Use of freshwater resources - outlook from EEA (Outlook 014) - Assessment published Jun 2007
Definition: The water exploitation index (WEI) is the annual total abstraction of freshwater divided by the annual total renewable freshwater resource, expressed in percentage terms. This indicator can be computed at the country level or, preferably, by river basin. A region is characterized as being under water stress, if it the water exploitation index exceeds 20%, and under severe water stress if it exceeds 40%. This indicator combines data on water availability and water withdrawals, and has thus also been referred to as withdrawals-to-availability index.
Alternatively, the underlying data can be used (i.e. data on water availability and water withdrawals for domestic use, industrial use, an agricultural use, respectively) to indicate seperately:
The water availability index is defined as the average freshwater resources available per person in a country or river basins. Regions can be labelled as water scarce if this value drops below 1000 m3 per person - however as the indicator uses population as a proxy for water uses it is less accurate.
Changes in annual water availability indicates the change in freshwater resources in a country or river basin over a given time period, primarily due to changes in upstream water use or climate change.
Changes in annual water abstraction indicates the change in water use in a country or river basin over a given time period. Changes can be presented separately for different socio-economic activities, i.e. water for domestic use, for use in manufacturing and electricity production, and for agricultural purposes.
Model used: WaterGAP
Ownership: European Environment Agency
Temporal coverage: 2000 - 2030
Geographical coverage: Austria, Belgium, Denmark, Cyprus, Czech republic, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Lichtenshtain, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Spain, Sweden, Swetzerland, Slovakia, Slovenia, United Kingdom
Key policy question: K: Is the abstraction rate of water use sustainable?
Total water abstraction in Europe is expected to decrease by more than 10 % between 2000 and 2030 with pronounced decreases in Western Europe.
Climate change is expected to reduce water availability and increase irrigation withdrawals in Mediterranean river basins. Under mid-range assumptions on temperature and precipitation changes, water availability is expected to decline in southern and south-eastern Europe (by 10 % or more in some river basins by 2030).
The sectoral profile of water abstraction is expected to change: withdrawals for the electricity sector are projected to decrease dramatically over the next 30 years as a result of continuing substitution of once-through cooling by less water-intensive cooling tower systems. Water use in the manufacturing sector may grow significantly. Agricultureis expected to remain the largest water user in the Mediterranen countries, with more irrigation and warmer and drier growing seasons resulting from climate change.
Note: Current water availability in European river basins and changes in average annual water availability under the LREM-E scenario by 2030
Center for Environmental Systems Research (University of Kassel, Germany), 2003-2004. Dataset: WaterGAP model.
Assessment includes baseline and Low greenhouse gas emission scenarios for Europe as a whole and within range of regions.
The changes in river-flow and groundwater recharge are expected to vary between regions, and to depend critically on the degree and types of climate change.
The following developments are expected for water availability forecasts
- Under the climate change assumptions outlined above (i.e. an increase in global average temperature over pre-industrial levels of 1.3 ?C by 2030 and 3.1 ?C by 2100), changes in average water availability in most European river basins are estimated to be relatively small over the next 30 years. Increases in annual run-off are expected for several river basins in northern Europe as average precipitation increases.
- In contrast, average run-off in southern European rivers is projected to decrease with increasing temperature and decreasing precipitation. In particular, some river basins in the Mediterranean region, which often already face water stress, may see decreases of 10 % or more below today's levels by 2030 (see Map 4.4). In the longer term, changes in water availability are likely to develop more noticeably, making the general developments expected above more pronounced.
While large decreases are expected in water withdrawals for cooling purposes in electricity production across Europe, there is considerable variation in the water use outlook of different regions and sectors (i.e. households and domestic purposes, manufacturing, cooling for electricity production, and agriculture and irrigation).
The following developments are expected for water use forecasts:
- Under the baseline scenario assumptions, water withdrawal across Europe is expected to decrease by about 11 %, to less than 275 km3 per year by 2030 (from about 300 km3 in 2000).
- Agriculture accounts for about one-third of the total water abstraction in Europe, used mostly for irrigation. The amount of irrigation water needed per crop and hectare depends mainly on soil and climate conditions, and on the efficiency of the irrigation systems. Estimates of future water abstraction for agriculture are closely correlated to estimates of the future area under irrigation. Under baseline assumptions, this is expected to increase by 20 % or more by 2030 in southern Europe, the EU candidate countries, and in Hungary, Malta, and Cyprus, while remaining more or less at current levels in other European countries.
