Demand Efficiency is the optimization of water use to gain more productivity per drop of water resource. Water Demand Efficiency allows to reduce user-end loss and misuse of water in order to ease pressures resources and limit unsustainable exploitation of water. This Tool introduces water demand efficiency, the need for integrated approaches, and pathways to enhance demand efficiency via social, technological and institutional mechanisms.
Demand efficiency actions can be taken independently from water availability. However, it is often driven by water scarcity. Demand efficiency aims to encourage better use of water before plans are made to increase supply capacity facilitating major financial and infrastructural savings for countries, cities and companies before additional capital is investment for new supply and conveyance facilities. It focuses on reducing loss and misuse during consumption in various water sectors (intra-sector efficiency). This requires reflection and re-evaluation on current water uses.
Using demand efficiency, countries, cities or companies can get most of the available water. A reduction in water use within each sector to optimum levels allows reasonable allocation between various users (cross-sectoral efficiency). In cases of water scarcity, this leads to more equitable distribution of water to vulnerable and marginalized users. Furthermore, it also leads to more water conservation. The process involves limited ecological consequences, allowing more water to be conserved or allocated towards maintaining environmental flows, ecosystem services and the development of in situ users of water through recreational activities, aquaculture, fisheries and energy (Figure 1).
Figure 1. Water allocation before and after demand efficiency