Water resource assessment for the Roper catchment Australia’s National Science Agency A report from the CSIRO Roper River Water Resource Assessment for the National Water Grid Editors: Ian Watson, Cuan Petheram, Caroline Bruce and Chris Chilcott ISBN 978-1-4863-1905-3 (print) ISBN 978-1-4863-1906-0 (online) Citation Watson I, Petheram C, Bruce C and Chilcott C (eds) (2023) Water resource assessment for the Roper catchment. A report from the CSIRO Roper River Water Resource Assessment for the National Water Grid. CSIRO, Australia. Chapters should be cited in the format of the following example: Petheram C, Bruce C and Watson I (2023) Chapter 1: Preamble: The Roper River Water Resource Assessment. In: Watson I, Petheram C, Bruce C and Chilcott C (eds) (2023) Water resource assessment for the Roper catchment. A report from the CSIRO Roper River Water Resource Assessment for the National Water Grid. CSIRO, Australia. Copyright © Commonwealth Scientific and Industrial Research Organisation 2023. 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 Roper River 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 Government. The Assessment was guided by two committees: i. The Assessment’s Governance Committee: CRC for Northern Australia/James Cook University; CSIRO; National Water Grid (Department of Climate Change, Energy, the Environment and Water); NT Department of Environment, Parks and Water Security; NT Department of Industry, Tourism and Trade; Office of Northern Australia; Qld Department of Agriculture and Fisheries; Qld Department of Regional Development, Manufacturing and Water ii. The Assessment’s joint Roper and Victoria River catchments Steering Committee: Amateur Fishermen’s Association of the NT; Austrade; Centrefarm; CSIRO, National Water Grid (Department of Climate Change, Energy, the Environment and Water); Northern Land Council; NT Cattlemen’s Association; NT Department of Environment, Parks Australia; Parks and Water Security; NT Department of Industry, Tourism and Trade; Regional Development Australia; NT Farmers; NT Seafood Council; Office of Northern Australia; Roper Gulf Regional Council Shire 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 its release. This report was reviewed by Kevin Devlin (Independent consultant). For further acknowledgements, see page xxii. 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 Looking along the Roper River at Red Rock, Northern Territory. Source: CSIRO – Nathan Dyer Appendices Waterlily (Nymphaea violacea) common to Northern Australia found in billabongs, waterholes and rivers Photo: CSIRO - Nathan Dyer Assessment products More information about the Roper River Water Resource Assessment can be found at https://www.csiro.au/roperriver. 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 case study report that considers the regulatory processes and approval steps required for land and water development in the Roper catchment. The case study brings information about NT’s current land and water regulatory and approvals landscape together and structures it in an orderly way. It is intended to provide a useful introduction to the topic for proponents and others with an interest in advancing new developments in the NT (and the Roper catchment in particular). • An overview report is provided for a general public audience. • A factsheet provides key findings for a general public audience. This appendix lists all such deliverables. Please cite as they appear. Methods report CSIRO (2021) Proposed methods report for the Roper Catchment - updated. A report from the CSIRO Roper River Water Resource Assessment for the National Water Grid. 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 Roper River Water Resource Assessment for the National Water Grid. CSIRO, Australia. Duvert C, Hutley LB, Lamontagne S, Bourke AJ, Alvarez Cortes D, Irvine DJ and Taylor AR (2023) Tree water sourcing at the Mataranka Springs Complex. A technical report from the CSIRO Roper River Water Resource Assessment for the National Water Grid. CSIRO, Australia. Hughes J, Yang A, Marvanek S, Wang B, Petheram C and Philip S (2023) River model calibration and scenario analysis for the Roper catchment. A technical report from the CSIRO Roper River Water Resource Assessment for the National Water Grid. CSIRO, Australia. Kim S, Hughes J, Ticehurst C, Stratford D, Merrin L, Marvanek S and Petheram C (2023) Floodplain inundation mapping and modelling for the Roper catchment. A technical report from the CSIRO Roper River Water Resource Assessment for the National Water Grid. CSIRO, Australia. Knapton A, Taylor AR, Petheram C and Crosbie RS (2023) An investigation into the effects of climate change and groundwater development scenarios on the water resources of the Roper catchment using two finite element groundwater flow models. A technical report from the CSIRO Roper River Water Resource Assessment for the National Water Grid. CSIRO, Australia. Lyons P, Barber M, Fisher K and Braedon P (2023) Indigenous water values, rights, interests and development goals in the Roper catchment. A technical report from the CSIRO Roper River Water Resource Assessment for the National Water Grid. CSIRO, Australia. Petheram C, Yang A, Seo L, Rogers L, Baynes F, Devlin K, Marvanek S, Hughes J, Ponce Reyes R, Wilson P, Stratford D, Philip S (2022) Assessment of surface water storage options and reticulation infrastructure in the Roper catchment. A technical report from the CSIRO Roper River Water Resource Assessment for the National Water Grid. CSIRO, Australia. Stokes C, Jarvis D, Webster A, Watson I, Jalilov S, Oliver Y, Peake A, Peachey A, Yeates S, Bruce C, Philip S, Prestwidge D, Liedloff A, Poulton P, Price B and McFallan S (2023) Financial and socio-economic viability of irrigated agricultural development in the Roper catchment. A technical report from the CSIRO Roper River Water Resource Assessment for the National Water Grid. CSIRO, Australia. Stratford D, Kenyon R, Pritchard J, Merrin L, Linke S, Ponce Reyes R, Blamey L, Buckworth R, Castellazzi P, Costin B, Deng R, Gannon R, Gilbey S, King D, Kopf K, Kopf S, McGinness H, McInerney P, Perna C, Plaganyi E and Waltham N (2022) Ecological assets of northern Australia to inform water resource assessments. A technical report from the CSIRO Roper River Water Resource Assessment for the National Water Grid. CSIRO, Australia. Stratford D, Merrin L, Linke S, Kenyon R, Ponce Reyes R, Buckworth R, Deng RA, McGinness H, Pritchard J, Seo L and Waltham N (2024) Assessment of the potential ecological outcomes of water resource development in the Roper catchment. A technical report from the CSIRO Roper River Water Resource Assessment for the National Water Grid. CSIRO, Australia. Taylor AR, Crosbie RS, Turnadge C, Lamontagne S, Deslandes A, Davies PJ, Barry K, Suckow A, Knapton A, Marshall S, Hodgson G, Tickell S, Duvert C, Hutley L and Dooley K (2023) Hydrogeological assessment of the Cambrian Limestone Aquifer and the Dook Creek Aquifer in the Roper catchment, Northern Territory. A technical report from the CSIRO Roper River Water Resource Assessment for the National Water Grid. CSIRO, Australia. Thomas M, Philip S, Stockman U, Wilson PR, Searle, R, Hill J, Bui E, Gregory, L, Watson, I, Wilson PL and Gallant G (2022) Soils and land suitability for the Roper catchment, Northern Territory. A technical report from the CSIRO Roper River Water Resource Assessment for the National Water Grid. CSIRO, Australia. Catchment report Watson I, Petheram C, Bruce C and Chilcott C (eds) (2023) Water resource assessment for the Roper catchment. A report from the CSIRO Roper River Water Resource Assessment for the National Water Grid. CSIRO, Australia. Overview report CSIRO (2023) Water resource assessment for the Roper catchment. An overview report from the CSIRO Roper River Water Resource Assessment for the National Water Grid. CSIRO, Australia. Factsheet on key findings CSIRO (2023) Water resource assessment for the Roper catchment. Key messages of reports to the CSIRO Roper River Water Resource Assessment for the National Water Grid. CSIRO, Australia. Shortened forms For more information on this figure or equation or table, please contact CSIRO on enquiries@csiro.au For more information on this figure or equation or table, please contact CSIRO on enquiries@csiro.au For more information on this figure or equation or table, please contact CSIRO on enquiries@csiro.au Units UNIT DESCRIPTION cm centimetre GL gigalitre (1,000,000,000 litres) GWh gigawatt hour km kilometre (1000 metres) L litre m metre mAHD metres above Australian Height Datum