Maribyrnong catchment

Maribyrnong catchment area​The Maribyrnong catchment lies north-west of Melbourne. It covers an area of 1,408 square kilometres, of which:

  • 10% retains its natural vegetation
  • 80% is used for agriculture
  • 10% is used for urban development – confined to greater Melbourne and larger townships within the catchment

The catchment includes the 160-kilometre Maribyrnong River – the second major river in the Port Phillip and Westernport region – which begins on the southern slopes of the Great Dividing Range, near Lancefield.

Rivers and creeks in this catchment tend to be deeply incised and have highly variable flows, with long periods of low flows. They usually have poor water quality and have lost riverbank and aquatic habitat.

The Maribyrnong catchment contains two sub-catchments:

 

Upper Maribyrnong system

The major waterways in the Upper Maribyrnong system are:

  • Jacksons Creek
  • Deep Creek
  • Emu Creek
  • Bolinda Creek
  • Boyd Creek
  • Number 3 Creek

Most of these begin in forested catchments that house significant animal and plant species, including several communities of Yarra pygmy perch and platypus. Other features special to the local community include birds of prey, grasslands and Aboriginal scar trees.

Challenges for waterway health in this system include:

  • the impacts of more intensive land use – such as urbanisation and agriculture
  • environmental flows
  • balancing the area’s social and environmental needs

Condition of key values

​Key value Condition Details
​Current: very low Platypus populations are very vulnerable, and have declined significantly since we began monitoring in 1998. We aim to stabilise populations over the next 20 years and improve them long-term.
20-year: very low
Long-term: moderate
​Current: low Fish populations have been fairly stable since the 1990s. There is a diverse community of fish, but only a moderate proportion of these are native. We aim to improve the numbers and abundance of native species.
20-year: moderate
Long-term: high
​Current: high There is a high number of frog species, though this has declined as recently as the 1990s. Our habitat works aim to improve the distribution of species.
20-year: high
Long-term: very high
​Current: low* The abundance and variety of waterway-dependent bird species is low. Our vegetation works will help by expanding the area and quality of habitat.
20-year: moderate
Long-term: high
​Current: low** Most streamside vegetation is of very low to moderate quality; however some small areas (mostly in the hilly headwaters) are very high. We will continue focusing on vegetation to improve this rating.
20-year: moderate
Long-term: high
​Current: moderate Macroinvertebrate conditions have remained stable since the 1990s – though this varies, with the highest being in forested waterways.  We aim to maintain this, and improve it long term.
20-year: moderate
Long-term: high
​Current: moderate Amenity will improve in key areas as we establish natural vegetation along waterways.
20-year: high
Long-term: very high

* Streamside birds only - does not include wetlands
** Limited data used to determine this rating

 

Lower Maribyrnong system

The major waterways in the Lower Maribyrnong system are:

  • Maribyrnong River
  • Arundel Creek
  • Stony Creek
  • Steele Creek
  • Taylors Creek

Waterways are greatly valued by the community, who have highlighted environmental features such as remaining native vegetation, platypus and growling grass frogs. They also particularly value recreational opportunities including boating, kayaking, fishing, rowing and bike riding.

Improving waterway condition is a challenge. Water quality has been significantly reduced due to the impacts of urbanisation and development and extensive land clearing, which has left little natural streamside vegetation.

Condition of key values

​Key value Condition Details
​Current: very low Platypuses are in very low numbers and at high risk of extinction. Significant improvement in conditions, including flows and habitat, are needed to ensure their survival.
20-year: very low
Long-term: low
​Current: low Fish species numbers and the ratio of native to introduced species are low, though this condition has been stable since the 1990s. Works to improve fish migration and flows will improve this score.
20-year: moderate
Long-term: high
​Current: low Frog species numbers are low but have been stable over the past decade. Their condition will improve over 20 years by linking habitat, though constraints on extensive habitat connectivity limit their long-term potential.
20-year: moderate
Long-term: moderate
​Current: low* Streamside birds are in moderate condition, with small improvements since the 1990s. Their long-term potential is limited due to constraints on extensive habitat connectivity.
20-year: low
Long-term: moderate
​Current: low** Native vegetation is in very low condition, though some remnant vegetation is scattered along the Maribyrnong River and Jacksons Creek, particularly in the Organ Pipes National Park and Sydenham Park.
20-year: moderate
Long-term: high
​Current: moderate Macroinvertebrates are in moderate condition. We aim to maintain this and overcome the impacts of further urbanisation, though this limits long-term outcomes.
20-year: moderate
Long-term: moderate
​Current: low Amenity enjoyed from waterways is low. We aim to improve vegetation along waterways, which provides a sense of naturalness and is a key influence on amenity.
20-year: moderate
Long-term: high

* Streamside birds only - does not include wetlands
** Limited data used to determine this rating

Did you know?

More than 5,800 Aboriginal sites have been recorded in the Maribyrnong catchment, most occurring near waterways.

 

Key facts

  • Area:
    1,408 square kilometres
  • Average flow:
    120 billion litres
  • Average rainfall:
    500mm (lower plains) to 1,000mm (ranges)
  • Traditional owners:
    Wurundjeri, Bunurong and Boon Wurrung people


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