The Shire of Harvey has four major river systems. Logue Brook in the north of the Shire drains into the Harvey River and the various associated irrigation and drainage channels, which eventually drain into the Peel-Harvey Estuary within the Shire of Waroona. The Wellesley River drains into the Brunswick River, which drains into the Collie River just before it drains into the Leschenault Estuary.
In addition, a chain of wetlands occur in the Bassendean dune system within the Shire of Harvey, including Lake Preston, Lake Josephine, Benger Swamp, Kemerton Wetlands and the Leschenault Estuary. Lake Preston is part of the Peel-Yalgorup System Ramsar site, which is considered to be of international significance.
The wetlands of the Swan Coastal Plain have been mapped and classified by Hill et al. (1996) as being Conservation, Resource Enhancement or Multiple Use. The Leschenault Estuary is the largest waterbody in the Shire of Harvey and is located between the locality of Australind and the Leschenault Peninsular Conservation Park and is classified as a Conservation Category Wetland.
The waterways and wetlands within the Shire of Harvey support a diverse range of plant communities dominated by Flooded Gums (Eucalyptus rudis), a range of Paperbarks (Melaleuca rhaphiophylla and M. cuticularis) and sedge species (Mattiske, 1996)
The Department of Water and Leschenault Catchment Council can provide more detailed information.