Murray-Darling Basin
26.1 Soil moisture

Supporting Information

The volumetric value for the line item for the 2010–11 year was 175,048,227 ML. The line item represents the volume of water in the unsaturated zone in the soil profile within the Murray–Darling Basin (MDB) region.  The following table presents breakdown information for the volumetric value on sustainable diversion limit (SDL) area basis.


Volume of water in the unsaturated zone in the soil profile in the MDB region at 30 June 2011
Water resource plan area

SDL area


 Volume (ML) 



SW19 Warrego – Paroo – Nebine SS29 Paroo  Qld 4,702,246
SS28 Warrego  Qld 11,621,548
SS27 Nebine  Qld 6,126,940
SW18 Condamine–Balonne SS26 Condamine–Balonne  Qld 15,664,300
SW17 Moonie SS25 Moonie  Qld 2,480,692
SW16 Qld Border Rivers SS24 Qld Border Rivers  Qld 4,019,058
SW15 NSW Border Rivers SS23 NSW Border Rivers  NSW 3,875,799
SW11 Barwon–Darling Watercourse SS19 Barwon–Darling Watercourse  NSW 571,622
SW12 NSW Intersecting Streams SS17 NSW Intersecting Streams NSW 17,715,954
SW14 Gwydir SS22 Gwydir NSW 5,302,173
SW13 Namoi SS21 Namoi  NSW 7,450,351
SW10 Macquarie–Castlereagh SS20 Macquarie–Castlereagh  NSW 16,398,819
Sub-total Northern Basin 95,929,502
SW9 Lachlan SS16 Lachlan  NSW 14,273,316
SW8 Murrumbidgee  SS15 Murrumbidgee NSW NSW 14,974,708
SW7 NSW Murray and Lower Darling SS18 Lower Darling  NSW 13,400,303
SS14 NSW Murray NSW 3,158,297
SW2 Vic Murray SS3 Kiewa Vic 406,750
SW3 Northern Victoria SS4 Ovens  Vic 1,659,428
SS5 Broken  Vic 896,298
SS6 Goulburn Vic 3,441,557
SS7 Campaspe  Vic 829,279
SS8 Loddon Vic 2,581,609
SW2 Vic Murray SS2 Vic Murray  Vic 2,827,490
SW4 Wimmera–Mallee  SS9 Wimmera–Mallee  Vic 10,968,204
SW6 Eastern Mount Lofty Ranges SS13 Eastern Mount Lofty Ranges  SA 609,657
SW5 SA Murray SS11 SA Murray SA 169,846
SS10 SA Non-prescribed areas  SA 8,371,083
SW6 Eastern Mount Lofty Ranges SS12 Marne–Saunders  SA 137,151
SW1 ACT  SS1 ACT ACT 413,747
Sub-total Southern Basin 79,118,725
Total for the region 175,048,227


Quantification Approach

Data Source

Data sources were (1) Bureau of Meteorology (the Bureau): National Climate Centre (NCC): daily climate grids (rainfall, temperature and solar radiation); Australian Hydrological Geospatial Fabric (AHGF), waterbody feature class, and (2) Commonwealth Scientific and Industrial Research Organisation (CSIRO): Australian water resource assessment – landscape (AWRA-L) model parameters; monthly climatological average radiation grids data.

Provided by

The Bureau.


Soil moisture for the MDB region was estimated based on the AWRA-L version 1.0.0 (Van Dijk 2010) surface soil, shallow soil and deep soil moisture model outputs.

Using climate grid data for the MDB region (including precipitation, temperature and solar radiation data), AWRA-L was used to estimate the soil moisture for each soil layer at each grid-point within the region. Only soil moisture within the landscape was considered; therefore, the surface areas of the major storages, lakes, off-channel water storages and other waterbodies were excluded from the analysis.

The total depth of water in all three layers of the soil column at each grid point was extracted. This depth was then multiplied by the surface area represented by each individual grid point to give a volumetric estimate for every grid point. The volume for each grid point was summed up to provide an estimate of soil moisture for the entire MDB landscape.

Assumptions, Limitations, Caveats and Approximations

The values provided in this note have not been compared to any real time measured data for the 2010–11 year.

The soil moisture estimates are subject to the assumptions of the AWRA-L v1.0.0 model detailed in Van Dijk (2010).

AWRA-L does not account for application of water via irrigation and lateral flow.

Uncertainty Information

The uncertainty estimate was not quantified.

Comparative year

There was no comparative line item in the 2010 Account.  The relevant volume calculated for the 2009–10 year was 184,799,454 ML.