Surface water bodies#

Last update: 2026-06-04

Warning

Public Version - Pending Discussion

Purpose and overview#

This section revises the reporting of information related to Surface Water Bodies in the 2nd and 3rd cycle of reporting of the Water Framework Directive River Basin Management Plans. It also presents a proposal for simplifying the electronic reporting in the 4th cycle.

Current structure - 3rd cycle#

The information about Surface water bodies was reported in five separate schemas:

the SWB_2022 schema, containing information about each surface water body (Figure 62)
the SWMET_2022 schema, containing information about the methodologies (see Surface water methodologies)
the GML_SurfaceWaterBody_2022 schema and GML_SurfaceWaterBodyLine_2022 schema, containing the SurfaceWaterBody spatial dataset.
the GML_SurfaceWaterBodyCentreline_2022 schema, containing the ancillary SurfaceWaterBodyCentreline spatial dataset.

        %%{init: {'theme': 'default'}}%%

classDiagram

class SWChemicalExemptionType ["«XSDcomplexType»
SWChemicalExemptionType"]  {
  «XSElement»
  + swChemicalExemptionType: ExemptionType_Enum
  + swChemicalExemptionPressure: SignificantPressureType_Enum
}


class SWPrioritySubstance ["«XSDcomplexType»
SWPrioritySubstance"]  {
  «XSElement»
  + swPrioritySubstanceCode: PS_Enum
  + swPrioritySubstanceCausingFailure: YesNoUnknownCode_Enum
  + swPrioritySubstanceExceedanceType: EQStandardType_Enum [0..3]
  + swPrioritySubstanceExceedanceInMixingZone: YesNoCode_Enum [0..1]
}

class SWAssociatedProtectedArea ["«XSDcomplexType»
SWAssociatedProtectedArea"]  {
  «XSElement»
  + euProtectedAreaCode: FeatureUniqueEUCodeType
  + protectedAreaType: ProtectedAreaType_Enum
  + protectedAreaObjectivesSet: ProtectedAreaObjectivesEnum [0..1]
  + protectedAreaObjectivesMet: YesNoInformation_Union_Enum [0..1]
  + protectedAreaComment: String1000Type [0..1]
  + protectedAreaExemption: ExemptionType_Enum [1..*]
}

class QualityElement ["«XSDcomplexType»
QualityElement"]  {
  «XSElement»
  + qeCode: StatusQE_Enum
  + qeStatusOrPotentialValue: QEStatusCode_Enum
  + qeMonitoringResults: MonitoringResults_Enum [0..1]
  + qeMonitoringPeriod: YearRangeType [0..1]
  + qeGrouping: FeatureUniqueEUCodeType [0..*]
  + qeStatusOrPotentialChange: ValueQEX_StatusOrPotentialChange_Enum
  + qeStatusOrPotentialComparability: SoPComparability_Enum [0..1]
  + qeEcologicalExemptionType: ExemptionType_Enum [1..*]
}

class FailingRBSP ["«XSDcomplexType»
FailingRBSP"]{
  «XSElement»
  + failingRBSP: RBSP_Enum
  + failingRBSPOther: OtherType [0..1]
}

class SWEcologicalExemptionType ["«XSDcomplexType»
SWEcologicalExemptionType"]  {
  «XSElement»
  + swEcologicalExemptionType: ExemptionType_Enum
  + swEcologicalExemptionPressure: SignificantPressureType_Enum
}

