Water quality is an important element of integrated water management in Australia, as elsewhere in the world.
Nevertheless, when it comes to the more traditional water quality concerns of eutrophication , fecal contamination and industrial pollution, Australia’s waterways overall are of high quality by global standards.
The simplest explanation for this is our low population density – only 22 million people in a country of 7.7 million square kilometres (we rank 233 of 239 global countries). Statistically, not enough people, sewage outfalls and factories to make a huge national impact, unlike in many European and Asian counties, for example.
Of course, our population is not uniformly distributed across the continent. Indeed, about 70% of the population resides in our 10 largest cities, nine of which are on the coast. Certainly rivers and coastal waters in these cities have experienced serious water quality problems that have required significant public and private investment in water quality control measures.
What is perhaps more interesting about water quality in Australia is, that for a small population, we have managed to massively impact on our natural watersheds in the pursuit of more and more agricultural and urban lands. Over the two or so centuries since European settlement, vegetation clearing has been extensive and unforgiving across much of eastern and southern Australia.
The consequences of this have been widespread landscape erosion and the transport of soil and associated constituents to our waterways and coasts. It has also led to the mobilisation of salt that sat dormant in the landscape for millennia. Diffuse source management of suspended sediments and salinity are possibly the most difficult water quality challenges we face at a national scale.
Australia’s water quality management policy was devised in the 1990s, as the ‘National Water Quality Management Strategy’ (NWQMS). The NWQMS provides a science-based guideline setting framework for water quality management. It is implemented through action plans designed for managing water quality in particular catchment areas – these allow for local environmental conditions and the needs of local communities to be considered.
Nationally significant examples are the Great Barrier Reef Water Quality Protection Plan and the Murray-Darling Basin Salinity Management Strategy. Both inform improved land management and related activities to protect water quality in connected rivers and coastal waters.
The National Water Quality Guidelines, revised most recently in 2000, consider water quality for human activities in relation to ecosystems, and consider the protection of up to six ecosystem types and a range of factors that can influence the effects of specific contaminants.
The underlying philosophy behind them is the setting of water quality objectives that will maintain acceptable ecosystem condition while meeting the needs of people who use a waterway, whether for drinking, industrial, recreational or other needs. They also provide for the protection of pristine or near-pristine rivers and wetlands where human needs are minimal or purely aesthetic.
*Find out more about the ‘Australian and New Zealand Guidelines for Fresh and Marine Water Quality’ (2000), at: http://www.mincos.gov.au/publications/australian_and_new_zealand_guidelines_for_fresh_and_marine_water_quality