Ord
1.1 Storages
Supporting information
The volume recognised in the water accounting statements (10,759,396 ML) represents the total volume of water held in storages that are used to administer water access entitlements at 30 June 2012. The volume includes the dead storage volume.
Total volume of water within each storage within the Ord region at 30 June 2011 and 30 June 2012 is given in the following table.
Storage |
Capacity (ML) |
Dead storage |
Volume at 30 June 2012 (ML) |
Volume at 30 June 2011 (ML) |
Lake Argyle |
10,755,830 |
324,000 |
10,599,780 |
14,920,380 |
Lake Kununurra |
100,825 |
87,000 |
96,990 |
95,286 |
Moochalabra Dam |
2,023 |
175 |
1,826 |
1,931 |
Arthur's Creek Dam |
65,000 |
Unknown |
60,800 |
60,450 |
Total |
10,923,678 |
411,175 |
10,759,396 |
15,078,047 |
The water volume in Lake Argyle decreased during the 2011–12 year from 139% full at 30 June 2011 to 99% full at 30 June 2012. The above capacity volume at the start of the 2011–12 year was due to the record rainfall conditions observed the previous year (see the 2011 Account).
Quantification approach
Data source
Provided by
Method
Storage volume at the start and end of the 2011–12 year was calculated using water level data (metres above Australian Height Datum) collected at each storage. Rating tables established for each storage were used to convert the height measurement to a volume.
The volume of individual storages was aggregated to present the total volume for the line item as detailed in the supporting information table.
Assumptions, limitations, caveats and approximations
Storage–volume curves represent specifically surveyed parts of the storage and may not reflect the storage–volume relationship across the entire storage.
Storages are subject to sedimentation and other physical changes over time, which in turn affects the accuracy of the storage–volume curves.