Freshwater resources are of major environmental, economic and social importance. Their distribution varies widely among and within countries. If a significant share of a country's water comes from transboundary rivers, tensions between countries can arise. In arid regions, freshwater resources may at times be limited to the extent that demand for water can be met only by going beyond sustainable use.
Freshwater abstractions, particularly for public water supplies, irrigation, industrial processes and cooling of electric power plants, exert a major pressure on water resources, with significant implications for their quantity and quality. Main concerns relate to overexploitation and inefficient use of water and to their environmental and socio-economic consequences.
The indicator presented here refers to the intensity of use of freshwater resources (or water stress). It is expressed as gross abstractions of freshwater taken from ground or surface waters in % of total available renewable freshwater resources (including water inflows from neighbouring countries), in % of internal resources (i.e. precipitation – evapotranspiration), and per capita. Water used for hydroelectricity generation (which is considered an in situ use) is excluded. Water abstractions by major primary uses and water abstractions for public supply, expressed in m3 per capita per day, are given as a complement.
This indicator gives insights into quantitative aspects of water resources, but may hide important variations at subnational (e.g. river basin) level.
Most OECD countries increased their water abstractions throughout the 1970s in response to demand by the agricultural and energy sectors. In the 1980s, some countries stabilised their abstractions through more efficient irrigation techniques, the decline of water-intensive industries (e.g. mining, steel), increased use of more efficient technologies and reduced losses in pipe networks. Since the 1990s trends in water abstractions have been generally stable. In some countries this is due to increased use of alternative water sources, including water reuse and desalination.
Indicators of water stress show great variations among and within individual countries. In about one-third of OECD countries, freshwater resources are under medium to high stress. In a few countries water resources are abundant and population density is low.
Although at national level most OECD countries show sustainable use of water resources, most still face seasonal or local water quantity problems, and several have extensive arid or semi-arid regions where water availability is a constraint on economic development.
At world level, it is estimated that, over the last century, the growth in water demand was more than double the rate of population growth, with agriculture being the largest user of water. Since 2000, the use of irrigation water in the OECD area slightly declined compared to agricultural production, but in about half of the OECD countries agricultural water use increased driven by expansion in the irrigated area.
By 2050, global water demand is projected to increase by about 55% due to growing demand from manufacturing, thermal power plants and domestic use (OECD, 2012a).
Information on the intensity of the use of water resources can be derived from water resource accounts and is available for most OECD countries. The definitions and estimation methods employed may vary considerably from country to country and over time. In general, data availability and quality are best for water abstractions for public supply, which represent about 15% of the total water abstracted in OECD countries. For some countries the data refer to water permits and not to actual abstractions.
OECD totals are estimates based on linear interpolations to fill missing values. Data for the United Kingdom refer to England and Wales only. Breaks in time series exist for Estonia, France, Hungary, Luxembourg, Mexico, Turkey and the United Kingdom.