Impacts and pressures
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- The pressures reported to affect most surface water bodies are pollution from diffuse sources causing nutrient enrichment, and hydromorphological pressures causing altered habitats.
- Lakes are generally least affected by pressures and their impacts. Pollution from diffuse sources is reported for a larger proportion of water bodies than pollution from point sources for all water categories except transitional waters. The highest proportion of water bodies affected by hydromorphological pressures and altered habitats impact is found for rivers.
Which are the major pressures and impacts affecting European waters?
Proportion of total number of classified water bodies with identified significant pressures (left column) and impacts (right column), for rivers, lakes, coastal waters, and transitional waters
Note: The percentage is calculated against the total number of classified surface water bodies in Member States reporting the specific pressure or impact type (or any pressure or impact for the blue bars). The number of Member States included is indicated in brackets. See the indicator specification for more details.
No pressures/impacts: Half of the lake water bodies (48%) have no significant pressures reported followed by 42% of the coastal water bodies with no pressures identified. Only one third of the river water bodies and one fifth of the transitional water bodies have no pressures reported. A similar difference between water categories is found for significant impacts.
Pollution pressures: Pollution pressures comprise all emissions to surface waters from point and diffuse sources, including nutrients, organic matter, acidifying substances and hazardous substances from local, regional or long-range trans-boundary pollution sources.
30% to 50% of the surface water bodies are affected by pollution pressures, with diffuse sources being the most important pollutant pressure. More than 40% of the river and coastal water bodies are affected by diffuse sources; whilst 20-25% of them are subject to point source pollution. Both point (46%) and diffuse sources (34%) affect many transitional waters. A lower proportion of lake water bodies are reported to be affected by pollution, reflecting the disproportionately large number of lakes reported from Sweden and Finland.
Impacts related to pollution pressures: Nutrient enrichment causing eutrophication is the most important impact of the pollution pressures. Coastal waters have the highest proportion of water bodies suffering from nutrient enrichment (42%), while lakes are least affected, with less than 20% reported to suffer from nutrient enrichment. Organic enrichment is reported to affect 10-15% of rivers, lakes and coastal water bodies, and is more important in transitional waters, where the proportion of affected water bodies is close to 30%. The latter is consistent with the high proportion of transitional water bodies exposed to point source pollution.
Acidification from long-range transported diffuse pollution affects 10% of river water bodies and 17% of lake water bodies in the few (7-10) Member States reporting this impact. Contamination by priority substances and contaminated sediments affect less than 20% of all classified water bodies, except in Sweden where nearly all surface waters have been reported affected by mercury pollution (see the indicator specification).
Hydromorphological pressures and altered habitats impact: Hydromorphological pressures comprise all physical alterations of water bodies modifying their shores, riparian/littoral zones, water level and flow. Examples of such pressures are damming, embankment, channelization and non-natural water level fluctuations.
Hydromorphological pressures and altered habitats are reported for a large proportion of classified water bodies, particularly in rivers (more than 40%) and transitional waters (40%). In lakes aproximately one third of the classified water bodies are reported to be exposed to hydromorpological pressures and 20% are reported to have altered habitats. A large part of the water bodies reported with these pressures and impacts are heavily modified or artificial. In coastal waters, hydromorphological pressures and altered habitats are reported for a low proportion of classified water bodies (10%). The proportions of water bodies exposed to hydromorphological pressures are almost the same as those having altered habitats.
Water abstraction affects about 8% of the river water bodies and 4% of the lake water bodies. Water abstractions may significantly affect the flow regime and water level fluctuations, which are major determinants of river and lake ecosystem function and services.
To which extent are waters in different parts of Europe affected by the main pressures?
Proportion of classified water bodies in different RBDs affected by pollution pressures, for rivers and lakes (left panel) and for coastal and transitional waters (right panel)
Note: The percentage is based on total number of classified water bodies. See the indicator specification for more details.
Proportion of classified water bodies in different RBDs affected by hydromorphological pressures, for rivers and lakes (left panel) and for coastal and transitional waters (right panel)
Note: The percentage is based on total number of classified water bodies. See the indicator specification for more details.
