Sydney
11.21 Other urban water increases
Supporting Information
Urban water utilities diverted 5,768 ML from streams to the urban water system during 2010–11 (see the following table). This volume is the portion of line item 17.11 Surface water allocation diversion that was diverted to the urban water system.
Urban holder |
Water source |
Water treatment plant |
Water diverted during 2010–11 (ML) |
Goulburn Mulwaree Council |
Wollondilly River |
Marulan |
85 |
Palerang Council |
Shoalhaven River |
Braidwood |
94 |
Sydney Water Corporation |
Hawkesbury and Lower Nepean Rivers |
North Richmond |
5,589 |
Total |
5,768 |
Quantification Approach
Goulburn Mulwaree Council
Data Source
Provided by
Method
Diversions to the water treatment plants (WTPs) were measured at the plants. At Marulan WTP, outflow from the plant was measured using a flow meter.
Assumptions, Limitations, Caveats and Approximations
Nil.
Uncertainty Information
The volume is based on metered data. Estimated accuracy based on meter accuracy and professional judgment is +/– 20%.
Palerang Council
Data Source
Provided by
Method
An ABB Magmaster-type induction meter was used to measure flow data.
Assumptions, Limitations, Caveats and Approximations
Nil.
Uncertainty Information
Sydney Water Corporation
Data Source
Provided by
Method
Volumes were derived from metered outflow data from WTPs.
The flow meter data are continually monitored and recordedusing the Integrated Instrumentation Control Automation and Telemetry System. The data are stored within a complex data management system. Adjustments are made to the data (if necessary) to correct any interruptions, errors and so on. Data have been extracted for 2010–11 from the data management system.
Assumptions, Limitations, Caveats and Approximations
As data on inflow to each WTP is not available, metered outflow is assumed to be equal to the surface water taken. The volume taken from surface water can be higher than the outflow volume due to losses associated with pipe systems and the filtration process.
This line item applies to SWC only for its water diversions from the Hawkesbury River to North Richmond WTP. All the other supplies to SWC are made by the Sydney Catchment Authority.
Uncertainty Information
The volume is based on measured data. Estimated accuracy based on meter accuracy is +/– 2%.
Comparative year
The following table compares the value for the 2009–10 year reported in this account with the corresponding value reported in the 2010 Account.
2011 Account line item |
2010 Account line item |
Value reported in the 2010 Account (ML) |
Value reported in the 2011 Account (ML) |
Additional information |
11.21 Other urban water increases |
19.3.1 Unregulated inflow of surface water into the urban water supply system |
6,295 |
0 |
This line item no longer occurs in the Water accounting statements. |