- Large decreases in water withdrawal for electricity production are likely. Many older power stations rely on once-through cooling systems, and newer plants are expected to replace many of these over the next 30 years. The newer plants usually operate with tower cooling systems, which should result in substantial reductions, of 50 % or more, in water withdrawal, despite an expected near doubling of thermal electricity production in Europe between 1990 and 2030.
- The development of water use in households varies considerably across Europe. On average a quarter of European water abstraction is for use in the 'domestic sector', which includes households and small businesses. The future water demand of this sector is highly uncertain and will depend on a wide range of factors, including the incomes and sizes of households (water use per person usually increases with income and with fewer people per household), the age distribution of the population (water use varies considerably between different age groups), tourism and water pricing (high water prices reduce the demand for water in households, but the relationship between prices and use is highly variable). Another important factor is technological change, which generally increases the water-use efficiency of household appliances, and thus reduces total water withdrawals.
- Increases in water abstraction for manufacturing are also expected with continuing growth in economic activity and output. Although future water-use estimates for different industries entail considerable uncertainty, the increases are expected to be significant (more than 20 % in most countries); in the faster-growing economies of the EU candidate countries, where current abstraction for manufacturing is relatively low, water use may even double. The large uncertainties in this estimate relate to the uptake of new less water-intensive technologies such as electronics, the future of existing water-intensive industries, and the possible emergence of more water-intensive manufacturing processes.
Regional features for fresh water use trends (water withdrawal forecasts) are expected the following:
- Water withdrawal in northern Europe is dominated by electricity production, and its share is expected to decrease substantially (see above). In contrast, withdrawal for manufacturing is likely to play a much larger role, despite increased water-use efficiency with technological change. And technological improvements in water-use efficiency are expected to lead to a further decrease or at least a stabilisation of average water use by households. Agricultural water withdrawal is relatively small, and may even decrease further with changing climate conditions, technologically-improved irrigation systems and a more or less constant area under irrigation.
- Water withdrawal for irrigation is the largest share of overall water abstraction in southern Europe and will be in future. Continuously improving efficiency in irrigation water use decreases water withdrawal per unit irrigated, but the savings are offset by an increase in the utilised irrigated area, leading to an increase of more than 15 % in withdrawals for agriculture (utilized irrigated area is assumed to expand by more than 20 % by 2030). However, even if the area under irrigation remains constant over the next 30 years, changing climate conditions alone are estimated to increase irrigation requirements by around 5 %. In the other main water-use sectors (electricity, manufacturing and domestic) the dynamics in southern Europe are expected to be similar to those in northern Europe, i.e. large decreases in withdrawals for electricity production and some increase for manufacturing.
New EU Member States:
A major uncertainty in the new EU Member States is future domestic water use.
- Water use per capita in households decreased markedly during the 1990s in all the countries expects Malta and Cyprus. Assuming that water use per person rises gradually to the level of other EU countries by 2030, total water abstraction by households may increase substantially (by as much as 74 %) despite decreasing populations and more water-efficient household appliances (average water use in these countries in 2000 ranged from about 40 m3 per person per year (Baltic countries) to more than 100 m3 per person per year (Cyprus) compared with the EU average of about 125 m3 per person per year).
- If water use per capita were to remain at 2000 levels instead of rising to the current EU average, domestic withdrawals would be only about half of the values projected for 2030 (i.e. total domestic water use would actually be less than today). This range (i.e. small decreases to major increase) highlights the large uncertainty in water-use projections, but also suggests avenues for future water savings in this and other regions.
- Water use in electricity production in the new EU Member States is likely to follow a similar dynamic to that in northern and southern Europe, i.e. marked decreases as power plants that rely on once-through cooling systems are replaced. As in other European regions, water use in the manufacturing sector is expected to increase with increasing economic activity. Agricultural water use is expected to remain more or less constant, as the adverse effects of climate change in this region are estimated to be of the same order of magnitude as the water savings expected from more efficient irrigation systems.
EU candidate countries:
- Changes in water use in the EU candidate countries are very dynamic; while total abstraction is expected to decline in most of Europe, they are expected to increase significantly in these countries (primarily in Turkey).
- The trend for withdrawals for manufacturing is expected to be similar to that in the rest of Europe, but somewhat more pronounced as economic activity is assumed to grow more quickly (in relative terms). In the domestic sector, Turkey is expected to experience marked increases because of continuing population growth (23.5 million more people by 2030) and increased per-capita water use (current per-capita use in households is about half the EU average). Water withdrawals may also increase somewhat in the agricultural sector, due to drier and warmer climate conditions and an expected rise in the area irrigated of around 20 %. Combined with the use of more water-efficient irrigation systems, overall water withdrawal increases for irrigation are estimated to be about 10 %.
Water stress trends are expected:
- If water withdrawal for electricity production plummets as assumed, water stress, particularly in the central European river basins (Rhine, Elbe), is expected to decrease significantly over the next 20 to 30 years. Indeed most large European river basins are likely to see decreasing levels of water stress over the next 30 years. The situation is different in river basins in the Mediterranean countries, where the interplay between decreasing water availability as a result of changing climate conditions and increasing water withdrawals for irrigation and manufacturing (and, in Turkey, for domestic use) is expected to lead to higher level of water stress (prominent examples are the Spanish rivers of Guadalquivir and Guadiana, and the Kizil Irmak in Turkey).
- A possible increase in water stress in general would also pose an increased risk on food production in drought-prone regions. Expanding irrigated areas in already water-stressed regions may deteriorate the ecological and chemical status of freshwater bodies in these areas in two ways: increased water abstraction may increase water stress levels, and agricultural return-flows may have a higher pollution load which could further decrease water quality. This underlines the indirect yet close linkages between water quality/quantity issues and agricultural policies.
- Another important dimension to water stress is the changes in intra-annual variability of water availability and abstraction, which may result in changes in the frequency of droughts and floods. Recent extreme weather events have been seen as a harbinger of future conditions, but research so far has fallen short of providing proof of a causal link to climate change. Nevertheless it has been argued that increases in precipitation and changing snow-melt patterns are likely to increase flood risk in northern Europe, and that continuing high water abstraction paired with the expected reduction in rainfall may lead to more frequent hydrological droughts in southern Europe.
Low greenhouse gas emission scenario
- Under a low greenhouse gas emissions scenario, temperature increases and precipitation changes are expected to occur at a slower rate than under the baseline scenario. Thus, the general pattern of change in water availability in a low emission scenario is expected to be nearly identical to the baseline pattern, but marginally smaller (the changes by 2030 differ by roughly 10 %). Thus, the expected impacts of different climate policies on annual river run-off are relatively small in the short and mid-term, mainly because of the enormous inertia of the global climate system. However, in the longer term, initiatives and policies that effectively mitigate severe climate change should also mitigate associated changes in water availability.
Under the low greenhouse gas emissions scenario, reductions in water withdrawal would be even more pronounced (by up to 10%), as fossil fuel power is replaced by renewable energy sources that are not cooling-intensive. However, water consumed (the part of the withdrawal that is not returned to the river) is projected to increase somewhat under both the baseline and the low emissions scenario, since evaporation is about twice as high in newer tower-cooling plants than in once-through cooling systems.
Input data to WaterGAP model - climate projections - output from ECHAM4/OPYC3 model data
provided by Intergovernmental Panel on Climate Change (IPCC)
Input data to WaterGAP model - climate projections - output from HadCM3 model data
provided by Met Office Hadley Centre
Input data to WaterGAP model - population growth - output from UNSTAT data, medium scenario
provided by United Nations Statistics Division (UNSTAT)
Input data to WaterGAP model - population distribution - output from CIESIN data
Input data to WaterGAP model - electricity production - output from IMAGE 2.1 data
Input data to WaterGAP model - GDP growth - output from IMAGE 2.1 data
Input data to WaterGAP model - irrigated area - output from digital map provided by Siebert and Döll (2001)
Output data from WaterGAP - Water availability and water withdrawals, water exploitation index
Policy context and targets
The indicator can be used to monitor a wide range of policies at global, regional and national levels. It provides, for example, the information on efficiency of water-use management plans.
Global policy context
At the global level problems of fresh water use and water stress are becoming ones of the most actual. The central aims were emphasized within UN "Millennium Development Goals" (7th goal to ensure environmental sustainability) and include reduction of proportion people without access to safe drinking water.
Pan-European policy context
In 2002 the EU launched a Water Initiative (EUWI) designed to contribute to the achievements of the Millennium Development Goals (MDGs) and World Summit for Sustainable Development targets for drinking water and sanitation, within the context of an integrated approach to water resources management. The EUWI covers EU region as well as EECCA regions.
The UNECE Convention on the Protection and Use of Transboundary Watercourses and International Lakes was signed by 34 UNECE countries and the European Community. The Convention establishes main principles and rules for its Parties to develop and promote coordinated measures of sustainable use of water and related resources of transboundary rivers and international lakes, as well as of institutional mechanisms to be created for it. The UNECE Convention on the protection and Use of Transboundary Watercourses and International Lakes is an important instrument for the protection of freshwater resources and the development of transboundary water cooperation.
EU policy context
Achieving the objective of the EU's Sixth Environment Action Programme (2001-2010), to ensure that rates of extraction from water resources are sustainable over the long term, requires monitoring of the efficiency of water use in different economic sectors at the national, regional and local level. The WEI is part of the set of water indicators of several international organisations such as UNEP, OECD, EUROSTAT and the Mediterranean Blue Plan. There is an international consensus about the use of this indicator.
The indicator describes how the total water abstractions put pressure on water resources identifying those countries having high abstractions in relation to their resources and therefore prone to suffer water stress. The changes in WEI help to analyse how the changes in abstractions impact on the freshwater resources by adding pressure to them or by making them more sustainable.
There is a number of agreements relate to European river water use management, for example of the oldest one is the International Commission for the Protection of the Rhine (ICPR). (Basel on July 11, 1950).
EECCA policy context
EECCA Environmental Strategy promotes sustainable water use based on long-term projection of available water resources. It sets goals to improve quality of waters (ecological, chemical) in national level as well in regional through the developed management of municipal water supply and sanitations. Also, the EECCA environment strategy has actions on development and implementation of integrated water management programmes based on river basin principles.
Some sub-regional policies aim to stimulate development and implementation of action plans to improve water resource management systems.
A regional Cooperation strategy to promote the rational use and conservation of water resources in Central Asia focus on the sustainable use of freshwater in the Aral Sea Water Basin. The strategy helps to support achievability of targets set in the Aral Sea Basin Water Vision 2025 developed with support from UNESCO (SABAS vision). The document provides recommendations for water distribution, particularly within agriculture sector, as well as an accent on improving hydro electricity technologies with 'less losses of water' over the 2025 horizon.
Number of transboundary rivers negotiations focus on sustain river's water use and are implemented for such river basins as Neman (Nemanus) and Western Dvina (Daugava); also for Dniester between Ukraine and Moldova.
LInks to other related policies:
There is no specific targets, however, some of them could influence indirectly on the indicator's issues in particular, share of domestic water withdrawal:
- to halve by 2015 the proportion of people who are unable to reach or afford safe drinking water (MDGs)
- to launch action plans to achieve aims in accordance with MDGs
- to improve management of river basin's water use (IUCN)
There is no qualitative targets. However several document put some action oriented targets, for instance, EU Water Initiative aims to establish water resource management plans by 2005 and the UNECE Convention on the Protection and Use of Transboundary Watercourses and International Lakes aims to implement rational and sustain water use within all Europe river basins and lakes for all countries (UNECE).
There are no specific agreements as to the quantitative targets related to this indicator. The EU requires all countries to promote sustainable water use based on long-term projection of available water resources and to ensure a balance between abstraction and recharge of groundwater. Both the Water Framework Directive and the 6th Environment Action Programme set out the goal to achieve a 'good status' (ecological, chemical and quantitative) for all EU water bodies by 2015. More generally, a warning threshold of at 20 % water exploitation index is widely used to indicate a river basin is water stressed, while sever water stress is indicated by values above 40 %. While this may indicate strong competition for water resources, this may (but does not necessarily have to) trigger frequent water crises, depending on the socio-economic and environmental context within river basins.
- to sustain water use within river basins (Baltic region, Black sea's region and Central Asia)
- to improve quality of safe drinking water (EECCA Environmental Strategy, Aral Sea Vision, regional agreements for river water use);
- to implement integrated management systems for water resource use (EECCA environmental strategy)'
- to implement new technologies for irrigation and hydro power plants (Aral Sea Vision, Water and Energy strategy for Central Asia)
- to contribute more than 20 km3 water for ecological services within Aral region by 2025 (Aral Sea Vision);
Related policy documents
Sixth Environment Action Programme
DECISION No 1600/2002/EC OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 22 July 2002 laying down the Sixth Community Environment Action Programme
Water Framework Directive (WFD) 2000/60/EC
Water Framework Directive (WFD) 2000/60/EC: Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 establishing a framework for Community action in the field of water policy.
World Summit on Sustainable Development Plan of Implementation
UN 2002: 'Plan of Implementation of the World Summit on Sustainable Development'
Methodology for indicator calculation
Indicators to approximate current Water Stress and/or to give an Outlook on future Water Stress can be calculated using the WaterGAP model (Water: Global Assessment and Prognosis; version 2.1). This is a global model that computes both water availability and water use on the river basin scale.