class SurfaceWaterBody ["«XSDcomplexType»
SurfaceWaterBody"]  {
  «XSElement»
  + euSurfaceWaterBodyCode: FeatureUniqueEUCodeType
  + euSubUnitCode: FeatureUniqueEUCodeType
  + surfaceWaterBodyCategory: SWCategoryCode_Enum
  + naturalAWBHMWB: NaturalCode_Enum
  + hmwbWaterUse: HMWBWaterUse_Enum [0..*]
  + hmwbPhysicalAlteration: HMWBPhysicalAlteration_Enum [0..*]
  + reservoir: YesNoUnclearReservoir_Enum [0..1]
  + surfaceWaterBodyTypeCode: String100Type
  + surfaceWaterBodyIntercalibrationType: SWIntercalibrationType_Enum [1..*]
  + surfaceWaterBodyTransboundary: YesNoNotApplicable_Union_Enum
  + swSignificantPressureType: SignificantPressureType_Enum [1..*]
  + swPressureOther: String1000Type [0..1]
  + swSignificantImpactType: SignificantImpactType_Enum [1..*]
  + swSignificantImpactOther: String1000Type [0..1]
  + swEcologicalStatusOrPotentialValue: EcologicalStatusCode_Enum
  + swEcologicalAssessmentYear: YearRangeType
  + swEcologicalAssessmentConfidence: Confidence_Enum
  + swEcologicalStatusOrPotentialExpectedAchievementDate: GoodStatus_Enum
  + swChemicalStatusValue: StatusCode_Enum
  + swChemicalAssessmentYear: YearRangeType
  + swChemicalAssessmentConfidence: Confidence_Enum
  + swChemicalMonitoringResults: ChemicalMonitoringResults_Enum [0..1]
  + swChemicalStatusGrouping: FeatureUniqueEUCodeType [0..*]
  + swChemicalStatusExpectedAchievementDate: GoodStatus_Enum
  + swMixingZones: YesNoNoInformation_Union_Enum
  + swMixingZonesProportion: NumberPercentageType [0..1]
}

class SWB {
  ["«XSDcomplexType»
SWB"] 
  «XSElement»
  + countryCode: CountryCode_Enum
  + euRBDCode: FeatureUniqueEUCodeType
}

SWChemicalExemptionType --> SWPrioritySubstance : SWChemicalExemptionType
SWPrioritySubstance --> SurfaceWaterBody : SWPrioritySubstance
SWAssociatedProtectedArea --> SurfaceWaterBody : SWAssociatedProtectedArea
QualityElement --> SurfaceWaterBody : QualityElement
FailingRBSP --> SurfaceWaterBody : FailingRBSP
SWEcologicalExemptionType --> SurfaceWaterBody : SWEcologicalExemptionType
SurfaceWaterBody --> SWB : SurfaceWaterBody

Figure 62 Class diagram for the SWB_2022 schema in the 3rd cycle of reporting.#

SWB_2022 schema - 3rd cycle#

The SWB_2022 schema was already partially revised with regard to the reporting of exemptions. See:

Other simplifications already discussed also apply to the revision of the SWB schema:

Removal of the textual reporting of “other” pollutants or RBSPs
Removal of the textual reporting of “other” pressures
Removal of the textual reporting of “other” impacts
Removal of the reporting of subunits

Figure 63 shows a simplified diagram to help focus the discussion on the remaining issues.

        %%{init: {'theme': 'default'}}%%

classDiagram


class SWPrioritySubstance {
  
  + swPrioritySubstanceCode: PS_Enum
  + swPrioritySubstanceCausingFailure: YesNoUnknownCode_Enum
  + swPrioritySubstanceExceedanceType: EQStandardType_Enum [0..3]
  + swPrioritySubstanceExceedanceInMixingZone: YesNoCode_Enum [0..1]
}

class FailingRBSP {
  + failingRBSP: RBSP_Enum
  
}

class QualityElement {
  
  + qeCode: StatusQE_Enum
  + qeStatusOrPotentialValue: QEStatusCode_Enum
  + qeMonitoringResults: MonitoringResults_Enum [0..1]
  + qeMonitoringPeriod: YearRangeType [0..1]
  + qeGrouping: FeatureUniqueEUCodeType [0..*]
  + qeStatusOrPotentialChange: ValueQEX_StatusOrPotentialChange_Enum
  + qeStatusOrPotentialComparability: SoPComparability_Enum [0..1]
}

