1 The ABS Water Account Australia (WAA) is one of the environmental-economic accounts produced by the ABS based on the System of Environmental-Economic Accounts (SEEA). It consists of supply and use tables (collectively referred to as flow tables) for both physical and monetary volumes. The aim of the WAA is to integrate data from different sources into a consolidated information set making it possible to link physical data on water to economic data, such as that in Australia's National Accounts.
2 Environmental-Economic accounts can provide information and improved understanding on a range of issues that include:
- a broader assessment of the consequences of economic growth;
- the contribution of sectors to particular environmental problems; and
- implications of environmental policy measures across sectors (for example, regulation, charges and incentives).
3 One advantage of environmental-accounts is that by linking together physical and economic data in a consistent framework it is possible to undertake scenario modelling. Issues that can be modelled include future water demand, assessing relative efficiencies in interactions between different sectors of the economy and the environment, and resource implications of structural change.
4 When the ABS produced the 1993–94 to 1996–97 and 2000–01 editions of
WAA, any readily available data on water resources from various government and non-government organisations were used and aggregated. This tied together industry, regional and state data into a single system showing the supply and use of water within the Australian economy.
5 The survey activity undertaken by the ABS for the 2009–10 WAA collected comprehensive data on all organisations supplying water in the Water supply, sewerage and drainage services industry in Australia, however the amount of survey information collected on water use from across the economy was less than that collected for the previous two editions of WAA (2004–05 and 2008–09). As with the previous editions, data from other sources was also used to fill gaps, as well as for data consistency and checking. There will be more information available from surveys for the WAA in 2010–11 and 2011–12.
ENVIRONMENTAL ACCOUNTING FRAMEWORK
6 The WAA was developed using the System of Environmental-Economic Accounts (SEEA) and the SEEA-Water. SEEA was first published by the United Nations in 1993, and revised in 2003. SEEA is a supplementary account to the System of National Accounts 1993 and will be elevated to an international statistical standard in 2012. Environmental accounts extend the boundaries of the System of National Accounts (SNA) framework to include environmental resources, which occur outside the economic production and asset boundaries measured by the SNA.
RELATIONSHIP BETWEEN THE WATER ACCOUNT AUSTRALIA AND NATIONAL ACCOUNTS
7 Water supply and use tables provide a framework to link core components of the National Accounts to physical information. Physical data are presented in supply and use tables while some linkages to economic data are also made.
PHYSICAL SUPPLY AND USE
8 The Physical water supply and use section presents aggregates of all available physical data (megalitres) in terms of the supply and use of water within the Australian economy for the financial year 2009–10. Supply and use tables illustrate the economic use of water and include: self-extracted, distributed, and regulated discharge (including in-stream use) and reuse.
9 The WAA presents information on the supply and use of water in the entire Australian economy in both physical and monetary terms.
10 The WAA includes the entire geographical area of Australia.
11 The use of saline water (including water from estuaries) for power generation and other industrial uses, although measurable and reported, is not included in the supply and use tables. This is because the scope of the WAA is fresh water only.
12 Coverage for both supply and use tables includes the following:
- individuals and companies that directly extract water from surface water and groundwater sources for their own use (e.g. domestic, industrial, agricultural or other uses);
- households, government and businesses that use water supplied by water providers for domestic, industrial, agricultural or other uses;
- water providers that extract water from surface water, groundwater and sea water for desalination, and supply it to customers for use (e.g. domestic, industrial, or other use). The majority of water providers are categorised in Water supply, sewerage and drainage services industry (ANZSIC 281) but the Mining, Manufacturing, and Electricity and gas supply industries also supply a small amount of water; and
- water providers that provide reuse water to their customers; other large organisations who treat water and make it available for subsequent reuse; other large organisations who discharge water directly to the environment (e.g. power stations, mines); and major in-stream water users, for example aquaculture and hydro-electricity generation, where this information is available.
13 Items not covered by the supply and use tables include:
Water consumption and use
- the volume of rainwater used by agricultural crops/pastures that are directly rain fed;
- discharges to the environment resulting from the run-off of irrigation water;
- the reuse/recycling of water on-farm or on-site (i.e. within homes or businesses);
- non-point/diffuse discharges; and
- the impact of storm water infiltration into the sewerage reticulation system.