mg milligrams mm millimetre ML megalitre (1,000,000 litres) ppt parts per trillion Data sources and availability The Roper River Water Resource Assessment obtained a range of data for use under licence from a number of organisations, including the following: • Australian Government (Geoscience Australia ) – GEODATA Topo 250K Series 3 – spatial data for mapping  Licence: Creative Commons Attribution 3.0 Australia, http://creativecommons.org/licenses/by/3.0/au/, (c) Commonwealth of Australia (Geoscience Australia) 2014  https://data.gov.au/dataset/ds-dga-c5c2d224-aa95-4b6b-9e0c- bd9f25301ffc/details?q=top%20250k%20series%203 – SRTM-derived 3 Second Digital Elevation Models Version 1.0  Licence: The 3 second DEMs were released under Creative Commons attribution licensing in ESRI Grid format  https://ecat.ga.gov.au/geonetwork/srv/eng/catalog.search?node=srv#/metadata/ 69888 – GEODATA 9 second DEM and D8: Digital Elevation Model Version 3  Licence: Creative Commons Attribution 4.0 International Licence  https://ecat.ga.gov.au/geonetwork/srv/eng/catalog.search?node=srv#/metadata/ 66006 • Esri – World Imagery Map Service – map service of satellite imagery for the world and high- resolution imagery for the United States and other areas around the world. Imagery is sourced from GeoEye IKONOS, Getmapping, AeroGRID, IGN Spain, IGP Portugal, i-cubed, USGS, AEX, Aerogrid, Swisstopo and by the GIS User Community.  https://www.arcgis.com/home/item.html?id=10df2279f9684e4a9f6a7f08febac2a9 • Atlas of Living Australia - a collaborative, national project that aggregates biodiversity data from multiple sources and is freely available and usable online. – https://www.ala.org.au/ • Australian Wetlands Database - online access to information on Australian Ramsar Wetlands and sites listed in the Directory of Important Wetlands in Australia , Australia’s internationally and nationally important wetlands respectively. – http://www.environment.gov.au/water/wetlands/australian-wetlands-database Glossary and terms Anthropogenic: a human impact on the environment. Aquifer: a permeable geological material that can transmit significant quantities of water to a bore, spring, or surface water body. Generally, ‘significant’ is defined based on human need, rather than on an absolute standard. Aquitard (confining layers): a saturated geological unit that is less permeable than an aquifer, and incapable of transmitting useful quantities of water. Aquitards often form a confining layer over an artesian aquifer. Artesian: a general term used when describing certain types of groundwater resources. Artesian water is underground water confined and pressurised within a porous and permeable geological formation. An artesian aquifer has enough natural pressure to allow water in a bore to rise to the ground surface. Subartesian water is water that occurs naturally in an aquifer, which if tapped by a bore, would not flow naturally to the surface. Artesian conditions refer to the characteristics of water under pressure. Basement: the crust below the rocks of interest. In hydrogeology it means non-prospective rocks below accessible groundwater. Commonly refers to igneous and metamorphic rocks which are unconformably overlain by sedimentary beds or cover material, and sometimes used to indicate ‘bedrock’ (i.e. underlying or encasing palaeovalley sediments). Benthic: the ecological region at the lowest level of a body of water such as an ocean or a lake, including the sediment surface and some sub-surface layers. Current development: the level of surface water, groundwater and economic development in place as of 1 July 2013. The Assessment assumes that all current water entitlements are being fully used. Development: see entries for ‘current development’ and ‘future irrigation development’. Discount rate: the percentage by which future cost and benefits are discounted each year (compounded) to convert them to their equivalent present value (PV) Drainage division: the area of land where surface water drains to a common point. There are 12 major drainage divisions in Australia. At a smaller scale, surface water drainage areas are also referred to as river basins, catchments, or watersheds. Drawdown: the lowering of groundwater level resulting from the extraction of water, oil or gas from an aquifer. Ecosystem services: the contributions that ecosystems make to human wellbeing. Eutrophication: the ecosystem response to the addition of artificial or natural substances, such as nitrates and phosphates, through fertilizers or sewage, to an aquatic system. One example is an ‘algal bloom’ or great increase of phytoplankton in a water body as a response to increased levels of nutrients. Environmental flows: describe the quantity, timing and quality of water flows required to sustain freshwater and estuarine ecosystems and the human livelihoods and well being that depend on these ecosystems. Flow regime: the entire pattern of flow in a river – from how long it lasts, to how frequently it flows and how large it is. Fecundity: the potential reproductive capacity of an individual or population. Fertigation: application of crop nutrients through the irrigation system (i.e. liquid fertiliser) Future irrigation development: is described by each case study storyline (see chapters 8 to 10); river inflow and agricultural productivity are modified accordingly. Geological basin: layers of rock that have been deformed by mega-scale geological forces to become bowl-shaped. Often these are round or oblong with a depression in the middle of the basin. Geological formation: geological formations consist of rock layers that have common physical characteristics (lithology) deposited during a specific period of geological time. Groundwater (hydrogeology): water that occurs within the zone of saturation beneath the Earth’s surface. The study of hydrogeology focuses on movement of fluids through geological materials (e.g. layers of rock). Groundwater basin: a groundwater basin is a non-geological delineation for describing a region of groundwater flow. Within a groundwater basin, water enters through recharge areas and flows toward discharge areas. Groundwater divide: a divide that is defined by groundwater flow directions that flow in opposite directions perpendicular to the location of the divide. Groundwater flow (hydrodynamics): within a groundwater basin, the path from a recharge area to a discharge area is referred to as a groundwater flow system, where travel time may be as short as days or longer than centuries, depending on depth. The mechanics of groundwater flow – the hydrodynamics – are governed by the structure and nature of the sequence of aquifers. Groundwater flow model: a computer simulation of groundwater conditions in an aquifer or entire groundwater basin. The simulations are representations based on the physical structure and nature of the sequence of aquifers and rates of inflow – from recharge areas – and outflow – through springs and bores. Groundwater level: in this report refers to the elevation of equivalent freshwater hydraulic head at 25 °C Groundwater recharge and discharge: recharge occurs where rainfall or surface water drains downward and is added to groundwater (the zone of saturation). Discharge occurs where groundwater emerges from the Earth, such as through springs or seepage into rivers. Hydrodynamics: the study of liquids in motion. Internal rate of return (IRR): the discount rate at which the net present value (NPV) is zero. Legume: pulse crop. Lithology: the character of a rock; its composition, structure, texture, and hardness. Net present value: a standard method for using the time value of money to appraise long-term projects by measuring the differences between costs and revenues in present value terms. Palaeochannel: refers to the main channel of ancient rivers, sometimes called the ‘thalweg’, the lowest point of incision along the river bed where coarser sediments are commonly deposited. Former river channels that are recognised in the surface (from aerial or satellite images) or subsurface (typically in aerial electromagnetic surveys or drilling). Permeability: a measurement describing the ability of any fluid (water, oil) to pass through a porous material. Values vary widely, with higher values corresponding to aquifers (i.e. highly permeable) and lower values corresponding to aquitards (i.e. less permeable). Refugia: habitat for species to retreat to and persist in. Regolith: weathered upper layer. Residual value: calculated as the proportional asset life remaining multiplied by the original asset