Sydney
19.4 Delivery to urban water system users

The urban water supply system is one of three subcomponents of Sydney's urban water system. The three subcomponents are the:

• urban water supply system
• wastewater system
• recycled water system.

In the 2012–13 year, all water supplied to the urban water supply system was sourced from surface water (11.12 Allocation diversion of surface water to urban water system) with a small volume of 596 ML sourced from the Fish River Water Supply Scheme by Lithgow City Council (11.9 Delivery of water to urban water system under inter-region agreement). Sydney Water Corporation in the past has also sourced water from desalinated water (11.6 Delivery of desalinated water to urban water system); however, no desalinated water was reported this year.

Potable and nonpotable urban water consumption (part of 19.4 Delivery to urban water system users) was 472,541 ML during the 2012–13 year, representing 88% of all urban water supply system outflows.The remaining outflows are reported as being lost through leakage (19.3 Leakage to groundwater) as well as other operational losses (19.20 Other urban water decreases), and a small volume was exported outside the region (19.11 Transfer of water outside of region).

The following figure shows all the inflows and outflows associated with the urban water supply system.

For more detail on a particular flow associated with the urban water supply system, refer to the line item notes.

Schematic diagram of water inflows and outflows during the 2012–13 year for Sydney's urban water supply system; line item numbers are provided in brackets

The recycled water system is one of three subcomponents of Sydney's urban water system. The three subcomponents are the:

• urban water supply system
• wastewater system
• recycled water system.
  

In the Sydney region, around 98% of the recycled water used was produced at wastewater treatment plants within the region and a small volume was imported.

During the 2012–13 year, approximately 44% of the recycled water was supplied for to private users for residential, industrial, agricultural, or commercial use (19.4 Delivery to urban water system users); about 29% was used for environmental purposes (19.5 Urban water discharge to surface water); and the remainder was used for on-site in-process.

The following figure shows all the inflows and outflows associated with the recycled water system.

For more detail on a particular flow associated with the recycled water system, refer to the line item notes. Note that volumes annotated with an asterisk (*) indicate flows between subcomponents and are not reported in the account. As such, these flows do not have an associated line item number.

Schematic diagram of water inflows and outflows during the 2012–13 year for Sydney's recycled water system; line item numbers are provided in brackets

The volume of water supplied through the urban system in 2012–13 was 495,132 ML.

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

Potable and nonpotable water supplied to the Sydney region via the urban system during the 2012–13 year

	Goulburn Mulwaree Council (ML)	Lithgow City Council (ML)	Shoalhaven City Council (ML)	Sydney Water Corporation (ML)	Wingecarribee Shire Council (ML)	Total water supplied (ML)
potable water supplied for residential use	1,447	1,822	2,821	336,212	3,149	345,451
potable water supplied for commercial, industrial and municipal use	830		2,228	98,725	537	102,320
potable water supplied for agriculture and/or individual irrigation	13			4,830	255	5,098
potable water supplied for other uses	2		293	15,827	154	16,276
non-potable water supplied for commercial, industrial and municipal use			2,282	1,114		3,396
recycled water supplied for residential use				2,064		2,064
recycled water supplied for commercial, industrial and municipal use	192		274	11,789	99	12,353
recycled water supplied for agricultural/individual irrigation	1,212		1,642	5,175		8,029
recycled water used in process or on-site (no recirculation)				144		144
Total	3,696	1,822	9,540	475,880	4,194	495,132

Goulburn Mulwaree Council databases.

Goulburn Mulwaree Council.

Goulburn Mulwaree Council uses the metered volume from water billing records to determine the volume of potable water supplied.

Nil.

The volume is based on measured data. Estimated uncertainty based on meter accuracy and professional judgment is +/– 5%.

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

Shoalhaven City Council.

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

The volumes shown are a calculation of the total metered volume from water billing records for the Shoalhaven Region and estimated factors to only include water usage within the the Sydney region National Water Account boundaries.

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

Water Efficiency Report 2012–13.

Sydney Water Corporation.

For potable water, the Sydney Water Corporation uses a water balance approach to determine volume of potable water supplied from the potable water supply system. The water balance is a reconciliation of the volume of water produced by the water treatment plants with all known and estimated end uses.

For non-potable and recycled water supplied for residential, commercial, industrial and municipal use, as well as agricultural and irrigation the volumes were 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.

The volume of 4,830 ML categorised as 'billed metered primary producers' is taken as 'supply to agriculture'.

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.

Nil.

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