14 Calculating water use by industries is not straightforward. Water use can include self-extracted water, distributed water, or reuse water and sometimes a combination of all three sources are used. Calculating water use estimates for an industry or business is made more complicated when water is also supplied to other users, or when water is used in-stream (e.g. for cooling or hydro-power). As such simply adding self-extracted water, distributed water, and reuse water to derive a figure for total water use can be misleading.
15 In the WAA, volumes of water used and supplied by each industry have been balanced to derive 'water consumption'. This figure takes into account the different characteristics of water supply and use of industries and is a way of standardising water use, allowing for comparisons between industries. As such the following accounting identities have been used:
- Total water use is equal to the sum of Distributed water use, Self-extracted water use and Reuse water use;
- Water consumption is equal to the sum of distributed water use, Self-extracted water use and Reuse water use less Water supplied to other users and less In-stream use. The use of Distributed water by the environment (Environmental Flows (see paragraphs 33-36), is not included in total water consumption.
16 For most industries, water use and water consumption are the same as most industries do not have any in-stream use or supply water to other users. However, water consumption and use will vary considerably for some industries, specifically the Water supply, sewerage and drainage services industry, Electricity and gas supply industry and Mining industry, where in-stream water use and water supply volumes are significant.
17 There are a variety of water sources that may be supplied as reuse water, including waste water (from sewerage systems), drainage water, storm water or other water providers (i.e. a 'bulk' reuse water supply). Sewerage systems collect and treat waste water which may be treated to primary, secondary or tertiary levels. Stormwater may also be collected using infrastructure separate to sewerage systems and, depending upon its intended use, may or may not be treated before being supplied as reuse water. Drainage water is also collected in regional collection drains managed by irrigation/rural water providers. This water may be supplied as reuse water to customers or discharged to the environment. This process is analogous to urban reuse systems, however the water is typically treated in urban systems before it is supplied.
18 The water discharged from the economy to the environment may be regulated or unregulated. Regulated discharge refers to water discharged after use where that discharge does not match the natural flow regime of the receiving water body. For example, the waste water discharged by sewerage service providers is a regulated discharge. The water discharged by the Electricity and gas supply industry after use in hydro-electric power generation is also regulated discharge.
19 The water discharged by households and other industries to sewerage or drainage systems, however, is not a regulated discharge as the water is not discharged directly to the environment. This does, however, become a regulated discharge, after it has been treated by the Sewerage industry and released back to the environment. Discharges from non-point sources, such as those from the Agriculture industry (e.g. run-off from irrigation), are not included in this publication and are therefore represented in the supply and use tables as "not available".
20 Data have come from a range of ABS surveys as well as State, Territory and Local Government agencies, water authorities and industry organisations.
21 The main ABS surveys used were:
- 2009–10 Water Supply and Sewerage Services Survey
- 2009–10 Agricultural Resource Management Survey
- 2008–09 Energy, Water and Environment Survey
- 2008–09 Economic Activity Survey
- 2009–10 Economic Activity Survey
Note that data from the latter three surveys listed above did not feed directly into the 2009–10 WAA. Rather, aggregate factors produced from the data collected in these surveys were used to estimate water use for 2009–10.
22 State and Territory government agencies and major businesses, including major state/territory water corporations, provided data that were used in this publication, including:
- In New South Wales, NSW Office of Water. In particular, the 2009–10 NSW Water Supply and Sewerage Benchmarking Report .
- In Victoria, the Department of Sustainability and Environment. In particular, the 2009–10 Victorian Water Accounts.
- In Queensland, the Queensland Statewide Water Information Management (SWIM) under arrangements with the Queensland Water Directorate.
- In Western Australia, the Department of Water, the Economic Regulatory Authority and major water corporations.
- In Tasmania, the Department of Primary Industries, Parks, Water and Environment.
23 Surveys conducted by other government agencies, industry associations, as well as annual reports of water providers were used. These include:
Methods for Calculating Water Supply and Use
- National Water Commission (NWC) and Water Services Association Australia (WSAA) 2009–10 National Performance Report - Urban Water Utilities.
- National Water Commission (NWC) National Performance Report 2009–10: Rural Water Service Providers.
- Annual/environmental reports for 2009–10 for various water providers.
24 These notes are intended as a general guide to the method of calculating estimates of water supply and use. For more detail on the methods please contact the Director, Environmental Accounts Section, Australian Bureau of Statistics.
