Murray–Darling Basin
5.2 Surface water allocation remaining – urban water system

Supporting information

The volumetric value for the line item for the 2011–12 year was 0 ML. The line item represents surface water allocation remaining for urban water systems in the Murray–Darling Basin (MDB) region as at 30 June 2011.

For the 2011–12 year, none of sustainable diversion limit (SDL) areas within the region reported surface water allocation remaining for urban water systems. 


All allocation remaining at the end of the water year is forfeited and therefore allocation remaining is zero for Queensland water resources plan (WRP) areas. While carry-over does not apply for urban water systems, most water supply schemes hold water in reserve for high priority urban use in Queensland.

New South Wales

Although there has been provision to carry-over remaining allocations, all the SDL areas reported zero volume.


There was allocation remaining for urban supplies in SDL areas within Victoria; however, reliable information was not available at the data collection stage of the 2012 Account to distinguish urban carry-over volumes.  Therefore, any carry-over volume for urban systems was included in carry-over volumes reported in line item 5.1 'Surface water allocation remaining'.

South Australia

All allocation remaining at the end of the water year for urban entitlements is forfeited and therefore allocation remaining is zero for the WRP areas.

Australian Capital Territory

In the ACT, no formal allocation announcement is made to extract water from storages. The allocation announcement for the year is assumed to be equal to the total entitlement volume. The difference between the allocation announcement and the allocation diversion is considered as forfeited. Therefore, allocation remaining (carry-over) was zero for this line item.

Quantification approach

Data source

(1) NSW Office of Water's Water Accounting section: New South Wales data; and (2) Murray–Darling Basin Authority: water audit monitoring (WAM) data received from Queensland (4 February 2013) South Australia (15 March 2013) and Victoria (21 March 2013). WAM data are stored in the Murray–Darling Basin Authority HYDRO database.

Provided by

Bureau of Meteorology (the Bureau).


Water sharing plans, water resource plans and the water legislation of each State and Australian Capital Territory specify:

  • the classes of licences that are permitted to carry forward any unused volumes
  • rules attached to the volume that may be carried forward.

Allocation remaining (carry-over) were as calculated by the States and Australian Capital Territory.

Assumptions, limitations, caveats and approximations

The line item value was under-estimated as a result of including Victorian urban carry-over volumes in line item 5.1 Surface water allocation remaining.

Uncertainty information

The uncertainty estimate was not quantified.