Author: Natchanok Ounping
Ounping, Natchanok, 2024 Groundwater Assessment of the Fractured Rock Aquifers in the Northern Flinders Ranges, South Australia, Flinders University, College of Science and Engineering
Terms of Use: This electronic version is (or will be) made publicly available by Flinders University in accordance with its open access policy for student theses. Copyright in this thesis remains with the author. You may use this material for uses permitted under the Copyright Act 1968. If you are the owner of any included third party copyright material and/or you believe that any material has been made available without permission of the copyright owner please contact copyright@flinders.edu.au with the details.
Iga Warta, Leigh Creek Station, Kalkalpurannha, and Yappala are self-supplied remote communities located in the hard rock area of the Northern Flinders Ranges. These four communities are identified as being very vulnerable to water insecurity in the next decade by the Department for Environment and Water. Groundwater presents a potential solution to mitigate this issue, as rainwater is highly variable due to the influence of arid and semi-arid climatic conditions. Therefore, groundwater assessment is required to obtain crucial information on the water quantity and quality of fractured rock aquifers in order to assist government agencies in formulating appropriate water strategies for each remote community. This study is designed to synthesise existing data in the desktop study stage from two major sources, the WaterConnect website and the scanned microfiche images managed by the South Australian government. The primary aquifers at Iga Warta, Leigh Creek Station, Kakalpurannha, and Yappala are Wilkawillina Limestone, Angepena Formation, Wonoka Formation, and Bonney Sandstone, respectively. These fractured rock aquifers are formed of different types of lithologies, resulting in diverse capacities to yield groundwater, and giving unique characteristics in groundwater quality. The Wilkawillina Limestone aquifer has a higher groundwater yield than the other three aquifers, with an average discharge rate of 6.73 L/sec, although it has the potential to provide groundwater of over 10 L/sec. The Angepena Formation, primarily comprised of shale and siltstone, and Wonoka Formations, predominantly formed of shale and limestone, have similar groundwater production capabilities, with a mean rate of 1.3 L/sec. The maximum rate of yield from these two aquifers is around 10 L/sec. The Bonney Sandstone has an average well yield rate of less than 1 L/sec and lacks the capacity to supply groundwater at a rate of higher than 3 L/sec.
All four aquifer formations have unique characteristics in groundwater chemistry. The Wilkiwillina Limestone aquifer exhibits a signature of pronounced hardness, and high chloride and sodium in its groundwater. The Angepena Formation aquifer also has high chloride, hardness, and sodium content, while groundwater extracted from the Wonoka Formation aquifer presents outstanding sodium, hardness, and chloride. The lack of available water chemistry data prevents the identification of a groundwater quality signature from the Bonney Sandstone aquifer. Additionally, the groundwater from the four fractured rock aquifers is unsuitable for consumption due to its physical and chemical characteristics above the values specified in the Australian Drinking Water Guidelines, including chloride, hardness, sodium, sulphate, total dissolved solids, and nitrate, although this groundwater remains suitable for non-potable application. The development for future use is possible in terms of quantity since the fractured rock aquifers exhibit the potential to yield high volumes of groundwater. However, groundwater quality from all aquifers should be treated to ensure its safety for consumption and to enhance user satisfaction.
Keywords: Fractured rock aquifers, Groundwater yield, Groundwater quality
Subject: Hydrology thesis
Thesis type: Masters
Completed: 2024
School: College of Science and Engineering
Supervisor: Eddie Banks