Murray-Darling Basin
28.1 Precipitation on landscape

Supporting Information

The volumetric value for the line item for the 2010–11 year was 819,237,686 ML. The line item represents the volume of all forms (rain, sleet, snow, hail, or drizzle) of water falling on the landscape within the Murray–Darling Basin (MDB) region. The following table presents breakdown information for the volumetric value on sustainable diversion limit (SDL) area basis.


Precipitation on the landscape in the MDB region for the 2010–11 year
Water resource plan area

SDL area


Volume (ML)   



SW19 Warrego – Paroo – Nebine SS29 Paroo  Qld 19,065,188
SS28 Warrego  Qld 53,666,963
SS27 Nebine  Qld 22,374,907
SW18 Condamine–Balonne SS26 Condamine–Balonne  Qld 85,537,248
SW17 Moonie SS25 Moonie  Qld 11,890,467
SW16 Qld Border Rivers SS24 Qld Border Rivers  Qld 21,146,789
SW15 NSW Border Rivers SS23 NSW Border Rivers  NSW 20,002,724
SW11 Barwon–Darling Watercourse SS19 Barwon–Darling Watercourse  NSW 2,172,260
SW12 NSW Intersecting Streams SS17 NSW Intersecting Streams NSW 71,458,914
SW14 Gwydir SS22 Gwydir NSW 22,857,455
SW13 Namoi SS21 Namoi  NSW 34,340,142
SW10 Macquarie–Castlereagh SS20 Macquarie–Castlereagh  NSW 68,818,257
Sub-total Northern Basin 433,331,315
SW9 Lachlan SS16 Lachlan  NSW 64,534,200
SW8 Murrumbidgee  SS15 Murrumbidgee NSW NSW 72,805,800
SW7 NSW Murray and Lower Darling SS18 Lower Darling  NSW 67,482,184
SS14 NSW Murray NSW 17,030,106
SW2 Vic Murray SS3 Kiewa Vic 3,370,891
SW3 Northern Victoria SS4 Ovens  Vic 12,174,382
SS5 Broken  Vic 4,563,407
SS6 Goulburn Vic 20,513,020
SS7 Campaspe  Vic 4,581,014
SS8 Loddon Vic 12,608,065
SW2 Vic Murray SS2 Vic Murray  Vic 20,346,078
SW4 Wimmera–Mallee  SS9 Wimmera–Mallee  Vic 44,652,240
SW6 Eastern Mount Lofty Ranges SS13 Eastern Mount Lofty Ranges  SA 2,018,812
SW5 SA Murray SS11 SA Murray SA 725,488
SS10 SA Non-prescribed areas  SA 35,134,029
SW6 Eastern Mount Lofty Ranges SS12 Marne–Saunders  SA 490,307
SW1 ACT  SS1 ACT ACT 2,876,347
Sub-total Southern Basin 385,906,371
Total for the region 819,237,686


Quantification Approach

Data Source

Bureau of Meteorology (the Bureau): Australian Water Availability Project (AWAP) monthly precipitation grids.

Provided by

The Bureau.


Monthly precipitation data was produced by the Bureau of Meteorology. It was based on daily data from approximately 6,500 rain gauge stations and interpolated to a 0.05 degree (approximately 5 km) national grid (Jones et al. 2007).

The average precipitation depth across the MDB landscape was determined as the weighted mean of precipitation occurring onto the relevant grid points within the region boundary. Points were weighted upon the area they represented within the MDB landscape to remove edge effects (where the area represented was not wholly within the MDB region) and the effect of changing area represented with changing latitude. The depth of precipitation was converted to a volumetric estimate by multiplying by the total area of the MDB landscape.

Only precipitation falling onto the landscape was considered in the line item. Precipitation falling onto storages, lakes, off-channel water storages and other water bodies was not included.

Assumptions, Limitations, Caveats and Approximations

The precipitation estimates were subject to approximations associated with interpolating observation point data to a national grid detailed in Jones et al. (2007).

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 559,425,235 ML.