Wildlife at the Western Treatment Plant
The Western Treatment Plant in Werribee has long been recognised as an area of high conservation value. Parts of the plant were declared a sanctuary for the protection of native fauna, including ducks and quail, in 1921. The plant encompasses a diverse and complex array of landforms, vegetation and wildlife.
The abundant wildlife and habitat of Werribee is a natural resource of considerable importance, not only to Melburnians, but also to state, national and international communities. In 1983, the western shores of Port Phillip Bay, including the Bellarine Peninsula, were designated a Wetland of International Importance under the Ramsar Convention. This classification included the Western Treatment Plant’s Lake Borrie and its surrounding lagoons and coastal mudflats. Under the Convention, sites must meet criteria based on the characteristics of the wetland or its value in supporting plants, animals or waterfowl.
The Western Treatment Plant supports large numbers and groups of waterfowl. The plant regularly supports more than 20,000 waterfowl, and has more than 1% of the population of several species of waders and ducks. This classification highlighted the need for a co-ordinated approach to the protection, conservation and enhancement of its natural and artificial attributes.
The significance of the area's contribution to conservation is further illustrated by its coverage under international agreements. These include the JAMBA (Japan Australia Migratory Bird Agreement) and the CAMBA (China Australia Migratory Bird Agreement), for the protection of migratory waders, and by State and local agreements for the protection of wetlands and other habitats. Many migratory species of waders listed in the JAMBA and CAMBA agreements occur in significant numbers at the Western Treatment Plant.
Twelve species of flora and fauna found at the Western Treatment Plant are listed under the Flora and Fauna Guarantee Act, and the plant has been given International Significance status for avifauna in four categories, National Significance for two, State Significance for six and Regional Significance for four.
Birds and Lake Borrie
Lake Borrie was originally a small swamp with paper bark trees and a few red gums, but it is now a part of the Melbourne Water sewage treatment lagoon series.
Lake Borrie is the most significant wetland in Victoria for migratory shorebirds, and one of the most significant drought refuges for ducks. During the 1982/83 drought the site was home to almost a third of all of Victoria’s ducks.
Migratory birds travel to Lake Borrie from as far as Alaska, Siberia, China and Japan, doubling their body weight on the abundant food over Summer before heading back overseas.
The Western Treatment Plant can house an estimated 65,000 birds at any one time.
The plant is considered to be one of the top 10 birdwatching areas in Australia, with over one third of the country’s species being recorded there (about 270 species). This is second only to Kakadu National Park.
Lake Borrie is one of only two Pied Cormorant breeding colonies in Victoria. Cormorants breed at the Western Treatment Plant during Autumn, and then travel to other areas of Australia during Spring and Summer to raise their young.
In the early 1980s the nesting sites of these birds was under threat due to the decline in the number of trees standing in Lake Borrie. Much of the timber had fallen or rotted away. To save this breeding colony of Pied Cormorants from extinction, Melbourne Water placed two artificial perching and nesting platforms in Lake Borrie.
The addition of these platforms resulted in a significant increase in the bird population and another five platforms were built. There are now approximately 700 breeding pairs of Pied Cormorants at the Western Treatment Plant that use the platforms and flooded trees in Lake Borrie and other lagoons for nesting sites, along with approximately 20 pairs of Darters.
Waterfowl using the large ponds include the Pink-Eared Duck, Chestnut Teal, Australian Shoveller, Australian Shelduck, Grebes and Blue-Billed and Black Ducks. Coots and Eastern Swamphens use pond fringes, while Swans and Pelicans tend to roost on the small muddy islands located amongst the dead trees. At early evening, returning from feeding sites on the plant and surrounding fields, hundreds of Straw-Necked and White Ibis come to roost on the trees in the lake.
Permits can be obtained for birdwatching at the Western Treatment Plant, and tours for birdwatchers can be arranged. For tour information, visit education.melbournewater.com.au or call 131 722. To book a tour, please contact us on line or call 131 722.
Mammals, reptiles and amphibians
Werribee also provides sanctuary for many other animals of importance. Amongst these are the Fat Tailed Dunnart and Legless Lizard, both of which have State Significance. Two frogs, the Warty Bell Frog and the Spotted Burrowing Frog, plus the Metallic Skink, White Lipped Snake and native Water Rat are all species of Regional Significance.
Flora
The Western Treatment Plant has a diverse array of vegetation communities and species. These create an essential relationship with the landform, land types and wildlife. Seven species of plants are classified as restricted or rare.