Investigations have been carried out in the first test area of the South East Water Resources Investigation. Drilling by Rotary and Cable Tool methods up to 555 feet deep has shown a near horizontal sequence of bedded limestones. The cable tool method has been found to be the most satisfactory way for sampling both the geological sequence and the groundwater, and for constructing holes for pump testing. It is recommended that this method only be used in future investigations. Three main geohydraulic units have been recognised; Unit A (aquifer), Unit B (aquifer), and Unit C (confining bed). The two aquifers may be hydraulically continuous over part of the area. The lithology suggests that Unit A has higher values for transmissivity and storage coefficient. The general direction of groundwater flow is to the west. Recharge to Unit A is local and therefore water quality depends on the geomorphologic environment; i.e. in swampy areas the salinity values are high and in the dune ranges the groundwater has a low salinity. Water quality in Unit B may be influenced by local recharge from Unit A. Recharge appears to be almost direct where there is no confining bed or indirect by lateral and vertical flow where a confining bed occurs. In the coastal zone drilling and geophysical work has shown a complex geological and hydraulic situation where groundwater is evaporated in Lake St. Clair which is a sink for groundwater. A salt water-fresh water interface was found on the eastern side of the lake which could be attributed to lack of flushing of the original seawater. A similar interface could have formed as a result of evaporation of groundwater from the lake. Further ground resistivity work should be carried out on the western side of Lake St. Clair during the North Coastal Survey (Stapledon and Bleys, 1969). Measurements of water levels and collection of water samples for salinity determinations should continue until at least the end of 1973. From September 1969 the E. & W.S. Department Office at Robe will be responsible for this phase of the investigation.