Sydney
13.2 Adjustment and forfeiture of surface water allocation - urban water system

The liability decrease to the surface water store from the forfeiture of a part of the allocation/claim considered for the urban water system is 584,696 ML.

The volume is the difference between calculated volumetric allocation stated in line item 21.2 (1,022,865 ML) and regulated diversions stated in line item 17.12 (438,169 ML).

Reconciliation of this line item is shown in the following table.

Calculation of surface water allocation for the urban system in the 2010-11 year

Calculation	Line item	Volume (ML)
	5.2 Opening balance (as at 1 July 2010)	0
add	21.2 Surface water allocation announcements – urban water system	1,022,865
less	17.12 Surface water allocation diversion	438,169
less	13.2 Adjustment and forfeiture of surface water allocation	584,696
equals	5.1 Closing balance (as at 30 June 2011)	0

 

Entitlement information was extracted from: Draft Water Sharing Plan – Greater Metropolitan Unregulated River Water Sources; databases and water management licences for Goulburn Mulwaree Council, Lithgow City Council, Shoalhaven City Council and Wingecarribee Shire Council. Line item 17.2 provides data sources for metered diversions from storages.

Bureau of Meteorology: calculated adjustment and forfeiture of allocation/claim; NSW Office of Water, Goulburn Mulwaree Council, Lithgow City Council, Shoalhaven City Council and Wingecarribee Shire Council: entitlement information. See 'Data provider' in line item 17.2 – metered diversions from storages.

Water management licences issued to the urban holders by the NSW Office of Water applicable to 2010–11 did not make provisions for the carry-over of any remaining allocation at the end of the year. Therefore, forfeiture of allocation on regulated flows for the entitlement category is the difference between the announced allocation/claim and measured diversions from the reservoirs for 2010–11. Calculation methods for the announced allocation and measured diversions are available in:

• line item 21.2 for the volumetric value for the announced allocation from regulated flows for the urban holder category
• line item 17.12 for metered diversions from reservoirs.

See 'Approximations, assumptions, caveats/limitations' in line item 21.2 for volumetric value for the announced allocation/claim, and in line item 17.12 for metered diversions from reservoirs.

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

Wingecarribee Shire Council – he volume is based on measured data. Estimated accuracy based on meter accuracy is +/– 7%. External flow verification audits for the flow meters are conducted annually by Hydrometric Consulting Services.

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

Lithgow City Council – the volume is based on measured data. Estimated uncertainty based on meter accuracy is   +/– 2%. Meters are calibrated annually by ABB (meter supplier).

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

The following table compares the value at 30 June 2010 reported in this account with the corresponding value reported in the 2010 Account.

 

Comparative information from the 2010 Account for line item 13.2

2011 Account line item	2010 Account line item	Value reported in the 2010 Account (ML)	Value reported in the 2011 Account (ML)	Additional information
13.2 Adjustment and forfeiture of surface water allocation – urban system	26.1.4 Adjustment and forfeiture of allocation on regulated flows – urban water access entitlement	521,320	0	This line item does not form part of the Water accounting statements for the 2011 Account