1.1 Storages

Supporting information

The volume reported for the opening (136,915 ML) and closing (97,182 ML) balance for storages represents the sum of individual storage volumes (including dead storage) for surface water storages operated by SA Water at 30 June 2011 and 30 June 2012 respectively.

For more information on major surface water storages, refer to the Surface water section of the 'Contextual information'.

The surface water storage volume, total storage capacity and dead storage are provided in the following table. 

Surface water storage volume at the start and end of the 2011–12 year
Surface water storage Total storage capacity (ML) Dead storage capacity (ML) Storage volume at 30 June 2012 (ML) Storage volume at 30 June 2011 (ML)
Kangaroo Creek Reservoir 19,000                  300                            5,544                      13,897
Little Para Reservoir 20,800                  188                            4,600                       9,416
Millbrook Reservoir 16,500                  188                            9,976                      10,980
Mount Bold Reservoir 45,900                    27                          11,496                      21,847
Myponga Reservoir 26,800                  163                          21,363                      20,975
South Para Reservoir 44,800                  310                          26,157                      38,501
Warren Reservoir 4,770                    22                            2,809                       4,494
Barossa Reservoir 4,510                    19 3,992 4,185
Happy Valley Reservoir 11,600                    71 8,924 10,399
Hope Valley Reservoir 2,764                  123 2,257 2,141
Onkaparinga Summit Reservoir 427                    64 64 80
Total 197,871 1,475 97,182 136,915

Quantification approach

Data source

Australian Water Resources Information System—Water storages.

Provided by

Bureau of Meteorology (the Bureau).


Surface water storage volume was measured using gauged water level height(s) in metres with respect to the Australian height datum for individual storages. The height measurement was converted to a volume using the storage-volume relationship(s) provided by SA Water. The storage volume of individual surface water storages was aggregated to present the total volume for this line item.

Assumptions, limitations, caveats and approximations

  • Storage-volume relationships were derived from surveys of specific parts of the surface water storage, and may not reflect the storage-volume relationship across the entire storage. 
  • Surface water storages are subject to sedimentation and other physical changes over time that in turn may affect the accuracy of the storage-volume relationships.

Uncertainty information

The uncertainty estimate was not quantified.

Comparative year

In the 2011 Account, storages used for urban water supply only (located off-stream and which harvested only minimal catchment runoff) were reported at line item 3.1 'Urban water system'. These storages were Barossa Reservoir, Happy Valley Reservoir, Hope Valley Reservoir and Onkaparinga Summit Reservoir.

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. As a consequence, the 2010–11 volume was restated as per the following table.

Restatement of comparative year information for line item 1.1 Storages
Storage name

2012 Account volume at 30 June 2011 (ML)

2011 Account volume at 30 June 2011 (ML)

Additional information

Kangaroo Creek Reservoir



Little Para Reservoir



Millbrook Reservoir 10,980 10,980  
Mount Bold Reservoir 21,847 21,847  
Myponga Reservoir 20,975 20,975  
South Para Reservoir 38,501 38,501  
Warren Reservoir 4,494 4,494  
Barossa Reservoir 4,185  


Happy Valley Reservoir 10,399  


Hope Valley Reservoir 2,141  


Onkaparinga Summit Reservoir 80  


Total 136,915 120,110