Water Footprint Analysis

Water footprint analysis is a volumetric accounting method that measures the appropriation of freshwater used to produce the goods and services consumed by an individual, community, business, or nation. Formalized in Arjen Hoekstra's Water Footprint Assessment Manual of 2011, it decomposes water use into three components: the green water footprint (rainwater consumed, mainly through crop evapotranspiration), the blue water footprint (surface and groundwater consumed), and the grey water footprint (the volume of freshwater needed to dilute pollution to meet ambient quality standards). By tracing water through supply chains and aggregating these components, the method reveals how much and what kind of water lies behind products and consumption — including virtual water embedded in trade — and then assesses whether that appropriation is sustainable relative to local water availability and pollution-assimilation capacity.