Impacts and pressures

Assessment versions

Published (reviewed and quality assured)

• No published assessments

Rationale

Justification for indicator selection

The pressures affecting the surface water bodies and the impacts resulting from them represent the main explanations for the failure of the surface water bodies to achieve good ecological status or potential. The main objective of the WFD is that all surface waters should be in good or high ecological status or potential by 2015. This indicator points to the main areas where measures should be made to achieve this objective. 

Scientific references

• No rationale references available

Indicator definition

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.

Units

The pressures and impacts are presented as percentage of total classified water bodies affected by count.

Policy context and targets

Context description

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.

Targets

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

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:

Fig.1
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.

Fig.2
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): 

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.

Fig.3
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.

Methodology references

No methodology references available.

Data specifications

EEA data references

• WISE WFD Database provided by Directorate-General for Environment (DG ENV)

Data sources in latest figures

Uncertainties

Methodology uncertainty

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.

Rationale uncertainty

No uncertainty has been specified