Melbourne

The volume recognised in the water accounting statements (132 ML) represents groundwater extraction under urban water access entitlements within groundwater management units in the Melbourne region.

The table below shows the breakdown of urban groundwater volumes extracted from Groundwater Management Units within the Melbourne region during 2009–10.

Data sources

South East Water: groundwater supply spreadsheet.
Western Water: IT database.

Providing agencies

South East Water and Western Water.

Method

The total volume of groundwater extracted under urban water access entitlements was the sum of the two following components:

• Lang Lang bore (South East Water)
  The volume of groundwater extracted was metered using a real-time smart meter at the Lang Lang bore.
• Lancefield bores (Western Water)
  The volume of groundwater extracted was metered daily from two Lancefield bores. Meters are located on pipes between the bores and the water treatment facility.
  
  

Uncertainty

Lang Lang bore: Derived from measured information. Estimated uncertainty is +/–2%.
Lancefield bores: Derived from measured information. Estimated uncertainty is +/–5%.
Uncertainty values refer to the Essential Services Commission’s standard confidence grades, as detailed in its June 2005 guideline for Approving, Conducting and Reporting Audits for Victorian Water Businesses. Refer to Water Industry Regulatory Audits 2010 (ESC 2010), Audit Report prepared individually for South East Water and Western Water, October 2010.

Assumptions, approximations and caveats/limitations

Nil.