The groundwater model described in this report was used to quantify the changes in salt loads to the River Murray and induced discharge to the degraded river flats of proposed future management options for the Loxton Irrigation Area. The options included maintaining the status quo (including current accession rates for current irrigation levels), irrigation channel rehabilitation to minimise transmission losses, improving irrigation practices and expanding the irrigated areas. A two layer MODFLOW model showed that partial rehabilitation by replacing the channel water delivery system with pipelines, could result in a reduction of induced salt loads to the river of 30% by 2047 compared with the no change scenario. If in addition, the irrigation efficiencies can be improved to 80%, the salt loads can be reduced by 50%, even if an additional 1600 ha are irrigated to the east of the existing irrigation area. As far as groundwater discharge to the northern and southern river flats are concerned, the model suggests partial rehabilitation (Option 2) will result in a reduction by 25% and 30% respectively, below the no change scenario levels by 2047. There is little difference between the impacts of Options 3 and 4, both resulting in a reduction of discharge by about 55% and 65% respectively. Future detailed modelling of the impacts of the management options will benefit from a greater knowledge of the distribution of groundwater salinity within the Pliocene Sands aquifer, particularly where the watertable mound is in direct contact with the river.