19.20 Other urban water decreases

Supporting Information

The volume reported (7,747 ML) represents decreases from the urban water system due to:

  • water treatment plant (WTP) losses (6,596 ML)
  • wastewater treatment plant (WWTP) losses (1,151 ML).
These losses are itemised in the following tables.

Inflow, outflow and process losses for each WTP in the Adelaide region in the 2010–11 year
Water treatment plant Inflow (ML) Outflow (ML) Loss (ML)
Anstey Hill 23,039 21,887 1,152
Barossa 10,262 9,773 489
Happy Valley 63,714 59,955 3,759
Hope Valley 15,933 15,174 759
Little Para 14,310 14,025 285
Myponga 6,052 5,692 360
Onkaparinga Summit Storage 4,875 5,083 (208)
Total 138,185 131,589 6,596

Inflow, outflow and process losses for each WWTP in the Adelaide region in the 2010–11 year
Wastewater treatment plant Inflow (ML) Outflow (ML) Process loss (ML)
Aldinga 555 491 64
Angaston 166 149 17
Bird-in-Hand 421 384 37
Bolivar   52,704 51,645 1059
Bolivar High Salinity 8,714 8,708 6
Christies Beach  9,761 9,761 0
Glenelg   17,561 17,561 0
Gumeracha 50 54 (4)
Hahndorf 358 358 0
Heathfield 749 749 0
Myponga   41 35 6
Victor Harbor 944 978 (34)
Total 92,024 90,873 1,151

Quantification Approach

Data Source

Readings may be from either the Supervisory Control and Data Acquisition (SCADA) database or manual field instrument readings, stored in the MetDaily file; SA Water WWTP records.

Provided by

Bureau of Meteorology.


Water Treatment Plant losses

Metered inflow and outflow data for the seven WTPs listed in the following table were obtained from SA Water's SCADA database and/or MetDaily file for most of these WTPs. Inflow data were not available for the Barossa and Hope Valley WTPs. Barossa and Hope Valley WTP inflow was calculated from the respective WTP outflow, allowing for a 5% loss through the treatment process. Outflow data were not available for the Anstey Hill WTP. Instead, it was calculated assuming a 5% treatment process loss. The total process loss is the difference between WTP inflow and outflow.

Quantification approach for water treatment plant losses in the 2010–11 year
Water treatment plant Inflow – quantification approach Outflow – quantification approach
Myponga Metered inflow Metered outflow
Anstey Hill Metered inflow Metered inflow × 0.95
Summit Storage Metered inflow Metered outflow
Happy Valley Metered inflow Metered outflow
Barossa Metered outflow × 1.05 Metered outflow
Little Para Metered inflow Metered outflow
Hope Valley Metered outflow × 1.05 Metered outflow

Wastewater treatment plant losses

The 2010–11 year inflow to and outflow from WWTPs within the Adelaide region were supplied by each WWTP. The data are measured by flow gauges that were manually read and recorded by plant operators. The WWTP loss was the difference between metered inflow and outflow.

Assumptions, Limitations, Caveats and Approximations

WWTP losses
  • Volume does not include community wastewater management systems (CWMS) because the data were unavailable.
  • Volume includes some wastewater collected from outside the Adelaide region and delivered to the Bird-in-Hand WWTP. However, this volume is negligible.
  • For the Christies Beach, Glenelg, Hahndorf and Heathfield WWTPs zero losses are assumed because only the outflows are measured, so inflow is assumed to be the same.

Uncertainty Information

The uncertainty estimate was in the range of +/– 10%.

Comparative year

This line item corresponds to 20.7 Other lumped water distribution decreases reported in the 2010 Account.

In the 2011 Account the following changes were made that caused values of the 2009–10 year to be restated.

  • potable water export to urban areas outside Adelaide region was reported elsewhere at line item 19.11 Transfer of water outside region
  • water treatment plant and wastewater treatment plant losses were reported here.

Restatement of the value published in the 2010 Account was made as the change was material, and increased the accuracy and comparability of the information provided to the users of the National Water Account. The changes and their respective values are detailed in the following table. The restated comparative year volume is 7,777 ML.

Restated comparative year information for line item 19.20 Other urban water decreases
2010 Account line item name
Description Volume at 30 June 2010 reported in 2010 Account (ML)
Value difference to volume reported due to reclassification (ML)
Volume at 30 June 2010 reported in 2011 Account (ML)
20.7 Other lumped water distribution decreases Potable water export 3,627 (3,627)  
WTP plant losses 7,051   7,051
WWTP plant losses 726   726
Total 11,404 (3,627) 7,777