A long history of subsidence and uplift, volcanic activity, and erosion and deposition in south-eastern Australia has produced a rich variety of inland and estuarine aquatic environments, including flowing waters (creeks, streams and rivers), standing waters such as lakes and swamps, and subterranean waters, such as that in groundwater and cave systems.

Each environment provides habitat for a variety of plants and animals. Many of these (such as fish and frogs) cannot inhabit any other environment, and others (such as the Sacred Ibis) congregate to form large and spectacular breeding colonies like the one at Kerang. Vegetation beside rivers and wetlands is often important to fauna that may breed here but forage elsewhere, such as the Regent Parrot. Old, gnarled red gums, slow, swirling waters and darting kingfishers are familiar to everyone who has camped on rivers in the north of the State.

Wetlands provide important water purification functions. Victoria has over 17,000 wetlands larger than 1 ha. These vary from the coastal Gippsland Lakes system and the extensive inland wetlands around Kerang to scattered examples of small freshwater meadows. Ten Victorian wetlands are listed for their international significance for bird species that migrate to Victoria in the southern summer from the northern hemisphere, and others are being considered for nomination to the list.

Rivers and wetlands also provide opportunities for recreation and sport, especially boating, angling and seasonal hunting. These activities can all have an impact on the native flora and fauna, and are therefore subject to responsible management and monitoring.

Rivers and wetlands are difficult to conserve adequately unless they are included in a land use system which appropriately manages the whole catchment area and ensures that the flow of water is sufficient to maintain the natural ecosystems.

About 35% of the State’s wetlands have been drained, and many rivers have been dredged or channelled, removing much of their habitat value; others are severely polluted. In areas outside national parks and State forests, the majority of streams are in poor or very poor condition, and only 5% are good or excellent.

The management of Victoria’s inland waters and wetlands, like those in most parts of the world, faces a number of challenges: excessive water extraction; land degradation (especially sediment deposition and salinity); the loss of riparian vegetation and wetlands; salt disposal to streams and wetlands; the inappropriate construction of dams and other barriers; increased nutrient levels and pollution; the loss of sites for egg-laying and shelter through desnagging, dredging and channelling of streams; and predation, competition and disease caused by the introduction or translocation of exotic species, such as European Carp.