price. Riparian: of, on, or relating to the banks of a watercourse. A riparian zone is the area of land immediately adjacent to a stream or river. Plants found within this zone are collectively known as riparian vegetation. This vegetation frequently contains large trees that stabilise the river bank and shade part of the river. River reach: an extent or stretch of river between two bends. Streamflow: is the flow of water in rivers and other channels (creeks, streams etc.). Water flowing in channels comes from surface runoff, from groundwater flow, and from water discharged from pipes. There are a variety of ways to measure streamflow – a gauge provides continuous flow over time at one location for water resource and environmental management or other purposes; it can be estimated by mathematical equations. The record of flow over time is called a hydrograph. Flooding occurs when the volume of water exceeds the capacity of the channel. Triple-bottom-line: an accounting framework that incorporates three dimensions of performance: social, environmental and financial. Watertable: the surface where the groundwater level is balanced against atmospheric pressure. Often, this is the shallowest water below the ground. List of figures List of tables Figures Figure 1-1 Map of Australia showing Assessment area .................................................................. 4 Figure 1-2 Number of dams constructed in Australia and northern Australia over time .............. 8 Figure 1-3 Schematic diagram of key components and concepts in the establishment of a greenfield irrigation development ................................................................................................ 10 Figure 1-4 Roper Bar on the Roper River ...................................................................................... 13 Figure 1-5 The Roper catchment .................................................................................................. 14 Figure 2-1 Schematic diagram of key natural components and concepts in the establishment of a greenfield irrigation development ............................................................................................. 20 Figure 2-2 Surface geology of the Roper catchment .................................................................... 24 Figure 2-3 The Gulf Fall comprises residual rises and hills, strike ridges, mesas and plateaux and intervening fluvial valleys .............................................................................................................. 25 Figure 2-4 Physiographic provinces of the Roper catchment ....................................................... 26 Figure 2-5 Major geological provinces of the Roper catchment .................................................. 29 Figure 2-6 The soil generic groups (SGGs) of the Roper catchment produced by digital soil mapping ........................................................................................................................................ 31 Figure 2-7 Red loamy soil (SGG 4.1) on the Sturt Plateau ............................................................ 35 Figure 2-8 Large areas of brown Vertosols (SGG 9) on alluvial plains along the major rivers are suited to irrigated grain and pulse crops, forage crops, sugarcane and cotton ........................... 36 Figure 2-9 The very deep, well-drained, sandy surfaced red massive loamy soils (Kandosol, SGG 4.1) overlying limestone in the Mataranka area are suited to a wide range of irrigated crops .. 38 Figure 2-10 Surface soil pH of the Roper catchment .................................................................... 39 Figure 2-11 Soil thickness of the Roper catchment ...................................................................... 40 Figure 2-12 Soil surface texture of the Roper catchment ............................................................. 41 Figure 2-13 Soil permeability of the Roper catchment ................................................................. 42 Figure 2-14 Available water capacity in the Roper catchment ..................................................... 43 Figure 2-15 Rockiness in soils of the Roper catchment ................................................................ 44 Figure 2-16 Historical rainfall, potential evaporation and rainfall deficit .................................... 46 Figure 2-17 Monthly rainfall in the Roper catchment at Mataranka and Ngukurr under Scenario A ..................................................................................................................................... 48 Figure 2-18 Monthly potential evaporation in the Roper catchment at Mataranka and Ngukurr under Scenario A ........................................................................................................................... 49 Figure 2-19 Annual rainfall at Mataranka and Ngukurr under Scenario A ................................... 49 Figure 2-20 (a) Coefficient of variation of annual rainfall, and (b) the coefficient of variation of annual rainfall plotted against mean annual rainfall for 99 rainfall stations around Australia ... 50 Figure 2-21 Runs of wet and dry years at (a) Mataranka, and (b) Ngukurr stations under Scenario A ..................................................................................................................................... 52 Figure 2-22 Percentage change in mean annual rainfall and potential evaporation under Scenario C relative to under Scenario A ....................................................................................... 54 Figure 2-23 Spatial distribution of mean annual rainfall across the Roper catchment under scenarios Cwet, Cmid and Cdry ..................................................................................................... 54 Figure 2-24 Monthly rainfall and potential evaporation for the Roper catchment under scenarios A and C .......................................................................................................................... 55 Figure 2-25 Simplified schematic diagram of terrestrial water balance in the Roper catchment 59 Figure 2-26 Simplified regional geology of the Roper catchment ................................................ 60 Figure 2-27 Groundwater from the Dook Creek Formation ......................................................... 61 Figure 2-28 Simplified regional geology for the entire spatial extent of the Mount Rigg Group of the McArthur Basin and the Tindall Limestone and equivalents of the Daly, Wiso and Georgina basins ............................................................................................................................................ 62 Figure 2-29 Simplified regional hydrogeology of the Roper catchment....................................... 65 Figure 2-30 Full extent of both the Cambrian Limestone Aquifer and Dook Creek Aquifer ........ 67 Figure 2-31 Groundwater bore yields for (a) the major aquifers hosted in the Tindall Limestone and equivalents and the Mount Rigg and Nathan groups and (b) other minor aquifers of the Roper catchment ........................................................................................................................... 68 Figure 2-32 Two-dimensional conceptual schematic of the interconnected aquifer system and its variability .................................................................................................................................. 69 Figure 2-33 Groundwater salinity for (a) the major aquifers hosted in the Tindall Limestone and equivalents and the Mount Rigg and Nathan groups and (b) other minor aquifers of the Roper catchment ..................................................................................................................................... 70 Figure 2-34 Annual recharge estimates for the Roper catchment ............................................... 72 Figure 2-35 Summary of recharge statistics to outcropping areas of key hydrogeological units across the Roper catchment ......................................................................................................... 73 Figure 2-36 Spatial distribution of groundwater discharge classes including surface water – groundwater connectivity across the Roper catchment .............................................................. 75 Figure 2-37 Modelled streamflow under natural conditions ....................................................... 76 Figure 2-38 Red Rock streamflow gauging station on the Roper River ........................................ 