Sydney
19.17 Adjustment and forfeiture of urban claim on surface water

Supporting information

This line item refers to the the total adjustment made on surface water allocations for the urban water system for the 2012–13 year. The volume is the difference between calculated volumetric allocation stated in line item 11.18 Increase of urban claim on surface water (1,040,588 ML) and regulated diversions stated in line item 11.12 Allocation diversion of surface water to urban water system (542,715 ML).

The volume recognised in the water accounting statements of 497,873 ML represents the adjustment made by the National Water Account to reconcile the water accounting statements; it does not represent an actual forfeiture of the licensed allocation by individual license holders at the end of the water year on 30 June.

Quantification approach

Data source

Water Sharing Plan for the Greater Metropolitan Unregulated River Water Sources; entitlement and diversion data recorded in databases and water management licences by New South Wales Office of Water; diversion data recorded in mass balance spreadsheets by Sydney Catchment Authority and databases by Goulburn Mulwaree Council, Lithgow City Council, and Wingecarribee Shire Council.

Provided by

The Bureau of Meteorology calculated adjustment and forfeiture of allocation/claim; entitlement and diversion information provided by the New South Wales Office of Water, Goulburn Mulwaree Council, Lithgow City Council, Shoalhaven City Council, and Wingecarribee Shire Council.

Method

Under the Water Sharing Plan, carry-over of any unused allocation at the end of the year is allowed for licences not issued under the 'major utility' category. The maximum volume of carry-over allowed is determined by the rules in the water sharing plan and the volume of water diverted under the licence. The carry-over volume for the licences reported under this line item have not been quantified. Therefore, for the purposes of the National Water Account, the carry-over volume (opening and closing balance as reported in line item 3.7 Urban claim on surface water) was assumed to be zero. In order to the balance the account, the liability decrease reported in this line item is equal to any remaining unused allocation.

Calculation methods for the announced allocation and measured diversions are available in:

Assumptions, limitations, caveats and approximations

See 'Approximations, assumptions, caveats/limitations' in line item 11.18 Increase of urban claim on surface water for volumetric value for the announced allocation/claim, and in line item 11.12 Allocation diversion of surface water to urban water system for metered diversions from storages.

Uncertainty information

Adjustment and forfeiture of allocation/claim was estimated. Uncertainty is ungraded.