Sustainable Development Goals

Indicator 6.4.1 - Change in water use efficiency over time

Water Use Efficiency (WUE) at national level is the sum of the efficiencies in the major economic sectors weighted according to the proportion of water withdrawn by each sector over the total withdrawals. The indicator measures changes in WUE and has been designed to address the economic component of SDG Target 6.4.

Target 6.4

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.

Change in water-use efficiency over time 


This indicator will improve knowledge on the efficiency and sustainability of water usage. Together with indicator 6.4.2, it will provide vital information to ensure that water resources support the world's ecosystems and continue to be available for future generations.

Key results

The monitoring concept of this indicator can be summarised as:

• The indicator should assess the impact of economic growth on the utilization of water resources;

• Only runoff water (so-called blue water) has to be considered in computing the indicator. This is particularly important when computing the indicator for the agricultural sector. For this reason, a specific parameter (Cr) has been introduced in the formula to estimate the amount of agricultural production done under rainfed conditions. For the same reason, the value of sub-sectoral productions making mainly use of non-abstracted water should be subtracted from the overall sectoral value added. 

• The indicator differs from water productivity as it does not consider the productivity of the water used in a given activity as an input to production, or even better the marginal productivity of the extra dose. Instead, this indicator will show how much the growth of the economy is linked to the exploitation of natural water resources, indicating the decoupling of economic growth from water use. In other terms, if the value added (VA) produced by the economy doubles, how much will the water use increase?

These points have led to the following definition of the indicator: the value added per water withdrawn, expressed in USD/m3 over time of a given major sector (showing over time the trend in water use efficiency).

Across the world, water use efficiency rose from 12.58 USD/m3 in 2000 to 18.17 USD/m3 in 2017. Estimates for water use efficiency range from as little as 0.2 USD/m3 for countries whose economies depend largely on agriculture, to 1,197 USD/m3 in highly industrialized, service-based economies that are less dependent on natural resources. The majority of countries (two thirds) have a water use efficiency between 5 and 100 USD/m3.

Regionally, water use efficiency in 2017 ranges from 2.2 USD/m3 in Central Asia, to 62.2 USD/m3 in Oceania, highlighting again the huge differences existing across the world. Several regions have been faster at increasing water use efficiency over time. The highest proportional increases have been recorded in Central Asia and Southern Asia, while Oceania and Northern Africa show lower improvements, and Latin America and the Caribbean registered an actual decline in water use efficiency.



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