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Report Card 2012–2013

The Yarra River and Port Phillip Bay Report Card was developed to report on the water quality at sites in Port Phillip Bay and its surrounding catchments. Click on the map or list below to explore.

Bay and Catchments

Water quality index
Land Use




Water Quality Index

Very Good




Very Poor

Citizen Science Data

Citizen Science monitoring site

Report Card for July 2012 – June 2013

The Yarra River and Port Phillip Bay Report Card has generated water quality index scores for the period July 2012 to June 2013. These scores are generated using a combination of standard indicators: nutrients, water clarity, dissolved oxygen, salinity, pH, metals and algae.

These are sampled monthly across 110 sites as part of catchment and bay monitoring programs.

The following section ‘Changes over time’ compares these annual scores and indicators from 2000 for the six catchments and the Bay. More detail on the specific catchments or bay is provided in their individual reports.

Site-specific details about indicators can be found via the site lists provided within the individual catchment and Bay reports or can be accessed directly from the map.

Please note that due to improvements in our calculation and quality processes, some sections of this Report Card were updated in 2016 in line with tigher requirements for minimal samples to calaculate the water quality index.

Summary Table: The table below shows the area-weighted distribution of site scores based on subcatchments and marine zones. See the scoring method for more information.

Area Score

Very Good
Near-natural high quality waterways

Forested upper catchments and entrance to Port Phillip Bay


Meets Victorian water quality standards

Upper catchments and Port Phillip Bay


Some evidence of stress

Mostly the main rivers and tributaries in the middle catchment areas on the urban fringe


Under considerable stress

Mostly lower reaches of the main rivers and urban tributaries


Very Poor
Under severe stress

Mostly small urban tributaries

Routine monthly monitoring across 110 sites accounts for 89 per cent of the Bay and catchments area. The remaining 11 per cent of unmonitored catchments are mostly rural and typically score as Fair for this region.

What does this mean?

Port Phillip Bay receives freshwater input from many rivers and drains across the Bellarine, Werribee, Maribyrnong, Yarra, Dandenong and Mornington catchments. Pollutants that accompany these inputs can adversely impact Bay water quality.

Most waterways in upper catchments receive good water quality scores because they are well forested and protected from the impacts of human activity. In the middle catchments area and in some upper catchments, rural land impacts (such as vegetation clearing around waterways, sediment runoff and use of agricultural chemicals) can affect the natural ecology of the waterways.

Water quality in the urban areas of catchments is generally much lower (rated Poor or Very Poor) due to the impacts from residential development and industry. Heavy rains wash litter, pollutants and stormwater into our waterways - which flow downstream and can affect water quality as far away as the Bay. These pollutants reduce the waterway's health and impact species such as fish, platypus, frogs and waterbugs.

Pollutants in urban areas can include: oils and hydrocarbons from vehicles; zinc from tyre rubber; other metals from industrial estates; soil from construction sites; and nutrients from garden fertilisers.

The period July 2012 to June 2013 received below average (18 per cent below average) rainfall, which was most notable during summer (36 per cent below average). (Source: Bureau of Meteorology, Melbourne Regional Office).

The weather was hot and dry over summer with an absence of the tropical storms experienced in previous summers. Such storms can introduce large volumes of water into waterways and can contribute to algal blooms in the Bay. Subsequently, there were few algal blooms in the Bay over the 2012-13 summer period.


The Report Card's water quality index is based on monthly sampling which can mean short-lived environmental and weather events that can impact water quality are not always captured. This section highlights events for the 2012-13 reporting period.

There was a short-lived and localised bloom of the tropical algae Lyngbya at Mothers beach, Mornington, in late summer that was identified as a non-toxic species.

To capitalise on good rainfall in the Yarra catchment an environmental water release was provided down the river over summer and aimed to improve the waterway's health, particularly in the stretch between Yering Gorge and Dights Falls. For more information see the Melbourne Water media release.


Lyngbya bloom, Mothers Beach - EPA Victoria Lyngbya bloom, Mothers Beach. Source: EPA Victoria

Melbourne CBD Yarra River, Parks Vic Yarra River, Melbourne CBD. Source: Parks Victoria

Changes over Time

Since the 1970s the Bureau of Meteorology has identified a long-term ‘drying’ trend in the Melbourne metropolitan region, which shows that the annual rainfall is decreasing by 50 mm every 10 years. This is one of the largest declines in Victoria.

