Abstract This paper describes the impact of ricehydraulic loading (percentage area under rice crop) ongroundwater levels and salinity in the Murrumbidgee irrigationarea (MIA), Australia using a MODFLOW-basedmodelling approach. The model simulations show that thegroundwater levels will be in equilibrium after a fall ofapproximately 1 m under most of the areas, however, thegroundwater salinity levels will rise by more than 1,000ls/cm in most parts of irrigation area. If the rice growingarea is reduced by 50 and 75%, there can be a net decline ingroundwater levels during the first 2 years and then a newquasi-equilibrium will be established. To downscale theseresults at the farm level, SWAGMAN Farm model inconjunction with groundwater outflow rates obtained froma three-dimensional MODFLOW model was applied fordetermining net recharge rates under rice for different areaswithin the MIA. The highest net recharge during 2005'2006 season was 0.84 ML/ha (84 mm) in parts of theirrigation system, whereas the average net recharge due torice hydraulic loading for the whole MIA during 2005'2006 season was estimated as 0.34 ML/ha (34 mm).