How EPA protects and monitors freshwater environments

EPA uses methods to help protect and monitor Victoria's rivers, streams and lakes.

EPA programs that relate to rivers and streams can be categorised as follows:

• Biological monitoring and assessment
• River health/environmental condition reports
• Environmental quality objectives
• Lakes program

Useful (non EPA) information about biodiversity management issues in rivers and streams is available.

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Biological monitoring and assessment

Traditional water quality monitoring involves measuring physical and chemical aspects of water. Common measurements include pH, salinity, turbidity, nutrient levels and the amount of dissolved oxygen in the water. These measures are used because they provide a 'snapshot' of environmental conditions at the moment the samples were taken.

EPA has moved towards a more holistic approach to environmental assessment in rivers and streams, which incorporates biological indicators of ecosystem health. The great value in directly monitoring the biological community is that it responds to all types of disturbances and toxicants, which can be assessed from relatively infrequent sampling of the community (for example twice a year). The nature of the biological community reflects the net effect of all environmental factors, including cumulative impacts over a period of weeks, months or years.

EPA conducts the majority of the invertebrate monitoring carried out across the State. An EPA Statewide biological monitoring program has been in place since 1990 that assesses macroinvertebrate communities using a rapid bioassessment method.

Aquatic invertebrates are small animals, generally less than 1cm long, including insects, snails, worms and shrimps. These animals are generally very abundant and can be found burrowed in mud, in or on woody debris, on the surface of stones in fast flowing riffles and among aquatic plants. As well as being important in their own right, invertebrates are critical to stream ecosystem functioning, both in the processing of energy, and as a food supply to yabbies, fish, platypus and birds.

There is now considerable data available on the response of invertebrates to various forms of pollution, to changes in catchment use (for example: agriculture, forestry, urbanisation), and of their general habitat preferences and ecology. Different types of invertebrates like to live in different parts of rivers and streams. These habitat preferences may include riffles, pools, backwaters, leaf packs or the streambed.

The presence or absence of specific types of invertebrates (small animals such as insects, snails, worms and shrimps) is just one way in which information can be obtained about environmental quality. Other information can be obtained from how many different types of animals are found in a stream (biological diversity), the number of animals found in a stream (abundance) and the relationship between all animals present (community structure).

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River health/environmental condition reports

Monitoring and assessment of environmental condition provides essential feedback on the state of our river systems. This feedback enables water resource managers to develop and refine programs, to direct resources and activities where they are needed most.

To measure the environmental conditions of rivers and streams, EPA incorporates biological indicators of ecosystem health as well as the traditional physical and chemical aspects of the water. A Statewide biological monitoring program has been in place since 1990 that assesses invertebrate (small animals such as insects, snails, worms and shrimps) communities using a rapid bioassessment method.

The information from the biological monitoring program is used to provide assessments of the environmental condition of rivers and streams across Victoria:

• EPA Publication 1008 - River health in north-east Victoria after the 2003 bushfires (Adobe PDF file, 72KB)
• EPA Publication SR6 - A quantitative study of bushfire impacts on the Buffalo and King Rivers: First year findings (Adobe PDF file, 693KB)
• River health – A snapshot of the effects of the 2003 bushfires (Adobe PDF file, 682KB)
• EPA Publication 908 - Environmental Condition of Rivers and Streams in the Ovens Catchment (overview)
• EPA Publication 909 - Environmental Condition of Rivers and Streams in the Ovens Catchment (detailed study)

View more information about bushfires and river health.

• EPA Publication 579 – River Health Bulletin The Health of Streams in the Maribyrnong Catchment (not available electronically. Contact the EPA Information Centre to obtain a copy)
• EPA Publication 580 – River Health Bulletin The Health of Streams in the Yarra Catchment
• EPA Publication 601 – River Health Bulletin The Health of Streams in the Western Port Catchment (Adobe PDF file, 126KB)
• EPA Publication 644 – The Health of Streams in the Glenelg Catchment
• EPA Publication 678 – The Health of Streams in the Goulburn and Broken Catchments
• EPA Publication 698 – The Health of Streams in the Werribee Catchment (Adobe PDF file, 234KB)
• EPA Publication 704 – The Health of Streams in the Campaspe, Loddon and Avoca Catchments (Adobe PDF file, 244KB)
• EPA Publication 713 – The Health of Streams in the Ovens Catchment (Adobe PDF file, 200KB)
• EPA Publication 832 – Environmental Condition of Rivers and Streams in the Latrobe, Thomson and Avon Catchments (Adobe PDF file, 703KB)
• EPA Publication 853 – Environmental Condition of Rivers and Streams in the Mitchell, Tambo and Nicholson Catchments (Adobe PDF file, 612KB).

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Environmental quality objectives

Surface waters and their aquatic ecosystems should be free of any:

• substance at a level or
• human impact

that would pose a risk to beneficial uses. These impacts are shown, for example, through human health impacts, the increased occurrence of fish kills and algal blooms, excessive growth of aquatic plants, sedimentation, loss of biodiversity and environmental flows, and litter and other harmful substances in water environments.

Victoria has developed a set of environmental quality objectives for the protection of aquatic ecosystems in rivers and streams for the State Environment Protection Policy (Waters of Victoria).

The objectives acknowledge there is a wide variety of aquatic ecosystem types, which all function quite differently and are affected/threatened by different issues. Environmental quality objectives are designed to protect these aquatic ecosystems.

The environmental quality objectives describe the level of environmental quality needed, in most surface waters, to avoid risks to beneficial uses and to protect them. If an objective is not attained, the beneficial uses are likely to be at risk. The non-attainment of an objective will trigger further investigation using a risk-based approach, to assess risks to beneficial uses. From this assessment, actions will be implemented or regionally appropriate objectives will be developed.

For more information, background papers on the objectives can be accessed from EPA's Publication Catalogue:

• EPA Publication 791.1 – Water Quality Objectives for Rivers and Streams – Ecosystem Protection (Adobe PDF file, 557KB)
• EPA Publication 792.1 – Nutrient Objectives for Rivers and Streams – Ecosystem Protection (Adobe PDF file, 597KB)
• EPA Publication 793.2 – Biological Objectives for Rivers and Streams – Ecosystem Protection (Adobe PDF file, 304KB).
• EPA Publication 961 – Guideline for Environmental Management: Risk-Based Assessment of Ecosystem Protection in Ambient Waters (Adobe PDF file, 1527KB or 1.5MB).

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Lakes program

Victoria has a wide variety of inland lakes including billabongs, volcanic lakes, sand-dune lakes and reservoirs. Some of these lakes have naturally high salinities and animal and plant communities that make them very different from lakes elsewhere in the world. Historically we have not had a good understanding of the ecology of our unique lake systems.

EPA's lakes project aims to develop a better understanding of how our lakes work and develop guidelines to help protect them. The guidelines are being developed through detailed studies of five lakes in the western district of Victoria – Bullen Merri, Purrumbete, Surprise (pictured), Colac and Modewarre. The project will set the course for future environmental condition assessment of Victorian lakes and support the evaluation and ongoing management of these ecosystems.

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