Sydney
17.11 Surface water allocation diversion

Users diverted 23,797 ML from streams in the Sydney region during 2010–11.

Diversions in this line item are made under water access licences in the Sydney region and can be categorised into diversions by individual holders for stock and domestic, and other lumped holders.

Details of the water rights associated with these diversions can be found under Water access information.

 Reconciliation of this line item is shown in the following table.

Calculation of the surface water allocation on water for the 2010-11 year

	Line item	Volume (ML)
	5.1 Surface water allocation remaining- opening balance	0
add	21.1 Surface water allocation announcements	149,535
less	17.11 Surface water allocation diversion	23,797
less	13.1 Adjustment and forfeiture of surface water allocation	125,738
equals	5.1 Surface water allocation remaining - closing balance	0

 

The following table provides a breakdown of the diversions made under this category.

Breakdown table of diversion of flows by other holders

Entitlement  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
Individual users1	Hawkesbury and Lower Nepean Rivers	–	18,029
Total			23,797

^{1 provided by the NSW Office of Water}

Data spreadsheets.

Goulburn Mulwaree Council.

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.

Nil.

The volume is based on metered data. Estimated accuracy based on meter accuracy and professional judgment is +/– 20%.

Draft Water Sharing Plan – Greater Metropolitan Unregulated River Water Sources and water use records in the spreadsheets managed by licensing field officers of the NSW Office of Water.

NSW Office of Water.

Water use was estimated by applying a 14% entitlement-use factor for 2010–11 to the total entitlement value for the category (see line item 21.1). The entitlement-use factor is based on a sample of metered data in the Hawkesbury catchment and comparing the metered samples against what they used for their entitlement. 

The calculation method is applied only to the categories of 'Individual holder for stock and domestic' and 'Other lumped holders' from unregulated flow for 2010–11. The metered area (used to calculate entitlement-use factor) represents only a sample of the Sydney region. The sample includes 147 licences in the Hawkesbury catchment representing 20% of the total entitlement for that catchment.

The volume was estimated. Estimated uncertainty is +/– 30% to 50% based on professional judgment and established practice within the NSW Office of Water.

Database maintained as spreadsheets.

NSW Office of Water.

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

Nil.

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

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

SWC.

Volumes were derived from metered outflow data from WTPs.

The flow meter data are continually monitored and recorded using the Integrated Instrumentation Control Automation and Telemetry System (IICATS). 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.

As data on inflow to each WTP are 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 SCA.

The volume is based on measured data. Estimated accuracy based on meter accuracy is +/– 2%.

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 17.11

2011 Account line item	2010 Account line item	Value reported in the 2010 Account (ML)	Value reported in the 2011 Account (ML)	Additional information
17.11 Other delivery of allocated surface water	14.6.5.4 Diversion of unregulated flows – urban holder	6,295	57,808	Restatement: These 3 line items have been merged for the 2011 Account, and the value has been amended to reconcile with the 2010 values.
	14.6.5.5 Diversion of unregulated flows – individual holder for stock and domestic	938
	14.6.5.6 Diversion of unregulated flows – other lumped class	50,575