There are no known major groundwater resources in the Garford area, which borders the Barton and Ooldea Ranges dunefield and Great Victoria Desert southwest of Coober Pedy. The groundwater that is used by graziers for stock watering occurs in sediments and weathered basement overlying the Gawler Craton, and is generally found largely by chance drilling efforts. To help remedy this situation a transient electromagnetic survey of the area was done by MESA Groundwater Div. to improve knowledge of basement topography, particularly in the vicinity of Tertiary palaeochannels where greater supplies of groundwater, albeit saline, might be found. The survey has mapped basement depth quite well, and has detected and partially delineated porous sediments within the overlying Permian basins. However, the TEM survey results do not show variations in the type of clays deposited above the palaeochannels, nor do they differentiate between Permian and Tertiary sediments.