Adelaide
11.9 Delivery of water to urban water system under inter-region agreement

The volume reported (47,477 ML) was the volume of water actually imported into the Adelaide region during the 2011–12 year after abstraction from the River Murray under the Class 6 water access entitlement (WAE) held by SA Water. This included non-potable and potable transfers as described in the following table.

The volume reported was different from the volume of water abstracted from the River Murray (59,030 ML) under the Class 6 WAE during the 2011–12 year, due to off-takes of water to consumers located outside the Adelaide region, transfer losses and quantification errors. The volume of water abstracted from the River Murray under Class 6 WAE was sourced from the Department of Environment, Water and Natural Resources Water Information and Licence Management Administration database.

WTP = Water treatment plant

A portion of the non-potable water transferred into the region for urban purpose was discharged into rivers and storages of the Adelaide region before diversion to the WTPs of the region for treatment.

Potable River Murray water abstracted under the entitlement is provided to users via the Swan Reach and Mt Pleasant WTPs.

• The Mt Pleasant WTP is located just outside the Adelaide region boundary and received River Murray water from the Mannum–Adelaide Pipeline. Water treated at Mt Pleasant WTP services users both inside and outside the Adelaide region. Water servicing users within the Adelaide region is reported as water abstracted under the entitlement.

• The Swan Reach WTP treats all River Murray water abstracted via the Swan Reach–Stockwell Pipeline and is located to the northeast of the Adelaide region. Following treatment at the Swan Reach WTP, potable water is transferred by the pipeline to supply the Barossa Valley, Lower North and Yorke Peninsula. A second pipeline branching from the Swan Reach–Stockwell Pipeline discharges into the South Para River upstream of the South Para Reservoir, where water is stored to supply the Barossa WTP. From that second pipeline, water can also be transferred to the Barossa Infrastructure Limited irrigation scheme in case of need.

The total volume of potable River Murray water imported into the region and delivered to customers is detailed in the following table.

More information on the entitlement can be found at line item 3.4 Urban inter-region claim on water.

The urban water supply system is one of three sub-components of Adelaide's urban water system. The three sub-components are the:

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

During the 2011–12 year, the majority (66%) of Adelaide's urban water was sourced from catchments within the region (line item 11.2). Imported River Murray (line item 11.9) water constituted approximately 31% of the urban water supply system's source water. Also, during the 2011–12 year, the Adelaide desalination plant commenced operating and made up the remaining 3% of Adelaide's urban water sources (line item 11.6).

Urban potable water consumption (line item 19.4) was 127,729 ML during the 2011–12 year, representing 84% of all outflows from the urban water supply system. A very small volume of water (2%) was transferred out of the region via normal operations in SA Water's service area (line item 19.11). Non-revenue water, including pipes bursting and background leakage (line item 19.3) and other losses (line item 19.20), made up the remaining urban water supply system outflows.

The following figure shows all the inflows and outflows for 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 for Adelaide's urban water supply system during the 2011–12 year; line item numbers are provided in brackets

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

Non-potable water transfers through the Murray Bridge–Onkaparinga Pipeline and the Mannum–Adelaide Pipeline were metered with a flow gauge.

Potable water transfers (non-consumption) through the Swan Reach–Stockwell Pipeline were measured by the metered flow of discharge from the pipeline to the South Para River.

Metered flows for the 2011–12 year were extracted from the SA Water's SCADA database and/or MetDaily file.

• Water imported from the River Murray is used in the year when it is imported and not stored for later years
• All non-potable water transferred into the region under the Class 6 WAE was included, although part of it does transit through rivers and storages before diversion to the WTPs. Evaporation and leakage from rives and storages prior to diversion to the WTPs is neglected.
• The inter-region claim to River Murray water is held on behalf of the Adelaide region; however, there is offtake from the three pipelines before entering the Adelaide region. Therefore the volume reported is less than the actual volume of water diverted from the River Murray under the Class 6 WAE held by SA Water.

Readings may be from either the Supervisory Control and Data Acquisition (SCADA) database or manual field instrument readings, stored in the MetDaily file, Geographic Information System (GIS) and customer service information system (CSIS) databases.

SA Water.

The volume of River Murray water transferred into the Adelaide region from the Swan Reach–Stockwell Pipeline is not metered at the point it enters the region, therefore potable consumption data were used to measure this volume. Similarly, potable consumption data were also used to measure the volume of River Murray transferred into the region folllowing treatment at Mt Pleasant WTP.

A shapefile of the Adelaide region was used to extract the service point numbers (SPNs) of meters within the Adelaide region from the SA Water GIS database. Only meters that were supplied with potable water from the Swan Reach and Mt Pleasant WTPs were considered. The SPNs were then used to extract water meter readings for the 2011–12 reporting period for individual water meters from the SA Water CSIS database.

Water consumption was calculated by analysing the difference between consecutive meter readings and summed for 2011–12. To account for meter readings that occurred immediately before or after 2011–12, metered consumption was apportioned based on the following equation:

Vr = ( tr / tm ) × Vm

Where:

Vr = volume for metered period within 2011–12 (kL)
tm = length of period between meter readings (days)
tr = length of metered period within 2011–12 (days)
Vm = volume for metered period (kL).

Both the Mt Pleasant and Swan Reach WTPs supply water to users outside the region. Therefore the volume reported underestimates the total volume of water abstracted from the River Murray under the Class 6 WAE.

An error was made when calculating the 2010–11 year volume published in the 2011 Account due to an incorrect understanding of the metered values provided by SA Water to quantify the volume transferred into the region via the Mannum–Adelaide Pipeline. This error has been corrected in the 2012 Account. Consequently, the volume has been restated from 45,346 ML (as published in the 2011 Account) to 48,299 ML as detailed in the following table.