77 Figure 2-39 Streamflow observation data availability in the Roper catchment ........................... 78 Figure 2-40 Median annual streamflow (50% exceedance) in the Roper catchment under Scenario A ..................................................................................................................................... 80 Figure 2-41 20% and 80% exceedance of annual streamflow in the Roper catchment under Scenario A ..................................................................................................................................... 81 Figure 2-42 Catchment area and elevation profile along the Roper River from its mouth to the upper Waterhouse River at elevation 270 mAHD ........................................................................ 81 Figure 2-43 Mean annual (a) rainfall and (b) runoff across the Roper catchment under Scenario A .................................................................................................................................................... 83 Figure 2-44 Maps showing annual runoff at (a) 20%, (b) 50% and (c) 80% exceedance across the Roper catchment under Scenario A .............................................................................................. 83 Figure 2-45 Runoff in the Roper catchment under Scenario A ..................................................... 84 Figure 2-46 Flood inundation map of the Roper catchment ........................................................ 85 Figure 2-47 Spatial extent and temporal variation of inundation in the Roper catchment ......... 86 Figure 2-48 Peak flood discharge and annual exceedance probability at gauge 9030250 (Red Rock) .............................................................................................................................................. 87 Figure 2-49 Groundwater fed waterhole near Bitter Springs, Mataranka ................................... 88 Figure 2-50 Instream waterhole evolution ................................................................................... 88 Figure 2-51 Location of river reaches containing permanent water in the Roper catchment ..... 89 Figure 2-52 Location of water quality sampling undertaken by previous studies ....................... 91 Figure 2-53 Tranquil reach on the Roper River ............................................................................. 92 Figure 3-1 Schematic diagram of key components of the living and built environment to be considered in the establishment of a greenfield irrigation development .................................... 99 Figure 3-2 Conceptual diagram of selected ecological values and assets of the Roper catchment ..................................................................................................................................................... 104 Figure 3-3 Waterlily (Nymphaea violacea) common to northern Australia found in billabongs, waterholes and rivers ................................................................................................................. 105 Figure 3-4 Location of protected areas and important wetlands within the Roper catchment 106 Figure 3-5 White-bellied sea-eagle (Haliaeetus leucogaster) in a wetland in northern Australia ..................................................................................................................................................... 114 Figure 3-6 Land subject to inundation (potential floodplain wetlands) and nationally important wetlands (DIWA) in the Roper catchment .................................................................................. 115 Figure 3-7 Grunters in the Roper catchment .............................................................................. 118 Figure 3-8 Distribution of freshwater turtles within the Roper catchment ............................... 120 Figure 3-9 Royal spoonbills are a representative species of the colonial and semi-colonial nesting waders functional group ................................................................................................ 122 Figure 3-10 Fisheries catch of banana prawns and their habitat in the Roper catchment marine region .......................................................................................................................................... 125 Figure 3-11 Mangrove and intertidal habitat associated with mud crabs in northern Australia ..................................................................................................................................................... 127 Figure 3-12 Locations of observed selected surface water dependent vegetation types in the Roper catchment ......................................................................................................................... 130 Figure 3-13 Distribution of species listed under the EPBC Act (Cth) and by the Northern Territory Government in the Roper catchment ......................................................................................... 131 Figure 3-14 Boundaries of the Australian Bureau of Statistics Statistical Area Level 4 (SA4) and Statistical Area Level 2 (SA2) regions used for demographic data in this Assessment .............. 134 Figure 3-15 Land use classification for the Roper catchment .................................................... 138 Figure 3-16 Map of regions in the Northern Prawn Fishery ....................................................... 142 Figure 3-17 Road rankings and conditions for the Roper catchment ......................................... 144 Figure 3-18 Vehicle access restrictions for the Roper catchment .............................................. 145 Figure 3-19 Common configurations of heavy freight vehicles used for transporting agricultural goods in Australia ........................................................................................................................ 146 Figure 3-20 Looking south along the Stuart Highway the main north–south transport artery of the Northern Territory ................................................................................................................ 146 Figure 3-21 Road speed restrictions for the Roper catchment .................................................. 147 Figure 3-22 Agricultural enterprises in the Roper catchment and amount of annual trucking to/from them .............................................................................................................................. 149 Figure 3-23 Electricity generation and transmission network and natural gas pipelines in the Roper catchment ......................................................................................................................... 151 Figure 3-24 Location, type and volume of annual licensed surface water and groundwater entitlements ................................................................................................................................ 153 Figure 3-25 Colonial frontier massacres in the Roper catchment .............................................. 158 Figure 3-26 Indigenous freehold (Aboriginal Land) in the Roper catchment as at July 2017 .... 160 Figure 3-27 Indigenous native title claims and determinations in the Roper catchment as at July 2017............................................................................................................................................. 161 Figure 4-1 Schematic diagram 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 .............................................................................................. 186 Figure 4-2 Area (ha) of the Roper catchment mapped in each of the land suitability classes for 14 selected land use options ...................................................................................................... 193 Figure 4-3 Agricultural versatility index map for the Roper catchment ..................................... 194 Figure 4-4 Climate comparisons of Roper sites versus established irrigation areas at Katherine (NT) and Ord River (WA) ............................................................................................................. 198 Figure 4-5 Annual cropping calendar for irrigated agricultural options in the Roper catchment ..................................................................................................................................................... 200 Figure 4-6 Soil wetness indices that indicate when seasonal trafficability constraints are likely to occur on Kandosols (sandy) and Vertosols (high clay) with a Bulman climate .......................... 