12. Water quantity
12. Water quantity
|exploitation index||how much of the available water do we consume anyway?||pressure|
|water use by sector||how do various sectors contribute to water quantity problems?||driving force||—|
|irrigated area||how does agriculture contribute to water quantity problems?||driving force|
|public water supply||how does public water supply contribute to water quantity problems?||driving force|
Water use by households and industry has decreased in many EEA member countries. However, water use for agriculture has increased, especially in southern Europe where it is a major contributor to water stress.
Water stress, which is pressure on the quantity and quality of water resources, has a profound influence on both human activities and the economy. Adequate water management to ensure reliable water supplies is essential to support all kinds of human activities and water-dependent ecosystems. Water abstraction is half the problem, the other half is related to pollution. This Chapter considers quantity issues, while quality problems due to nutrients are dealt with in Chapter 13.
Water availability problems occur when the demand for water exceeds the amount available during a certain period. They occur frequently in areas with low rainfall and high population density (mainly around cities and in popular tourist areas along the Mediterranean coast), and in areas with intensive agricultural or industrial activity (e.g. the densely populated areas of north-western Europe). Apart from causing problems providing water to users, over-exploitation of water has lead to the drying-out of natural areas in western and southern Europe, and to salt-water intrusion in aquifers around the Mediterranean coast.
Over the past decade, the amount of water abstracted for public water supply has fallen by about 10 % (Figure 12.1). The amount of irrigated farmland in southern Europe has increased by nearly 20 % during the past 15 years, leading to a significant increase in water use by agriculture. Since 1994, however, this trend appears to have levelled off slightly.
Trends in public water supply and agricultural water use
Source: EEA-ETC/IW (public water supply); Eurostat/FAO (irrigated area)
Note: Public water supply data from: Austria, Denmark, Finland, Germany, the Netherlands and the UK (England and Wales only). Irrigated area data from: France, Greece, Italy, Portugal and Spain.
The amount of water abstracted for public water supply has fallen by about 10 % since 1985.
Water use by agriculture in southern Europe has increased due to the marked increase in irrigation over the past 15 years.
12.1. Water resources in Europe
Water resources are unevenly distributed, with annual average run-off ranging from more than 3 000 mm in western Norway to 100-400 mm over much of central Europe and less than 25 mm in central and southern Spain. Some countries rely heavily on water flowing in from across their borders.
To meet their needs, the northern, central and southern regions abstract, on average, around 1 %, 25 % and 26 % respectively of their renewable freshwater resources each year. However, in central Europe, the main use of abstracted water is cooling water for energy production. Most of this water is returned virtually unchanged to the water body it was abstracted from and can be used again. In southern Europe, the main use of abstracted water is agricultural. Around 80 % of this water is consumed and is therefore not available for other uses.
The ratio between total water abstraction and total renewable water resources in a region, known as the exploitation index, provides a good indication of water quantity problems. Figure 12.2 shows that countries in the Nordic and central regions reduced their exploitation of water between 1980 and 1995 by 30 % and 10 % respectively. In southern Europe, however, exploitation has remained more or less constant. In 1995, more than 25 % of renewable water resources were exploited in Belgium, Germany, Italy and Spain. The exploitation index was between 10 % and 15 % in Denmark, France, the Netherlands and Portugal. Austria, Luxembourg and the Nordic countries do not have problems with exploitation (the index is less than 5 %).
Water exploitation in three European regions
Note: The water exploitation index is the ratio between total water abstraction and total renewable resources in a region. Central Europe: Austria, Belgium, Denmark, Germany, the Netherlands and the UK. Southern Europe: France, Italy and Spain. Nordic countries include Sweden and Finland.
The water exploitation index has decreased in Nordic and central European countries over recent years. It has remained stable in southern Europe.
The continued deterioration in the quality and quantity of water – particularly groundwater – led the European Council to call for a detailed EU action programme to be drawn up to protect and manage groundwater as part of an overall policy on water protection. The draft Groundwater Action and Water Management Programme (European Commission, 1996) required a programme of actions aimed at sustainable management and protection of freshwater resources to be implemented by 2000 at national and Community level. Many of the draft programme’s recommendations are included in the proposed Water Framework Directive (European Commission, 1997).
12.2. Water use by sectors
The major uses of abstracted freshwater in the EEA area are cooling water for power generation and irrigation in agriculture (Figure 12.3).
Water use in EEA member countries by sector, latest available
Note: Public water supply is used by households and industry. Businesses with direct water abstraction, e.g. from boreholes, are included in the industry sector.
|Cooling and agriculture account for nearly two-thirds of water use in the EEA area.|
Total abstraction varies from around 200 m3/inhabitant/year in Denmark, Luxembourg and the UK to more than 800 m3/inhabitant/year in Italy, the Netherlands and Spain (Figure 12.4). This variation is due to: high water use by industry in northern countries; the large amounts used as cooling water in Belgium, France, Germany and the Netherlands (normally taken directly from large rivers and discharged back again after use); and high water use for agriculture in southern countries.
Total water abstraction in EEA member countries by region and by
major uses, latest available year
Source: EEA- ETC/IW
12.3. Water use by agriculture
Data on trends in the amount of water used for irrigation in Europe is not available. A substitute is to consider the land area subject to irrigation (Figure 12.5). This shows an increase of about 7 % in the irrigated area in southern Europe between 1990 and 1996. Figure 6.4 shows particularly rapid growth in Greece during this period, although Italy and Spain have experienced the largest absolute growth.
Development in irrigated area in Europe by region, 1980-1996
Note: Nordic: Finland, Iceland, Norway and Sweden. Central: Austria, Belgium, Denmark, Germany, Ireland, Luxembourg, the Netherlands and the UK. South: France, Greece, Italy, Portugal and Spain.
