Murray-Darling Basin
10.4 Recharge from surface water

Supporting Information

The volumetric value for the line item for the 2010–11 year was 322,955 ML. The following table provides detailed volumetric information for the line item. 


Groundwater recharge from surface water in the Murray–Darling Basin region in the 2010–11 year
Groundwater resource plan area

Groundwater sustainable diversion limit area  


 Volume (ML)  



GW15 Namoi Alluvium GS51 Upper Namoi Alluvium NSW


GW12 Macquarie–Castlereagh Alluvium GS31 Lower Macquarie Alluvium NSW


Sub-total Northern Basin


GW10 Lachlan Alluvium GS30 Lower Lachlan Alluvium NSW


GW9 Murrumbidgee Alluvium GS33 Lower Murrumbidgee Alluvium, shallow: Shepparton Formation and deep: Calivil Formation and Renmark Group NSW


GS36 Mid-Murrumbidgee Alluvium NSW


Sub-total Southern Basin


Total for the region



Groundwater recharge from surface water was only calculated for those New South Wales sustainable diversion limit (SDL) areas for which there was a groundwater model and groundwater recharge from a river was considered to be an important component of the groundwater balance. SDL areas other than those included in the table exist and may be relevant to the line item, however, relevant information was not available for the 2011 Account.

Quantification Approach

Data Source

Inputs to the New South Wales groundwater models draw from knowledge of the hydrogeology and surface water processes to initialise parameters for river bed conductance and thickness.

Provided by

NSW Office of Water.


Groundwater interaction with surface water can be represented in MODFLOW models in several ways. Options that have been used in the New South Wales groundwater models are the MODFLOW river package and the MODFLOW drain package.

For more details about MODFLOW calculations, see documentation at MODFLOW website (United States Geological Survey 2011).

Assumptions, Limitations, Caveats and Approximations

Groundwater models make numerous assumptions and approximations to represent water balance (refer to the MODFLOW website for more details).

Estimates of water level in rivers that are input to groundwater models are usually taken to be monthly average levels, and the levels would usually have a high level of uncertainty unless a river gauge is located within the groundwater model cell.

Uncertainty Information

The uncertainty estimate was not quantified. It is currently not feasible to estimate the uncertainty of modelled groundwater recharge from surface water from outputs of a MODFLOW groundwater model.

Comparative year

The value reported as comparative year corresponds to the line item 15.2.2 Groundwater recharge from connected surface waterthat was reported in the 2010 Account.