201 Figure 4-7 Influence of planting date on dryland grain sorghum yield at Bulman for (a) a Kandosol and (b) a Vertosol ........................................................................................................ 203 Figure 4-8 Influence of available irrigation water on grain sorghum yields for planting dates (a) on 1st February and (b) 1st August, for a Kandosol with a Bulman climate .............................. 204 Figure 4-9 A melon crop growing in the Mataranka area of the Sturt Plateau .......................... 206 Figure 4-10 Fluctuations in seedless watermelon prices at Melbourne wholesale markets from April 2020 to February 2023 ....................................................................................................... 211 Figure 4-11 Modelled land suitability for Crop Group 7 (e.g. sorghum (grain) or maize) using furrow irrigation in (a) the wet season and (b) dry season ........................................................ 223 Figure 4-12 Sorghum (grain) ....................................................................................................... 223 Figure 4-13 Modelled land suitability for mungbean (Crop Group 10) in the dry season using (a) furrow irrigation and (b) spray irrigation .................................................................................... 226 Figure 4-14 Mungbean ................................................................................................................ 226 Figure 4-15 Modelled land suitability for soybean (Crop Group 10) in the dry season using (a) furrow irrigation and (b) spray irrigation .................................................................................... 229 Figure 4-16 Soybean.................................................................................................................... 229 Figure 4-17 Modelled land suitability for peanut (Crop Group 6) using spray irrigation in (a) the wet season and (b) the dry season ............................................................................................. 232 Figure 4-18 Peanuts .................................................................................................................... 232 Figure 4-19 Modelled land suitability for cotton (Crop Group 7) using furrow irrigation in (a) the wet season and (b) the dry season ............................................................................................. 236 Figure 4-20 Cotton ...................................................................................................................... 236 Figure 4-21 Modelled land suitability for Rhodes grass (Crop Group 14) using (a) spray irrigation and (b) furrow irrigation ............................................................................................................. 240 Figure 4-22 Rhodes grass ............................................................................................................ 240 Figure 4-23 Modelled land suitability for Cavalcade (Crop Group 13) in the wet season using (a) spray irrigation and (b) furrow irrigation .................................................................................... 243 Figure 4-24 Lablab ....................................................................................................................... 243 Figure 4-25 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 ........................................................................................................ 247 Figure 4-26 Melon crop in Mataranka area ................................................................................ 247 Figure 4-27 Modelled land suitability for (a) mango (Crop Group 1) and (b) lime (Crop Group 2), both grown using trickle irrigation.............................................................................................. 250 Figure 4-28 Mangoes .................................................................................................................. 250 Figure 4-29 Modelled land suitability for Indian sandalwood (Crop Group 15) grown using (a) trickle or (b) furrow irrigation ..................................................................................................... 253 Figure 4-30 Indian sandalwood and host plants ......................................................................... 253 Figure 4-31 Quinoa crop ............................................................................................................. 256 Figure 4-32 Black tiger prawns .................................................................................................... 257 Figure 4-33 Barramundi .............................................................................................................. 258 Figure 4-34 Schematic of marine aquaculture farm ................................................................... 259 Figure 4-35 Land suitability in the Roper catchment for marine species aquaculture; (a) lined ponds and (b) earthen ponds ...................................................................................................... 263 Figure 4-36 Land suitability in the Roper catchment for freshwater species aquaculture; (a) lined ponds and (b) earthen ponds ...................................................................................................... 265 Figure 5-1 Schematic diagram of key engineering and agricultural components to be considered in the establishment of a water resource and greenfield irrigation development .................... 273 Figure 5-2 Hydrogeological units with potential for future groundwater resource development ..................................................................................................................................................... 282 Figure 5-3 Hydrogeological cross-section through the Cambrian Limestone Aquifer (CLA) in the south to south-west of the Roper catchment ............................................................................ 284 Figure 5-4 Depth to the top of the Cambrian Limestone Aquifer (CLA) ..................................... 285 Figure 5-5 Depth to standing water level (SWL) of the Cambrian Limestone Aquifer (CLA)...... 286 Figure 5-6 Lower reach of Elsey Creek that is groundwater-fed near the junction with the Roper River ............................................................................................................................................ 289 Figure 5-7 Modelled drawdown in groundwater level in the Cambrian Limestone Aquifer (CLA) under (a) Scenario A current licensed entitlements and (b) Scenario B35 at ~2070 ................. 290 Figure 5-8 North-west to south-east cross section traversing the Dook Creek Formation........ 292 Figure 5-9 Depth to the top of the Dook Creek Aquifer (DCA) ................................................... 293 Figure 5-10 Dolostone outcrop in the bed of Weemol Spring .................................................... 294 Figure 5-11 Depth to standing water level (SWL) of the Dook Creek Aquifer (DCA) ................. 295 Figure 5-12 Modelled drawdown in groundwater level in the Dook Creek Aquifer (DLA) for (a) Scenario B6, 6 GL/year hypothetical groundwater development (1 GL/year at six locations for the period 2059 to 2069); (b) Scenario B12, 12 GL/year hypothetical groundwater development (2 GL/year at six locations for the period 2059 top 2069); and (c) Scenario B18, 18 GL/year hypothetical groundwater development (3 GL/year at six locations for the period 2059 to 2069) ..................................................................................................................................................... 297 Figure 5-13 Types of managed aquifer recharge (MAR) ............................................................. 300 Figure 5-14 Managed aquifer recharge (MAR) opportunities for the Roper catchment independent of distance from a water source for recharge ...................................................... 302 Figure 5-15 Managed aquifer recharge (MAR) opportunities in the Roper catchment within 5 km of major rivers ............................................................................................................................. 303 Figure 5-16 Potential storage sites in the Roper catchment based on minimum cost per ML storage capacity .......................................................................................................................... 