25 A complete list of water providers in 2009–10 was compiled using the ABS Business Register (ABSBR) supplemented by additional information supplied by State and Territory regulatory departments, industry bodies, and other water data providers. All water providers identified were surveyed in the ABS 2009–10 Water Supply and Sewerage Services Survey.
26 Water providers provided information on:
- Volume of water extracted from the environment and/or the volume of water received from other water providers (this information was used to reconcile total supplies and to avoid double counting of water volumes).
- Volumes of water supplied to particular industries (e.g. Agriculture, Mining and Manufacturing) and for household use. This information was reconciled with water use as reported by water users. It also enabled the calculation of coefficients (e.g. ML/employee) for industries for which there was little or no data on water use.
- The amount of water used by the water supply organisation (including mains flushing and water used on parks and gardens operated by councils that supplied water).
- Volume of water lost from the supply system (including customer meter errors and system water losses).
- Volume of water discharged by location.
- Volumes of reuse water supplied to particular industries (e.g. Agriculture, Mining and Manufacturing) and for household use. Water reuse volumes were not imputed where water providers did not provide reuse water volumes.
- Distributed water supplied to households and the number of connections served by water supply and sewerage services. Where information was not available for distributed water supplied to households, neighbouring or matched Local Government Area (LGA) coefficients based on average megalitre use per connection were used.
- The amount of water released for environmental flows. This only includes those environmental flows released in accordance with a specific plan prepared in conjunction and/or approved by the appropriate environmental (resource) regulator (see paragraphs 33-36).
27 For Agriculture:
- Distributed water use was the amount supplied to the Agriculture industry by water providers.
- Total water consumption by Agriculture was sourced from the 2009–10 ABS Agricultural Resource Management Survey. Generally, the amount of distributed and reuse water consumed (collected on the ABS 2009–10 Water Supply and Sewerage Services Survey) was subtracted from total water consumed; the remainder was assumed to be self-extracted water. Note that self-extracted water for the Agriculture industry includes all groundwater that is extracted by Agriculture businesses.
- Reuse water usage includes water used from regional reuse schemes.
- Data for Victoria were confronted by the Victorian Water Register (Department of Sustainability and Environment, State Government Victoria, 2010).
- Two different views of agriculture are provided in the 2009–10 WAA: an industry view and an activity view (presented in the Appendix only). In an industry view all businesses are coded to an industry according to the Australian and New Zealand Standard Industrial Classification (ANZSIC 2006). An industry view provides direct links to the economic information in the System of National Accounts. This enables data such as industry value added to be compared to water consumption.
- The Agriculture industry view presents only the agricultural activity that occurs in businesses where the primary income producing activity (i.e. the activity with value added that exceeds the value added of any other activity carried out by the same business) of the business is agricultural production. Businesses which undertake some agricultural activity but for which other activities provide most of the income are excluded from the Agriculture industry view. For example, a business which generates most of its income from transporting agricultural produce, but also grows some agricultural commodities would be classified to the industry Transport, postal and warehousing industry. The agricultural production is still counted but is attributed to the Transport, postal and warehousing industry. As such the industry view of Agriculture shows a lower level (around 5%) of water consumption than the agricultural activity view.
- The tables and graphs presented in the Agriculture section of this publication present an industry view for agriculture, while the Appendix presents an activity view. Note that, as in the 2008–09 WAA, the Physical water supply and use tables in this publication present the industry view, whereas previous editions of the WAA presented an activity view, so care must be taken when comparing the different sets of estimates.
- Note that the ABS publication Water Use on Australian Farms, 2009-2010 (ABS cat. no. 4618.0) presents an activity view of agriculture - therefore total consumption estimates are slightly different to the industry estimates presented in the Physical water supply and use tables in the 2009–10 WAA. However, the activity estimates presented in the Appendix are the same as those published in Water Use on Australian Farms.
28 For Mining and Manufacturing:
- Distributed water use was the amount supplied to the Mining and Manufacturing industries by water providers.
- Reuse water use was the amount supplied to the Mining and Manufacturing industries by water providers.
- Estimates for self-extracted and in-stream water use and water discharges were modelled (see paragraph 32) by simple application of aggregate factors based on outputs from the 2008–09 Energy, Water and Environment Survey (EWES) and the 2008–09 and 2009–10 ABS Economic Activity Surveys (EAS) (note that these factors were based on economic data and were adjusted for inflation using ABS Producer Price Indexes (PPI) data (ABS cat. no 6427.0)). Note that for the 2008–09 WAA, estimates were sourced directly from the 2008–09 EWES, a three-yearly survey that was not run in respect of the 2009–10 reference period.
