A water well survey of the eastern portion of the Hundred of Adelaide was carried out and 320 water wells were visited. The groundwater is obtained predominantly from fractured hard rocks, and consequently there is a large variation in well yields and water quality. In general, well yields are low and many landowners east of Norton Summit are building dams rather than rilling for groundwater. The groundwater is used mainly for irrigation of orchards and market gardens, stock supplies and domestic purposes. A large proportion of the area, however, consists of undeveloped natural bushland. No groundwater pollution was detected during the survey but increasing residential development in the area may cause problems if no provision is made for systematic effluent disposal.