Rapp-Bode dam, Saxony-Anhalt, Germany

Source: H Lange, Bruce Coleman Ltd

A wide range of human activities can adversely affect the condition of the aquatic environment. Disturbances can result from a human activity in a seemingly unrelated area often far away from the impact site, and delayed in time. The great majority of issues involving European water availability and water quality are therefore most prominent in areas with high population densities, concentrated industrial activity and/or intensive agriculture. In addition, physical changes imposed on watercourses for construction of reservoirs, channelisation of rivers and improvement of land drainage have destroyed or are threatening many wetland habitats.

The close relationship between human activities and the condition and management of freshwater resources implies that conditions, except for widespread acidification, are better in the sparsely populated and humid Nordic countries than in the rest of Europe. Table 33.1 indicates that no marked differences separate the freshwater conditions in Eastern countries from those prevailing in Southern and Western Europe. However, it should be emphasised that there are areas of concern within all of the four European regions: Nordic, Eastern, Southern and Western countries. Habitat destruction through physical changes made to watercourses, groundwater overexploitation and contamination, eutrophication, toxic pollution and acidification are but a few water-related issues that can affect water use locally or regionally.

The available freshwater in an area (or country) is the total amount moving in rivers and aquifers. It originates either from precipitation over the area itself, or from water that enters the area in rivers and regional aquifers.

Europe as a whole faces no water shortage problem but there exists a regional imbalance between supply and demand. The annual runoff in Europe is shown in Map 5.2, the total quantity for the continent being 3100 km³/year. The abstraction of water on a continental basis was 480 km³/year in the late 1980s, that is, about 15 per cent of available resources. In addition to the regional imbalance, the natural runoff variation from season to season, or from one year to the next, can set constraints on water usage.

The reliable runoff which can serve as a continuous supply source, even under drought conditions, is considerably less than average runoff, and depends on the local hydrological regime. As an illustration, the average annual 10-day minimum runoff is 1 to 3 l/s per km² for a portion of Western Europe. This is the amount of water which on average would be available during the 10 driest days of the year without artificial storage or transfers. For Europe as a whole, this corresponds to about 300 to 900 km³/year, compared with the present annual abstraction of 480 km³/year.

On top of the natural variation between seasons and years, long-term trends are possible. Multi-annual dry or wet periods can occur simultaneously over large regions in Europe. Climate change also may worsen the resource situation in many regions (see Chapter 27).

Around many large urban and industrial centres, of all Western European countries except Ireland, water abstraction has surpassed the natural recharge of groundwater and surface water resources. Overexploitation problems are, in particular, severe in coastal areas of the Southern European countries (eg, Spain, Italy, Greece), but areas of the Czech Republic, Hungary, Poland, the Russian Federation, Slovak Republic and Ukraine also face similar problems. In the case of groundwater abstraction, overexploitation leads gradually to lowered groundwater levels, which can in turn damage vegetation which is dependent upon shallow groundwater. It may further induce salt water intrusion in coastal aquifers, preventing their use for drinking water purposes. In urban areas, lowered groundwater levels can cause ground subsidence and damage to buildings.

The overexploitation of water resources, resulting from the regional imbalance between supply and demand, is clearly not sustainable. As long as it continues, overexploitation will lead to tension and hostility between water users, as well as expensive, and often futile, attempts to increase the resource base.

Quality degradation further limits the availability of water for consumptive uses. Even water use for purposes other than human consumption is often prevented or limited because of poor quality. Thus, water quality needs to be considered as a broad term describing the suitability of water to sustain various human and ecological uses of the water resource. For example, high concentrations of nitrate or toxic substances restrict the use of water for drinking, and high concentrations of organic matter ­ and consequently low oxygen concentrations ­ in rivers set constraints on the survival of valuable fish, such as salmon and trout species. Nitrate occurring in high concentrations in groundwater and surface water can be a danger to human health, and it is considered to be the most important limiting nutrient for coastal and marine eutrophication.

• fertiliser and manure surplus, leading to nitrate leaching;
• inappropriate use of pesticides;
• mining activities and deposition of hazardous wastes;
• atmospheric deposition of pollutants;
• salt water intrusion in coastal areas, caused by overexploitation of aquifers.

In many areas with intensive agriculture, in all parts of Europe, the quality of groundwater and surface water is threatened by nitrate leaching from the topsoil. Nitrate emissions from the domestic and industrial sectors are far less important than the contribution from agriculture.

