Murray–Darling Basin
17.5 Overbank flood spilling

Supporting information

The volumetric value for the line item for the 2011–12 year was 299,151 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 2011–12 year
Surface water resource plan area

Sustainable diversion limit area


 Volume (ML) for the 2011–12 year 



SW19 Warrego–Paroo–Nebine SS29 Paroo  Qld 0
SS28 Warrego Qld 0
SS27 Nebine Qld 1,000
SW18 Condamine–Balonne SS26 Condamine–Balonne  Qld 259,151
SW17 Moonie SS25 Moonie  Qld 7,000
SW16 Qld Border Rivers SS24 Qld Border Rivers Qld 32,000
Sub-total Northern Basin 299,151
Total for the region 299,151

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. Therefore, line item information applies only to the Northern Basin of the region. 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

Murray–Darling Basin Authority: Water audit monitoring (WAM) data received from Queensland (4 February 2013) and stored in the HYDRO database.


Provided by

Bureau of Meteorology (the Bureau).


The WAM data used for this line item were estimates. The estimates are made by local officers based on a combination of user returns and local knowledge.

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 +/– 20% to 40%.