class SurfaceWaterBody   {
  
  + euSurfaceWaterBodyCode: FeatureUniqueEUCodeType
  + surfaceWaterBodyCategory: SWCategoryCode_Enum
  + naturalAWBHMWB: NaturalCode_Enum
  + hmwbWaterUse: HMWBWaterUse_Enum [0..*]
  + hmwbPhysicalAlteration: HMWBPhysicalAlteration_Enum [0..*]
  + reservoir: YesNoUnclearReservoir_Enum [0..1]
  + surfaceWaterBodyTypeCode: String100Type
  + surfaceWaterBodyIntercalibrationType: SWIntercalibrationType_Enum [1..*]
  + surfaceWaterBodyTransboundary: YesNoNotApplicable_Union_Enum
  + swSignificantPressureType: SignificantPressureType_Enum [1..*]
  + swSignificantImpactType: SignificantImpactType_Enum [1..*]
  + swEcologicalStatusOrPotentialValue: EcologicalStatusCode_Enum
  + swEcologicalAssessmentYear: YearRangeType
  + swEcologicalAssessmentConfidence: Confidence_Enum
  + swChemicalStatusValue: StatusCode_Enum
  + swChemicalAssessmentYear: YearRangeType
  + swChemicalAssessmentConfidence: Confidence_Enum
  + swChemicalMonitoringResults: ChemicalMonitoringResults_Enum [0..1]
  + swChemicalStatusGrouping: FeatureUniqueEUCodeType [0..*]
  + swMixingZones: YesNoNoInformation_Union_Enum
  + swMixingZonesProportion: NumberPercentageType [0..1]
}

SWPrioritySubstance --> SurfaceWaterBody : SWPrioritySubstance
FailingRBSP --> SurfaceWaterBody : FailingRBSP
QualityElement --> SurfaceWaterBody : QualityElement

Figure 63 PARTIAL class diagram for the SWB_2022 schema in the 3rd cycle of reporting.#

Surface water - descriptive data - 4th cycle#

The proposed structure for the 4th cycle electronic reporting is presented in the class diagram in (Figure 64) and a brief description of each table is included in Table 56.

        ---
config:
  class:
    hideEmptyMembersBox: true
  layout: dagre
  theme: neutral
---
classDiagram
direction TB

class SurfaceWaterBody {
    + euSurfaceWaterBodyCode: wiseIdentifier
    + surfaceWaterBodyCategory: WaterBodyCategory
    + naturalAWBHMWB: NaturalAWBHMWB
    + swIntercalibrationType: IntercalibrationType [1..n]
    + swTypeIdentifier: wiseIdentifier
    + surfaceWaterBodyTransboundary: YesNo
    + reservoir: ReservoirType
    + swMixingZonesProportion: PercentageInterval
}

class SWStatus {
    + euSurfaceWaterBodyCode: wiseIdentifier
    + swEcologicalStatusOrPotentialValue: EcologicalStatus
    + swChemicalStatusValue: ChemicalStatus
}

class SWPollutant {
    + euSurfaceWaterBodyCode: wiseIdentifier
    + swPollutantCode: Parameter
    + swPollutantCausingFailure: YesNoUnknown
    + swThresholdExceedance: wiseIdentifier [0..n]
    + swPollutantExceedanceInMixingZone: YesNoUnknownNotApplicable
    
    + swPollutantAssessmentPeriod: range
    + swPollutantAssessmentMethod: AssessmentMethod [1..n]
    + swPollutantAssessmentConfidence: AssessmentConfidence

    + swThresholdIdentifier: wiseIdentifier [1..n]
    + swGroupingIdentifier: wiseIdentifier [0..n]
}

class SWPressureImpact {
    + euSurfaceWaterBodyCode: wiseIdentifier
    + swPressureType: PressureType [0..1]
    + swImpactType: ImpactType  [0..1]
}

class SWHeavilyModifiedWaterBody {
    + euSurfaceWaterBodyCode: wiseIdentifier
    + hmwbPhysicalAlteration: HMWBPhysicalAlteration [0..n]
    + hmwbWaterUse: HMWBWaterUse [0..n]
}

class SWQualityElement{
    + euSurfaceWaterBodyCode: wiseIdentifier
    + qeCode: QualityElement
    + qeStatusOrPotentialValue: EcologicalStatus
    + qeStatusAssessmentPeriod: range
    + qeStatusAssessmentMethod: AssessmentMethod [1..n]
    + qeStatusAssessmentConfidence: AssessmentConfidence
    + qeClassificationIdentifier: wiseIdentifier [1..n]
    + swGroupingIdentifier: wiseIdentifier [0..n]
}
class SWGrouping{
    + swGroupingIdentifier: wiseIdentifier
    + euSurfaceWaterBodyCode: wiseIdentifier
}

