Water efficiency is the concept of using less net water for an equivalent purpose or process. For example, using less water to produce the same weight of final product (measured in l/kg or m3/kg or m3/ton produced). There are two main ways to improve efficiency. The first is to use technology that uses less water input to do the same thing (for example, drip irrigation). The second is to collect and reuse water (treated if necessary) so that less incoming water is needed.
Improved efficiency does not always mean less water is used. If production is increasing, a factory may require as much or more water as before, but can produce more goods for the same amount of water. An alternative name is water intensity. Associated terms include ‘water use ratio’ (WUR) and ‘water use intensity’ (WUI).