307 Figure 5-17 Potential storage sites in the Roper catchment based on minimum cost per ML yield at the dam wall ........................................................................................................................... 309 Figure 5-18 Roper catchment hydro-electric power generation opportunity map ................... 310 Figure 5-19 Cost of water in $/ML versus cumulative divertible yield at 85% annual time reliability ..................................................................................................................................... 314 Figure 5-20 Migratory fish and water-dependent birds in the vicinity of the potential Waterhouse River dam site ......................................................................................................... 316 Figure 5-21 Potential Waterhouse River dam site on the Waterhouse River: cost and yield at the dam wall ...................................................................................................................................... 317 Figure 5-22 Migratory fish and water-dependent birds in the vicinity of the potential upper Flying Fox Creek dam site............................................................................................................ 319 Figure 5-23 Upper Flying Fox Creek dam site on the Flying Fox Creek: cost and yield at the dam wall .............................................................................................................................................. 320 Figure 5-24 Schematic cross-section diagram of sheet piling weir ............................................ 321 Figure 5-25 Rectangular ringtank and 500 ha of cotton in the Flinders catchment (Queensland) ..................................................................................................................................................... 323 Figure 5-26 Suitability of land for large farm-scale ringtanks in the Roper catchment ............. 325 Figure 5-27 Annual reliability of diverting annual system and reach target for varying pump start thresholds ................................................................................................................................... 327 Figure 5-28 Annual reliability of diverting annual system and reach target for varying pump start thresholds assuming end-of-system flow requirement before pumping can commence is 400 GL ..................................................................................................................................................... 329 Figure 5-29 Annual reliability of diverting annual system and reach target for varying pump start thresholds assuming end-of-system flow requirement before pumping can commence is 1000 GL ................................................................................................................................................ 330 Figure 5-30 50% annual exceedance (median) streamflow relative to Scenario A in the Roper catchment for a pump start threshold of 1000 ML/day and a pump capacity of 20 days ......... 331 Figure 5-31 80% annual exceedance (median) streamflow relative to Scenario A in the Roper catchment for a pump start threshold of 1000 ML/day and a pump capacity of 20 days ......... 332 Figure 5-32 Annual reliability of diverting annual system and reach targets for varying pump rates assuming a pump start flow threshold of 1000 ML/day ................................................... 333 Figure 5-33 Most economically suitable locations for large farm-scale gully dams in the Roper catchment ................................................................................................................................... 339 Figure 5-34 Suitability of soils for construction of gully dams in the Roper catchment ............ 340 Figure 5-35 Reported conveyance losses from irrigation systems across Australia .................. 348 Figure 5-36 Efficiency of different types of irrigation systems ................................................... 349 Figure 5-37 Potential piped reticulated layout along the Waterhouse River ............................. 356 Figure 5-38 Nominal conceptual layout of potential irrigation area on Flying Fox Creek .......... 359 Figure 6-1 Schematic diagram of key components affecting the commercial viability of a potential greenfield irrigation development .............................................................................. 366 Figure 6-2 Map showing locations of the five case study dams used in this review .................. 387 Figure 6-3 Trends in gross value of agricultural production (GVAP) in (a) Australia and (b) the NT over 40 years (1981–2021) ......................................................................................................... 389 Figure 6-4 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 ............................................................................................ 391 Figure 6-5 Regions used in the input–output (I–O) analyses relative to the Roper catchment assessment area .......................................................................................................................... 396 Figure 7-1 Schematic diagram of the components where key risks can manifest when considering the establishment of a greenfield irrigation or aquaculture development ............ 405 Figure 7-2 Locations of the river system modelling nodes at which flow–ecology relationships are assessed, showing the location of the hypothetical modelled dam locations (A–E), water harvesting nodes and groundwater development related changes in surface flow .................. 413 Figure 7-3 Billabong, Roper catchment ...................................................................................... 418 Figure 7-4 Spatial heatmap of change in important flow metrics for barramundi across the catchment ................................................................................................................................... 419 Figure 7-5 Changes in barramundi–flow relationships by scenario across the model nodes .... 420 Figure 7-6 Changes in the weighted maximum flow-habitat suitability for barramundi based upon the species’ recognised preferences across a 1:13 year flood event ................................ 422 Figure 7-7 Roper River ................................................................................................................ 423 Figure 7-8 Spatial heatmap of mean asset flow regime change across the Roper catchment, considering change across all assets in the locations which each asset is assessed .................. 424 Figure 7-9 Mean of node changes in asset–flow relationships by scenario across all model nodes ..................................................................................................................................................... 425 Figure 7-10 Locations of the wetland, mangrove and melaleuca habitats used to assess lateral connectivity ................................................................................................................................. 426 Tables Table 2-1 Soil generic groups (SGGs), descriptions, management considerations and correlations to Australian Soil Classification (ASC) for the Roper catchment .................................................. 32 Table 2-2 Area and proportions covered by each soil generic group (SGG) for the Roper catchment ..................................................................................................................................... 34 Table 2-3 Projected sea-level rise for the coast of the Roper catchment .................................... 55 Table 2-4 Streamflow metrics at gauging stations in the Roper catchment under Scenario A ... 79 Table 3-1 Freshwater, marine and terrestrial ecological assets with freshwater dependences 112 Table 3-2 Definition of threatened categories under the EPBC Act (Cth) and the Northern Territory wildlife classification system........................................................................................ 132 Table 3-3 Major demographic indicators for the Roper catchment ........................................... 134 Table 3-4 SEIFA scores of relative socio-economic advantage for the Roper catchment .......... 135 Table 3-5 Key employment data for the Roper catchment ........................................................ 136 Table 3-6 Value of agricultural production within the wider SA4 region and estimates of the value of agricultural production for the Roper catchment ........................................................ 