Sydney
5.2 Surface water allocation remaining - urban water system

Supporting Information

The volume recognised in the Statement of water assets and water liabilities represents the volume of surface water allocation remaining for licensed entitlements for the major urban utilities at the end of the reporting period.

Quantification Approach

Data Source

Draft Water Sharing Plan – Greater Metropolitan Unregulated River Sources; entitlement data recorded in databases and water management licences for Goulburn Mulwaree Council, Lithgow City Council, Shoalhaven City Council and Wingecarribee Shire Council.

Provided by

Bureau of Meteorology – calculated opening and closing balance; NSW Office of Water, Shoalhaven City Council, Goulburn Mulwaree Council, Lithgow City Council and Wingecarribee Shire Council – entitlement data.

Method

For each water management licence, the licensed water management year is from 1 July to 30 June. At the end of the water management year, any unused allocation is forfeited. Therefore, the allocation remaining on 30 June 2011 is 0 ML, as shown in the following table.

Calculation of surface water allocation remaining - urban water system for the 2010–11 year
Calculation
Line item
Volume (ML)

 

Opening balance (as at 1 July 2010)

0

add

21.2 Surface water allocation announcements - urban system

1,022,865

less

17.12 Surface water allocation diversion - urban system

438,169

less

13.2 Adjustment and forfeiture of surface water allocation - urban system

584,696

equals

Closing balance (as at 30 June 2011)

0

Assumptions, Limitations, Caveats and Approximations

Nil.

Uncertainty Information

For entitlements – the allocation/claim was derived from the Draft Water Sharing Plan – Greater Metropolitan Unregulated River Water Sources. Uncertainty was not quantified.

Goulburn Mulwaree Council – the volume is based on metered data. Estimated accuracy based on meter accuracy and professional judgment is +/– 20%.

Sydney Water Corporation – the volume is based on measured data. Estimated accuracy based on meter accuracy is +/– 2%.

Comparative year

The following table compares the value for the 2009–10 year reported in this account with the corresponding value reported in the 2010 Account.

 

Comparative information from the 2010 Account for line item 5.1

2011 Account line item

2010 Account line item

Value reported in the 2010 Account (ML)

Value reported in the 2011 Account (ML)

Additional information

5.2  Surface water allocation remaining – urban water system

Not applicable

Not applicable

0

Line item presentation: this line item was not included in the 2010 Account Water accounting statements. In order to reconcile the allocation on the urban water system appropriately it has been included in the 2011 Account as an eliminated line item.

The scope of this line item has changed in this account from that in the 2010 Account. The scope was changed because of a change in the definition of the region. The 2011 Account considers that all tranfers of water between stores are eliminated from the Water accounting statements and will be presented in the individual Resources and systems note. Line item 5.2 Surface water allocation remaining – urban water system represents a claim on the surface water store on behalf of the urban water system and therefore is not included in the Water accounting statements.