Sydney
5.2 Surface water allocation remaining – urban water system
Supporting information
The volume for this line item is 0 ML.
This line item represents the volume of remaining surface water allocations for licensed entitlements–major urban utilities and local water utilities at the end of the reporting period.
While carryover of unused surface water allocation is allowed for licences categorised under Local water utility, the carryover volume could not be quantified. Therefore, for the purposes of the National Water Account, the opening and closing balance (carryover volume) reported was 0 ML.
Account |
Volume (ML) |
|
|
Opening balance (as at 30 June 2011) |
0 |
add |
21.2 Surface water allocation announcements – urban water system |
1,038,355 |
less |
17.12 Surface water allocation diversion – urban water system |
440,989 |
less |
13.2 Adjustment of surface water allocation – urban water system |
597,366 |
Closing balance (as at 30 June 2012) |
0 |
Quantification approach
Data source
Water Sharing Plan for the Greater Metropolitan Region Unregulated River Water Sources: entitlement data recorded in databases and water access entitlements for Goulburn Mulwaree Council, Lithgow City Council, Shoalhaven City Council, Palerang City Council and Wingecarribee Shire Council.
Provided by
Calculated opening and closing balances provided by the Bureau; entitlement data is from New South Wales Office of Water, Shoalhaven City Council, Goulburn Mulwaree Council, Lithgow City Council and Wingecarribee Shire Council entitlement data.
Method
Mapping entitlement values stated in the Water Sharing Plan for the Greater Metropolitan Region Unregulated River Sources, water management registers, and licence and trading statistics to the relevant categories of entitlements. Diversion data were obtained from the relevant authorities as shown in line item 17.11. For each water management licence, the licensed water management year is from 1 July to 30 June.
Under the Water Sharing Plan, carryover 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 carryover allowed is determined by the rules in the Water Sharing Plan and the volume of water diverted under the licence. The carryover volume for the licences reported under this line item have not been quantified. Therefore, for the purposes of the National Water Account, the carryover volume (opening and closing balance as reported here) 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:
- line item 21.2 for the volumetric value for the announced allocation
- line item 17.12 for metered diversions from storages.
Assumptions, limitations, caveats and approximations
- Carryover has not been quantified.
Uncertainty information
For entitlements: the allocation/claim was derived from the Water Sharing Plan for the Greater Metropolitan Region 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%.
New South Wales Office of Water: values associated with this line item were estimated. Estimated uncertainty is +/– 30% – 50% based on professional judgment and established practice within the New South Wales Office of Water.