Sydney
19.4 Delivery to urban water system users

Supporting Information

The volume of water supplied through the urban system in 2010–11 was 474,594 ML.

A breakdown of potable and nonpotable water supplied through the urban system is provided in the following table.


Potable and non-potable water supplied to the Sydney region via the urban system

 

Sydney Water Corporation (ML)

Shoalhaven City Council (ML)

Wingecarribee Shire Council (ML)

Total water supplied for 2010-11

Potable water supplied for residential use

320,670

5,840

4,098

330,608

Potable water supplied for commercial, industrial and municipal use

106,774

3,858

0

110,632

Potable water supplied for other uses

30,361

576

0

30,937

Nonpotable water supplied for residential use

0

5

0

5

Nonpotable water supplied for commercial, industrial and municipal use

0

2,412

0

2,412

Total

457,805

12,961

4,098

474,594

 

Quantification Approach

Shoalhaven City Council – supply of potable water

Data Source

Meter reads and property categorisations, which are complied in the water billing system.

Provided by

Shoalhaven City Council.

Method

Shoalhaven City Council used the total metered volume from water billing records to determine the volume of potable water supplied.

Assumptions, Limitations, Caveats and Approximations

Nil.

Uncertainty Information

The volume is based on measured data and the water balance. Estimated uncertainty based on meter accuracy and professional judgment is +/– 2%.

Sydney Water Corporation – supply of potable water

Data Source

Table 10 of the Sydney Water Corporation's (SWC) Water Efficiency Report 2010–11.

Provided by

SWC.

Method

SWC uses a water balance approach to determine volume of potable water supplied from the potable water supply system (Water Efficiency Report 2010–11). The water balance is a reconciliation of the volume of water produced by the water treatment plants with all known and estimated end uses.

Assumptions, Limitations, Caveats and Approximations

Nil.

Uncertainty Information

The volume is based on measured data and the water balance. Estimated uncertainty based on meter accuracy and professional judgment is +/– 2%.

Sydney Water Corporation – supply of potable water for other use

Data Source

SWC's Water Efficiency Report 2010–11.

Provided by

SWC.

Method

This item represents the total volume of potable water supplied other than for residential, commercial, industrial and municipal use. The volume includes the following components derived from water balance calculations and the measured data at each water treatment plant. The water balance is a reconciliation of the volume of water produced by the water treatment plants with all known and estimated end uses.

Breakdown table of potable water supplied for other uses by SWC



Component

Volume (ML) 2010–11

Source

Billed metered primary producers

4,548

Derived from the Water Efficiency Report, Table 10

Billed metered other

7,711

Derived from the Water Efficiency Report, Table 10

Billed unmetered

2,435

Estimate used in water balance in the Water Efficiency Report Table 9

Unbilled metered and unbilled

5,080

Derived from the Water Efficiency Report, Table 10

Unauthorised

495

Estimate used in water balance in the Water Efficiency Report, Table 9

Meter under-registration

8,974

Estimate used in water balance in the Water Efficiency Report, Table 9

Water balance - billing cycle

1,387

Difference between the water balance used in the Water Efficiency Report, Table 9 and the measured data at each Water Filtration Plant.

Unexplained difference

1

Unexplained difference

Total 

30,631

 

Assumptions, Limitations, Caveats and Approximations

The component 'billed primary producers' (4,548 ML) is taken as 'supply to agriculture', and total of the remaining components (30,631 ML) is taken as 'other supplies including non-metered, unbilled components'.

Uncertainty Information

The uncertainty was not quantified.

Wingecarribee Shire Council – supply of potable water

Data Source

ABB Magflow meters to measure outflows at water treatment plants, the Supervisory Control and Data Acquisition (SCADA) system and Wingecarribee Shire Council data spreadsheets.

Provided by

Wingecarribee Shire Council.

Method

This item represents the total volume of potable water supplied for residential, commercial, industrial and municipal use. The total volume is derived from data collected from calibrated outflow meters at water treatment plants, minus the volume estimated as leakage and bursts.

Assumptions, Limitations, Caveats and Approximations

Information required to separate the volume of potable water supplied to residential; and commercial, industrial and municipal use categories are not available.

Uncertainty Information

The volume is based on measured data. Estimated uncertainty based on meter accuracy is +/– 7%.

Comparative year

The following table compares the value at 30 June 2010 reported in this account with the corresponding value reported in the 2010 Account.

 

Comparative information from the 2010 Account for line item 19.4

2011 Account line item

2010 Account line item

Value reported in the 2010 Account (ML)

Value reported in the 2011 Account (ML)

Additional information

19.4 Urban water use

Not applicable

Not stated


Line item presentation: this is a new line item not reported in the 2010 Account