A groundwater survey in the Callington area was carried out to determine water usage along the Bremer River between Callington and Bletchley and also to determine the effects of a proposed irrigation scheme along the Bremer escarpment, utilising treated sewage effluent from the new town of Monarto. The survey showed most groundwater to occur in Kanmantoo Group rock of Cambrian Age. Borehole yields are very low (less than 0.7 1/sec) and salinities high, (2200-3000 mg/1). Water from the Bremer River is predominantly used to irrigate lucerne. It was found that pumping is the major cause of the drying up of the river during summer months. The proposed irrigation site appears unsuitable due to the poor drainage of the underlying rocks which would enhance the development of perched water tables.