A hydrological survey to update groundwater information on the 1:250,000 mapsheet areas KOPPERAMANNA, GASON and PANDIE PANDIE was carried out during April-May 1979. Data on the above three areas has been incorporated into one report because of the areas' topographic and hydrogeological similarities. Only 13 water wells were located, including 10 flowing wells which were photographed. The groundwater is used for stock and domestic purposes. The Tertiary-Quaternary aquifers, which are mainly associated with drainage lines, have quite variable salinities ranging from 407 to 9953 mg/1, and yields ranging from 16 to 216 cubic m/day. Standing water levels vary from 3 to 26 m below the surface. The most important aquifer of the area is the Algebuckina Sandstone, which is also the main aquifer of the Great Artesian Basin. Its depth and water pressure increase in a northerly direction. Salinities range from 483 to 1059 mg/1, while yields range from 1176 to 3279 cubic m/day. Wellhead temperatures range between 76ºC to 98ºC. The recharge to the Tertiary-Quaternary sediments is derived from local rainfall, and is enhanced along drainage lines. The Algebuckina Formation receives most of its recharge from south-western Queensland and northern New South Wales. There are no foreseeable pollution problems in the area.