Community Wastewater Management Systems (CWMS)

Several areas within the City of Onkaparinga do not have access to SA Water’s wastewater network.  In these areas, Council owns and operates a community wastewater management system (CWMS) to collect, treat and reuse wastewater.

The CWMS includes seven wastewater networks in Clarendon, Morphett Vale, McLaren Flat, McLaren Vale, Willunga, Maslin Beach, and Sellicks Beach and relies on two treatment plants which treat the wastewater and provides it to the Willunga Basin Water Company for reuse in the region.

Three of the networks — Clarendon, Morphett Vale and Maslin Beach — dispose of untreated effluent directly to SA Water’s sewer system, and council is charged ongoing fees by SA Water for this service.