After discovery of a significant source of ancient water in the Anangu Pitjantjatjara Yankunytjatjara (APY) Lands last year as part of the Goyder Institute for Water Research’s G-FLOWS (Facilitating Long-term Outback Water Solutions) project (Stage 3), work has begun mapping the size and shape of the resource using a variety of geophysical techniques.
The Institute’s G-FLOWS project brings together a team of over 20 staff with expertise in hydrogeology, hydrology, geophysics, groundwater modelling, spatial analysis and programming from CSIRO, Flinders University, Geological Survey of SA and DEW to help map groundwater resources in the remote area.
A team from CSIRO have recently completed a second tranche of on-ground geophysical surveys around the location of the palaeochannel target. Because of the information collected during the drilling program, a range of techniques were able to be tested and validated with a view to using them to characterise groundwater resources in data poor areas. These included using passive seismic along the previous active seismic line, measuring a tomographic set around the main drillsite (DH1), and placing a sensor at two other bore sites. All DH1 drillholes were logged using Induction Conductivity. Transient electromagnetic (TEM) measurements were taken at 250 m spacings along the active seismic line at 12 stations.
As the design of this work deviated from the original plan and agreement with Traditional Owners, they were consulted on the proposed new design, with Traditional Owners Witjuti George, Max Wonka and Wonka Wonka giving clearance for the work to go ahead.
A final tranche of geophysical field work involving gravity, surface and borehole magnetic resonance measurements will be undertaken by CSIRO in a few weeks’ time that will build up further lines of evidence into the extent and nature of the groundwater resources.
The project will then enter its final phase where results from the various components will be brought together to evaluate the opportunities and constraints for groundwater resource development in the APY region, and more broadly provide information and products to help future water resources planning, investment and management both in South Australia and further afield.
Contact project leader Adrian Costar (DEW) for more information.