- Mine dewatering was assumed to be self-extracted in-stream (non-consumptive) use by the Mining industry. The water is usually used on-site or subsequently discharged to the environment.
- Only division level estimates are published at the State/Territory level (sub-division splits are presented at the National level) due to lack of survey input data for the Mining and Manufacturing industries. In previous editions of WAA, estimates for ANZSIC sub-division splits were published for Mining and Manufacturing for all states, however the modelled data which formed the basis of the 2009–10 estimates were deemed not sufficiently reliable for publication at the sub-division level.
29 For Electricity and gas supply
- For the 2004–05 and 2008–09 editions of WAA, data for water use by electricity generators were sourced from the ABS Electricity Generators Survey of Water Use (a census of all energy producers with a greater than 10 MW capacity), however this survey was not run in reference to 2009–10, so these data were based on modelling using reliable administrative data from annual reports, websites and the National Greenhouse Energy Reporting System (NGERS).
30 For "Other" industries (includes construction, service industries, government, education, health, arts and recreation - see Glossary
for list of industries):
- Estimates of water use were modelled (see paragraph 32) by simple application of aggregate factors based on outputs from the 2008–09 EWES and the 2008–09 and 2009–10 ABS Economic Activity Surveys (similar to Mining and Manufacturing - see paragraph 28), information supplied by water providers via the ABS 2009–10 Water Supply and Sewerage Services Survey, as well as the application of industry specific coefficients.
- Data on bore water use for parks and gardens in Western Australia was provided by Western Australia's Department of Water.
31 For household water use:
- Distributed and reuse water use was the amount supplied to households by water providers (these data were sourced mainly via the ABS 2009–10 Water Supply and Sewerage Services Survey.
- Self-extracted water use by households was calculated by applying average regional "volume (kL) per connection" coefficients and applying these to the households known not to be served by water providers (estimated by subtracting the connections served by water providers from the total number of households in each State and Territory). Data on domestic bore water use in Western Australia was provided by WA Department of Water. Note that self-extracted water use estimates for households do not include rainwater tank usage for households connected to mains supply.
32 Water use modelling:
- ABS conducts a detailed energy and water use survey every three years for the Mining, Manufacturing, Construction, Electricity Generation and the service industries. This survey (the Energy, Water and Environment Survey, or EWES) was conducted for the 2008–09 reference year, with the results feeding directly into the 2008–09 edition of WAA. The survey will be conducted again in the 2011–12 reference year. Water use by these industries has been modelled in this 2009–10 edition of WAA. Note that the water use estimates for households and agriculture are still conducted on the basis of annual surveys.
- The water use modelling incorporates reported water use information from the 2008–09 EWES and corresponding industry output information from the annual ABS Economic Activity survey 2008–09. The relationship between water as a production input and industry output is identified from these 2008–09 survey results and applied to the 2009–10 Economic Activity Survey. This structural relationship is assumed constant between years, meaning that the efficiency of water use is assumed to the same between 2008–09 and these modelled water use estimates for 2009–10. Changes in water use efficiency will be identified when updated survey information becomes available in the 2011–12 reference year.
33 Key Commonwealth, State and Territory water agencies recognise two forms of water used for Environmental Flows:
- Planned (rules-based) environmental water relates to statutory requirements to maintain specific water regimes (e.g. particular levels, flow rates, aquifer pressures).
- Held (entitlement-based) environmental water relates to specific entitlements, which accrue annual allocations of water that can be extracted (or left in-stream) for environmental purposes.
34 In previous editions of the WAA the Physical water supply and use tables presented "water supplied to the environment as Environmental Flows":
- on the supply side of the tables in the Distributed column; and
- on the use side of the tables in the Environment row in both the Distributed and Reuse columns. Note that for the 2004–05 and earlier editions of the WAA there were no data available for 'reuse' Environmental Flows.
