Protecting Melbourne's Water Catchments
Melbourne is widely regarded as having high quality drinking water. There are a number of reasons for this, the main one being the purity of the source. About 90% of our water supply comes from uninhabited catchment areas. Melbourne is one of only a few major cities in the world that has such catchments.
More than 157,000 hectares of natural forest has been allocated for the purpose of harvesting drinking water. Many of these catchments have been closed to public access for over 100 years. Some of them are now National Parks managed by Melbourne Water and Parks Victoria.
Melbourne Water works hard to maintain and safeguard the natural advantage of our water source: the forested catchments. Bushfires, erosion and unauthorised public entry into the catchments are some of the risks that have to be managed.
Melbourne Water has to ensure that human access to the water supply catchments is restricted to minimise the risk of human-borne disease entering our water supply system. The system of uninhabited catchments provides a significant barrier against contamination of the water supply by Cryptosporidium, Giardia and other pathogenic microorganisms.
People do not have to enter the water itself to threaten the water supply system. Walking along paths within the catchments or driving through the roads poses an equal threat. Melbourne Water pays particular attention to the roads in the catchments to ensure appropriate drainage is constructed and maintained to minimise erosion and sediment flowing into the water.
In recent years, we have increased security for the catchments and our water supply assets by upgrading signage and security systems. Our security team patrols the catchments regularly and every year people are prosecuted and fined for unauthorised entry.
Life in the forested catchments
The foresight of our city founders in establishing uninhabited water supply catchments enables Melburnians to enjoy a high standard of drinking water. This has also meant that life in the forested catchments has remained largely undisturbed for more than 100 years, preserving the biodiversity of the ecosystem.
The mountain ash forests have an understorey of tree ferns, and gullies of cool, temperate rainforest. Mountain ash trees are among the world's tallest, sometimes towering to more than 100 metres. Large pristine areas of these and other vegetation within the catchment are of national and state significance, including the Slender Tree-fern.
The catchments also have a vast range of indigenous eucalypt species, as well as a huge array of smaller understorey flora including Cinnamon and Myrtle Wattle, Prickly Currant Bush, Common Ground-Fern and Rough Tree-Fern.
Mountain ash forests support particular ecological conditions that cannot be found elsewhere. The large areas of undisturbed forests are ideal habitat and crucially important for the conservation of hollowdwelling species including bats, forest owls and parrots. Among the most significant of these is the endangered Leadbeater's Possum, one of Victoria's faunal emblems.
The catchments also support extensive tracts of old-growth mountain ash forest, conditions that are critical for animals such as the Yellow-Bellied Glider - a gliding possum.
An amazing diversity of species and populations of birds can be found, including the Pink Robin, Yellow-tailed Black Cockatoo, Australian King-Parrot, Silvereye, Pied Currawong and Grey Goshawk. Crimson Rosellas (right) are also common in these pristine forests.
Large fallen logs are critical habitat for small mammals, reptiles and myriad invertebrates, providing basking sites for reptiles like the Highland Copperhead and Tiger Snake, and subterranean nesting sites for the Native Bush Rat. Other animals such as the many species of brightly coloured velvet worms use large fallen logs to hunt prey such as slugs.
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- Protecting Melbourne's Water Catchments (PDF, 116kb)