The natural corridor of the Yarra is vital to Melbourne’s amenity and liveability. It provides some of the most popular green open spaces for recreating and enjoying a natural setting, and hence is a cornerstone for community well-being. A rich habitat for native plants and animals, for many species the continuity and vegetation of the river corridor are vital to their survival.
But the green environs of the Yarra continue to shrink from the pressure of urban growth and encroaching development. In the Lower Yarra the erection of huge apartment buildings is the most obvious problem, but just as damaging is the cumulative impact of many developments on single home sites. In the upper reaches of the river, the problem is that indigenous vegetation is being cleared to make way for expanding suburbia, infrastructure, new golf courses and the like.
The Yarra River and its environs are a continuous corridor of public green space and unbroken wildlife habitat along the entire length of the river.
The health and values of the Yarra are closely linked to its water flows – both the quantity and the variability/pattern of flows. Many aspects of native plants’ and animals’ lives are dependent on different flow levels and flow “events”. Examples include:
But the capture and extraction of the Yarra’s water to supply residences, factories and farms in the Greater Melbourne area has significantly altered both the quantity and pattern of river flows.
The program to release environmental flows down the Yarra which commenced in September 2011 is helping restore some of the natural flow pattern; but not all of the natural flows (e.g. inundation of floodplains) can be so restored.
Currently, no effort is being made to restore the natural quantity/level of flows, or size of the river. The river’s size governs the abundance of species, and has social values, being a factor in the river’s heritage, and water based recreation such as paddling. (NB We are not advocating big floods that would damage property or assets above the natural floodplain.)
As widely acknowledged, the ecological and social values of the Yarra are dependent on it being pollution-free. Pollution can make its way into the river through multiple sources and in varying forms, including:
The Yarra’s water can support all its naturally occurring aquatic life forms and is free of all pollutants that may be harmful to them or humans.
The environmental and social values of the Yarra are related to it being home for a wide variety of plants and animals, especially indigenous species. However, the number and population of native species are severely affected by the spread of introduced species, notably weeds, exotic fish, domestic stock and feral animals. Nonetheless the circumstances vary widely along the river and across the catchment. In the older urban areas exotic garden plants and pet animals are valued by the community. On sporting fields and golf links, open mowed exotic grass is the norm. In agricultural areas, stock animals and food crops are intended. It is in the parks, bushland and the waterway itself where the objective is for only indigenous species.
Revegetation with indigenous plant species is being undertaken by many community groups and most local authorities, and there are numerous success stories. But the attractiveness of exotic plants and animals, and the fact that many out-compete native species are formidable barriers, such that it is doubtful whether the overall situation is improving.
All the flora and fauna of the Yarra catchment are indigenous species except:
The community values the Yarra in many ways beyond those described above. These social values include its rich human heritage (both indigenous and non-indigenous); the many forms of recreation beside and on the river; its inspiration to artists, photographers, authors and poets; the personal stories and associations with it; and the role the Yarra plays in civic and cultural events and celebrations.
The community value of the river has an important impact on its environmental values, because “people protect what they love”.
All Melburnians: