13.1 Adjustment and forfeiture of surface water allocation

Supporting information

This line item refers to total forfeiture of water allocations for all surface water supply in the Perth region not related to urban water systems or irrigation schemes.

The volume recognised in the water accounting statements (13,903 ML) represents the total volume of terminated surface water licences during the 2011–12 year.

Quantification approach

Data source

Water Resource Licensing database.

Provided by

Department of Water.


The portion of surface water allocation that has not been abstracted at the end of the 2011–12 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 abstraction is estimated to be the full allocation (refer to line item 17.11), this component of the forfeiture is assumed to be zero.

Entitlements that are terminated during the 2011–12 year are also considered to be forfeitures.

Assumptions, limitations, caveats and approximations

Given that the abstraction data are estimated, the forfeiture is subject to the same assumptions and limitations of the abstraction data (refer to line item 17.11).

Uncertainty information

The uncertainty estimate was not quantified.