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

This line item refers to the total forfeiture of water allocations for the major surface water storages within the Perth region that supply water to the urban water system.

All but one of the 14 surface water resources are used for urban water supply within the Perth region. The other (Helena River), primarily supplies water to the Kalgoorlie Goldfields, located outside of the Perth region boundary.

Department of Water: Water Resource Licensing database, Water Corporation: Operational Data Storage System database.

Department of Water.

The portion of surface water allocation that has not been abstracted at the end of the 2010–11 year is forfeited. That is, there is no carryover of entitlements into next year's account.

For all but one of the 14 surface water urban supply licences within the Perth region, the licensed water management year is from 1 July to 30 June. For these licences, the forfeiture that occurs at the end of the 2010–11 year is calculated as the total annual allocation for these surface water resources minus the total allocation diversion, as shown in the following table.

The water supply licence for Dwellingup has a water management year that ends on 30 September. Therefore, the forfeiture reported for Dwellingup is calculated as the total annual allocation minus the total allocation diversion between 1 October 2009 and 30 September 2010.

Total forfeiture for all surface water resources within the Perth region is calculated in the following table.

 

Total forfeiture for surface water resources within the Perth region for the 2010–11 year

		Volume (ML)
	Licences with a water management year from 1 July to 30 June
	Allocation announcement (refer to 21.2)	239,990
less	Allocation diversion (refer to 17.12)	115,569
	Subtotal forfeiture	124,421
plus	Forfeiture for Dwellingup (reported on 30 Sept 2010)	90
	Total forfeiture on 30 June 2011	124,511

 

Nil.

The uncertainty estimate was not quantified.

The following table presents substantive changes in the line item reported in this 2011 Account with the corresponding line item in the 2010 Account.

 

Comparative year information for line item 13.2

2011 Account line item	2010 Account line item	2011 Account volume for the 2009–10 year (ML)	2010 Account volume for the 2009–10 year (ML)	Change from the 2010 Account to the 2011 Account
13.2 Adjustment and forfeiture of surface water allocation - urban water system	26.1.2.4 Adjustment and forfeiture of allocation on regulated flows–high security, urban holder	98,885	98,885	Change in line item name and number