Water Use on Australian Farms methodology

This publication contains statistics on agricultural water use (including pastures and crops irrigated) and irrigation water sources.

These statistics provide data to support agricultural water use policy and planning by governments, industry, research organisations and regional communities.

The water use and irrigation water source statistics in this publication relate to the 2020-21 financial year and have been produced primarily using data from the 2020-21 Agricultural Census.

Businesses on the Australian Bureau of Statistics' Business Register (ABSBR) were in scope for the 2020-21 Agricultural Census if:

• they undertook agricultural activity, and
• the estimated value of their agricultural operations (EVAO) was $40,000 or greater

Estimates from the 2020-21 Agricultural Census are based on a response from 85.4% of the 102,164 agricultural businesses identified as in scope.

The ABSBR is based on the Australian Business Register (ABR). Businesses and organisations are included on the ABR when they register with the Australian Taxation Office for an Australian Business Number (ABN).

ABR data is supplied to the ABS by the ABR Registrar under A New Tax System (Australian Business Number) Act 1999 which requires that such data be only used for the purpose of carrying out functions of the ABS. Any discussion of data limitations or weaknesses is in the context of using the data for statistical purposes and is not related to the ability of the data to support the ABR’s core operational requirements.

Legislative requirements to ensure privacy and secrecy of this data have been followed. Results have been released in accordance with the Census and Statistics Act 1905 and the Census and Statistics Determination 2018.

When registering for an ABN, businesses are required to nominate the type of activity they will be undertaking. This information is used to allocate businesses to an industry in the ABSBR as defined in the 2006 edition of the Australian and New Zealand Standard Industrial Classification (ANZSIC).

Businesses are identified as undertaking agricultural activity if any of their primary or secondary productive activities fall within the ANZSIC Agriculture Subdivision.

EVAO is an ABS construct used to estimate the extent of agricultural activity undertaken, and relative size of agricultural businesses.

It is calculated by applying three-year average prices to estimated livestock sales, livestock numbers and crop production of a business. For businesses below the $40,000 threshold, or with no previously reported agricultural activity, a derived value of operations based on turnover reported in its Businesses Activity Statement (BAS) is used as a proxy.

Businesses selected in the 2020-21 Agricultural Census were asked to complete and return a survey form. Paper and electronic versions of the survey form were available.

Administrative data from non-ABS sources were also used to supplement reported data.

The agricultural water use and irrigation water sources data items collected as a part of the 2020-21 Agricultural Census are below. 

Survey responses are checked for completeness, coherence, and accuracy. Where possible, follow-up contact is made with agricultural businesses to resolve reporting problems. Missing response(s) may be imputed using information provided historically, or from similar agricultural businesses that have responded.

Data is then aggregated and weighted to account for:

• agricultural businesses that did not respond
• any new agricultural businesses not surveyed because they were not present on the ABSBR when the initial survey frame was created.

Before finalising statistics, estimates are compared against and may be adjusted to better align with other information sources including:

• other ABS surveys
• administrative data, including data from the Bureau of Meteorology and the then Department of Agriculture, Water and Environment
• industry estimates and expectations, and
• reports on rainfall, temperature, climatic events, and natural disasters.

The estimates in this publication are based on information obtained from agricultural businesses that responded to the 2020-21 Agricultural Census. As not all businesses responded, the estimates are subject to sampling variability and may differ from the estimates that would have been produced if information had been obtained from all businesses.

The most common measure of the likely difference resulting from not all businesses responding is given by the standard error. There are about two chances in three that a sample estimate will differ by less than one standard error from the estimate that would have been obtained if all businesses had responded, and about nineteen chances in twenty that the difference will be less than two standard errors.

In this publication, relative standard error (RSE) is used to measure 'sampling' variability. RSEs are calculated by expressing the standard error as a percentage of the estimate to which it refers. Estimates should be used with caution that have:

• RSEs between 10% and 25% - this level of sample variability may be too high for some purposes
• RSEs between 25% and 50% - this level of sample variability may be too high for most practical purposes
• RSEs greater than 50% - this level of sample variability is considered unreliable for general use

Some detailed estimates in this publication have been confidentialised to avoid potential identification of agricultural holdings in accordance with the Census and Statistics Act 1905 and the Census and Statistics Determination 2018.

Where detailed estimates have been suppressed for reasons of confidentiality, they have been included in relevant aggregated totals.

Where figures have been rounded, discrepancies may occur between sums of the component items and totals.

National, state/territory and substate estimates are presented in this publication, including estimates for the following regions:

• Statistical Area Level 4 (SA4) regions
• Statistical Area Level 2 (SA2) regions
• Natural Resource Management (NRM) regions
• Local Government Area (LGA) regions
• Murray Darling Basin (MDB) region

National, state/territory, SA4 and SA2 estimates have been produced using Edition 3 of the Australian Statistical Geography Standard (ASGS).  Other regional estimates have been produced using area-based correspondences from SA2 estimates:

• LGA estimates - ASGS 2021 SA2 to 2021 LGA correspondence
• NRM estimates - ASGS 2021 SA2 to 2016 NRM Regions correspondence
• MDB estimates - are aggregates of NRM estimates

Other ABS publications containing agricultural data are listed on the ABS’ Agricultural Statistics page. The ABS also issues a daily Release Advice on the website which details products to be released in the week ahead.

For inquiries about these and related statistics, contact the Customer Assistance Service via the ABS website Contact Us page.

The ABS Privacy Policy outlines how the ABS will handle any personal information provided to us.

ABS publications draw extensively on information provided freely by individuals, businesses, governments, and other organisations. Their continued cooperation is very much appreciated. Without it, the wide range of statistics published by the ABS would not be available. Information received by the ABS is treated in strict confidence as required by the Census and Statistics Act 1905.