Freshwater eutrophication is also a pan-European problem of major concern. The effects of eutrophication (eg, excessive growth of phytoplankton and filamentous algae, turbid water, oxygen deficiency and undesirable shifts in the biological structure of lakes) are caused by nutrient (especially phosphorus) enrichment of the waterbodies. Phosphorus emissions arise predominantly from point sources (domestic and industrial effluents), but the share of agriculture is not insignificant (see Chapter 14). If measures are not taken to reduce diffuse emissions from agriculture, this share is predicted to increase as point source contributions decrease due to improved sewage treatment and substitution of phosphorus-containing detergents.

Organic pollution of freshwaters with increased concentrations of ammonium and pathogenic microorganisms, oxygen deficiency and impoverished living conditions for biological communities, is a third major pan-European problem linked to the management of freshwater. These problems are, in particular, found in the more densely populated parts of the continent with no or insufficient treatment of sewage effluents. This is the case in the majority of Eastern and Southern European countries and in a few Western European countries as well. In other parts of Europe (Nordic, and the great majority of Western countries) use of more advanced sewage treatment technologies has led to significantly improved water quality in terms of lower organic matter and ammonium concentrations and better oxygen conditions.

Acidification of water affects its use for drinking and has profound impacts on the biological communities of rivers and lakes. The Nordic countries especially face severe acidification problems (see Chapters 5 and 31).

Discharge of saline waters from coal mines to surface waters is a severe environmental problem which particularly affects Poland, the Czech Republic and Ukraine. Such waters are highly corrosive if used for domestic or industrial purposes.

There is evidence that the scale of freshwater pollution caused by heavy metals, organic micropollutants and radionuclides is local and/or regional rather than pan-European, and the problems are predominantly related to untreated point-source emissions from a great variety of industries (see Chapter 20). In general, there have been too little monitoring data available for an overall assessment of the magnitude and extent of freshwater pollution by these substances. However, several severe cases of water pollution by heavy metals and radionuclides have been reported for the eastern countries of the Danube basin, the Russian Federation and Ukraine. For total pesticides, model calculations indicate that the quality of groundwater is threatened under most of the arable land in Europe (see Map 5.9).

Rivers and their floodplains interact in a number of ways. Undisturbed floodplains perform the following functions:

• as areas used by fauna for reproduction and as migration and travel corridors;
• provide shade, thus reducing water temperature and solar radiation reaching the surface of the river;
• reduce sediment and nutrient inputs to the river, thus improving water quality;
• increase water retention capacity during flood periods.

This natural balance between rivers and their floodplains has been disturbed by human intervention in almost all European countries.

In-river changes also take place as a result of regulation works, and these generally change the heterogeneous meandering river into a homogeneous straight channel with uniform flow and less habitat diversity than in the undisturbed situation. Upstream channelisation may also increase flood risks downstream. The most important in-river changes are:

• increased slope of the river bed;
• unstable sediment and increased transport of sediments;
• destruction of the pool-riffle sequence;
• reduced habitat and species diversity;
• reduced self-purification.

Major river regulation works have been carried out in almost all European countries for multiple purposes. The most common include those aimed at improving navigation and flood control, production of hydroelectricity, and improving drainage of adjacent farmland. Whatever the purpose of the regulation work, the natural interactions between the river and its floodplain are reduced or even destroyed. In addition the migration of fish, such as salmon, trout and sturgeon, to their spawning grounds in upstream river reaches is prevented because of barriers at locks, dams and weirs.

On the water supply side, the most serious development seems to be the possible consequences of climate change. The societal impacts of climate change will be particularly striking through its consequences on the water cycle, whether as droughts and soil moisture deficit, or as sea-level rise, floods and increased erosion.

Southern Europe (35°­50°N, 10°W­45°E) was selected by the Intergovernmental Panel on Climate Change (IPCC) as one of five areas for estimating changes up to the year 2030 resulting from pre-industrial conditions. The estimated warming from a 'business-as-usual' scenario is about 2°C in winter, and varies from 2 to 3°C in summer. There is some indication of increased precipitation in winter. However, estimated summer precipitation decreases by 5 to 15 per cent, and summer soil moisture by 15 to 25 per cent, although the IPCC states that confidence in the regional estimates is low.

