Inland Waters

Water Quality

Water quality is fundamental to the ecosystem services that inland waters provide, such as drinking water, cycling of nutrients, maintenance of biodiversity, and recreational and cultural opportunities. Many elements of the environment, such as urban and agricultural landscapes, flow regimes, riparian vegetation and in-stream habitat affect water quality. In 2005, water quality objectives for salinity were met at 68% of sites across Victoria, and objectives for total nitrogen, total phosphorus, and turbidity were met at less than half the sites monitored. Concentrations of total nitrogen and total phosphorus posed a risk to ecosystem health at about 80% of lowland sites in 2005. Water quality is generally poorer in lowland rivers and wetlands, water storages and weirs, as they accumulate pollutants received from the catchment upstream. Increased nutrient inputs, river regulation and low streamflow are now recognised as a major cause of cyanobacterial blooms in rivers.

The maintenance of good water quality requires regional-scale management, but it is also one aspect of inland waters that most individuals can do something about, through simple actions like keeping pollutants out of stormwater drains. The degradation of important receiving waters such as Port Phillip Bay, Western Port, Gippsland Lakes and the Murray River is a major driver of water quality improvement programs.

This section focuses on four key water quality variables: salinity, turbidity, total nitrogen and total phosphorus. Ongoing threats to water quality are identified, and implications of the current condition are discussed. This section also provides an overview of management responses and presents recommendations relating to water quality in Victoria.

Part 4.3.4 - Water Quality (PDF - 3.5 MB)