Measuring the global water footprint, including all economic activities, is a pending task; in agriculture it is an urgent task, as more than 77% of water is consumed in agriculture. Water productivity is a more relevant indicator, given the need to produce more with less water.
The water footprint is an indicator of the volume of water used to produce a good or service and its origin; the green footprint is rainwater, the blue footprint is surface and groundwater and the grey footprint is polluted water.