14.2 Adjustment and forfeiture of groundwater allocation – urban water system

Supporting information

The line item (140 ML) represents the volume of groundwater allocation adjustment for the urban water system in the Sydney region.

Adjustment of the groundwater allocation volume is equal to the total allocation announcement for the Sydney region (reported at line item 22.2) because of the following two points:

  • groundwater extraction in the Sydney region could not be quantified in a way that is complete, neutral and free from material error
  • carryover could also not be quantified in a way that is complete, neutral and free frommaterial error.

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

Calculation of the groundwater liability decrease for the urban system in the 2011–12 year
Line item
Volume (ML)


6.2 Opening balance (as at 30 June 2011)



22.2 Groundwater allocation announcements – urban system



6.2 Closing balance (as at 30 June 2012)



14.2 Adjustment of groundwater allocation – urban system


Quantification approach

Data source

Provided by

The Bureau calculated forfeiture of allocation; New South Wales Office of Water provided entitlement information.


Under the Water Sharing Plan, carryover of any unused allocation at the end of the year is allowed for groundwater access licences. The maximum volume of carryover allowed is determined by the rules in the Water Sharing Plan and the volume of water extracted under the licence. As the volume of water extracted under these licences could not be quantified, the carryover volume could also not be quantified. Therefore, for the purposes of the National Water Account, the carryover volume (opening and closing balance in line item 6.2) was assumed to be zero.

Assumptions, limitations, caveats and approximations

As extractions and carryover were not quantified, the adjustment was 100% of the water access entitlement.

Uncertainty information

For entitlements - the allocation/claim was derived from the Water Sharing Plan for the Greater Metropolitan Groundwater Sources.  Uncertainty was not quantified.