Pollution pressures (Fig. 1 and 2)
A large proportion of the water bodies in particular in the regions with intensively agriculture and high population density are affected by pollution pressures. Regulations and measures have significantly reduced point source pollution in recent decades. Nevertheless, discharges from waste water treatment plants and industries and the overflow of wastewater from sewage systems still cause pollution. Despite some progress in reducing agricultural inputs of pollutants, the diffuse pollution from agriculture is still a significant pressure. Thus increased reduction of diffuse pollution is needed to achieve good water quality and ecological status. The RBDs and Member states with a high proportion of water bodies affected by diffuse pollution, are in particular found in north western Europe, comparable to the regions with high fertiliser input and high river nitrate concentration.
Pollution pressures in rivers and lakes (Fig 2., left)
The highest pollution pressures in river and lake water bodies are reported in River Basin Districts in the Netherlands and Belgium (Flanders), as well as in southern Italy, south-eastern England, and smaller parts of northern Germany, where more than 90% of the water bodies are exposed to pollution pressures. Other problem areas are in the rest of Germany (except the two RBDs in the southeastern and southwestern part), the Czech Republic, Southern England, Northern France, most of Ireland, southern Portugal, as well as several single RBDs in other Member States, where 70-90% of freshwater bodies are reported to be exposed to pollution pressures.
Pollution pressures in transitional and coastal waters (Fig 2., right)
For coastal and transitional waters, the worst areas where more than 90% of water bodies are reported to be exposed to pollution pressures are in the Baltic region (southern Finland, south-eastern Sweden and north-eastern Germany), in the Greater North Sea region (south-western Sweden, north-western Germany, the Netherlands and Belgium (Flanders)), southern Portugal, as well as the Romanian part of the Black Sea region. In the Bulgarian part of the Black Sea 70-90% of their coastal and transitional water bodies are reported to be exposed to pollution pressures. Also along the coast of Brittany in France, eastern Ireland both sides of northern Italy, as well as south-western Portugal, more than 70% of classified water bodies are reported to be exposed to pollution pressures.
The lowest proportion of coastal and transitional water bodies exposed to pollution pressures are reported from the north-eastern coast of Poland, as well as around the Greek islands, where more than 90% of the coastal and transitional water bodies are reported to be without significant pollution pressures.
Hydromorphological pressures (Fig. 1 and 3)
The main challenge in managing water flows and water levels is to meet the reasonable needs of the different water users, while leaving enough water in the environment to conserve river, lake and wetland habitats and species.
Numerous human structures and activities have resulted in vast hydromorphological modifications which have greatly impacted the ecological function of European surface waters. In the River Basin Management Plans, the majority of EU Member States indicate that pressures related to urban development, flood defence, power generation including hydropower, inland water navigation and straightening and land drainage for agriculture are important pressures affecting the hydro-morphological status of water bodies.
Hydromorphological pressures and altered habitats are the most commonly occurring pressure and impact in rivers, while in lakes and transitional waters these pressures and impacts are roughly as common as the pollution pressures and impacts. However, hydromorphological pressures and altered habitats are sometimes affecting only a minor part of a water body (for example, physical shore-line alterations in lakes or barriers in rivers), and may thus have less serious ecological consequences than pollution pressures, which often deteriorate the water quality of the whole water body.
Hydromorphological pressures in rivers and lakes (Fig 3., left)
The hydromorphological pressures in rivers and lakes are reported to be most severe in RBDs in the Netherlands, Germany, Poland, Hungary and south-east England, and less severe in RBDs in Finland, the Baltic countries, Romania, as well as in many RBDs in Spain, Portugal, Italy, Greece, Bulgaria and Cyprus.
Hydromorphological pressures in transitional and coastal waters (Fig 3., right)
In coastal and transitional waters the hydromorphological pressure is considerably less than in freshwater bodies, and is mainly a problem along the Greater North Sea coast of Germany, the Netherlands and Belgium, as well as the southern coast of Italy.
Indicator specification and metadata
Main pressures and impacts affecting rivers, lakes, transitional waters and coastal waters. The indicator can be used to illustrate variations between different water categories and geographical variations.
The pressures and impacts are presented as percentage of total classified water bodies affected by count.
