Farming systems throughout the Murray-Darling Basin are under increasing scrutiny from the perspective of ecological sustainability of farm and catchment systems. In northern Victoria, the dairy industry is a major user of water, and contributes to the environmental issues. Changes in irrigation water price, availability and policy will invariably impact on the viability of dairy farming in this region, but the diversity of dairy farm systems suggests that the impact will vary between farms. Two case study farms, a 'water reliant' farm and a 'fodder reliant' farm, were used to examine economic and social impacts of changes in water price, availability and policy.