13.2 Adjustment and forfeiture of surface water allocation – urban water system

Supporting information

The volume recognised in the water accounting statements (418 ML) represents the total forfeiture of water allocations for urban surface water entitlements in the Ord region during the 2011–12 year.

The urban water supply licences relate to the following surface water resources:

  • Moochalabra Dam for Wyndham town supply
  • Ord River channel for water supply to Lake Argyle Village.

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, i.e. there is no carry-over of entitlements into next year's account.

The water supply licences for Wyndham and Lake Argyle Village have a water management year that ends on 31 March. Therefore, the forfeiture reported for both urban licences are calculated as the total annual allocation minus the total allocation diversion between 1 April 2011 and 31 March 2012.

Total forfeiture for both urban water supply licences is the forfeiture reported on 31 March 2012. 

Assumptions, limitations, caveats and approximations

Forfeiture is calculated based on available abstraction data. Where the abstraction data are estimated, the forfeiture is subject to the same assumptions and limitations of the abstraction data (refer to line item 17.12).

Uncertainty information

The uncertainty estimate was not quantified.