Canberra
10.6 Leakage from urban water system

Supporting Information

This line item refers to the volume of water lost from the urban supply system to the groundwater system. These losses include leakage from pipes, service reservoirs and service connections prior to the customer water meters.

Calculated losses from both ActewAGL and Queanbeyan City Council urban delivery systems
Agency 2010–11 volume (ML)
ActewAGL 2,607
QCC 492
Total 3,099

Quantification Approach

(1) ActewAGL

Data Source

ActewAGL billing data.

Provided by

ActewAGL.

Method

The ActewAGL real losses were calculated in line with Water Services Association of Australia (WSSA) National Performance Framework. The real losses from the distribution system is the difference between the system input volume and the total of the billed water exported (supply to Queanbeyan), billed metered consumption, billed unmetered consumption, unbilled metered consumption, unbilled unmetered consumption, unauthorised consumption and customer meter under-registration.

Assumptions, Limitations, Caveats and Approximations

  • Losses from the water distribution system store cannot be distinguished between leakage to groundwater and leakage to landscape, and therefore a combined estimate is provided.
  • Background losses from the potable water supply system include losses from ongoing leakage, pipe bursts and other components.

Uncertainty Information

The uncertainty estimate was not quantified.

(2) Queanbeyan City Council

Data Source

Queanbeyan City Council (QCC).

Provided by

QCC.

Method

The 2009–10 leakage from Queanbeyan potable water supply system was calculated from the estimated leakage from water network (reported as 1.19 ML/d). This is calculated by using the difference between what QCC purchases from ACTEW and what QCC sells to their customers.

Assumptions, Limitations, Caveats and Approximations

  • Losses from the water distribution system store cannot be distinguished between leakage to groundwater and leakage to landscape, and therefore a combined estimate is provided.
  • Background losses from the potable water supply system include losses from ongoing leakage, pipe bursts and other components.

Uncertainty Information

The uncertainty estimate was not quantified.

Comparative year

This line item corresponds to line item 20.2.2 Leakage from water distribution system to groundwater, reported in the 2010 Account. The following table presents substantive changes to the 2009–10 volume reported in the 2011 Account with the corresponding line item in the 2010 Account. The reasons for the changes, with their respective values, are detailed in the table and summarised hereafter: values were not available for the 2010 Account; however can now be derived for the 2009–10 year.

Comparative year information – Line item 10.6 Leakage from urban water system
Corresponding 2010 Account line item Agency Value reported for the 2010 Account closing balance (ML) Prior period error correction to the 2010 Account  (ML) Value difference due to scope change (ML) Restated value for the 2010 Account closing balance (ML)
20.2.2 Leakage from water distribution system to groundwater ActewAGL  0 2,482 0 2,482
QCC 0 434 0 434
Total   0 2,916 0 2,916