Sydney
17.11 Surface water allocation diversion
Supporting Information
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.
Line item |
Volume (ML) |
|
|
5.1 Surface water allocation remaining- opening balance |
0 |
add |
149,535 |
|
less |
17.11 Surface water allocation diversion |
23,797 |
less |
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.
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
Quantification Approach
Goulburn Mulwaree Council
Data Source
Provided by
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
Uncertainty Information
The volume is based on metered data. Estimated accuracy based on meter accuracy and professional judgment is +/– 20%.
NSW Office of Water
Data Source
Provided by
Method
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.
Assumptions, Limitations, Caveats and Approximations
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.
Uncertainty Information
The volume was estimated. Estimated uncertainty is +/– 30% to 50% based on professional judgment and established practice within the NSW Office of Water.
Palerang Council
Data Source
Provided by
Method
An ABB Magmaster-type induction meter was used to measure flow data.
Assumptions, Limitations, Caveats and Approximations
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
Provided by
Method
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.
Assumptions, Limitations, Caveats and Approximations
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.
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.
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 |