Murray–Darling Basin
17.5 Overbank flood spilling

Supporting information

The volumetric value for the line item for the 2012–13 year was 437,901 ML. The line item represents floodwaters that have overflowed the river channel top-of-bank (includes floodwater to floodplains 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 during the 2012–13 year
Surface water resource plan area

Sustainable diversion limit area

 State

 Volume for the 2012–13 year (ML)
Code Name
SW20 Warrego–Paroo–Nebine SS29 Paroo  Qld 0
SS28 Warrego Qld 0
SS27 Nebine Qld 0
SW19 Condamine–Balonne SS26 Condamine–Balonne  Qld 275,415
SW18 Moonie SS25 Moonie  Qld 3,000
SW17 Qld Border Rivers SS24 Qld Border Rivers Qld 159,486
Sub-total Northern Basin 437,901
Total for the region 437,901

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. The values shown in the above table were estimated from abstracted overland flood volumes. These volumes 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 (5 February 2014) and stored in the HYDRO database.

 

Provided by

Bureau of Meteorology.

Method

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 floodwaters that have overflowed from the river channels was not available.
  • In the reported volume (which is abstracted overland flow) 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%.