This document contains metadata for the hydrodynamics products produced by the Great Artesian Basin Water Resource Assessment

The Habanero Enhanced Geothermal System (EGS) in central Australia has been under development since 2002, with several deep (more than 4000 m) wells drilled to date into the high-heat-producing granites of the Big Lake Suite. Multiple hydraulic stimulations have been performed to improve the existing fracture permeability in the granite. Stimulation of the newly-drilled Habanero-4 well (H-4) was completed in late 2012, and micro-seismic data indicated an increase in total stimulated reservoir area to approximately 4 km². Two well doublets have been tested, initially between Habanero-1 (H-1) and Habanero-3 (H-3), and more recently, between H-1 and H-4. Both doublets effectively operated as closed systems, and excluding short-term flow tests, all production fluids were re-injected into the reservoir at depth. Two inter-well tracer tests have been conducted: the first in 2008, and the most recent one in June 2013, which involved injecting 100 kg of 2,6 naphthalene-disulfonate (NDS) into H-1 to evaluate the hydraulic characteristics of the newly-created H-1/H-4 doublet. After correcting for flow hiatuses and non-steady-state flow conditions, tracer breakthrough in H-4 was observed after 6 days (compared to ~4 days for the previous H-1/H-3 doublet), with peak breakthrough occurring after 17 days. Extrapolation of the breakthrough curve to late time indicates that approximately 60% of the tracer mass would eventually be recovered (vs. approximately 80% for the 2008 H-1/H-3 tracer test). This suggests that a large proportion of the tracer may lie trapped in the opposite end of the reservoir from H-4 and/or may have been lost to the far field. The calculated inter-well swept pore volume is approximately 31,000 m³, which is larger than that calculated for the H-1/H-3 doublet (~20,000 m³). A simple 2D TOUGH2 tracer model, with model geometry constructed based on the current conceptual understanding of the Habanero EGS system, demonstrates good agreement with the measured tracer returns in terms of timing of breakthrough in H-4, and observed tracer dispersion in the tail of the breakthrough curve.

This data set comprises one of three archives of Geoscience Australia work in the project "A Consistent Approach to Groundwater Recharge Determination in Data Poor Areas". The project was carried out by CSIRO and Geoscience Australia and was funded by the National Water Commission Raising National Water Standards program. The data contained included Original data sourced for the project, Final data produced by the project, MXD's of maps created, and tools used within the project. The archives created for this project comprise: 1. Data archive. Data set stored in the GA CDS. Geocat Record number 79804 2. Adminstration and publication archive. Documents stored in TRIM Project P10/67 RECHARGE-DISCHARGE PROJECT 3. References archive. Endnote library located at \\nas\eg\water\References\Recharge_Discharge_Project.enl For more information about the creation of these archives, including the location of files, see TRIM D2014-102808 For more information about the project, see the following references: Leaney F, Crosbie R, O'Grady A, Jolly I, Gow L, Davies P, Wilford J and Kilgour P. 2011. Recharge and discharge estimation in data poor areas: Scientific reference guide. CSIRO: Water for a Healthy Country National Research Flagship. 61 pp (GA Record No. 2011/46 GACat # 71941) Jolly I, Gow L, Davies P, O'Grady A, Leaney F, Crosbie R, Wilford J and Kilgour P. 2011. Recharge and discharge estimation in data poor areas: User guide for the recharge and discharge estimation spreadsheets and MapConnect. CSIRO: Water for a Healthy Country National Research Flagship. 40 pp. (GA Record No. 2011/35 GeoCat # 71940) Pain, C.F., Gow, L.J, Wilford, J.R. and Kilgour, P. 2011. Mapping approaches to recharge and discharge estimation and associated input datasets. A report for CSIRO: Water for a Healthy Country National Research Flagship. (Professional Opinion No. 2011/01 GeoCat # 70392)

Water resource assessment for the Great Artesian Basin. Synthesis of a report to the Australian Government from the CSIRO Great Artesian Basin Water Resource Assessment

In many areas of the world, vegetation dynamics in semi-arid floodplain environments have been seriously impacted by increased river regulation and groundwater use. With increases in regulation along many rivers in the Murray-Darling Basin, flood volume, seasonality and frequency have changed which has in turn affected the condition and distribution of vegetation. Floodplain vegetation can be degraded from both too much and too little water due to regulation. Over-regulation and increased use of groundwater in these landscapes can exacerbate the effects related to natural climate variability. Prolonged flooding of woody plants has been found to induce a number of physiological disturbances such as early stomatal closure and inhibition of photosynthesis. However, drought conditions can also result in leaf biomass reduction and sapwood area decline. Depending on the species, different inundation and drought tolerances are observed. Identification of groundwater-dependent terrestrial vegetation, and assessment of the relative importance of different water sources to vegetation dynamics, typically requires detailed ecophysiological studies over a number of seasons or years as shown in Chowilla, New South Wales [] and Swan Coastal Plain, Western Australia []. However, even when groundwater dependence can be quantified, results are often difficult to upscale beyond the plot scale. Quicker, more regional approaches to mapping groundwater-dependent vegetation have consequently evolved with technological advancements in remote sensing techniques. Such an approach was used in this study. LiDAR canopy digital elevation model (CDEM) and foliage projected cover (FPC) data were combined with Landsat imagery in order to characterise the spatial and temporal behaviour of woody vegetation in the Lower Darling Floodplain, New South Wales. The multi-temporal dynamics of the woody vegetation were then compared to the estimated availability of different water sources in order to better understand water requirements.