The model, developed at the University of Kassel, Germany, has two main components: A global hydrology model and a global water use model.
WaterGAP's global hydrology model simulates the characteristic macro-scale behaviour of the terrestrial water cycle to estimate water availability. The model uses both land use and climate data at a 0.5 x 0.5 degree latitude-longitude grid. Thus it can compute water availability for both past and present temperature and precipitation regimes, as well as using output from climate models for expected future conditions
WaterGAP's global water use model consists of four main sub-models that compute water use for the domestic, manufacturing, energy, and agriculture sectors. For domestic, manufacturing and energy water use most calculations are conducted at a country level, and subsequently distributed across a 0.5 x 0.5 degree latitude-longitude grid depending on the distribution of population and power plants. For agricultural activities, most computations are conducted on a 0.5 x 0.5 degree latitude-longitude grid, based climatic condition and a world-wide map of irrigated areas.
A drainage direction map then allows the analysis of the water resources situation (including water stress) in all larger river basins. This methodology allows calculating water related indicators both on the country level and on the river basin scale, depending on what is more relevant to address specific policy questions.
A more detailed version of the model exists for EEA member states (except Iceland). Compared with the global version, the European model sees (i) improved country-level calibration for domestic water use, based on better abstration data available in this region; (ii) the use of a data on the geographical explicit location of power station and their cooling water requirements; and (iii) estimates of water use for manufacturing presented seperately for six water intensive industrial activities.
Methodology for gap filling
The water use models for domestic, industrial and electricity-related water use have been calibrated against observed past trends on the country level, where reliable data to do so is available. Where this is not the case, parameters derived from regional averages have been used. For more detail see Floerke & Alcamo (2004) and Alcamo et al. (2003).
No methodology references available.
Floerke and Alcamo (2004) presented a list of some of the main factors determining water use that are particularly uncertain in the European version of WaterGAP. In general, these also hold true for the global version.
Domestic – In most European countries the relationship between future income and water use seems to be well defined. However, in a countries undergoing a major economic transition, it is not possible to define a reliable relationship between income and water use. Another source of uncertainty in estimating future water use in the domestic sector is the future population of water users.
Manufacturing – The water use intensity of different industries is a major uncertainty in most countries. But perhaps more important is the water use of industries that are not now important but will become important over the next 30 years. Key questions are, what will these industries be and how much water will they use?
Electricity Production – Major uncertainties in this sector are the use lifetime of power stations, the percentage of new power stations having tower versus once-through cooling, and their future geographic location. Also important is the uncertainty of future thermal electricity production, and general electricity production trends.
Agriculture – Major unknowns in the agriculture sector are the future extent of irrigated crops, the types of crops to be irrigated, and future climate conditions.
Additional to the above, the uncertainty of the model's estimates on future water availability depend much on the reliability of the land use and climate data used.
Data sets uncertainty
See above 'methodological uncertainties'.
Additionally, data on current and past water use need to be considered with reservation due to the lack of common European definitions and procedures for calculating water abstraction and freshwater resources. For some countries in the European, Caucasus and Central Asia no reliable time series on water use by sector exist.
These data uncertainties affect model calibration and are propagated through to the modeled results.
Water stress indicators give an aggregate measure of the pressures that anthropogenic water use places on freshwater resources and related environmental systems. While this a good first categorization of water stress in different countries and river basins, this approach is not likely to be precise in distinguishing the different reasons of water stress due to data and model uncertainty.
It should be stressed, that this water stress indicator is calculated solely based on quantitative information and does not directly address water quality issue. Nevertheless it has been argued that high quantatitive water stress values often also imply some qualitative water stress.
While higher levels of water stress often coincide with higher frequency in droughts, no direct relationship exists. Thus this indicator should only be used with care when addressing assessing droughts (although, with some methodological modifications this can, and has been, done)
Please note that water stress indicators are most useful when presented at the river basin scale, as country values are at risk of missing water stress prone river basins due to averaging. Thus any water stress indicator should always (also) be reported at the river basin level, if possible.
More information about this indicator
See this indicator specification for more details.
Environmental scenarios (Primary topic)
Typology: Descriptive indicator (Type A - What is happening to the environment and to humans?)
- Outlook 014
Contacts and ownership
EEA Contact InfoAnita Pirc Velkavrh
EEA Management Plan2010 (note: EEA internal system)
For references, please go to www.eea.europa.eu/soer or scan the QR code.
This briefing is part of the EEA's report The European Environment - State and Outlook 2015. The EEA is an official agency of the EU, tasked with providing information on Europe’s environment.
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