139 Table 3-7 Overview of agriculture commodities transported into and out of the Roper catchment ................................................................................................................................... 148 Table 3-8 Schools servicing the Roper catchment ...................................................................... 154 Table 3-9 Number and percentage of unoccupied dwellings and population for the Roper catchment ................................................................................................................................... 155 Table 4-1 Land suitability classes based on FAO (1976, 1985) as used in the Assessment ........ 191 Table 4-2 Crop groups (1 to 21) and individual land uses evaluated for irrigation (and rainfed) potential ...................................................................................................................................... 192 Table 4-3 Qualitative land evaluation observations for locations in the Roper catchment shown in Figure 4-3 ................................................................................................................................ 195 Table 4-4 Crop options where performance was evaluated in terms of water use, yields and gross margins .............................................................................................................................. 197 Table 4-5 Soil water content at sowing, and rainfall for the 90-day period following sowing for three sowing dates, based on a Bulman climate on Vertosol .................................................... 202 Table 4-6 Performance metrics for broadacre cropping options in the Roper catchment: applied irrigation water, crop yield and gross margin (GM) for three environments ............................. 207 Table 4-7 Sensitivity of cotton crop gross margins (GMs) to variation in yield, lint prices and distance to gin ............................................................................................................................. 209 Table 4-8 Sensitivity of forage (Rhodes grass) crop gross margins (GMs) to variation in yield and hay price ...................................................................................................................................... 210 Table 4-9 Performance metrics for horticulture options in the Roper catchment: annual applied irrigation water, crop yield and gross margin (GM) ................................................................... 210 Table 4-10 Sensitivity of watermelon crop GMs to variation in melon prices and freight costs 212 Table 4-11 Performance metrics for plantation tree crop options in the Roper catchment: annual applied irrigation water, crop yield and gross margin (GM) ........................................... 213 Table 4-12 Likely annual irrigated crop planting windows, suitability, and viability in the Roper catchment ................................................................................................................................... 216 Table 4-13 Sequential cropping options for Kandosols .............................................................. 217 Table 4-14 Production and financial outcomes from the different irrigated forage and beef production scenarios for a representative property on the Sturt Plateau ................................. 219 Table 4-15 Sorghum (grain) ........................................................................................................ 224 Table 4-16 Mungbean ................................................................................................................. 227 Table 4-17 Soybean ..................................................................................................................... 230 Table 4-18 Peanut ....................................................................................................................... 233 Table 4-19 Cotton........................................................................................................................ 237 Table 4-20 Rhodes grass ............................................................................................................. 241 Table 4-21 Cavalcade .................................................................................................................. 244 Table 4-22 Rockmelon ................................................................................................................. 248 Table 4-23 Mango ....................................................................................................................... 251 Table 4-24 Indian sandalwood .................................................................................................... 254 Table 4-25 Indicative capital and operating costs for a range of generic aquaculture development options .................................................................................................................. 266 Table 4-26 Gross revenue targets required to achieve target internal rates of return (IRR) for aquaculture developments with different combinations of capital costs and operating costs . 268 Table 5-1 Summary of capital costs, yields and costs per ML supply, including operation and maintenance (O&M) ................................................................................................................... 276 Table 5-2 Opportunity-level estimates of the potential scale of groundwater resource development opportunities in the Roper catchment ................................................................. 281 Table 5-3 Summary of estimated costs for a 500-ha irrigation development using groundwater ..................................................................................................................................................... 283 Table 5-4 Mean modelled groundwater levels at six locations within the Cambrian Limestone Aquifer (CLA) under scenarios A and B ....................................................................................... 288 Table 5-5 Mean modelled groundwater discharge from the CLA at streamflow gauging station (G9030013) ................................................................................................................................. 291 Table 5-6 Mean modelled groundwater levels in different parts of the DCA for scenarios A and B ..................................................................................................................................................... 296 Table 5-7 Mean modelled groundwater discharge at streamflow gauging station (G9030003) and (G9030108) representative of groundwater discharge from the DCA to the Wilton River and Flying Fox Creek respectively for the period 2059 to 2069 ........................................................ 298 Table 5-8 Potential dam sites in the Roper catchment examined as part of the Assessment ... 311 Table 5-9 Summary comments for potential dams in the Roper catchment ............................. 311 Table 5-10 Estimated construction cost of 3-m high sheet piling weir ...................................... 321 Table 5-11 Effective volume after net evaporation and seepage for ringtanks of three average water depths and under three seepage rates near the Jalboi River in the Roper catchment ... 334 Table 5-12 Indicative costs for a 4000-ML ringtank .................................................................... 335 Table 5-13 Annualised cost for the construction and operation of three ringtank configurations ..................................................................................................................................................... 336 Table 5-14 Levelized cost for two different capacity ringtanks under three seepage rates ...... 337 Table 5-15 Actual costs of four gully dams in northern Queensland ......................................... 341 Table 5-16 Cost of three hypothetical large farm-scale gully dams of capacity 4 GL ................. 342 Table 5-17 High-level breakdown of capital costs for three hypothetical large farm-scale gully dams of capacity 4 GL ................................................................................................................. 342 Table 5-18 Effective volumes and cost per ML for a 4-GL storage with different average depths and seepage loss rates at Wildman in the Roper catchment ..................................................... 343 Table 5-19 Cost of construction and operation of three hypothetical 4-GL gully dams ............ 