Global freshwater demand is projected to increase substantially in the coming decades, making water one of the most fiercely contested resources on the planet. Water is linked to many economic activities, and there are complex channels through which water affects economic growth. The purpose of this report is to provide background information useful for a quantitative global assessment of the impact of water scarcity on growth using a multi-region, recursive-dynamic, Computable General Equilibrium (CGE) model. The paper provides a detailed review of the literature on water, water scarcity, sectoral activity and economic growth, and identifies the possibilities and bottlenecks in incorporating water use into a CGE framework. It covers agricultural water consumption, with special attention to irrigation, water use in energy production, and demands for water by households, industry and services. Finally, it discusses water supply and allocation.