Management of development along the Yarra has become more controversial as Melbourne’s population has grown and density of development has increased.
There are competing pressures in these areas between residential and commercial development, and the desire for open space and natural features.
There are also pressures around the form development should take – such as what buildings should look like and how big they should be – and where those developments should go.
Nature under stress
The stress on the Yarra’s natural systems is growing. The story is the same for the key tributaries of the Yarra – the Merri, Darebin and Plenty creeks.
Many native plants and animals have been lost as their habitat has disappeared. Weeds and invasive species of fish and animal have colonised the river.
Some threatened and protective native species are still found in the Yarra River and its tributaries. Platypus can still be found in parts of the river, but numbers are declining. Remaining fish species include the Macquarie perch, galaxias, southern pygmy perch and blackfish, but they are threatened by poor water quality, and physical barriers to movement in the river.
Although there have been efforts to revegetate, the results are patchy and the health of the river itself continues to be compromised by its history of habitat loss.
Poor water quality
Water quality varies across the course of the Yarra River, from very good in the upper catchment to very poor in the lower part of the river.
The Yarra’s water quality has been of major concern to government, regulators and the community for some time.
Urban stormwater run off causes problems, with hard surfaces like roads and buildings allowing high levels of litter, chemicals, and other materials to flow into our stormwater systems.
High rainfall can mean stormwater enters the sewage system causing it to overflow, which results in diluted raw sewage entering the Yarra.
Run-off from farms, which can include chemicals and fertilisers, as well as run-off from roads, or creek and river banks cleared of vegetation, include large amounts of sediment. Carried downstream, this seiment contributes to the muddied, brown colour of the river.
Past industrial sites along the river can also leave a legacy of issues, such as contamination with toxic chemicals.