Perth
3.8 Urban claim on groundwater

Supporting Information

This line item represents the volume of groundwater allocation remaining for urban water supply licence entitlements at the end of the 2010–11 year.

Quantification Approach

Data Source

Department of Water: Water Resource Licensing database and licensee meter readings.

Provided by

Department of Water.

Method

For all but one of the 10 bore fields within the Perth region, the licensed water management year is from 1 July to 30 June. For these licences, any unused allocation at the end of the water management year is forfeited and, therefore, the allocation remaining at the end of the reporting period is zero.

The groundwater supply licences for the Gingin bore field have a water management year that ends on 30 September. Therefore, the allocation remaining at the end of the 2010–11 year for the Perth region is the unused component of the annual allocation for the Gingin bore field.

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


Volume of groundwater allocation remaining for the urban water system at the start and end of the 2010–11 year

Gingin account

Volume (ML)

 

Opening balance (as at 30 June 2010)

157

add

Allocation announcement

230

less

Abstraction up to 30 June 2011

128

less

Forfeiture (on 30 Sept 2010)

105

 

Closing balance (as at 30 June 2011)

154

 

Assumptions, Limitations, Caveats and Approximations

Nil.

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 3.8

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

3.8 Urban claim on groundwater

7.14 Allocation from connected surface water on regulated flows remaining–urban holder

157

230

Volume restated due to subsequent availability of actual meter readings (see line item 11.13)

Change in line item name and number