The Serpentine River source is in the Darling Scarp and the river discharges into the Peel inlet near Mandurah, Western Australia. The Darling Scarp (previously known as the Darling Range or Darling Ranges) is a low Escarpment running north-south to the east of the Mandurah is a city in Western Australia located approximately south of the state capital Perth, Western Australia.
The upper reaches of the river flow into Serpentine Dam which provides drinking water to the Perth metropolitan area. The river below the dam wall flows through the Serpentine Falls National Park, as the name suggests.