Policy context and targets
The indicator presents the main results on pressures and impacts, as reported in the first river basin management plans reported under the WFD. The WFD came into force on 22 December 2000, and according to the directive the first river basin management plans should be published at the latest nine years after the directive entered into force. There are however serious delays in some parts of the EU, and in some Member States consultations are still on-going.
The WFD requires that Member States collect and maintain information on the type and magnitude of significant pressures and impacts on their water bodies. The common understanding of a ´significant pressure´ is any pressure that on its own, or in combination with other pressures, may lead to failure to achieve the WFD objectives of achieving good status. Pressures are emissions of pollutants (e.g. point and diffuse source emissions of nutrients, organic matter, hazardous substances, wet and dry deposition of long-range transboundary air pollution), emission of cooling water, physical changes made to water bodies changing their hydrological and/or morphological characteristics, water abstraction and biological pressures such as introduction or accidental spreading of invasive species. Impacts in the WFD sense means effects of these pressures on water bodies in terms of various kinds of environmental problems occurring in water, such as nutrient enrichment, organic enrichment, acidification, salinization, temperature increase, altered habitats, contamination with chemicals, water scarcity etc. The full list of pressures and impacts is given in WFD CIS guidance no.3.
The indicator is directly linked to the objective of the WFD. The main objective of the WFD is that all surface waters should be in good or high ecological status or potential by 2015, or 15 years after the entry into force of the directive. The indicator shows the number of water bodies where management measures are needed, which measures that would be most effective and in which regions the need for measures is highest.
Related policy documents
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.
WFD CIS Guidance Document No. 3
CIS Guidance Document No. 3: Analysis of pressures and impacts. Report from the WFD Common Implementation Strategy.
Methodology for indicator calculation
Source of data: The WISE-WFD database contains the data as reported in the River Basin Management Plans (RBMPs). The indicator is based on an extract of the WISE-WFD database as of May 2012.
Type of data: The data pressures and impacts reported to affect single water bodies. Pressures and impacts are reported for a water body only if it is affected. There are two levels of reporting pressures, i.e. single pressures and aggregated pressure types. Some Member States have reported at both levels and some have reported only at one level. In all cases a water body is considered to be affected by a pressure if it is reported with the aggregated pressure type and/or any of the corresponding disaggregated pressure types.
All Swedish surface water bodies have been reported to be affected by diffuse pollution sources and impacted by contamination by priority substances due to mercury pollution. As this mercury pressure and impact prevent the comparison with other Member States, the Swedish water bodies where the pressure and/or impact reporting is related to diffuse mercury pollution only, are redefined as unaffected.
Data coverage: The Member States are required to report pressures and impacts for all their surface water bodies, given that the water bodies are affected. Some Member States have not reported pressures and/or impacts. In some cases only certain types of pressures and impacts are reported. This means either that the other pressure and impact types are not relevant or they are not reported. The Member States not reporting pressures and impacts at all are:
- Pressures: Denmark, Luxembourg, Slovakia, Slovenia
- Impacts: Denmark, Ireland, Luxembourg, the Netherlands, Poland, Slovakia, Slovenia
The pressures and impacts are presented as percentage relative to the total number of classified water bodies. This means that no data on pressures and impacts are given for unclassified water bodies. The unclassified water bodies are found in RBDs where there is either no reporting or all water bodies are reported as unclassified: The Wallonian and Brussels regions in Belgium, parts of Spain, Sardinia and Sicily in Italy, and a few other very small RBDs (Norway and Iceland (European Economic Area countries) will not report until 2015). All together there is a substantial proportion of water bodies that are delineated, but not classified:
- Rivers: 13%
- Lakes: 23%
- Transitional waters: 30%
- Coastal waters: 21%
Calculation: The percentage of water bodies affected by the different pressures or impacts is calculated against the total number of classified water bodies. Calculation details for the different figures are given below:
The percentage is calculated against the total number of classified surface water bodies in Member States reporting the specific pressure or impact type (or any pressure or impact for the blue bars). The number of Member States included is indicated in brackets. For comparison, the total number of Member States with classified surface water bodies is 25, 23, 21 and 16 for rivers, lakes, coastal waters and transitional waters, respectively. It is impossible to differentiate between Member States not reporting a specific pressure or impact, or Member States for which the specific pressure or impact is not affecting any water bodies. In the latter case, removing these Member States leads to overestimation of the proportion of water bodies affected by the specific pressure or impact.
