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.

 

Breakdown of diversion of flows by other urban entitlement holders

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

Data spreadsheets.

Provided by

Goulburn Mulwaree Council.

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

Database maintained as spreadsheets.

Provided by

NSW Office of Water.

Method

An ABB Magmaster-type induction meter was used to measure flow data. 

Assumptions, Limitations, Caveats and Approximations

Nil.

Uncertainty Information

The volume is based on metered data. Estimated accuracy based on meter accuracy is +/– 2%. Meters are calibrated annually by ABB (meter supplier).

Sydney Water Corporation

Data Source

Data managed and maintained in an internal data management system by the Sydney Water Corporation's Operations Division (Hydraulic Systems Services).

Provided by

SWC.

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.

 

Comparative information from the 2010 Account for line item 11.21

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.