Murray–Darling Basin
6.1 Groundwater allocation remaining

Supporting information

The volumetric value for the line item for the 2011–12 year was 2,498 ML. The value represents the allocation remaining for groundwater where it is permissible to carry over unused non-urban groundwater allocations at the end of the 2011–12 year.

The line item comprises of remaining allocations from Angas Bremer (1,742 ML) Marne Saunders (756 ML) groundwater sustainable diversion limit (SDL) areas in South Australia. No other groundwater SDL area has reported remaining allocations.

The following rules apply to the unused groundwater allocations within the Angas Bremer prescribed wells area (PWA) (Government of South Australia n.d.):

  1. Subject to Rule 2, water (except recharged water) taken and used from the wells in the Angas Bremer PWA will be allocated as a volume that may be taken and used in any water-use year.

  2. Subject to rules 3 and 4, any unused portion of up to 30% of a water allocation for any water-use year (excluding recharged water) may be taken and used after the end of that water-use year (at any time over the subsequent three water-use years) with an allocation for a subsequent water-use year.

  3. The combined amount of an allocation from a subsequent water-use year and any allocation from an earlier water-use year shall not exceed 130% of the allocation of that subsequent water-use year in which the combined allocations are taken and used.

  4. For rules 1 to 3, a water-use year means the period between 1 July in any calendar year and 30 June in the following calendar year.

For the Marne Saunders SDL area, carry-over volumes shall not exceed (Government of South Australia 2010b):

  • 20% of the volume of the base water allocation as at 1 July of the post-credit year, regardless of variations in the volume of the base water allocation that occur during that water use year, if the water is allocated in the fractured rock aquifer management zone
  • 10% of the volume of the base water allocation as at 1 July of the post-credit year, regardless of variations in the volume of the base water allocation that occur during that water use year, if the water is allocated in the Unconfined Zone 1, Unconfined Zone 2, Unconfined Zone 3, Unconfined Zone 4, Unconfined Zone 5, Unconfined Zone 6, Confined Zone A, Confined Zone B or Renmark Group Aquifer management zones.

For the Marne Saunders SDL area, a carry-over allocation expires at the end of the post-credit year.

Quantification approach

Data source

South Australia's Department of Environment, Water and Natural Resources: water information and licence management data.

Provided by

South Australia's Department of Environment, Water and Natural Resources.

Method

Carry-over for Angas Bremer and Marne Saunders was deducted from the unused portion of the gazetted allocation and is calculated as up to the limits, specified in respective water allocation plans, of the water allocated for the 2011–12 year.

Assumptions, limitations, caveats and approximations

Nil.

Uncertainty information

The uncertainty estimate was not quantified.

Comparative year

Availability of updated information resulted in the restatement of the 2010–11 year volume. The respective volumes associated with the change are detailed in the following table.


 

Restatement of comparative year information made for the line item 6.1 Groundwater allocation remaining
Segment

2012 Account volume at 30 June 2011 (ML)

2011 Account volume at 30 June 2011 (ML)

Difference due to updated information (ML)

Northern Basin 0 0 0
Southern Basin 2,139 1,958 181
Whole region 2,139 1,958 181


Details of updating 2010–11 volume are as follows:

  • The volume reported for Angas Bremer SDL area in the 2011 Account has been reduced by 398 ML due to updated information.
  • Allocation carry-over volume for Marne Saunders SDL area were not reported in the 2011 Account due to lack of information.  This volume (579 ML) is reported in the 2012 Account.