These scenarios show that the water availability could be particularly threatened in Southern Europe, where the intensity of water use is already very high, and water scarcity has become a recurring problem.

Groundwater depletion occurs when annual abstractions exceed annual recharge. This is now taking place in many regions of Europe. As 65 per cent of European citizens depend on groundwater for drinking, any loss of these resources is very serious.

Whereas water supply is limited, this does not seem to apply towater demand. In Europe the demand for water has grown quickly and, although available statistics are difficult to interpret, some forecasts show continued growth (Figure 33.1).

The total per capita water abstraction varies between European countries from about 100 m³/year (Malta) to about 2000 m³/year (Estonia). The average water demand within EU countries increased by 35 per cent from 1970 to the end of the 1980s, and it is still increasing.

In order to understand the consumption trends, abstraction must be considered by sectors.

Domestic

Domestic water use is increasing in Central and Eastern European countries. In Western Europe it is rather stable or slightly growing (ie, few persons per household, many water appliances). Whereas household needs for drinking, washing and cooking could be adequately met by less than 100 l/capita per day or 35 m³/capita per year, present household consumption in Europe is roughly 150 to 300 l/capita per day. Furthermore, leakage from public distribution networks is a large problem in most countries. For example, 25 to 30 per cent losses are estimated for France, Spain and the UK, but may be 50 per cent in some cases.

Agricultural

The agricultural sector is a highly significant water user in most European countries. About a quarter of the water abstracted in Europe is used for agriculture as a whole, and irrigated agricultural land covers 18 million ha (1989) in Europe west of the former USSR. The irrigated area has increased by 70 per cent over 20 years in this part of Europe. It is particularly important (in terms of per cent of arable land) in the Balkan countries (excluding former Yugoslavia), Italy, the Iberian peninsula and The Netherlands. In the former USSR, more than 20 million ha were irrigated in the late 1980s. Agriculture counts for more than 50 per cent of all water abstraction in Albania, Bulgaria, Greece, Italy, Romania and Spain.

Some of the problems which can occur when irrigation is allowed to deplete river flows beyond sustainability are illustrated by the disastrous depletion of water in the Aral Sea, which has lost two thirds of its volume since 1965 (see Chapter 6).

Agricultural water use is generally increasing all over Europe, but is slower than the increase in irrigated areas. This probably reflects some improvements in irrigation technology. However, the efficiency of water use in irrigation can still be further improved (eg, by drip irrigation and tailwater re-use). On a global basis, irrigation comprises some three quarters of all water utilisation, of which 60 per cent is never used by the plants it is intended for. In the EU, it is estimated that roughly 50 per cent of irrigation water (35 km³/year out of 74.5) is lost through seepage or evaporation before it reaches the point of use.

It is difficult to foresee how the reform of the Common Agricultural Policy (CAP) will affect water consumption which, among other things, may lead to more bio-energy forests and increased agro-tourism in the EU (see Chapter 22). However, there is encouragement to add value to agricultural products, which can lead to growth in the food-processing industry, and an increasing demand for high quality water.

Industrial

Industry's water needs vary widely between countries. In Finland, Germany and Belgium, industry accounts for about 80 to 85 per cent of all water abstraction, whereas more agrarian countries (Greece, Portugal, Spain) abstract less than 30 per cent for industry. Industrial water use has for some time been stable or reduced in Western Europe, probably due to improved technologies. However, in some Central and Eastern European countries (eg, Bulgaria and the former USSR) industrial use of water is still increasing (UNECE, 1992).

The electricity-generating industry will probably increase its demand for cooling water, in contrast to other industrial sectors. For both process and cooling purposes, there seem to be significant opportunities for reducing water consumption through increased recycling.

Water pollution levels and trends in Europe are, in general, not encouraging. However, in a number of countries (eg, Nordic and some Western European) legislation and action programmes, aimed at reducing point source emissions of contaminants, have in recent years halted pollution and improved surface water quality. However, all across Europe, the emissions from diffuse sources continue to threaten the quality of inland waters, examples being intensive farming and atmospheric deposition. This is due to the fact that many countries have invested large sums in improved treatment of industrial and domestic wastewater without, at the same time, paying sufficient attention to a simultaneous reduction of emissions of contaminants from other sectors such as agriculture. It should also be noted that, although the water quality of many larger European rivers may gradually improve, there are a multitude of small brooks and streams which continue to suffer because of neglect.

