The area covered in this survey comprises about 100 square miles. The main rivers are the Angas and Bremer, the major townships Strathalbyn and Langhorne Creek. There is a marked population concentration adjacent to the rivers, due possibly to the ready supply of water when the rivers are flowing, and to the better groundwater as regards supply and salinity in that vicinity. Much of the land has been cleared, and used for the irrigation of lucerne and vineyards where water is of sufficient quality and quantity. Elsewhere the land is used for cereal growing and for the grazing of sheep and cattle. Investigation of the extent of the basin to the north was undertaken in search of regions of possible water intake into the lower aquifer of the basin. This lower aquifer, a Miocene limestone sequence, contains water of lower salinity than that of the upper Quaternary sand aquifer. The aquifers are separated by a confining layer of clay with average thickness 3 metres (10ft.), and as yet no source of intake of less saline water into the lowest aquifer has been established. A borehole survey was also requested in order to obtain locations, stratigraphic logs, and current values of salinity from any bores in the area.