Water-use efficiency – UN-Water analytical brief

25 October, 2021

Ahead of COP 26 UN Climate Change Conference, UN-Water has launched an analytical brief on water-use efficiency. The brief has been prepared by the UN-Water Expert Group on Water Scarcity, which is coordinated by the Food and Agriculture Organization of the United Nations (FAO).

Given changing socio-economic and climatic conditions and the level of uncertainty over future trends in freshwater scarcity, water efficiency gains will play a central role in adapting to climate change.

Sustainable Development Goal (SDG) target 6.4.1 is to, by 2030, substantially increase water-use efficiency across all sectors and ensure sustainable withdrawals and supply of freshwater to address water scarcity and substantially reduce the number of people suffering from water scarcity.

This brief examines the method adopted by the SDGs and compares it with specific sector approaches for evaluating the efficiency of freshwater use. It makes the case that operational water accounting will be needed to validate any claimed efficiency gains.

Globally, in recent years, there have been notable gains in efficiency in the areas of energy generation and industry. However, while the adoption of technology, including precision irrigation, has boosted the productivity of agriculture, there is little or no evidence of irrigation water-use efficiency measures ‘freeing up’ water for other uses or being returned to the environment as recharge or drainage.

Global water withdrawals may be slowing but the pressure on freshwater resources will not relax, meaning we will need stronger policy instruments and governance systems alongside ‘joined-up’ water technology to ensure that efficiency gains are shared with beneficiaries who need them most.

  • Access and download the brief here.