Perth

This line item refers to groundwater extraction from domestic non-licensed bores within the Perth region.

Data source

Western Australian Department of Water: Water Resource Licensing database.

Australian Bureau of Statistics (ABS): domestic bore survey database.

Data provider

Western Australian Department of Water.

Method

The Department of Water does not have sufficient metering information relating to actual extraction from domestic non-licensed bores to determine the total volume of water extracted. Consequently, the allocation extraction was estimated based on ABS (2009) survey results for the Perth metropolitan area. These usage figures in the Perth metropolitan area were then extrapolated to also include the Mandurah region. The estimated annual extraction per bore is 0.44 ML per year, which is based on the initial results of the Department of Water’s domestic bore metering project for several dozen domestic bores across Perth.

Uncertainty

Ungraded.

Approximations, assumptions, caveats/limitations

The estimate for domestic non-licensed extraction is based on a number of assumptions, including:

• The ABS domestic bore survey is relevant for the Mandurah area, for which there is no alternative, independent research or evidence available.
• The usage based on the Department of Water’s research for several dozen bores was used to estimate the usage of all unlicensed bores in the region.