The Peel-Harvey Estuarine System (Nyungar: Djilba)[1] is a natural estuarine system that lies roughly parallel to the coast of Western Australia and south of the town of Mandurah.
The strip of land between the Indian Ocean and the estuarine system carries the Old Coast Road and to the east is the Forrest Highway which is the main thoroughfare between Perth and the coastal towns of the south west corner of the state including Bunbury and Busselton.