Ord
17.2 River outflow from the region

Supporting Information

The volume recognised in the water accounting statements (18,104,939 ML) represents the combined volume of water outflow from the Ord River to the Cambridge Gulf, and that from the Keep River to the Timor Sea.

The breakdown of outflow from the Ord and Keep rivers is provided in the table below. 

Outflows from the Ord and Keep rivers for the 2010–11 year

Catchment

Gauge station

Discharge (ML)
Ord River

Ord River @ Tarrara Bar (Station No. 809339)
King River @ Cockburn North (Station No. 809314)

15,693,176
521,763
 

Ord River Subtotal

16,214,939
Keep River

Keep River @ Legune Road Crossing (Station No. G8100225)
Sandy Creek @ Legune Road Crossing (Station No. G8100210) 

1,433,000
457,000
 

Keep River Subtotal

1,890,000

Total surface water flow out of region

18,104,939

 

Quantification Approach

Data Source

Western Australian Department of Water: Water Information database, Hydstra database.

Provided by

Bureau of Meteorology.

Method

The outflow to the sea is calculated as the sum of the annual discharge from the following gauging station locations:

  • Ord River @ Tarrara Bar (Gauge No. 809339)
  • King River @ Cockburn North (Gauge No. 809314)
  • Keep River @ Legune Road Crossing (Gauge No. G8100225)
  • Sandy Creek @ Legune Road Crossing (Gauge No. G8100210).

Flow data were available from these gauging stations.

Assumptions, Limitations, Caveats and Approximations

It is assumed that the measured flow at the gauging stations is equal to the amount of water that eventually flows out of the region. In some cases, the location of the gauge is many kilometres from the coast.

Uncertainty Information

Derived from measured data. A description of the uncertainty is below.

The Western Australian Department of Water assigns quality codes to flow data in accordance with the following table:

Department of Water flow data quality codes
Quality code Description
1 Very good record
2 Very good record – corrections applied
3 Good record – corrections or estimations applied
4 Estimated record – good
5 Estimated record – fair
6 Estimated record – poor
10 Estimated record – not reviewed/quality not known
11 Theoretical rating
12 Estimated rating

Flow data provided by the Western Australian Department of Water was quality coded as follows:

- flow data for site 809314 was quality coded:

  • '2' for July 2010
  • '2' for January 2011
  • '3' for February 2011
  • '12' for March and April 2011
  • '3' for May and June 2011

- flow data for site 809339 was quality coded:

  • '2' for January 2011 
  • '10' from 22 June 2011 to 30 June 2011.

The Northern Territory Department of Natural Resources, Environment, The Arts and Sport assigns quality codes to flow data in accordance with the following table:

Department of Natural Resources, Environment, The Arts and Sport flow data quality codes
Quality code Description
Blank All recorded data is continuous and reliable
? Data not quality coded
* Unverified telemetry data (use with caution)
NA No available record

Flow data provided by the Northern Territory Department of Natural Resources, Environment, The Arts and Sport was quality coded as follows:

- flow data for both sites was quality coded 'Blank' for the year.

Comparative year

The following table compares the value for the 2009–10 year reported in this account with the corresponding value reported in the 2010 Account.

Comparative information from the 2010 Account for line item 17.2

2011 Account line item

2010 Account line item

Value reported in the 2010 Account (ML)

Value reported in the 2011 Account (ML)

Additional information

17.2 River outflow from the region

14.2 Streamflow into downstream entity

2,971,718

2,971,718

Change in line item name and number