Organic waste from sewage and industry, causing loss of oxygen and severely degraded water quality, is now largely under control in Nordic and Western European countries. However, lack of sufficient sewage treatment in many Central, Eastern and Southern European countries as well as a few Western countries (see Chapter 14) still causes serious problems. Moreover, illegal or accidental spills of slurry and silage juice are occurring across Europe, spoiling, in particular, small streams in agricultural areas.

Nutrients from wastewater and agriculture cause widespread eutrophication of European rivers and lakes. Point source control measures are slowly reducing phosphate concentrations, although seldom to levels that reverse eutrophication, which is still often caused by release of sediment-bound phosphorus and phosphorus inputs from diffuse sources. Nitrate levels are still high, particularly in small rivers and groundwater in areas of Western and Central Europe with intensive agriculture and high application rates of fertilisers and manure. In many instances, nitrate concentration limits considered safe for human consumption are exceeded in European groundwater. Larger rivers and lakes normally have nitrate concentrations well below drinking water standards.

Heavy metal pollution of waters and sediments poses human health risks, in particular through fish consumption. Decreasing trends for mercury are now evident in some countries (eg, Norway, Sweden, Finland). Until the 1970s the Rhine was heavily polluted by mercury and cadmium, but levels have been significantly reduced since then because of improved wastewater treatment and replacement of these substances in industrial processes. However, water pollution from synthetic chemicals has become a new cause for concern. Organic micropollutants, including some much-used pesticides, are now widespread in the environment, with concentrations exceeding standards in many areas of intensive agriculture. In addition, their fate and ecological impact are often unknown.

Since the 1970s, acidification of European freshwaters, damaging aquatic life and changing the natural water quality, is known to have taken place in large areas where susceptible geology combines with deposition of acidifying compounds, mainly from fossil-fuel combustion (see Chapter 31). Another serious potential threat from airborne pollution is radioactivity from nuclear accidents, as witnessed after the Chernobyl accident (see Chapter 18).

Groundwater pollution is likely to become increasingly acute and widespread in coming years, particularly because of uncontrolled waste deposits, leaking petrochemical tanks, and ongoing percolation of pollutants into aquifers.

Groundwater pollution problems are exacerbated because natural regeneration of clean groundwater is extremely slow. The velocity of groundwater flow is in the order of a few metres per month or year in many aquifers. Purification techniques are developing, but are still very costly. Some soil contamination (eg, with chlorinated hydrocarbons or heavy metals) is for practical purposes irreversible today.

Several large European rivers have catchment areas shared between many countries (eg, Danube, Rhine, Elbe, Neman, Zapadnaya Dvina), and in some cases collaboration between riparian countries has been initiated to protect water resources. As examples of the importance for national water resources, The Netherlands receives 85 per cent of its water from transboundary rivers (eg, Rhine, Maas). Hungary receives an annual equivalent of nearly 1200 mm over the country from the Danube, whereas only 65 to 70 mm of runoff is actually generated within Hungary (see Figure 5.4). There are some 110 bilateral and multilateral agreements to regulate water quality, use and economy in Europe, thus helping to reduce international dispute over water supply sharing (UNECE, 1993). Other international agreements, such as the EC directives on water quality, also contribute to safeguarding European water resources for the future.

In recognition of the basin-wide, upstream­downstream and riparian interdependencies in the development, use and protection of the waters (particularly transboundary rivers), their basins and ecosystems, increasing effort in recent years has been devoted to integrated river basin management to ensure their sustainable development.

Under the terms of the Bucharest Declaration signed in 1985, the countries of the Danube basin began a programme of international joint sampling and analysis of water quality at border crossing points on the river Danube. This initiative was followed by the formulation of the Environmental Programme for the Danube River Basin, with the overall aim of strengthening collaboration between countries on the examination and development of solutions to environmental problems in the region. It was established for a three-year period at a 1991 meeting in Sofia of riparian countries, international and non-governmental organisations, and certain G-24 countries as financing partners, with the aim of developing a strategic action plan for the basin. This was signed by ministerial declaration in 1994.