"Hydromorphology" denotes the combination of the aggregated pressure types "Water flow regulations and morphological alterations of surface water", "River management", "Transitional and coastal water management" and "Other morphological alterations".The impact type "Contamination" means surface water bodies with the impact contamination by priority substances and/or contaminated sediment. The impact type "Other impacts" means surface water bodies with at least one of the impacts "Saline intrusion", "Elevated temperatures" or "Other significant impacts".
Wherever the Swedish pressures or impacts reporting is related to airborne mercury pollution only, the water bodies are considered not to be affected by the given pressures or impacts, respectively. In the "No pressures" bars this occurs when the aggregated diffuse pressure type is the only pressure and the impacts description indicates diffuse pollution from mercury only. In the "No impacts" bars this occurs when contamination by priority substances is the only impact (Sweden did not report the impact type "contaminated sediments") and the impact description does not indicate contamination by other priority substances than mercury. The numbers of redefined water bodies are thus:
Pressures: Rivers: 6441, Lakes: 3507, Transitional waters: 0, Coastal waters: 68.
Impacts: Rivers: 11070, Lakes: 4903, Transitional waters: 0, Coastal waters: 93.
In the "Diffuse sources" bars, Swedish water bodies reported with the aggregated diffuse pressure type as the only diffuse pressure type and the impact description indicates diffuse mercury pollution only are redefined as not affected by diffuse pressures, that is:
Rivers: 11033, Lakes: 4895, Transitional waters: 0, Coastal waters: 89.
In the "Contamination" bars, Swedish water bodies reported with the impact contamination by priority substances, but the impact description does not indicate contamination by other priority substances than mercury are redefined as not affected by the impact "Contamination”, that is:
Rivers: 14669, Lakes: 6915, Transitional waters: 16, Coastal waters: 389.
A water body is defined as affected by pollution pressures if it is reported with the aggregated pressure type “Point sources” and/or “Diffuse sources“ and/or any of the corresponding disaggregated pressure types. For Sweden, water bodies are redefined as not affected by pollution pressures if the aggregated diffuse pressure type is the only pollution type reported and the impact description indicates diffuse mercury pollution only. The following numbers of water bodies are redefined (EU RBD codes):
|EU RBD CODE||Lakes and rivers||Transitional and coastal waters|
In the Cyprus "EU-summary report Articles 5 & 6" (submitted March 2005), in Table SWPI2-4, four out of 25 coastal water bodies (16%) were reported to be impacted by pollution (nutrients; BOD). However, these data were not reported in WISE, and thus were not taken into account.
A water body is defined as affected by hydromorphological pressures if it is reported with any of the aggregated pressure types "Water abstraction", "Water flow regulations and morphological alterations of surface water", "River management", "Transitional and coastal water management" and "Other morphological alterations" and/or any of the corresponding disaggregated pressure types.
Methodology for gap filling
No methodology for gap filling has been specified. Probably this info has been added together with indicator calculation.
No methodology references available.
No uncertainty has been specified
Data sets uncertainty
The percentage of water bodies affected by the different pressures and impacts is calculated against the total number of classified water bodies in the Member States reporting these specific pressures or impacts. In using this calculation to represent the situation in all EU Member States it is assumed that the Member States included in the calculation are representative for the whole EU. This is not necessarily the case. Generally a pressure or impact reported by many Member States (e.g. diffuse source pressure) will be more representative than one reported only for a few (e.g. acidification). Also, it should be kept in mind that the results shown only represent the classified water bodies and are thus not representative for all water bodies across the EU.
No uncertainty has been specified
WISE WFD Database
provided by Directorate-General for Environment (DG ENV)
Water (Primary topic)
Typology: Descriptive indicator (Type A - What is happening to the environment and to humans?)
- WFD 001
Contacts and ownership
EEA Contact InfoPeter Kristensen
EEA Management Plan2012 1.4.2 (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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