The gentle hills and plains of the Willunga Basin sit beneath the Willunga escarpment and surround the Onkaparinga River and its estuary. The highly modified landscape, cleared mostly for grazing, was once Box woodland, grassland and sand heath communities, which now remain only along roadsides and in parks and reserves, making up less than 10% of the subregion.
Several plant communities, and species, are listed as threatened and the pressure continues from the southward creeping suburbs of Adelaide and lifestyle residents.
The viticulture industry in the McLaren Vale winegrowing area promotes primary production, tourism, lifestyle opportunities and employment. It is supported by good quality groundwater and the use of treated effluent water. The agricultural nature of the area is protected under the Character Preservation (McLaren Vale) Act 2012.