Melbourne
18.12 Entitled extraction of allocated groundwater to urban water system

Supporting information

The volume reported in the water accounting statements (0 ML) represents the volume of water extracted from groundwater for urban water supply. During the 2011–12 year both South East Water and Western Water reported a zero volume of groundwater extracted under their groundwater entitlements.

The zero volume reported by South East Water is inconsistent with records from the Victorian Water Register. The register records that South East Water extracted a volume of 3 ML under their entitlement to Koo Wee Rup Water Supply Protection Area—groundwater. It is unclear how this inconsistency arose; however, given the small volume the impact on the account is not considered material.

Quantification approach

South East Water

Data source

Internal database.

Provided by

South East Water.

Method

The volume reported is the smart meter (real-time) metered volume of water extracted from the Lang Lang bore.

This water is taken from groundwater to supply water tankers for irrigation. The stand pipe that extracts the water from the groundwater bore has been closed because of low demand, as a result of South East Water providing alternative solutions and high rainfall.

Assumptions, limitations, caveats and approximations

Assumes the meters and readings are accurate.

Uncertainty information

Meter type: Elster R2000 100 mm – uncertainty is +/–2%.

Western Water

Data source

IT database.

Provided by

Western Water.

Method

This volume is calculated as the total metered volume of groundwater taken from two Lancefield bores. Meters are located on pipes between the bores and the water treatment facility. Meter readings are recorded daily.

Groundwater usage by Western Water during the 2011–12 year

Bore

Usage (ML)

Lancefield Bore 2

0

Lancefield Bore 3

0

Assumptions, limitations, caveats and approximations

Nil.

Uncertainty information

The uncertainty estimate is +/– 5% in accordance with manufacturer's annual bulk meter test.

Comparative year

In the 2011 Account, it was not possible to separate urban and non-urban entitlements to groundwater. Therefore, the volume of groundwater extracted for all groundwater entitlements was reported at line item 18.11 'Groundwater allocation extraction'.

In the 2012 Account, data provided has enabled urban water entitlements to groundwater to be reported separately in the Melbourne Account. Consequently, the volume has been restated as 12 ML.

Comparative year information for line item 18.12 Entitled extraction of allocated groundwater to urban water system
Groundwater management unit Entitlement holder 2012 Account volume for the 2010–11 year (ML) 2011 Account volume for the 2010–11 year (ML)
Koo Wee Rup Water Supply Protection Area—groundwater South East Water                           4 reported as part of line item 18.11
Lancefield Groundwater Management Area Western Water                           8 reported as part of line item 18.11
Total extractions                         12