Dr Robert M. Argent
Pressures
Inland water
At a glance
Overall, the key pressures affecting inland water environments have changed little since 2011, with climatic and pest-based pressures increasing, land-use and management pressures remaining largely stable, and some stabilisation occurring in the pressure of water resources development.
This period provided the first cooler than average year since 2001, along with the warmest, third-warmest and fifth-warmest years on record for Australia. It also included 2011 as the second-wettest year on record, whereas recent years have produced significant record rainfall deficiencies in parts of Australia.
Invasive species pressures include those from cane toads, common carp, gambusia, goldfish, and various Weeds of National Significance. Cane toads have reportedly spread into the Kimberley and upper reaches of the Fitzroy River in Western Australia, while 2 aquatic weeds (sagittaria/arrowhead and water hyacinth) were added to the Weeds of National Significance list in 2012.
No recent water-affecting land-use or management changes have been observed on a nationally significant scale. The broadest land-cover effects on water quality since 2010–11 are likely to have arisen from post–La Niña fires in savanna and rangeland areas. About 50–70 million hectares of the northern savannas burn each year, contributing to the ongoing tropical aquatic ecosystem pressures. In addition, Queensland’s land-clearing rate of nearly 300,000 hectares per year exceeds all other states and territories combined.
Urban water consumption figures from larger centres have generally increased. To assist in meeting demands, Australia’s climate-resilient water sources (desalination and recycled water plants) produced more than 440 gigalitres (GL) in 2012–13, amounting to approximately 25 per cent of the estimated production capacity of 1821 GL. More than two-thirds of this was for urban use. Groundwater use for urban demand is not a large proportion of the total water supply for the country, although it continues to be a key supply resource for Perth and for many rural areas.
The primary pressures on our inland water environments have not changed significantly since 2011, although—as noted in the Drivers report—there has been movement in some of the drivers of environmental change during that period, particularly when compared with the decade leading up to 2011. The twin drivers of economic growth and population growth have continued to increase pressure on the supply and use of water.
The few wetter years that followed the millennium drought eased the pressure on total water available to the environment in some areas. Land-use and management pressures—such as irrigation and cropping, and stocking changes—continued to influence inland waters. Pest species have responded to both climate and management efforts. Mining development, particularly of coal-seam gas, has the potential to increase pressure in coming years, as does the promise of accelerated development and growth in northern Australia.
Topics
Argent RM (2016). Inland water: Pressures. In: Australia state of the environment 2016, Australian Government Department of the Environment and Energy, Canberra, https://soe.environment.gov.au/theme/inland-water/framework/pressures, DOI 10.4226/94/58b656cfc28d1
