Adelaide
Water accounting policies

a. Introduction

The information presented in the Adelaide region report is based on agreements between the South Australian Department for Water, the South Australian Water Corporation (SA Water) and the Bureau of Meteorology (the Bureau).

The report has been prepared using an accrual basis of water accounting, with the exception of the water flow information. The water attribute being quantified is volume and the unit of account is megalitres (ML).

For clarity of presentation, water transfers from the River Murray into the Adelaide region to supply the urban water system and irrigation schemes are reported as transfers directly into these systems, although part of that water is actually conveyed by the rivers and stored in the surface water storages in the region prior to its abstraction by these systems.

Water held in off-channel water stores (farm dams) is not identified as a water asset as the National Water Account considers that it has already been abstracted from the pool of water available for public sharing that is managed by the state licensing authority; however, information about off-channel water stores is provided in the off-channel storages section of the 'Water resources and systems' note because it is considered useful to users of the National Water Account and the water they intercept reduces inflows into the water assets of the region.

b. Recognition of water assets and water liabilities

Only water that is held or managed by the state licensing authority, the region's irrigation scheme, or the urban water system is defined as a water asset. Water liabilities consist of present commitments to supply water, the discharge of which is expected to result in a decrease of the region's water assets or an increase in another water commitment to supply water. Provided its volume can be quantified in a way that is complete, neutral and free from material error, the volume of the water asset or water liability is recognised in the Statement of Water Assets and Water Liabilities.

The volume of line item 2.5 Other groundwater assets included in the water accounting statements is recognised as the managed groundwater volume plus the balance of recharged water credits.

  • The managed groundwater volume is an average annual groundwater volume available for extraction, usually estimated by the jurisdictions for each managed groundwater management unit (prescribed wells areas, in the case of the Adelaide region). The managed groundwater volume is only recognised as a groundwater asset in the water accounting statements if there is evidence that the volume results from an assessment of the available resources to be extracted.
  • Recharged water credits accrue from water drained or discharged to groundwater through managed aquifer recharge. Recharged water credits increase the extractable portion of groundwater; therefore, the recharged water credit balance (credit carried over) is recognised as part of the groundwater asset.

c. Recognition of changes in water assets and water liabilities

The increases and decreases to the reported water assets and water liabilities consist of changes that can be quantified in a way that is complete, neutral and free from material error. These volumes are presented in the Statement of Changes in Water Assets and Water Liabilities and the Statement of Water Flows.

Precipitation and evaporation are recognised only in relation to the surfaces of open storage volumes (9.1 Precipitation on surface water and 17.1 Evaporation from surface water). They do not represent all precipitation, evaporation and evapotranspiration within the region (notably, these processes occurring from the landscape are not captured).

That portion of runoff that flows into the surface water store (storages and rivers) is quantified and recognised in the Statement of Changes in Water Assets and Water Liabilities. This runoff includes precipitation captured in the catchment, less evaporation and infiltration, and is recorded as 9.4 Runoff to surface water.

Allocation announcements on entitlements that create a water liability have been recognised as an increase in water liabilities. Note that the definition of entitlements that create a water liability for the purpose of the National Water Account (refer to 'Glossary') may be different to the meaning applied by the jurisdiction. For more information on allocations, refer to the Water rights, entitlements, allocations and restrictions note.

d. Water assets and water liabilities that fail the recognition criteria

The volumes of several water assets and water liabilities identified in the Adelaide region were not recognised in the water accounting statements but replaced by dashes ('–') as they 'failed the recognition criteria' specified in the Australian Water Accounting Standard 1, because:

  • they could not be quantified in a way that is complete, neutral and free from material error;
  • in the case of water assets, they were unlikely to provide a future benefit to the region or to the region's stakeholders; and
  • in the case of water liabilities, they were unlikely to result in a decrease in the water region's water assets or an increase in another water liability when the obligation is discharged.

The description of those water assets and water liabilities that failed the recognition criteria is given in the following line item notes:

e. Changes to water assets and water liabilities that fail the recognition criteria

The volumes of several changes to water assets and water liabilities identified in the Adelaide region were not reported in the water accounting statements but replaced by dashes ('–') as they 'failed the recognition criteria' specified in the Australian Water Accounting Standard 1, because:

  • they could not be quantified in a way that is complete, neutral and free from material error;
  • in the case of changes to water assets, they were unlikely to provide a future benefit to the region or the region's stakeholders; and
  • in the case of changes to water liabilities, they were unlikely to result in a decrease in the region's water assets or an increase in another water liability when the obligation was discharged.

The description of those changes to water assets and water liabilities that failed the recognition criteria is given in the following line item notes:

f. Restatement of comparative year information

Several comparative year volumes in the water accounting statements were restated from the 2011 Account in order to provide more useful information to the users. Restatements may be due to:

  • error in the 2011 Account, referred to as a prior period error
  • change in scope (for instance, to include more of the region's area in the definition of a line item in order to present more complete information)
  • classification of water assets, water liabilities or water transactions in different line items in order to present clearer information
  • improvement in quantification methodology
  • increase in the data available to quantify a line item.

The notes attached to the line items of the water accounting statements give the details of all the restatements made.