Melbourne
19.11 Transfer of water outside of region
Supporting Information
The transfer is part of the regular operations of Western Water in providing water to customers within their service area. The service area of Western Water overlaps with the boundary of the Melbourne region.
Quantification Approach
Data Source
Provided by
Method
The volume of water diverted from Mount Macedon to Woodend is metered and read weekly.
Assumptions, Limitations, Caveats and Approximations
Uncertainty Information
Comparative year
This item corresponds to line item 20.6 Water transferred-out reported in the 2010 Account. In the 2010 Account, this line item was unquantified. However, the volume of urban water transferred out of the region was incorrectly reported at line item 14.9 Diversion of surface water for transfer-out under inter-basin agreement.
In the 2010 Account, the volume reported at line item 14.9 Diversion of surface water for transfer-out under inter-basin agreement included:
- potable water supply from Western Water to Woodend
- non-potable water supply from Western Water to Woodend from Macedon storage
- non-potable water exported from Melbourne Water via the Tarago catchment to Gippsland Water.
An improved understanding of the nature of the inter-region surface water commitment identified non-potable and potable water supplied from Western Water is not transferred under an inter-region commitment rather, this transfer is part of the regular operations of Western Water in providing water to customers within their service area. Thus, these volumes should be reported as a transfer out of the region from the urban water system.
Restatement of the value published in the 2010 Account was made as the change was material and increased the accuracy and comparability of the information provided to the users of the National Water Account. The changes and their respective values are detailed in the following table. The restated comparative year volume is 135 ML.
2010 Account line item name |
Water exported |
Volume at 30 June 2010 reported in the 2010 Account (ML) |
Value difference to volume reported due to prior period error correction (ML) |
Volume at 30 June 2010 reported in 2011 Account (ML) |
14.9 Diversion of surface water for transfer-out under inter-basin agreement |
Non-potable water exported from Melbourne Water via the Tarago catchment to Gippsland Water |
546 |
-546 |
|
Potable water supply from Western Water to Woodend |
58 |
|
58 |
|
Non-potable water supply from Western Water to Woodend from Macedon storage |
77 |
|
77 |
|
Total |
|
681 |
-546 |
135 |