Irrigated areas have increased during the past 15-20 years, especially in southern Europe.
Around 94 % of water use for irrigation in the EU occurs in the south. The amount of water used for irrigation in Italy and Spain is about 10 times higher than in the central EU countries combined. France, Greece and Portugal each use about the same amount of water for irrigation as central EU countries. The role of irrigation in southern Europe is completely different from central and northern countries. Irrigation is essential to improve production in the dry summers of the south. However, reform of the Common Agricultural Policy should lead to planting of crops with lower water demands. Introduction of more efficient irrigation systems should also reduce water use.
Water charges are not generally related to the true cost (including environmental impact) and are not the same for all users. This is particularly true for agricultural users, who are considered to pay very low charges that are related to neither the quantity used nor the real environmental impact. Economic instruments – in this case abstraction charges and pricing mechanisms — are widely regarded as valuable tools for achieving sustainable water management. Use of economic instruments for irrigation therefore deserves further attention. Water charges have been one reason for the decline in water use by households and industry.
12.4. Water use by households and industry
Public water supply in selected European countries has declined in the decade from 1985 (Figure 12.6). There are a number of reasons for this decline, including greater awareness of water use; water metering; increased water charges and taxes; restrictions on garden watering; fewer leaks; and widespread use of more efficient appliances such as low- or dual-flush toilets
Groundwater is the source of over 75 % of the water for public water supply in Austria, Denmark, Iceland and Portugal. In Belgium (Flanders), Finland, France, Germany, Luxembourg and the Netherlands between 50 % and 75 % of the public water supply is abstracted from groundwater (Eurostat, 1997). Groundwater is increasingly preferred for public water supply because it is generally higher quality than surface water and requires less treatment. This has led to over-abstraction and a lowering of the groundwater table in many parts of Europe. Consequences include: the drying-up of spring-fed rivers, such as in Denmark; destruction of many wetlands (with examples from 'dry' countries like Spain and 'wet' countries like the Netherlands); and salt-water inflow to aquifers along the Mediterranean coast.
Public water supply in selected European countries
Note: Based on information from Austria, Denmark, Germany, Finland, the Netherlands and the UK (England and Wales only).
Public water supply fell by 8-10 % in a number of European countries between 1987 and 1995.
|Brewery water savings cut energy bill|
The water-saving target set by Carlsberg in 1977 has resulted in a 50 % reduction in the amount of water used per litre of beer produced at its Copenhagen brewery. Washing, pasteurisation and bottling machines were modified to recycle water, while processes were systematically revised and modified to encourage water saving. These changes to machinery and processes saved a total of 200 000 m3/year of water. A similar approach was applied to the brewing area, where cleaning water is now collected in a tank, pumped through a filter and re-used. This saves 35 000 m3/year of water and 400 tonnes/year of sodium hydroxide.
Reducing water use has also allowed Carlsberg to reduce energy consumption. Effluent leaving the plant tends to be at around 30-35°C, but the temperature of the water entering the plant is 10°C. This temperature difference shows that the water has gained energy during the process. Reducing the amount of water used also reduces the amount of effluent, leading to energy savings of approximately 25 % per litre of beer produced.
Source: Carlsberg, Denmark
12.5. Indicator improvement
Many of the indicators in this Chapter are not yet available as time series. For existing indicators, improved harmonisation is needed of data and methodologies for estimating and reporting water abstractions and water use (particularly focusing on the treatment of cooling water and water use for irrigation), including sectoral breakdowns.
For the future, indicators are needed on the intensity and efficiency of water use (leakage) by countries, including sectoral breakdowns. Response indicators would be desirable on the costs of producing water fit for human consumption and the use of pricing mechanisms (charges) to assure Cost Recovery Principle which is a cornerstone of European water policy. Positive indicators on the elimination of subsidies and the internalisation of pollution costs in prices would also be desirable.
Analysis of the effectiveness of demand side vs supply side strategies for alleviating water stress should be considered, as well as of the effectiveness of the Groundwater Action Programme and the Drinking Water Directive for improving the quality of drinking waters.
|Table 12.1: Total water abstraction per inhabitant in EEA member countries|
|Unit: m3 per inhabitant per year|
|Luxembourg||183||154||Average for 1990-95 is 143.|
Note: Denmark: 1977 data given for 1980. France: 1981 data given for 1980. Germany: 1981 and 1983 data given for 1980 and 1985 data respectively and for former West Germany only. Netherlands: 1981 and 1985 data given for 1980 and 1985 respectively. Portugal: 1989 data given for 1990. UK data is for England and Wales only and excludes water abstraction for power generation.
12.7. References and further reading
EEA (1998). Europe’s Environment: The second assessment. European Environment Agency, Copenhagen.
EEA (1999a). Groundwater quality and quantity in Europe. Environmental assessment report No 3. European Environment Agency, Copenhagen.
EEA (1999b). Environment in the European Union at the turn of the century. Chapter 3.5 Water Stress. European Environment Agency, Copenhagen.
EEA (1999c). Sustainable water use in Europe - sectoral use of water. Environmental assessment report No 1. European Environment Agency, Copenhagen.
European Commission (1996). Proposal for a European Parliament and Council Decision on an action programme for integrated groundwater protection and management. COM(96)315 final. European Commission, Brussels.
European Commission (1997). Proposal for a Council Directive establishing a framework for Community action in the field of water policy. COM(97)49 final. European Commission, Brussels.
Eurostat (1997). Estimation of renewable water resources in the European Union. Luxembourg.