Sydney
19.4 Delivery to urban water system users

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

 

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

Shoalhaven City Council.

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

Nil.

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

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

SWC.

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.

Nil.

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

SWC's Water Efficiency Report 2010–11.

SWC.

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

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'.

The uncertainty was not quantified.

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

Wingecarribee Shire Council.

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.

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

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

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