35 It is apparent that some water utilities do not measure all Environmental Flows and there is subsequent uncertainty around the level estimates. In the 2008–09 WAA, Environmental Flows estimates were primarily based on flows of 'held environmental water' as these are volumetric based (i.e. ML) and reported by water suppliers. Rules-based environmental flows are not always recorded in volume terms and may not always be included within reporting of total Environmental Flows. The estimates of Environmental Flows presented in the 2008–09 WAA are thus likely to be an underestimate and should be used with caution.
36 For the above reasons, Environmental Flows are not separately identified in the 2009–10 edition of WAA. The Environmental Flows that were reported in surveys are presented within the estimates for distributed, reuse water and in-stream water supplied and used by the Water supply, sewerage and drainage services and Electricity and gas supply industries. Consumption for these industries is not affected by this treatment of Environmental Flows volumes (i.e. these flows are defined as non-consumptive use).
Data Quality and Reliability
37 Data for the WAA are from a range of sources with variable degrees of consistency and reliability.
38 All water supply, distributed water use and reuse water information was collected by the ABS and checked for coherence with other data sources. This information can be used with a high degree of confidence.
39 Data on self-extracted water use was compiled from a range of sources. The degree of confidence that can be attached to these estimates is variable:
MONETARY SUPPLY AND USE
- Water supply, sewerage and drainage services industry estimates were based on the ABS 2009–10 Water Supply and Sewerage Services Survey and can be used with a high degree of confidence.
- Agriculture industry estimates were based on the ABS 2009–10 Agricultural Resource Management Survey and can be used with a high degree of confidence.
- Electricity and gas supply estimates can be used with a medium level of confidence as these data were based on sound modelling procedures using good quality administrative data.
- Mining and Manufacturing industry estimates at the State/Territory level should be used with a medium-low degree of confidence as estimates for these industries were modelled based on economic data collected in the 2009–10 ABS Economic Activity Survey.
- Only a limited amount of survey data were available for "other" industries - estimates were mostly based on coefficients of water use. These estimates should be used with a low degree of confidence.
- For households, estimates for distributed and reuse water use were based on information collected on the ABS 2009–10 Water Supply and Sewerage Services Survey and can be used with a high degree of confidence; self-extracted water use was based on coefficients of water use and can be used with a medium degree of confidence.
40 The Monetary supply and use section presents aggregates of all available quantitative monetary data (dollars) in terms of the supply and use of water within the Australian economy for the financial year 2009–10. Supply and use tables illustrate the economic transactions associated with the use of water and the provisions of sewerage, waste water and drainage services (also referred to as water related services).
41 The monetary chapter covers the following:
- supply of distributed water and water related services in the economy by the Water supply, sewerage and drainage services industry;
- expenditure on water and water related services by industries, households and governments; and
- value added to the economy by the major water-using industries.
42 The scope of the section is limited to "net distributed water" which, in this context, is defined as water that has been supplied from one economic unit to another for a fee, creating a measurable economic transaction. The net distributed water excludes distribution losses and supply to the environment for which there is no matching economic transaction.
43 Monetary data for the supply (sales) of distributed water and monetary data for the use (purchase) of distributed water by industries, governments and households have been integrated during the compilation process. This requires some adjustments to input data to ensure consistency of information in the water accounts.
44 Comparisons of changes over time in measures of industry value added are based on chain volume estimates. Chain volume estimates adjust for the impact of inflation, thus allowing comparisons of financial data across time periods to be made on volume basis, the recommended method in the System of National Accounts (SNA). With chain volume measures, the prices used in valuation refer to the prices of the previous year. Further information on the calculation of chain volume measures can be found in the information paper Introduction of Chain Volume and Price Indexes, Sep 1997
(ABS cat. no. 5248).
45 It is difficult to separately identify the revenue from reuse water with that from distributed mains supply. Therefore, estimates on revenue and expenditure on distributed water also include transactions associated with reuse water.
46 Many businesses and households use self-extracted water for their own use, such as farms for irrigation or hydro power plants to generate electricity. Estimates for the value of self-extracted water have not been included in this section due to lack of reliable data.
47 Data presented in this section are drawn from a variety of sources including those used in the Physical water supply and use section. In addition to these sources, the following ABS data were used:
48 Administrative data were also sourced:
Methods for Calculating Monetary Supply and Use
- Water suppliers' annual financial reports
- Public administration and finance data
49 The data collected from these sources were collated to a uniform standard and aggregated to a State and Territory level.
