21.4 Increase of inter-region commitment on surface water

Supporting Information

This line item refers to the annual allocation of water from Helena River (Mundaring Reservoir) to the Kalgoorlie Goldfields, located outside of the Perth region.

Quantification Approach

Data Source

Department of Water: Water Resource Licensing database.

Provided by

Department of Water.


Mundaring Reservoir is part of the urban water supply system, so it has the same licence agreements for abstraction of water as the other 13 major storages (see line item 21.2).

The total surface water allocation announcement is assumed to equal 100% of the annual entitlement.

Assumptions, Limitations, Caveats and Approximations

The announced allocation is made after a review, by the Department of Water, of the storage water level of Mundaring Reservoir in October of every year.

Uncertainty Information

There is no uncertainty associated with this value.

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 21.4

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

21.4 Increase of inter-region commitment on surface water

25.6 Other lumped surface water liability increases



Change in line item name and number