Murray-Darling Basin
17.5 Overbank flood spilling

Supporting Information

The volumetric value for the line item for the 2010–11 year was 652,699 ML. The line item represents flood waters that have overflowed the river channel top of bank (includes flood water to flood plains but excludes flood waters to seasonally connected wetlands and other surface water stores).

The following table summarises the information for the line item for the Murray–Darling Basin (MDB) region. 


Overbank flood spilling in the MDB region in the 2010–11 year
Surface water resource plan area

Sustainable diversion limit area


 Volume (ML)  



SW19 Warrego – Paroo – Nebine SS29 Paroo  Qld 8
SS28 Warrego Qld 0
SS27 Nebine Qld 100
SW18 Condamine–Balonne SS26 Condamine–Balonne  Qld 463,541
SW17 Moonie SS25 Moonie  Qld 2,000
SW16 Qld Border Rivers SS24 Qld Border Rivers Qld 187,050
Sub-total Northern Basin 652,699
Total for the region 652,699


Overbank flood spilling is classified as an unregulated event. The line item is applicable to several jurisdictions within the region.  However, volumes for this line item were only available for Queensland. The volumes shown in the above table have been classified under the unsupplemented entitlement class within Queensland.

No information was available for the other water resource plan areas for this line item.

Quantification Approach

Data Source

Water audit monitoring (WAM) data received from Queensland (22 December 2011) and stored in the Murray–Darling Basin Authority HYDRO database.

Provided by

Murray–Darling Basin Authority.


The WAM data used for this line item were estimates based on user returns. These estimates were provided by users of the water and submitted to water authorities.

Assumptions, Limitations, Caveats and Approximations

Information on all flood waters that have overflowed from the river channels was not available.

In the reported volume for the line item, it is possible that whole volume may not be from overflows from river channels because it was not possible to distinguish between harvesting from landscape and river overflows.

Uncertainty Information

The uncertainty estimate for the volumes provided in this line item is +/– 40%.

Comparative year

The value reported as comparative year corresponds to the line item 14.4 Overbank flood spilling that was reported in the 2010 Account.