Most of the climate change models for South Africa predict a reduction in freshwater availability by 2050. Population growth is projected at 3% per annum, implying increased domestic water use. In addition to these factors, the concern for ecological sustainability and increased water pollution due to increased industrial, mining and agricultural activities, water availability for sectoral production activities is expected to decline. This decline has an impact on sectoral output, value added and households’ welfare. Using a computable general equilibrium approach, this study investigates the possible impact of global change on households’ welfare. The simulation results show that water scarcity due to global change can potentially lead to a general deterioration in households’ welfare. The poor households, whose incomes are adversely impacted, are the most vulnerable to the consequences of the impact of global change on water resources in South Africa. This vulnerability can only be reduced if welfare policies that maintain food consumption levels for the least and low-income households are implemented.