SWHeavilyModifiedWaterBody "0..n" -- "1" SurfaceWaterBody 
SurfaceWaterBody "1" -- "1" SWStatus
SWStatus "1" -- "0..n" SWQualityElement
SWStatus "1" -- "0..n" SWPressureImpact
SWStatus "1" -- "0..n" SWPollutant

SWQualityElement ..> SWGrouping: swGroupingIdentifier
SWPollutant ..> SWGrouping: swGroupingIdentifier

classDef default fill:white,stroke:#000;
classDef forFixing fill:white,stroke:#f00;
classDef otherDataset fill:lightyellow,stroke:#000;

Figure 64 Surface water - 4th cycle#

Table 56 Surface water - 4th cycle - brief table description#
Table	Description
SurfaceWaterBody	modified The `SurfaceWaterBody` table contains the attributes that describe the surface water body and that do not vary with the status of the water body. Therefore the table can be prepared immediately, even if the 4th cycle RBMPs have not yet been finalised. All the attributes existed in the 3rd cycle reporting.
SWHeavilyModifiedWaterBody	modified
SWStatus	new The `SWStatus` table synthesizes information about the status of the water body. Formally, the `chemicalStatusValue` could be derived from the information in the `SWPollutant` table. If, and only if, `chemicalStatusValue = 'unknown'` and no assessment of the chemical status was done, may all corresponding rows in the `SWPollutant` table be missing. (An ERROR will raised by the quality control, since this is a non-compliance and should not be reported by mistake.) Likewise, the `swEcologicalStatusOrPotentialValue` could be derived from the `SWQualityElement` table. If, and only if, `swEcologicalStatusOrPotentialValue = 'unknown'` and no assessment of the ecological status was done, may the corresponding rows in the `SWQualityElement` table be missing. (An ERROR will raised by the quality control, since this is a non-compliance and should not be reported by mistake.)
SWPollutant	modified The `SWPollutant` table contains data related to the chemical status at substance level. The information about the assessment method, assessment confidence, and assessment period can be reported at pollutant level, allowing more flexibility in reporting different situations for different pollutants or indicators of pollution. (If the same method, confidence and period apply to all substances assessed for a surface water body, then identical values can be reported for all substances).
SWQualityElement	new The `SWQualityElement` table gathers the data related to ecological status or potential. The assessment method, confidence and period is reported using the same pattern applied for surface water pollutants.
SWGrouping	new If grouping was not used, this table is not necessary. If grouping was used for the assessment of ecological or chemical status, the `SWGrouping` table is used to define sets of water bodies that were monitored and assessed as an ensemble. The same ensemble can be used for different purposes. The same water body can be a member of different ensembles. The `groupingIdentifier` value uniquely identifies an ensemble using the WISE identifier syntax. The `euSurfaceWaterBodyCode` identifies a member of the ensemble. If an ensemble is used in the assessment of a given element, then at least one of its water bodies must be monitored for that element (e.g. must have `swPollutantAssessmentMethod = 'monitoring'`). (To avoid mistakes and ambiguities, the `groupingIdentifier` value must be different from any known water body identifier. It is recommended to use a clear pattern to avoid conflicts with existing and future water body identifiers. For example, using a ‘_SWGROUPING’ suffix).
SWPressureImpact	modified. For the water bodies that do not achieve good ecological status or potential in 2027, the significant pressures causing poor ecological status or potential are reported in the `SWEcologicalExemption` table (see Figure 38) and do not need to be reported again in the `SWPressureImpact` table. For water bodies that do not achieve good chemical status in 2027, the significant pressures are reported in the `SWChemicalExemption` table (see Figure 40) and do not need to be reported again in the `SWPressureImpact` table. For cases where a pressure is not causing failure, but still causes an impact that needs to be managed, the `SWPressureImpact` table should be used. Note that the reporting of pressures and impacts is combined into a single `SWPressureImpact` table. In the 3rd cycle, the XML structure did not allow a specific pressure to be link to a given impact. In the proposed structure, this is possible (but not mandatory). Illustrative examples will be provided.

