Gulf catchments resulting from four scales of direct increase in agricultural output (rows) for the various categories of agricultural activity (columns) ............................... 414 Table 7-1 Water resource development and climate scenarios explored in this ecology analysis ..................................................................................................................................................... 430 Table 7-2 Ecological assets used in the Southern Gulf catchments Water Resource Assessment and the different ecology groups used in this analysis............................................................... 432 Table 7-3 Reporting qualitative values for the flow dependencies modelling as rank percentile change of the hydrometrics ........................................................................................................ 434 Table 7-4 Scenarios of different hypothetical instream dam locations showing mean changes of ecology flows for groups of assets across each asset’s respective catchment assessment nodes ..................................................................................................................................................... 447 Table 7-5 Examples of significant pest and disease threats to plant industries in the Southern Gulf catchments .......................................................................................................................... 455 Table 7-6 Regional weed priorities and their management actions in Southern Gulf catchments ..................................................................................................................................................... 457 Table 7-7 High-risk freshwater pest fish threats to the Southern Gulf catchments .................. 459 Table 7-8 Water quality variables reviewed – their impacts on the environment, aquatic ecology and human health ....................................................................................................................... 468