Murray–Darling Basin
18.18 Other groundwater decreases
Supporting information
The volumetric value for the line item for the 2011–12 year was 24,271 ML. The line item represents the reduction of supplementary entitlements during the 2011–12 year in New South Wales as stipulated in water sharing plans (see the following table). New South Wales supplementary access licence volumes are included in line item 2.5 Other groundwater assets as groundwater assets. These licence volumes are set to decrease each year until they disappear completely to bring all groundwater entitlements to a level of extraction that is sustainable.
Groundwater resource plan area | Groundwater sustainable diversion limit area |
State |
Volume (ML) for the 2011–12 year |
|
Code |
Name |
|||
GW15 Gwydir Alluvium | GS24 | Lower Gwydir Alluvium | NSW | 1,992 |
GW14 Namoi Alluvium | GS29 | Lower Namoi Alluvium | NSW | 2,087 |
GS47 | Upper Namoi Alluvium | NSW | 4,022 | |
GW12 Macquarie–Castlereagh Alluvium | GS26 | Lower Macquarie Alluvium | NSW | 240 |
Sub-total Northern Basin | 8,341 | |||
GW10 Lachlan Alluvium | GS25 | Lower Lachlan Alluvium | NSW | 2,124 |
GW9 Murrumbidgee Alluvium | GS28 | Lower Murrumbidgee Alluvium (deep; Calivil formation and Renmark Group) | NSW | 4,120 |
GW8 Murray Alluvium | GS27 | Lower Murray Alluvium (Deep: Renmark Group and Calivil formation) | NSW | 9,686 |
Sub-total Southern Basin | 15,930 | |||
Total for the region | 24,271 |
Quantification approach
Data source
Provided by
Bureau of Meteorology (the Bureau).
Method
Assumptions, limitations, caveats and approximations
It has been assumed that groundwater basic right is included in the permissible consumptive volume provided in relevant water sharing plan if no information is available to decide otherwise.
Uncertainty information
Comparative year
Availability of updated information resulted in the restatement of the 2010–11 year volume. Updated information was available for supplementary entitlement volumes for Lower Gwydir, Lower Macquarie and Lower Lachlan alluviums. As a result, asset volume for these three alluviums has been reduced by 204 ML for the 2010–11 year. This volume is included in this line item to reflect the asset change.
The respective volumes associated with the change are detailed in the following table.
Segment | 2012 Account volume for the 2010–11 year (ML) | 2011 Account volume for the 2010–11 year (ML) | Difference due to updated information(ML) |
Northern Basin | 8,575 |
8,380 |
195 |
Southern Basin | 6,254 |
6,245 |
9 |
Whole region | 14,829 |
14,625 |
204 |