Over the period covered in this Report Card (2000-13) there has been a recovery from long-term drought (1998-2009) to generally wetter conditions. Increased flows in recent years have improved salinity and dissolved oxygen in the rivers and streams, but have also transported more sediment and nutrients to the Bay.

This climatic backdrop shaped much of the water quality condition for the region over this period, the Dandenong catchment was characterised by poor water quality regardless of climate. In this catchment water quality reflects the impacts of predominately urban and industrial land use.

The ‘Actions’ section below outlines projects and initiatives that will contribute toward addressing the issues outlined above.

Specific Bay and catchments reports provide further details about water quality changes experienced at a local level.

Plot of score history for catchments and bay Plot of score history for catchments and bay


The government, authorities and community work together to protect and improve our waterways and the Bay. Initiatives can range from large capital projects such as building wetlands to smaller projects such as planting streamside vegetation and installing raingardens.

What's happened?

Driven by the key water quality issues identified, major projects were implemented to improve waterway health in the Bay and catchments and included the following initiatives:

  • The construction of the largest stormwater treatment wetland in the southern hemisphere: The Dandenong Valley Wetland is one of 50 wetlands built over the past decade as part of a $60 million program aimed at improving the health of rivers, creeks and Port Phillip Bay by trapping about 5,000 tonnes of suspended soils, 9 tonnes of phosphorus and 28 tonnes of nitrogen every year.
  • EPA and Melbourne Water initiated investigations to identify possible causes and response actions for the long-term poor water quality in Dandenong Creek. This effort identified high levels of metals in the water as well as insecticides and fungicides in the sediments of Dandenong Creek and its tributaries. EPA is working with industrial businesses in the catchment to improve business practices and to reduce pollutants being discharged to the creek.
  • A partnership with Frankston City Council and Mornington Peninsula Shire to proactively identify and address high-risk pollution sources that may impact water quality and contribute to algal blooms at their local beaches.
  • A partnership with Life Saving Victoria and the Victorian government in 2013-14 to rollout water quality forecasting at 10 bayside beaches (Seaford, Half Moon Bay, Beaumaris, Sandridge, Altona, St Kilda, Elwood, Mentone, Mordialloc and Frankston).
  • Project funding as part of the Living Victoria Fund which focuses on reducing polluted water and stormwater runoff and includes major benefits for Port Phillip Bay.
  • The Melbourne Water 10,000 Raingardens Program was launched in 2008 and has since worked with homes, schools and businesses across the Port Phillip and Westernport region to build more than 10,000 raingardens. Raingardens help filter pollutants from stormwater and to slow down its flow, which prevents erosion and habitat destruction.
  • Provided almost $140,000 in grants supporting community action to improve water quality in the Yarra River and Port Phillip Bay.
  • Announced round three of the Communities for Nature Grants Program, which focuses on projects to improve water quality in the Yarra River and Port Phillip Bay.
  • Instigated EPA's summer litter campaign ‘A cleaner Victoria is in your hands’ which encourages people to report litter thrown from vehicles via EPA's online reporting tool or mobile apps. It is specifically aimed at creating awareness about the impact of litter on our natural assets such as the Bay and its catchments.
  • Improved communication of water quality to the community through the launch of the new website cleaneryarrabay.vic.gov.au.

For more information on initiatives that are improving our waterways in the Port Phillip Bay and catchments in 2012-13 please visit: Waterways Local Updates 2012-13

What's planned

A number of priority areas and actions have been identified for the Bay and catchments that will build on existing projects and initiatives. Priority management actions include:

  • A number of priority areas and actions have been identified for the Bay and catchments that will build on existing projects and initiatives. Priority management actions include:
  • Melbourne Water's Healthy Waterways Strategy - outlines Melbourne Water's role in managing rivers, estuaries and wetlands in the Port Phillip and Westernport region.
  • Melbourne Water's Stormwater Strategy focuses on managing stormwater to protect and improve the health of waterways and bays.
  • Parks Victoria's Marine Natural Values ecosystem condition assessment reporting is currently being developed for marine parks across the state, including the four marine-protected areas (Jawbone, Point Cook, Rickett's Point and Port Phillip Heads) in Port Phillip Bay.
  • Ten councils were invited by the Victorian Government to apply for a share of $100,000 to deliver litter prevention and clean-up programs along the Yarra River and Port Phillip Bay as part of their Litter Hotspots program.
  • Roll out EPA's litter campaign pack to councils across the state to encourage people to report litter all year round.

Program Partners

Department of Environment and Primary Industries Environmental Protection Agency Melbourne Water