{ "culture": "en-US", "name": "", "guid": "", "catalogPath": "", "snippet": "Reduced standing water level (RSWL) contour lines representing regional watertable at 25m intervals. These contours are derived from the watertable trend surface and reference metres above the Australian Height Datum (mAHD). The contour spacing are 25m intervals except where watertable height is below 25m AHD. Below 25m AHD, extra contours are included (0 and 10m AHD) to improve definition of regional low point in groundwater elevation (a groundwater sink) that is associated with some large salt lakes (such as around Kati Thanda - Lake Eyre and Lake Frome). \n\nThese contours provide information on regional trends in watertable across the whole of the Kati Thanda - Lake Eyre Basin (KT-LEB) region. Evans et al. (2024) details the hydrogeology of the KT-LEB region. So as to provide coverage across the whole region, the regional watertable was constructed using waterlevel measurements from any near surface aquifer, not just aquifers in the Cenozoic. Most bores in the KT\u2013LEB have only a single water level reading, which generally was measured soon after the bore was constructed. Hence, the composite water level mapping does not represent a particular point in time. In addition, waterlevel measurements that were used to create the surface were not density corrected due to many bores missing salinity data. Despite some local limitations such as this, the watertable trend and depth to water mapping is generally consistent at the basin scale, and correlates strongly with the regional topography.", "description": "

The watertable contours are derived from the regional watertable trend surface and reference m(AHD). The regional watertable trend surface for the KT-LEB is derived from interpolation of water level data available for the shallowest aquifers intersected across the entire KT-LEB region (Evans et al. 2024).<\/SPAN><\/P>

While most of the water level data are sourced from bores screened in Cenozoic sediment aquifers, additional water level data from near-surface aquifers in older pre-Cenozoic rocks and sediments (to maximum depths of 100 m below surface) were also included in the analysis. This approach enabled broader regional understanding of groundwater level trends across the entire basin in places where Cenozoic aquifers do not occur. <\/SPAN><\/P>

The water level data was obtained from the state and territory groundwater bore databases. Sources of archival groundwater bore data evaluated for the KT\u2013LEB included Queensland Government (2023), NT Government (2023); SA Government (2023) and NSW Government (2023).In some places, the regional watertable surface may not represent the local watertable in the unconfined aquifer, particularly where the shallowest aquifer may be semi-confined. <\/SPAN><\/P>

The water level data used to create these maps were not corrected for variations in water density due to the regional scale nature of the assessment, the lack of bores with co-located salinity and water level data, and the highly variable groundwater salinity in many Cenozoic aquifer (Evans et al. 2024). Developing local-scale water level maps, particularly in areas of highly saline groundwater, would require data to be corrected for variations in water density. Such areas include near salt lakes such as lakes Eyre and Frome, or areas where groundwater salinity varies considerably across short distances such as on the Strzelecki Sandplain to the west of Strzelecki Creek.<\/SPAN><\/P>

The watertable regional trend surface and associated contours do not account for perched aquifers that may occur in some places above the level of the regional watertable. Perched aquifers can be locally important water sources for wetlands and GDEs, although they are generally of limited areal extent.<\/SPAN><\/P>

Most bores screened in Cenozoic aquifers in the KT\u2013LEB have only a single water level reading. These readings are generally measured soon after the bore was constructed. Hence, the composite water level mapping does not represent a particular point in time. <\/SPAN><\/P>

Despite some of the limitations, the watertable regional trend surface, contours and depth to standing water level water mapping is consistent at the basin scale and demonstrates that shape of watertable correlates strongly with the regional topographic features such as catchment boundaries.<\/SPAN><\/P><\/DIV><\/DIV><\/DIV>", "summary": "Reduced standing water level (RSWL) contour lines representing regional watertable at 25m intervals. These contours are derived from the watertable trend surface and reference metres above the Australian Height Datum (mAHD). The contour spacing are 25m intervals except where watertable height is below 25m AHD. Below 25m AHD, extra contours are included (0 and 10m AHD) to improve definition of regional low point in groundwater elevation (a groundwater sink) that is associated with some large salt lakes (such as around Kati Thanda - Lake Eyre and Lake Frome). \n\nThese contours provide information on regional trends in watertable across the whole of the Kati Thanda - Lake Eyre Basin (KT-LEB) region. Evans et al. (2024) details the hydrogeology of the KT-LEB region. So as to provide coverage across the whole region, the regional watertable was constructed using waterlevel measurements from any near surface aquifer, not just aquifers in the Cenozoic. Most bores in the KT\u2013LEB have only a single water level reading, which generally was measured soon after the bore was constructed. Hence, the composite water level mapping does not represent a particular point in time. In addition, waterlevel measurements that were used to create the surface were not density corrected due to many bores missing salinity data. Despite some local limitations such as this, the watertable trend and depth to water mapping is generally consistent at the basin scale, and correlates strongly with the regional topography.", "title": "Watertable RSWL contours", "tags": [ "Kati Thanda - Lake Eyre Basin", "bores", "regional watertable", "Lake Eyre geological Basin", "Marion-Noranside Basin", "Austral Downs Basin", "Tirari Sub-basin", "Callabonna Sub-basin", "Cooper Creek Palaeovalley" ], "type": "", "typeKeywords": [], "thumbnail": "", "url": "", "minScale": 625000, "maxScale": 5000, "spatialReference": "", "accessInformation": "© Commonwealth of Australia (Geoscience Australia) 2026. This product is released under the Creative Commons Attribution 4.0 International Licence. http://creativecommons.org/licenses/by/4.0/legalcode", "licenseInfo": "

© Commonwealth of Australia (Geoscience Australia) 2026. This product is released under the Creative Commons Attribution 4.0 International Licence. http://creativecommons.org/licenses/by/4.0/legalcode<\/SPAN><\/P><\/DIV>" }