Perth
Accountability Statement

1. This water accounting report has been prepared and presented in accordance with the Australian Water Accounting Standard 1, with the following exceptions:

• No assurance statement was prepared because the standard for, and practice of, assurance of water accounting reports are currently in development.
• 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 2013, such as extreme precipitation and significant water rights purchases. This information is publicly available elsewhere.
• Asset changes for water stores (surface water, groundwater, and urban water) have been included in the Statement of Changes in Water Assets and Water Liabilities, without a corresponding water store asset volume being included in the Statement of Water Assets and Water Liabilities for the following line items:

    – 1.2 Unregulated river
    – 1.3 Regulated river
    – 1.4 Lakes and wetlands
    – 2.1 Water table aquifer
    – 2.2 Underlying aquifer
    – 3.2 Wastewater system
    – 3.3 Recycled water system

    This is because water store flows and levels could be quantified but storage volumes for these items could not.

• Groundwater outflows at the coast have been offset (reporting the net result of outflows and inflows) due to limitations in the available quantification approach (line item 18.2 Groundwater outflow to outside region at coast).
• The volumes of water assets and water liabilities including the volumes of changes to water assets and water liabilities that failed the recognition criteria were reported in the water accounting statements with dashes ('–') in order to highlight data and knowledge gaps that may affect the water accounting statement balances.

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; hence, for a few line 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 preparing this report are explained in the 'Water accounting policies' note. The Bureau of Meteorology is responsible for these interpretations.

Ian Prosser

Assistant Director, Water Information Services

Bureau of Meteorology

27 February 2014