343 Table 5-20 Equivalent annualised cost and effective volume for three hypothetical 4-GL gully dams ............................................................................................................................................ 344 Table 5-21 Summary of conveyance and application efficiencies .............................................. 346 Table 5-22 Water distribution and operational efficiency as nominated in water resource plans for four irrigation water supply schemes in Queensland ........................................................... 347 Table 5-23 Application efficiencies for surface, spray and micro irrigation systems ................. 350 Table 5-24 Preliminary costs for nominal conceptual layout ..................................................... 357 Table 5-25 Cost summary ........................................................................................................... 359 Table 6-1 Types of questions that users can answer using the tools in this chapter ................. 369 Table 6-2 Indicative capital costs for developing two irrigation schemes based on the most cost- effective dam sites in the Roper catchment ............................................................................... 373 Table 6-3 Assumed indicative capital and operating costs for new off- and on-farm irrigation infrastructure .............................................................................................................................. 374 Table 6-4 Price irrigators can afford to pay for water based on the type of farm, the farm water use, and annual gross margin (GM) of the farm ......................................................................... 376 Table 6-5 Farm gross margins (GMs) required to cover the costs of off-farm water infrastructure (at the suppliers’ target internal rate of return (IRR)) ................................................................ 377 Table 6-6 Water pricing required to cover costs of off-farm irrigation scheme development (dam, water distribution, and supporting infrastructure) at the investors target internal rate of return (IRR) .................................................................................................................................. 379 Table 6-7 Farm gross margins (GMs) required to achieve target internal rate of return (IRR) given different capital costs of farm development (including an on-farm water source) ......... 380 Table 6-8 Equivalent costs of water per megalitre for on-farm water sources with different capital costs of development, at the internal rate of return (IRR) targeted by the investor ..... 381 Table 6-9 Risk adjustment factors for target farm gross margins (GMs), accounting for the effects of reliability and severity (level of farm performance in ‘failed’ years) of periodic risks ..................................................................................................................................................... 383 Table 6-10 Risk adjustment factors for target farm gross margins (GMs), accounting for the effects of reliability and timing of periodic risks......................................................................... 384 Table 6-11 Risk adjustment factors for target farm gross margins (GMs), accounting for the effects of learning risks ............................................................................................................... 385 Table 6-12 Summary characteristics of the five dams used in this review................................. 387 Table 6-13 Summary of key issues and potential improvements arising from a review of recent dam developments ..................................................................................................................... 388 Table 6-14 Indicative costs of agricultural processing facilities .................................................. 392 Table 6-15 Indicative costs of road and electricity infrastructure .............................................. 393 Table 6-16 Indicative road transport costs between the Roper catchment and key markets and ports ............................................................................................................................................ 393 Table 6-17 Indicative costs of community facilities .................................................................... 394 Table 6-18 Key 2016 data comparing the Roper catchment with the related I–O analysis regions ..................................................................................................................................................... 397 Table 6-19 Regional economic impact estimated for the total construction phase of a new irrigated agricultural development (based on two independent I–O models) .......................... 399 Table 6-20 Estimated regional economic impact per year in the Roper catchment resulting from four scales of direct increase in agricultural output (rows) for the different categories of agricultural activity (columns) from two I–O models ................................................................. 400 Table 6-21 Estimated impact on annual household incomes and full time equivalent (FTE) jobs within the Roper catchment resulting from four scales of direct increase in agricultural output (rows) for the different categories of agricultural activity (columns) ........................................ 401 Table 7-1 Water resource development and climate scenarios explored in the ecology analysis ..................................................................................................................................................... 414 Table 7-2 Ecology assets used in the Roper Water Resource Assessment and the different ecology groups used in this analysis ........................................................................................... 416 Table 7-3 Descriptive values for the flow relationships modelling as rank percentile change of the hydrometrics considering the change in mean metric value against the natural distribution observed in the modelled baseline series of 109 years. For more information see Stratford et al. (2023) .......................................................................................................................................... 417 Table 7-4 The mean number of days per year with depth greater than three depth thresholds over Roper Bar representing low, medium and high confidence for allowing biotic passage ... 428 Table 7-5 Scenarios of instream dams showing end-of-system (EOS) flow and mean impacts for groups of assets across each asset’s respective catchment assessment nodes ........................ 430 Table 7-6 Scenarios of dams with management of environmental flows showing end-of-system (EOS) flow and mean ecological change on flows for groups of assets across each asset’s respective catchment assessment nodes ................................................................................... 431 Table 7-7 Scenarios of water harvesting with the benefits of end-of-system (EOS) annual flow requirements ............................................................................................................................... 431 Table 7-8 Scenarios of water harvesting with different minimum flow pump start thresholds (ML/day) ...................................................................................................................................... 432 Table 7-9 Scenarios of water harvesting with different pump capacities (pump rate as days of flow above the threshold required to take the extraction target from the river) ..................... 433 Table 7-10 Scenarios of water harvesting with different river system irrigation targets (GL/year) ..................................................................................................................................................... 433 Table 7-11 Scenarios of groundwater development .................................................................. 434 Detailed location map of the Roper catchment and surrounds For more information on this figure please contact CSIRO on enquiries@csiro.au As Australia’s national science agency and innovation catalyst, CSIRO is solving the greatest challenges through innovative science and technology. CSIRO. Unlocking a better future for everyone. Contact us 1300 363 400 +61 3 9545 2176 csiroenquiries@csiro.au csiro.au For further information Environment Dr Chris Chilcott +61 8 8944 8422 chris.chilcott@csiro.au Environment Dr Cuan Petheram +61 467 816 558 cuan.petheram@csiro.au Agriculture and Food Dr Ian Watson +61 7 4753 8606 ian.watson@csiro.au