6.1 Groundwater allocation remaining

Supporting Information

This line item refers to all groundwater supply in the Perth region not related to urban water systems or irrigation schemes. It includes water supply to individual users in the agricultural, industrial and commercial sectors.

The volume recognised in the Statement of water assets and water liabilities (159,413 ML) represents the volume of groundwater allocation remaining for these licence entitlements at the end of the 2010–11 year.

Quantification Approach

Data Source

Department of Water: Water Resource Licensing database.

Provided by

Department of Water.


The allocation remaining was calculated as shown in the following table.

Volume of groundwater allocation remaining at the start and end of the 2010–11 year



Volume (ML)


Opening balance (as at 30 June 2010)



22.1 Groundwater allocation announcement



18.11 Groundwater allocation extraction



14.1 Adjustment and forfeiture of groundwater allocation



Closing balance (as at 30 June 2011)



The total allocation remaining on 30 June 2011 for private user entitlements is relatively large compared to that for urban water supply (see line item 6.2). This is because there are many private user entitlements within the Perth region that do not have an anniversary date occurring on 30 June (in general, the water management year commences when the licence is issued).

Assumptions, Limitations, Caveats and Approximations


Uncertainty Information

The uncertainty estimate was not quantified.

Comparative year

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 6.1

2011 Account line item

2010 Account line item

2011 Account volume at 30 June 2010 (ML)

2010 Account volume at 30 June 2010 (ML)

Change from the 2010 Account to the 2011 Account

6.1 Groundwater allocation remaining Groundwater allocation remaining–other lumped holders



Prior period error: incorrect dates used when calculating the allocation remaining

Change in line item name and number