50 Output and value added:
51 For households:
- Expenditure on distributed water is calculated by taking total volume and connected properties reported by each water utility, calculating average consumption values per household and applying the utility's fixed and variable tariff structures to these average values. Where tariff information is not available, an average water rate ($/kL) was applied to the volume of water consumed by the households within those service areas. This methodology has been applied to the 2008-09 household expenditure estimates, resulting in downward revisions to each of the State/Territory and National estimates. These revisions reduce the estimated value of household expenditure on distributed water by 8% at the National level. Please contact the Director of Environmental Accounts within the ABS for additional detail on the impacts of these revisions at the State and Territory level.
52 For government:
- Government expenditure and social transfers in kind monetary data were obtained from ABS Australian System of National Accounts, 2009–10 (unpublished data).
53 For industries:
- Expenditure was estimated using modelled financial data sourced from ABS 2008–09 Energy, Water and Environment Survey, 2008–09 Agriculture Commodity Survey and 2008–09 Electricity Generators Survey of Water Use.
54 Water efficiency
Data Quality and Reliability
- Water efficiency can be expressed as the amount of industrial output produced from a corresponding unit of water used in the production process. We express this in the monetary tables as industry gross value added ($ millions) per GL of water used. Comparisons between industries and changes over time in the average gross value added per GL of water use is complicated by the impact of prices, particularly for Agriculture and Mining, where commodity prices can vary substantially from year to year. This is relevant for analyses of incomes (current prices) generated per GL of water consumed in a given year. For this reason, the percentage change movements in industry gross value added per GL of water consumed between 2008–09 and 2009–10 have been calculated using chain volume measures of industry gross value added. It should also be noted that the data represent industry averages. Changes over time in the mix of commodities produced by a broad level industry such as Agriculture, Mining or Manufacturing could result in significant changes in the average water use.
55 The data are high quality at the highest aggregated level, such as for the total revenue from sales of water and water related services by the Water supply, sewerage and drainage services industry (i.e. the supply side estimates). The revenue reported in this publication covers revenue from sales of water and related services, community service obligations and government grants for non-capital/ operational services and excludes government grants for capital purposes, gifted assets, developer's contributions, investment activities, income from fixed assets disposals and rent and consulting income. There is less confidence in the estimates of revenue from sales of rural distributed water in some states due to paucity of information.
56 Use side estimates for industries and governments were based on several ABS surveys and National Accounts data. There is a lack of information on expenditure on water and related services by industries and governments. Therefore, compared to the supply side, there is less confidence in these estimates. Use side estimates for industries were based on model estimates while expenditure for governments were based on National Accounts data (unpublished). Note that the use data for 2008–09 has been revised since the 2008–09 publication, so comparisons between 2008–09 and 2009–10 refer to the revised 2008–09 data. Data on water expenditure will be collected via the Economic Activity Survey in the 2010–11 financial year and will be used to compile monetary estimates for the 2010–11 WAA.
GROSS VALUE OF IRRIGATED AGRICULTURAL PRODUCTION
57 The Gross Value of Irrigated Agricultural Production (GVIAP) was estimated using data from the ABS 2009–10 Agricultural Resource Management Survey (see Agricultural Commodities, 2009–10, Australia
(ABS cat. no. 7121.0), and Water Use on Australian Farms, 2009–10
(ABS cat. no. 4618.0), as well as other ABS collections and administrative data used to calculate the value of agricultural commodities produced (see Value of Principal Agricultural Commodities Produced, 2009–10, Australia
, (ABS cat. no. 7503.0)).
Method of Calculation
58 The ABS methodology for calculating GVIAP is described in the information paper Methods of estimating the Gross Value of Irrigated Agricultural Production
(ABS cat. no. 4610.0.55.006). The GVIAP statistics presented in the 2009–10 WAA and the publication Gross Value of Irrigated Agricultural Production, 2009–10
(ABS cat. no. 4610.0.55.008) are derived using this method. Note that in 2009–10 there was a slight change to the methodology used to estimate the gross value of irrigated agricultural production for livestock and therefore a break in the time series (see the explanatory notes in Gross Value of Irrigated Agricultural Production 2009–10
(ABS cat. no. 4610.0.55.008) for more details).
Data Quality and Reliability
59 Calculation of the gross value of irrigated production is based on several assumptions so these estimates should be used and interpreted cautiously.
60 The next release of the WAA, in respect of 2010–11, is scheduled for November 2012.