Aldinga Washpool and Blue Lagoon are situated just to the south of the conservation park, with the Washpool area covering almost . The Blue Lagoon is a smaller lagoon, situated at the north-eastern end. The Washpool is one of few remaining coastal estuarine lagoon systems and wetlands on the coast of greater Adelaide, and provides important habitat for waterbirds (such as the hooded plover) and other flora and fauna. The wetland fills up as the winter rains come, and can dry out from about October to May each year. It is a popular area for birding, and a breeding ground for the endangered yellowish sedge skipper butterfly.