14.1 Adjustment and forfeiture of groundwater allocation

Supporting information

The volume recognised in the water accounting statements (32,483 ML) represents the total volume of terminated groundwater licences for individual users in the Perth region during the 2012–13 year. This line item refers to all groundwater supply not related to urban water systems or irrigation schemes.

Quantification approach

Data source

Water Resource Licensing database.

Provided by

Department of Water.


The portion of groundwater allocation that has not been extracted at the end of the year is forfeited. The forfeiture is calculated as the total annual allocation for each licence minus total allocation diversion; however, given that the volume of extraction is estimated to be the full allocation (see line item 18.11 Entitled extraction of allocated groundwater to users), this component of the forfeiture is assumed to be zero.

Entitlements that are terminated during the year are also considered to be forfeitures.

Assumptions, limitations, caveats and approximations

Given that the extraction data are estimated, the forfeiture is subject to the same assumptions and limitations of the extraction data (refer to line item 18.11 Entitled extraction of allocated groundwater to users).

Uncertainty information

The uncertainty estimate was not quantified.

Comparative year

The volume of adjustment and forfeiture of groundwater allocation for the 2011–12 year has changed from that presented in the 2012 Account. Please refer to Restatement of comparative information in the 'Water accounting policies' for more information.