Adelaide
17.8 Entitled diversion of non-allocated surface water to urban water system

The volume reported (101,099 ML) was the volume of water harvested from runoff produced within the Adelaide region that supplied the region's urban water supply system in the 2011–12 year.

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

Bureau of Meteorology.

The volume of water diverted to the urban water system from Adelaide's surface water (that was harvested from runoff within the region) was calculated by subtracting the volume of River Murray water transferred into the region's urban water system (line item 11.9 Delivery of water to urban water system under inter-region agreement) and the volume of desalinated water transferred from the Adelaide desalination plant (line item 11.6 Delivery of desalinated water to urban water system) from the total volume of inflows into the urban water system, as shown in the following table.

Volume of surface water diverted to the urban water system during the 2011–12

Calculation	Description	Volume (ML)
	Total volume of inflows into the urban water system	152,392
less	11.9 Delivery of water to urban water system under inter-region agreement	47,477
less	11.6 Delivery of desalinated water to urban water system	3,816
	11.2 Entitled diversion of non-allocated surface water to urban water system	101,099

As detailed in the following tables, the total volume of inflows into the Adelaide region's urban water system (152,392 ML) comprised of:

• inflows into the regions' water treatment plants (148,915 ML); and
• direct delivery to urban customers of potable water imported into the region (3,477 ML).

Inflows into the regions' water treatment plants (WTPs) during the 2011–12 year

Water treatment plant	Water source/reservoir	Quantification approach	Volume (ML)
Anstey Hill	Millbrook Tank	Metered inflow	27,439
Barossa	Barossa Reservoir	Metered outflow + 5%	15,030
Happy Valley	Happy Valley Reservoir	Metered inflow	61,070
Happy Valley	Adelaide desalination plant	Metered inflow	3,816
Hope Valley	Hope Valley Reservoir	Metered outflow + 5%	20,103
Little Para	Little Para Reservoir	Metered inflow	10,093
Myponga	Myponga Reservoir	Metered inflow	5,880
Summit Storage	Summit Reservoir	Metered inflow	5,484
Total			148,915

The inflows into the WTPs were either quantified as measured inflows into the WTPs or calculated from measured outflows from the WTPs by adding a 5% factor to account for process losses.

Potable water imported into the region was abstracted from the River Murray and treated in water treatment plants (WTPs) outside the region via the following routes:

• the Swan Reach–Stockwell Pipeline (SRSPL) after treatment at the Swan Reach WTP
• the Mount Pleasant WTP that received River Murray water from the Mannum–Adelaide Pipeline (MAPL).

This calculation method assumes the following:

• Water imported from the River Murray (line item 11.9 Delivery of water to urban water system under inter-region agreement) is used in the year when it is imported and not stored for later years; and
  
• Leakage and evaporation from rivers and storages in the Adelaide region of water imported from the River Murray are not considered.

The uncertainty estimate is not quantified.

This line item corresponds to line item 17.8 'Non-allocated diversions - urban water system' reported in the 2011 Account.

In the 2011 Account, storages that were used for urban water supply only (located off-stream and harvested only minimal catchment runoff) were reported at line item 3.1 'Urban water system'. The storages were Barossa Reservoir, Happy Valley Reservoir, Hope Valley Reservoir and Onkaparinga Summit Reservoir. As a consequence, the 2011 Account considered the inflows of water into these storages instead of inflows into the water treatment plants they supplied in order to quantify the total volume of inflows into the urban water system.

In the 2012 Account, these storages were reported at line item 1.1 Storages in order to be consistent with the classification of storages applied to the other regions of the National Water Account. Inflows into these storages were therefore replaced in the 2012 Account by inflows into the water treatment plants they supplied to quantify the total volume of inflows into the urban water system.

In the 2011 Account, an error was also made when quantifying line item 11.9 'Delivery of water to urban water system under inter-region agreement'.

The 2010–11 year volume of line item 17.8 'Entitled diversion of non-allocated surface water to urban water system' was restated from 120,014 ML in the 2011 Account to 92,965 ML in the 2012 Account to reflect this change of classification of the storages and to correct the quantification error made on line item 11.9. The following tables show how the restated volume was quantified.

Volume of surface water diverted to the urban water system during the 2010–11 year

Calculation	Description	Volume (ML)
	Total volume of inflows into the urban water system	141,264
less	11.9 Delivery of water to urban water system under inter-region agreement	48,299
	17.8 Entitled diversion of non-allocated surface water to urban water system	92,965

As detailed in that line item note, line item 11.9 'Delivery of water to urban water system' under inter-region agreement was restated from 45,346 ML in the 2011 Account to 48,299 ML in the 2012 Account.

The total volume of inflows into the urban water system is constituted by the inflows into the water treatment plants and the import of potable water into the region.

 

Inflows into the regions' water treatment plants (WTPs) during the 2010–11 year

Water treatment plant	Water source/Reservoir	Quantification approach	Volume (ML)
Anstey Hill	Millbrook Tank	Metered inflow	23,039
Barossa	Barossa	Metered outflow + 5%	10,262
Happy Valley	Happy Valley	Metered inflow	63,714
Hope Valley	Hope Valley	Metered outflow + 5%	15,933
Little Para	Little Para	Metered inflow	14,310
Myponga	Myponga	Metered inflow	6,052
Summit Storage	Summit Storage	Metered inflow	4,875
Total			138,185

 

Inflow of potable water into the Adelaide region during the 2010–11 year

Source	Volume (ML)
Swan Reach WTP via Swan Reach–Stockwell Pipeline	3,022
Mount Pleasant WTP via Mannum–Adelaide Pipeline	57
Total	3,079