Many factors influence the quality of Victoria’s water resources, including the nature of our catchments and river systems, human activity and even an ancient inland sea.
The Great Dividing Range separates Victoria into the north and west, and the south and east.
Rivers north of ‘the Divide’ are part of the Murray-Darling Basin and either flow into the River Murray or the lakes and wetlands of the north west.
Victoria’s west often has high salinity levels in the groundwater, soil and rivers.
Southern and eastern rivers flow to the coast and the coastal embayments like the Gippsland Lakes and Port Phillip Bay.
The Great Dividing Range also defines our two main types of groundwater: Fractured Aquifers of the Uplands, and the Sedimentary Plains of the Lowlands.
The top of Victoria’s catchments have more forested natural landscapes to collect water.
This means less material like leaf litter and soil washes into rivers and streams and results in more pristine water quality.
As you move downstream from the top of the catchment, the catchment tends to be less steep and used more for agriculture.
Unless it is in a state or national park, much of the native plant life has been cleared and there have been agricultural, industrial and urban developments.
These changes tend to lower the water quality in the surrounding rivers and streams.
There is often a high level of residential and industrial development towards the coast and where the land is flatter.