The study area is underlain by two aquifer systems - unconfined Cainozoic marine limestones and confined Tertiary fossiliferous limestones and sands. Both aquifers contain saline groundwater which is flowing slowly to the west under low gradients. Discharge from the confined aquifer is by upward leakage with a head difference upwards of 1-2 metres. Regional water table levels are rising in the low-lying Coastal Plain area because of the increased local recharge caused by clearance of native vegetation. Where the water table rises to within 1-2 metres of the ground surface, widespread dryland salinisation occurs. Confined aquifer pressure levels are also rising because the increased recharge in the recharge areas of SW Victoria is rapidly transmitted downgradient. A regional reduction in recharge levels is required to control the dryland salinity problem, which has already affected hundreds of hectares in the study area and is gradually worsening. The source of salt responsible for the area of high salinity in the water table aquifer north of Coomandook is not known with certainty. Dolomitisation processes in basement as well as overlying calcareous sediments could also warrant further examination.