Murray–Darling Basin: Governance
Accountability Statement
1. This water accounting report has been prepared and presented in accordance with the Australian Water Accounting Standards, with the following exceptions:
- No assurance statement was prepared because the standard for, and practice of, assurance of water accounting reports are currently not available.
- Notes on the quantification approaches and levels of uncertainty are incomplete because the knowledge base is often inadequate.
- No information is disclosed about material events that occurred after 30 June 2018, such as extreme precipitation and significant water rights purchases. This information is publicly available elsewhere.
2. The report has been compiled from the best data available, as detailed in the water accounting statement notes, in the time available to compile it from a number of sources. The Bureau of Meteorology takes a nationally-consistent approach to report preparation and presentation, but for a few items there may be local data of higher quality that were not used.
3. All significant and specific interpretations of the Australian Water Accounting Standard 1 for the purpose of the preparation of this report are explained in the 'Water accounting policies' note. The Bureau of Meteorology is responsible for these interpretations.
Dr Robert Argent
General Manager Water
Bureau of Meteorology
27 June 2019
Water accounting policies
Introduction
The information presented in the Murray–Darling Basin region water accounting report is based on agreements between the Bureau of Meteorology (the Bureau) and:
- the Murray–Darling Basin Authority (MDBA)
- Snowy Hydro Limited.
This report has been prepared using an accrual basis of water accounting, with the exception of the physical water flow information. The water attribute being quantified is volume, and the unit of account is megalitres (ML) in quantifying and either ML or gigalitres (GL) in presenting. Where a reported volume is negative, it is shown in brackets. The applicable reporting period is from 1 July 2017 to 30 June 2018. The surface water diversion volumes reported in 'Key findings' and 'Water access and use' are net volumes. The reported surface water diversion volumes also exclude interceptions (plantations and run-off dams). Volumes reported in all other sections of this report were the gross volumes for the region if not specifically stated as net volumes.
Recognition of water assets and water liabilities
Only water that is held or managed by the jurisdictional licensing authority and from which future benefit can be derived by stakeholders of the region is identified as a water asset.
Water liabilities are constituted by present commitments to supply water, the discharge of which is expected to result in a decrease in 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.
Water held in storages that has already been abstracted from the entitlement system (e.g. farm dams) is deemed not to be part of the region (regardless of the storage's size or connection to the system). This is because the attendant water right has already been exercised.
The volume of groundwater assets included in the water accounting statements has been recognised as the sustainable diversion limits (SDL) for SDL resource units defined under the Basin Plan.
Recognition of changes in water assets and water liabilities
The increases and decreases to the water assets and water liabilities reported consist only of changes that can be quantified in a way that is complete, neutral, and free from material error. These volumes are reported in the Statement of Changes in Water Assets and Water Liabilities or the Statement of Water Flows.
Precipitation and evaporation are recognised on storage surfaces and only for major rivers within the region. These include storages, lakes, weirs, and locks in the regulated and unregulated rivers. It does not represent all precipitation, evaporation and evapotranspiration within the region (notably, these processes occurring from the landscape are not captured).
The portion of runoff from landscape that flows into the surface water store is quantified and recognised in the Statement of Changes in Water Assets and Water Liabilities and the Statement of Water Flows. This runoff includes precipitation captured in the catchment less estimated evaporation and seepage and is recorded as runoff to surface water.
Allocations announced on regulated entitlements have been recognised as increases in water liabilities. Note that the definition of regulated or unregulated entitlements for the purpose of the National Water Account (refer to 'Glossary') may be different to the meaning applied by the jurisdiction. Please refer to the Water access and use note for more information on the allocations.
The volume of water that returns after urban use, recorded as discharge from urban supply system and discharge from wastewater system, meets the identification criteria as an increase to water assets; wherever it could be quantified accurately, it is recognised in the Statement of Changes in Water Assets and Water Liabilities and Statement of Water Flow.
Other groundwater increases and other groundwater decreases do not represent any physical groundwater flow. The volumes provided represent the change of the long-term estimates of volumes for extraction between the reporting year and the previous year. These changes were as a result of revision of SDL volumes, implementation of new water sharing plans, abolition of existing plans, or changes made to New South Wales supplementary access licences. Both the Statement of Changes in Water Assets and Water Liabilities and Statement of Water Flows include 'Other groundwater increases' and 'Other groundwater decreases'.
Changes to water assets and water liabilities that fail the recognition criteria
There are no items to report under this category for the 2018 Account.
Restatement of comparative year information
In accordance with the Australian Water Accounting Standard 1, comparative year volumes must be restated in the statements if there was a prior-period error or a change in item presentation. Comparative year volumes are not required to be restated if there is a change in scope or methodology or subsequent data availability for the quantification of an item.