The necessity for transboundary management of the river Rhine was recognised for shipping as early as the end of the eighteenth century. The transboundary pollution aspect was given attention in 1932, when the Dutch government protested against emissions of residual salt into the French part of the river. After World War 2, the pollution of the river increased and, in 1950, the International Rhine Commission started to study wastewater and water quality problems. The international cooperation against pollution was strengthened by the agreement, signed in Berne in 1963, regarding the International Commission for the Protection of the Rhine against Pollution. This was followed by Council Decision (77/586/EEC), to conclude the Convention for the Protection of the Rhine against chemical pollution to the Berne agreement of 1963. Especially to accelerate ecological improvements in the Rhine, ministers from riparian countries decided in 1986 to establish the Rhine Action Programme, with the following aim:

The ecosystem of the Rhine must become a suitable habitat to allow the return to this great European river of the higher species which were once present here and have since disappeared (such as salmon). (ICPR,1992)

In order to improve water quality ecological conditions in the Elbe (one of the most impacted larger rivers in Europe) and its tributaries, an agreement (Vereinbarung über die Internationale Kommission zum Schutz der Elbe ­ IKSE) was signed in 1990 by riparian countries and the EC.

Extensive international collaboration is now also taking place on the North and Baltic seas and the Mediterranean to reduce riverine emissions of nutrients and dangerous substance s (see Chapter 6). Nevertheless, limited water resources, industrial pollution, mining activities, and/or dam construction plans regularly create some international tension. Two examples are disputes between Portugal and Spain on the sharing of the water of the Tajo river, and between Hungary and the Slovak Republic on the construction of the Gabcikovo dam on the Danube.

It is vitally necessary to balance Europe's water use with the long-term available resources. Resources are renewable, but limited, and scarcity is expected to increase in Southern and Eastern Europe. At the same time, pollution trends are constraining potential water use, whereas total water demand is increasing. Such trends are clearly not sustainable.

The following goals might be considered in management plans designed to improve the condition of freshwater resources:

• To provide Europe's population with sufficient water which is safe for drinking and general hygiene.
• Make available sufficient supplies of adequate quality water for other consumptive uses to meet realistic economic goals.
• Not to allow water abstraction to exceed natural recharge for long durations.
• To maintain adequate water and soil resources for biological protection, without resource depletion.
• To reduce nutrient emissions to limit eutrophication.
• To maintain or re-establish the self purification capacity of rivers.
• To improve the physical condition of European rivers to provide habitats for diverse flora and fauna.

Optional strategies and actions for reaching the above goals, and for adjusting Europe's water policies to maintain stability, include:

• Collecting of accurate information on the quantity and quality of water resources, as well as consumption patterns. Today, status assessments and prognoses are seriously hampered by lack of recent, accurate and comparable data. The need for an international and harmonised monitoring network for water resources has been recognised by several international organisations, eg, the GEMS/WATER global freshwater monitoring network established jointly in 1979 by UNEP, WHO, WMO and UNESCO (WHO/UNEP, 1989).
• On the supply side, giving priority to improving water quality, by: 1) preventing pollution at source; 2) restoring natural water resources to ecologically sound conditions; and 3) restoring the balance between the amounts of fertilisers added to soils, and the withdrawal of such substancesby crops.Actions should be guided by cost-effectiveness.
• Continuing and intensifying efforts to introduce water-saving techniques to all sectors. There is a particular need for improving irrigation technology.
• On the demand side, regarding water as an economic good. Equitable allocation of water resources as a production factor should be based on market principles, however safeguarding drinking water may require special costing.
• Identifying the value of water resources (like other natural resources) in national economic accounting. Continued depreciation of resource stock value should be considered early in national policy making.
• Basing water resources management at all decision levels on an ecosystems approach. Sustainable water management requires a holistic view of the interrelations between: 1) groundwater, surface water, and the other elements of the water cycle; 2) landuse, economic and social activity, and water resource status; and 3) water quantity and water quality.

Water management should be linked to catchments, and be carried out with the participation of a well-informed public.

• Strengthening the provision of education and information.
• Further development of structures and procedures for solving conflicts between competing water users, at national as well as European level.

Consideration and implementation of such stategies and options in local, regional, national and international water policies would certainly help to fulfil the Dublin Statement on Water and Sustainable Development (ICWE, 1992), which calls for:

fundamental new approaches to the assessment, development and management of freshwater resources, which can only be brought about through political commitment and involvement from the highest levels of government to the smallest communities. Commitment will need to be backed by substantial and immediate investments, public awareness campaigns, legislative and institutional changes, technology development, and capacity building programmes. Underlying all these must be a greater recognition of the interdependence of all people, and of their place in the natural world.