4 Inland water

1.2 Australia’s water resources and use

Australia’s water resources can be assessed, in part, according to drainage divisions and our withdrawal of water for other uses from the environment (abstraction).

1.2.1 Australia’s surface water resources, by drainage division

The state and trend of, and outlook for, Australia’s inland water environments vary dramatically across the continent, at all scales of resolution. It is sensible to consider water issues by catchment or sets of catchments, so that the health of entire systems can be assessed. Australia’s 12 drainage divisions are the top level of our catchments (Figure 4.1).

Although the states or territories are usually responsible for environmental assessments (e.g. state SoE reports), some natural drainage lines cut across more than one jurisdiction—for example, the Murray–Darling extends across five jurisdictions. This creates a challenge in aligning environmental assessments by jurisdiction with specific divisions. In addition, because the drainage divisions are very large, the state and trend of the water environment and the pressures on it vary significantly within a division; this applies particularly to the North-east Coast, South-east Coast and Murray–Darling divisions. Where appropriate, the variations in assessments within a division are noted and discussed below.

Most drainage divisions are large enough to encompass most groundwater systems. That is, boundaries of recharge and discharge areas of aquifers are wholly contained within the boundaries of the drainage division. The major exception to this is the Great Artesian Basin, which lies under parts of the North-east Coast, Murray–Darling, Lake Eyre and Gulf of Carpentaria divisions.

A key feature of these drainage divisions is whether rivers are perennial (permanently flowing) or nonperennial (seasonally flowing) (Figure 4.2), and whether rivers or wetlands are protected or have special management status with respect to the environment (Figure 4.3). For example, the ecological character of each of the 64 Australian wetlands listed under the Ramsar Convention for Wetlands of International Importance is protected as a matter of national environmental significance by the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act). Wetlands of national importance are listed on the Directory of Important Wetlands in Australia, and in some states are protected by state legislation or considered in planning processes. State-level legislation provides varying levels of protection for selected wetlands, lakes and rivers throughout Australia. Rivers and inland water bodies occurring within the boundaries of the National Reserve System may be protected to varying degrees by federal, state and territory governance arrangements. Rivers and wetlands may also be afforded protection through mechanisms such as market-based incentives, covenants and management agreements.

Water bodies mapped in Figure 4.3c are specifically protected by state-level legislation, including State Environmental Planning Policy No. 14—Coastal Wetlands (NSW); wild rivers as defined in the National Parks and Wildlife Act 1974 (NSW); Wild Rivers Act 2005 (Qld); Heritage Rivers Act 1992 (Vic); Environmental Protection (Swan Coastal Plain Lakes) Policy 1992 (WA); Environmental Protection (Peel Inlet-Harvey Estuary) Policy 1992 (WA); Environmental Protection (Gnangara Mound Crown Land) Policy 1992 (WA); Environmental Protection (South West Agricultural Zone Wetlands) Policy 1998 (WA); Environmental Protection (Western Swamp Tortoise Habitat) Policy 2003 (WA); and certain defined wetlands classified as environmentally sensitive areas under the Environmental Protection Act 1986 and Environmental Protection (Environmentally Sensitive Areas) Notice 2005 (WA, data supplied by the Department of Environment and Conservation). At the time of writing, maps for State Environmental Planning Policy No. 14—Coastal Wetlands (NSW) were in the process of being reviewed to improve their accuracy.

1.2.2 Water availability and use

Australia as a nation could not exist without taking water out of the natural environment and using it for domestic and productive purposes. Australia uses about 5% of its total renewable freshwater resources, compared with about 20% for the United States and 43% for Italy (based on 2006 data).¹ The regional distribution of use is highly uneven across Australia, however, with some regions extracting half the available water. Per person, we use more than all other countries of the Organisation for Economic Co–operation and Development except New Zealand, Canada and the United States.

In the water year 2008–09, we extracted 59 839 gigalitres (GL) of water from the environment—of this, 9673 GL was extracted by water service providers and 50 166 GL was directly extracted by water users.² Of the total, 47 459 GL was returned to the environment as regulated discharge. The majority of this discharge (44 484 GL) was in–stream use for hydro–electric power generation.

Australia’s water consumption was 14 101 GL in 2008–09, a decrease of 25% from 2004–05, when it was 18 767 GL (Table 4.1 and Figure 4.4). Agricultural activities accounted for 6996 GL (about 50%) of total Australian water consumption in 2008–09. This is a decrease from 2004–05 (12 191 GL; 65%), reflecting restricted supplies during southern Australia’s extended drought. This drought went from 2000 to 2010 (sometimes known as the millennium drought), although in some areas it began as early as 1997. Somewhat remarkably, over the period 2006–09 the gross value of irrigated agriculture was maintained and even increased despite the decrease in water availability.² The relationship between water availability for agriculture and economic sustainability at the farm, community, regional and national scales is clearly a complex one. The sources of water distributed for use across the jurisdictions appears in Table 4.2.

Source: Australian Bureau of Statistics²

Source: Australian Bureau of Statistics²

Reuse water made up 348 GL (almost 4%) of total water supplied by water providers in 2008–09; of this, 98% (341 GL) was supplied through water utilities and 30% (102 GL) was used by agriculture.

The scarcity of water supplies that developed over the past decade and the resulting investment in new water infrastructure largely explain the increase in the average price of distributed water, from $0.40 per kilolitre(/kL) in 2004–05 to $0.78/kL in 2008–09. Urban water prices have continued to increase across Australia, reflecting significant state and territory investments in new water infrastructure. Households paid a national average of $1.93/kL and agriculture, $0.12/kL; this difference is partially explained by the higher level of treatment required for supplied drinking water. Water is, however, still a minor fraction (<2%) of household expenses and has not increased at the same rate as expenditure on housing or energy.⁴

The economic return for water used varies across industries. In 2008–09, the gross value added per gigalitre of water consumed was:

• agricultural production—$4 million
• mining industry—$226 million
• manufacturing industry—$164 million.

In total, Australian industries added about $1.2 trillion of gross value for the water used in 2008–09.