Water liabilities
The following comparative year volumes related to water liabilities were restated from the 2017 Account due to the update of carryover volumes that were provided after publication. The comparative year items restated in the 2018 Account include following surface water and groundwater:
- Allocation remaining: individual users
- Allocation remaining: environmental purposes
- Adjustment and forfeiture: individual users
- Adjustment and forfeiture: environmental purposes
Groundwater use and overbank flow
The following comparative year volumes related to groundwater use and overbank flow were restated from the 2017 Account due to a change in presentation. The change in presentation included the separation of groundwater supply for salinity and water table management from groundwater supply to individual users. In addition, overland flow take was separated from overbank flow, where previously these items were classified as a single flow. The comparative year items restated in the 2018 Account include:
- Allocated extraction: individual users
- Allocated extraction: salinity and water table management
- Groundwater allocation: individual users
- Allocation: salinity and water table management
- Adjustment and forfeiture: salinity and water table management
- Overbank flow
- Overland flow take
- River and floodplain losses
Prior period errors
The following comparative year volumes were restated from the 2017 Account due to prior period errors:
- Storages
- Allocated diversion: environmental purposes
- Groundwater adjustment and forfeiture: urban system
- Groundwater allocation: urban system
Reporting of water trade
It is assumed that all water traded (allocation trade) within the Murray–Darling Basin region was provided to an account holder within the region, even though delivery may have been provided via the distribution network to a location outside of the region.
Water trades are not reported in the water accounting statements; however, some water trades result in the conversion of the category and purpose of use, which will affect their classification. It is believed these effects are reflected in relevant information for allocation remaining, allocation announcements, allocation diversion, and forfeiture and adjustments in the water accounting statements.
Information about interstate, inter-valley and intra-valley trade is included in the Water market activity note.
Reporting of external transfers
Transfers of water that occur across the boundaries of the Murray–Darling Basin region and impact on the water assets and water liabilities of the region are reported in the water accounting statements. Information about these transfers is also provided in the 'Water resources' section of the 'Geographic information' (Figure R8) note.
Level of reporting in case of bulk entitlements in Victoria
When water is managed under a bulk entitlement in Victoria (see Water entitlements rights and use and other statutory water rights section under 'Water rights'), the 2018 Account reports at the level of the collective retail water access entitlements issued under the bulk entitlements. This means that the water liabilities identified against the region are the allocations announced on these retail entitlements and for bulk entitlements held for the benefit of the environment. Where a bulk entitlement holder has a claim over water located outside the region, that claim will likewise be identified as a water asset of the region.
National Water Account against the Murray-Darling Basin Authority's Transition Period Water Take Report
Water abstractions and other relevant information including allocations, carryover and entitlements in the Murray–Darling Basin region are also reported by the Murray-Darling Basin Authority in its Transition Period Water Take Report (WTR).
Some volumes reported in this account differ from the volumes reported in the WTR due to different approaches being adopted to present information.
Reconciliations
Introduction
The following reconciliation tables verify:
- how the region’s closing water storage in the Statement of Water Flows reconciles to the total water assets reported in the Statement of Water Assets and Water Liabilities
- how the region’s change in water storage in the Statement of Water Flows reconciles to the change in net water assets reported in the Statement of Changes in Water Assets and Water Liabilities.
Closing water storage with total water assets
| 2018 ML | 2017 ML | |
| Closing water storages presented in the Statement of Water Flows | 18,085,624 | 22,132,247 |
| Surface water | ||
| Storages | 11,991,640 | 15,919,026 |
| Rivers | 772,331 | 976,365 |
| Lakes and wetlands | 1,836,095 | 1,890,208 |
| Other assets | 14,168 | 12,908 |
| Groundwater | ||
| Aquifers | 3,471,390 | 3,333,740 |
| Total water storage as presented in the Statement of Water Assets and Water Liabilities | 18,085,624 | 22,132,247 |
| add Other water assets | ||
| Claims: inter-region | 399,732 | 267,600 |
| Total water assets | 18,485,356 | 22,399,847 |
Net change in water storage to the change in net water assets
| 2018 ML | 2017 ML | |
| Change in net water assets as presented in the Statement of Changes in Water Assets and Water Liabilities | (2,471,554) | 3,084,469 |
| adjustments for: | ||
| Change in non-physical water assets | ||
| Claims: inter-region | (132,132) | 340,543 |
| Total change in non-physical water assets | (132,132) | 340,543 |
| Change in water liabilities | ||
| Surface water liability | ||
| Allocation remaining: individual users | (1,318,771) | 2,179,960 |
| Allocation remaining: urban system | 0 | 0 |
| Allocation remaining: environmental purposes | 23,907 | 239,882 |
| Groundwater liability | ||
| Allocation remaining: individual users | (153,121) | 33,867 |
| Allocation remaining: environmental purposes | 5,048 | 6,657 |
| Total change in water liabilities | (1,442,937) | 2,460,366 |
| Net change in water storage as presented in the Statement of Water Flows | (4,046,623) | 5,885,378 |