Essay on Melbourne’s water supply
Water Collection
In Melbourne around 80% of our drinking water comes from closed water catchments in the Yarra Ranges and the rest comes from open water catchments. 157,000 hectares of forest has been closed to the public for over 100 years. These native forests filter rainwater as it flows across land into creeks, rivers and our reservoir storages. Open water catchments have mixed land uses (like farming) instead of being used exclusively to harvest water. Open water catchments are called “open” catchments because it is also opened to the public for recreational activities. There are 11 reservoirs scattered throughout Victoria all varying in size (see Figure 1.0).
Water Treatment
Water from Melbourne’s closed catchments requires minimal water treatment because of the isolation of the sources. Small amounts of chlorine are added to destroy any waterborne disease-causing microorganisms. The amount of chlorine added is equivalent to less than half a teacup in an average-size backyard swimming pool. Water in Melbourne is also fluoridated and lime is also added to raise the pH level of the water back to neutral, limiting the possibility of corrosion to household pipes and fittings. Although 80% of Melbourne’s water is treated minimally 20% requires full treatment. Water from Sugarloaf Reservoir receives full treatment, as it is fed by water from the Yarra River, Maroondah Aqueduct, and the Sugarloaf Pipeline. The water is fully treated as it leaves the reservoir at the Winneke Water Treatment Plant. For the water to become drinkable Coagulation, Clarification, Filtration, Disinfection, pH correction and Fluoridation is used to treat it.
