Victoria’s water environments are diverse and are among our most valuable natural assets.
The most recent monitoring results were included in the 2013 State of the Environment report, and are set out below.
Condition of freshwater ecosystems
- Assessments of Victoria’s river health carried out for the Third Index of Stream Condition 2004-2010 (ISC) released in 2013, show that only 23% of major rivers and tributaries in Victoria were in good or excellent condition, 43% were in moderate condition, and 32% were in poor to very poor condition.
- Almost half the basins in Victoria have less than 10% of major rivers and tributaries in good or excellent condition. The basins in the east of the State had more river length in good or excellent condition compared with basins in the west.
- More than half of Victoria’s wetlands (56%) are in good or excellent condition, however, the extent of wetlands is declining.
- There has been a continued decline in freshwater biodiversity with many species listed as threatened.
- As at 2013, three species of fish were regionally extinct. A further 20 aquatic fauna species were critically endangered, 17 endangered, 26 vulnerable, and seven near threatened.
- Between 2007 and 2013, nine inland aquatic vertebrate species declined in status and four species were added to the Advisory List because of decreasing populations.
- Only five species improved their threatened status.
- Native fish populations are under pressure, with alien species common in many rivers. Waterbirds are showing a long-term decline across eastern Australia. Macro-invertebrate community health remains poor in western catchments.
- Statewide information on the number and distribution of introduced aquatic species remains poor and has not been updated since the 2008 Victorian State of the Environment report
Major river and tributary flows
- Drought conditions between 1996 and 2010 severely reduced Victoria’s river flows across many catchments.
Victorian streamflow compared to long-term average
- Results from the Third ISC assessments show that only 8 of the 29 river basins had flow regimes in good condition for more than 50% of the length assessed. The basins in the east of the state generally had more river length with good or excellent flows conditions compared with basins in western Victoria.
- Nearly all areas were adversely affected by the drought and the south-west of Victoria was the most severely affected.
- Many river basins continue to have large water volumes extracted for consumption. The impacts of this are particularly critical during drought periods. The current Environmental Water Reserve is inadequate to maintain the ecosystem health of many inland waters and is further reduced during drought periods.
Surface water quality
- While it is not possible to report on water quality trends, including whether water quality objectives are being met, previous assessments have shown that water quality is poor in much of Victoria. Lowland areas and the west of the state generally have the poorest water quality.
Groundwater levels and quality
- Groundwater levels declined in many areas during the drought. Generally these have recovered with increased rainfall from 2011. However, long-term declines have continued in Gippsland areas associated with the Latrobe Valley coal mines and offshore oil and gas extraction.
- There remain critical gaps in our understanding of the condition of Victoria’s ground water resources, including their sustainable use.
Main image: Denis Fox