21.6 Other surface water liability increases

Supporting information

The volume for this line item is 0 ML.

The Sydney Catchment Authority manages banked environmental flow in the Sydney region.

Between 1 June 2005 and 3 March 2008, environmental flow releases into the Hawkesbury and Nepean rivers required under the Sydney Catchment Authority's water management licence were halved as directed by the minister responsible for water in New South Wales due to the continuing drought. A condition of halving the flows was that the ydney Catchment Authority would maintain a rolling 12-month bank in storage reservoirs and release the banked water as directed by the minister. The total banked water was 5,363 ML at the beginning of the 2011–12 year.

No banked environmental flow releases were made during the 2011-12 year in accordance with the New South Wales Office of Water directive that releases from banked environmental water cease from 1 July 2011. This coincided with the implementation of the Greater Metropolitan Region Water Sharing Plan.

As a result of reservoir spills that occurred during flooding in March 2012, the water recorded as being in the bank was deleted.

Reconciliation of this line item is shown in the following table.

Calculation of other surface water liability increases in the 2011–12 year
Line item
Volume (ML)


5.6 Opening balance (as at 30 June 2011)



21.6 Other surface water liability increases



17.16 Other delivery of allocated surface water



13.6 Other surface water liability decreases



5.6 Closing balance (as at 30 June 2011)


Quantification approach

Data source

The Sydney Catchment Authority and the New South Wales Office of Water agreement; Sydney Catchment Authoirty database of daily requirements and releases; Sydney Catchment Authority compliance reporting to the New South Wales Office of Water.

Provided by

Sydney Catchment Authority.


The volume stated for this line item is based on agreements between the Sydney Catchment Authority and New South Wales Office of Water.

Assumptions, limitations, caveats and approximations


Uncertainty information

The uncertainty was not quantified.