The Patawalonga Creek is a tidal river and estuary system located in the western suburbs of Adelaide, within the City of Holdfast Bay. It flows into the Patawalonga Basin, a managed lake system that ultimately discharges into Gulf St. Vincent. The creek forms part of a broader urban catchment, receiving flows from several other waterways including the Sturt River and Brown Hill Creek. Historically a natural creek, significant engineering works have transformed its mouth with lock gates and sheet piling to create the modern Patawalonga Lake, separating it from the sea. The surrounding area features a mix of urban development, recreational spaces, and remnants of native vegetation, including Swamp Paperbark and Kangaroo Honey-myrtle communities, which provide important habitat within the metropolitan coastline.