This document lists metadata for the hydrogeology products produced by the Great Artesian Basin Water Resource Assessment.

Poster prepared for International Association of Hydrogeologists Congress 2013 Sonic drilling is a relatively new technology that was used successfully to obtain relatively uncontaminated and undisturbed continuous core samples with excellent (>99%) recovery rates to depths of 206m in unconsolidated fluvio-lacustrine sediments of the Darling River floodplain. However, there are limitations with the standard sonic coring method. Sands, in particular, are disturbed when they are vibrated out of the core barrel into the flexible plastic sampling tube. There can be changes to moisture content, pore fluid chemistry and sediment mineralogy on exposure to the atmosphere, even when the samples are processed and analysed soon after collection. The option exists during sonic drilling to encapsulate the core in rigid polycarbonate lexan tubes. Although this increases costs and reduces drilling rates, atmospheric exposure of the core during drilling is reduced to the ends of the lexan tubes before being capped. In addition, the tubes can be purged with an inert gas such as argon. Lexan coring is best carried out below the watertable as the heat from drilling dry clays can cause the polycarbonate to melt. In the study, 60 sonic holes (4.5 km) and 40 rotary mud holes (2 km) were obtained as part of a program to map and assess potential groundwater resources and managed aquifer recharge (MAR) targets over a large area (7,500 km2) of the Darling River floodplain. Two of the sonic bores were drilled to depths of 60 metres to obtain lexan-encapsulated core samples. These cores were used to obtain less perturbed samples for pore fluid analysis (salinity, major ions, trace metals, stable isotopes), textural analysis, and analysis of mineral phases to help assess aquifer clogging potential (using XRD, XRF, SEM). An additional advantage of the lexan coring was the recovery of encapsulated and intact sediment intervals for determining porosities, effective porosities, hydraulic conductivities, and other geophysical and petrophysical measurements. By painting some tubes black, sand samples were also successfully obtained for optically stimulated luminescence (OSL) dating. Alternatively, opaque black lexan can be made to order by the supplier. Overall, the superior sample integrity obtained from lexan coring enables a greater range of hydrogeological and hydrochemical parameters to be assessed.

The Great Artesian Basin Water Resource Assessment (GABWRA) provided fundamental underpinning information for the Great Artesian Basin (GAB). Key data sets produced by GABWRA include contact surfaces between major aquifers and aquitards within the GAB. This poster covers the 3D visualisation of these surfaces in GOCAD (R) and in the Geoscience Australia World Wind 3D data viewer. Poster prepared for the International Association of Hydrogeologists congress 2013, Perth, Australia

This report describes the findings of the Great Artesian Basin Water Resource Assessment that have led to advancing the understanding of the GAB. It encapsulates findings that are presented in four region reports and a technical report on conceptualising the GAB that were prepared for the Assessment. Advancing the conceptual understanding of the GAB requires careful evaluation of the geological framework (i.e. the layers of rock), description of how the geology translates into hydrostratigraphy (i.e. the relative ability of specific layers to store and transmit water) and investigation of the groundwater conditions (i.e. watertable, groundwater levels, and inferred movement). It is the geological framework, hydrostratigraphy and groundwater conditions that are the basis for conceptualising water resources in the GAB. The conceptual understanding of the GAB provides the foundation for assessing water availability and providing guidance to water policy and water resource planning.

Poster prepared for International Association of Hydrogeologists Congress 2013 The Broken Hill Managed Aquifer Recharge (BHMAR) project has successfully mapped a multi-layered sequence of aquitards and aquifers, as well potential groundwater resource and managed aquifer recharge (MAR) targets, in the top 100m of the Darling Floodplain. Near-surface aquitards overlying the Pliocene target aquifers (fluvial Calivil Formation (CFm) and marine Loxton-Parilla Sands (LPS)), were identified initially as variably conductive layers in airborne electromagnetic (AEM) data, and validated by drilling and complementary borehole geophysical, textural, hydrogeological and hydrochemical studies. The stratigraphic unit underlying the Pliocene aquifers is the Miocene upper Renmark Group (uRG). Drilling and AEM data have confirmed this unit is present throughout the study area, deposited predominantly as thick muds. Facies and biofacies analysis suggests these muds were deposited on a low relief sedimentary plain with a high water table and numerous permanent water bodies, with relatively minor sand bodies deposited in narrow anastomosing fixed channel streams. Groundwater in the upper uRG is saline, and muddy sediments form a strongly conductive layer beneath the Pliocene aquifers. This is a much harder geophysical target than the upper confining aquitards, as the target lies at depths of 80-120m, which is near the depth resolution of the AEM system. Furthermore, there is little conductivity contrast between the Pliocene and uRG sediments except in areas where there is fresh groundwater in the former. Hydrochemical and hydrodynamic data shows that there is limited hydrological connection between the uRG and less saline Pliocene aquifers, except where the Pliocene is underlain by uRG channel sands. These channels are much narrower (10s to ~100m) and thinner (1 to 10m) compared with palaeochannels in the overlying CFm. Where the channels are connected, there can be a distinct salinity gradient from the Pliocene into the uRG sands, indicating localised mixing. Given the potential for up-coning of saline groundwater in these instances, a number of sites (e.g. Menindee Common), have been assessed as unsuitable for MAR. Overall, the uRG muds act as a good lower confining aquitard to the Pliocene aquifers over most of the project area, including a number of potential MAR and groundwater resource targets.