The water footprint measures a human demand on freshwater. It is a multi-dimensional indicator that shows water consumption by source and polluted volumes by type of pollution; all components of a total water footprint are specified geographically (in place) and temporally (in time).

Water use and water consumption may have various meanings in the world; however, in regards to water footprint, their definitions are as follows:

Water use is measured in terms of water volumes consumed (evaporated) and/or polluted per unit of time. Usually three types of water usage are distinguished:

  1. Consumptive use of rainwater stored in soils as soil moisture (green water).
  2. Consumptive use of water withdrawn from groundwater or surface water (blue water).
  3. Pollution of water (grey water).

Water consumption refers to loss of water from the available ground-surface water body in a catchment area, which happens when water evaporates, returns to another catchment area or the sea or is incorporated into a product.