Adelaide
6.1 Groundwater allocation remaining

Supporting information

The closing balance at 30 June 2012 for groundwater allocation remaining is reported as 6,641 ML. This includes rollover of native groundwater allocations and recharged groundwater credits to the following year:

  • Native groundwater refers to water stored underground as a result of natural processes.
  • Recharged groundwater refers to water stored underground as a result of active processes. Following a period of time termed a 'recharge' period, a portion of this water is made available for reuse. This arrangement is called managed aquifer recharge (MAR).

Water licences existed in areas with an operational water allocation plan (WAP). These water licences were managed under the relevant WAP that described the licence operating conditions including water allocations and carryover rules:

During the 2011–12 year, licences were also issued on the Dry Creek PWA, although no water allocation plan there had yet commenced. There was no carryover of native groundwater permitted on licences in Dry Creek PWA for the 2011–12 year. No MAR scheme existed in Dry Creek PWA during the 2011–12 year either.

The following table shows for the 2011–12 year and the 2010–11 year the breakdown of the groundwater allocation remaining per category and groundwater management area.

Groundwater allocation remaining by category and management area.
Category 

Prescribed area

2011–12 (ML)

2010–11 (ML)

Native groundwater—rollover from prior year Barossa PWRA

466

McLaren Vale PWA 1,673

1,651

Northern Adelaide Plains PWA

0

0

Dry Creek PWA

0

n/a

Sub-total 2,139 1,651
Recharged water credits—to be carried forward  Barossa PWRA

0

0

McLaren Vale PWA

1

1

Northern Adelaide Plains PWA 4,501

3,296

Dry Creek PWA

0

n/a

Sub-total 4,502 3,297
Total

6,641

4,948


As shown in the table above, the opening balance at 1 July 2012, carried forward from the 2010–11 year, was 4,948 ML but it does not include rollover of native groundwater allocations for the Barossa PWRA as these data were not available at the time when this report was compiled. Therefore, no meaningful comparisons of rollover volumes between years can be made.

The table below shows the line items and calculations that determine the water liability on the groundwater asset for the 2011–12 year. Links to the related line items are also provided. The water liability at the beginning of the year (opening balance of the allocation remaining) increases due to allocation announcements and decreases due to extractions made during the year. Volumes permitted to be carried forward to the next year (closing balance of the allocation remaining) are determined at the end of the year. Unused allocated volumes that are not permitted to be carried forward are forfeited.  

  

Groundwater liability calculations in the 2011–12 year
Calculation

Line item

Volume (ML)

Opening balance 6.1 Groundwater allocation remaining  
Native groundwater

1,651

Recharged groundwater

3,297

Total

4,948

add 22.1 Groundwater allocation announcement  
Native groundwater

42,718

Recharged groundwater

1,205

Total

43,923

less 18.11 Groundwater allocation extraction

17,379

less 14.1 Adjustment and forfeiture of groundwater allocation

24,851

Closing 6.1 Groundwater allocation remaining  
balance Native groundwater

2,139

  Recharged groundwater

4,502

  Total

6,641


For further information on groundwater extractions that create a liability refer to line item 33.3 Groundwater access entitlement for allocation extraction.

Other than Dry Creek PWA, groundwater resources in the Adelaide region that do not have a WAP are managed by a Notice of Prohibition. Under that type of management arrangement, no water liability is created prior to the extraction taking place (see line item 18.7 Extraction – other statutory right).

Quantification approach

Data source

Water Information and Licence Management Administration (WILMA) database; and database detailing managed aquifer recharge credit calculations.

Provided by

South Australian Department of Environment, Water and Natural Resources (DEWNR).

Method

Native water allocation

Carryover of native groundwater allocations for the 2010–11 and 2011–12 years was extracted from the WILMA licensing database.

Recharged water credits

The DEWNR database detailing managed aquifer recharge credit calculations was used to differentiate new recharged water credits (line item 22.1 'Groundwater allocation announcements') from previously applied but not used or not expired recharged water credits carried over to the 2011–12 year. Recharged water credits to be carried forward to the 2011–12 year relate only to practices completed in the previous recharge period, the 2010–11 year.

Assumptions, limitations, caveats and approximations

In some situations the operating rules applicable to managed aquifer recharge schemes were created under Environment Protection Authority guidance and may differ from the content of the relevant water allocation plan.

Uncertainty information

The uncertainty estimate is not quantified.

Comparative year

The line item value at 30 June 2011, provided by DEWNR for the 2012 Account, was different from the value at the same date published in the 2011 Account due to the availability of better quality data. The following table details the restatement made in the 2012 Account.

Restatement of comparative year information for line item 6.1 Groundwater allocation remaining
Category Prescribed area

2012 Account volume at 30 June 2011 (ML)

2011 Account volume at 30 June 2011 (ML)

Additional information

Native groundwater—rollover to following year Barossa PWRA



 
McLaren Vale PWA

1,651

1,665

Better data available

Northern Adelaide Plains PWA

0

0

 
Dry Creek PWA

n/a

n/a

 
Sub-total

1,651

1,665

 

Recharged water credits—rollover to following year Barossa PWRA

0

0

 
McLaren Vale PWA

1

10

 
Northern Adelaide Plains PWA

3,296

1,886

Better data available

Dry Creek PWA

n/a

n/a

 
Sub-total 3,297 1,896  
Total  

4,948

3,561

 

– not quantified