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.

 

Volume of water for each storage within the Ord region at the end of the 2011–12 and 2010–11 years

Storage

Capacity (ML)

Dead storage
(ML)

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

Bureau of Meteorology, water storage product; Tropical Forestry Services, storage database.

Provided by

Bureau of Meteorology and Tropical Forestry Services.

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.

Uncertainty information

Derived from measured data. Uncertainty range +/–5%.