Under the Community Stream Sampling and Salinity Mapping Project, the Australian Government through the Department of Agriculture, Fisheries and Forestry and the Department of Environment and Heritage, acting through Bureau of Rural Sciences, funded an airborne electromagnetic (AEM) survey to provide information in relation to land use questions in selected areas along the River Murray Corridor (RMC). The proposed study areas and major land use issues were identified by the RMC Reference Group at its inception meeting on 26th July, 2006. This report has been prepared to facilitate recommendations on the Liparoo - Robinvale study area. The work was developed in consultation with the RMC Technical Working Group (TWG) to provide a basis for the RMC Reference Group and other stake holders to understand the value and application of AEM data to the study area. This understanding, combined with the Reference Groups assessment of the final results and taking in account policy and land management issues, will enable the Reference Group to make recommendations to the Australian Government.

A summary of the presentations and outcomes of the 5th Technical Advisory Group workshop for the Palaeovalley Groundwater project.

Legacy product - no abstract available

During this period planning began for the second phase of theProject, a hydrogeological assessment of the Basin based on available data. The Steering Committee at its meeting on 2 December 1982 discussed ways in which the existing hydrogeological data might be presented, and later that month Bureau of Mineral Resources (BMR) hydrogeologist R.Evans visited the State Authorities to arrange ways of transferring hydrogeological data to BMR; work on the hydrogeological phase is scheduled to start in July 1983. At BMR, C.M. Brown and A.E.Stephenson continued to compile 1:3/4 million scale geological maps, and prepared an outline of the bulletin on the geological synthesis; cartographer G Butterworth began the compilation and drafting of the 1:1 million geological map. Members of the Steering Committee noted with regret the death on 9 January of one of their number, Mr Don Currey, Supervising Geologist of the State Rivers and Water Supply Commission. Mr Currey's contribution to the Project is recorded with appreciation.

Seawater intrusion (SWI) is a problem globally due to changes in catchment water balances and rising sea levels. The northern coastline of Australia is an area of incipient SWI hazard; however, there is limited understanding of the characteristics of SWI. This study undertook a regional TEMPEST AEM survey of the Darwin coastal plains over the Koolpinyah Dolostone (KD) aquifer, to inform understanding of SWI in this important urban and peri-urban water source. Calibration and validation of AEM data involved sonic and rotary mud drilling, borehole geophysical and geological logging, and laboratory analysis of lithologies, pore fluids and groundwater samples. The AEM data provide greater spatial detail of critical elements of the hydrostratigraphy, and map a complex SWI interface in 3D. A potential SWI hazard to the main producing aquifer has been identified, with SWI ingress through preferential flow paths mapped along structural corridors. There is also extensive leakage of saline groundwater beneath the tidal Adelaide and Mary River floodplains. The existing regional hydrogeological model requires major revision to incorporate the significant weathered zones and salt stores, more restricted extent of dolostone in the aquifer,, and preferential recharge zones and groundwater flow paths to the KD aquifer identified through this study. Assessment of SWI risk to the groundwater resource requires additional hydrodynamic data targeted using the AEM data, and incorporation of results within a predictive groundwater model. The study demonstrates the value of regional, AEM surveys in understanding SWI proceses in karstic aquifers, particularly in data-poor, inaccessible or environmentally sensitive areas.

The success of Aquifer Storage and Recovery (ASR) schemes rely on defining appropriate design and operational parameters in order to maintain high injection rates over the long term. The objective of this study was to develop a methodology to define the water quality criteria and hence minimum pre-treatment requirements to allow recharge at an acceptable scale. Laboratory column studies using four types of treated source water were performed at constant temperature (19°C) with light excluded, to determine the potential for near-well clogging for a proposed ASR scheme. The source water was turbid raw water from the Darling River and three treated waters including bank filtration, coagulation, and coagulation and granular activated carbon (GAC). Over the 37 days of the experiment, declines in hydraulic conductivity occurred in the columns packed with representative aquifer fluvial sands. The GAC treated town water gave an 8% decline in hydraulic conductivity, which was significantly different from the other three source waters with mean declines of 26-29%. Over the first 3 cm of column length, where most clogging occurred in each column, the mean hydraulic conductivity declined by 10% for GAC treated water compared with 40 to 50% for the other source waters. Evidence from polysaccharide concentrations and bacterial numbers in columns when they were dissected and analysed at the end of the experiment confirmed that biological growth was the dominant form of clogging in the treated waters. Further chemical clogging through precipitation of minerals was found not to occur within the laboratory columns, and dispersion of clay was also found to be negligible.

Available as copy of original only.

This report covers the period during which a joint BMR-BRGM team prepared and started the computer based simulation of the Great Artesian Basin. Geological and hydrologic data were first collected from Federal and State authorities and then processed either manually or automatically. Processed data were then used to prepare input and calibration documents, including geological documents (geometry of system) and hydrologic documents (potentiometry). The first run of the mathematical model was obtained for the initial steady-state, and results appeared very encouraging.

The structural and stratigraphic remnants of geologically ancient rivers, many dating to at least the Eocene, are widespread across the arid interior of Australia. Changing climatic conditions throughout the Cenozoic have dried the continent to such an extent that surface water now rarely flows in these palaeovalley systems. However, the fluvial sediments which were deposited as valley-fill sands and gravels may function as high quality aquifers which are capable of storing and transmitting significant quantities of groundwater. In many of Australia's outback deserts such palaeovalley aquifers commonly provide the only reliable source of potable water available for remote aboriginal communities, pastoral stations and mining enterprises.

This GA Professional Opinion report is one of a series of 4 reports being undertaken by the GA Groundwater Group under the National Collaboration Framework Project Agreement with the Office of Water Science (in DSEWPaC). The Laura Basin in north Queensland is a priority coal-bearing sedimentary basin that is not currently slated for Bioregional Assessment.