Surface water - codelists - 4th cycle#

For the Reservoir codelist, see Figure 65.
All reservoirs must be reported as artificial or heavily modified lakes.
- See the definitions in Table 57.
For the HMWBWaterUse codelist, see Figure 65.
For heavily modified water bodies only, use this codelist to report the water use for which the water body has been designated. According to Art. 4(3) of the WFD, the water use for which a HMWB was designated is the water use that would be affected significantly by the changes that would be necessary to achieve good ecological status.
- See the definitions in Table 58.
- See the mapping table to the 3rd cycle values in Table 59.
For the HMWBPhysicalAlteration codelist, see Figure 65.
For heavily modified water bodies only, use this codelist to report the physical alteration that has resulted in the designation of the surface water body as a HMWB.
In the context of designation as a HMWB, physical alterations means any significant alterations that have resulted in substantial changes to the hydromorphology of a surface water body such that the surface water body is substantially changed in character. In general, these hydromorphological characteristics are long term and alter both the morphological and hydrological characteristics.
- See the definitions in Table 60.
- See the mapping table to the 3rd cycle values in Table 61.
For the AssessmentMethod codelist, see Figure 51.
The codelist is used to report the assessment method for the chemical status and the assessment method for the ecological status.
The same codelist is used for groundwater bodies, to report the assessment method of quantitative status, and the assessment method of chemical status.
- See the definitions in Table 47.
For the AssessmentConfidence codelist, see also Figure 51.
The codelist allow the reporting of the level of confidence in the results of the status assessment The same codelist is used for groundwater bodies.
- See the definitions in Table 48.
For the PressureType codelist, see Figure 86 in the section PressureType codelist - 4th cycle

        ---
config:
  class:
    hideEmptyMembersBox: true
  layout: dagre
  theme: neutral
---
classDiagram
direction TB

class HMWBWaterUse{
<<enumeration>>
  widerEnvironment_natureProtection
  widerEnvironment_culturalHeritageProtection
  transport
  tourism
  urban_drinkingWaterSupply
  agriculture_irrigation
  aquaculture
  industry_waterSupply
  energy_hydropower
  energy_nonHydropower
  floodProtection
  agriculture_landDrainage
  urban_other
  otherSustainableHumanDevelopmentActivities
  unknown
}

class HMWBPhysicalAlteration{
<<enumeration>>
  locks
  transversalBarrier
  longitudinalBarrier
  dredging 
  landReclamation
  landDrainage
  other
}

class Reservoir{
<<enumeration>>
  river
  riverAndLake	
  lake	
  artificial	
  notAReservoir
  inapplicable
}

classDef default fill:white,stroke:#000;
classDef forFixing fill:white,stroke:#f00;

Figure 65 Reservoir codelist, HMWBWaterUse codelist, and HMWBPhysicalAlteration codelist - 4th cycle#

Table 57 Codelist - 4th cycle - Reservoir#
Notation	Label	Definition
river	Reservoir in former river	Select this option only if the whole surface water body represents a reservoir (or part of a reservoir) created by damming a river.
riverAndLake	Reservoir in former chain of rivers and lakes	In cases where the reservoir has been created by damming a water body which contained chained rivers and lakes.
lake	Reservoir in former lake	If the whole surface water body represents a reservoir (or part of a reservoir) created by modifying a pre-existing lake, or if the surface water body includes some small reservoirs which are not significant enough to be identified as separate surface water bodies.
artificial	Artificial reservoir	In cases where the reservoir has been created by human activity in a location where no water body existed before, and which has not been created by the direct physical alteration, movement or realignment of an existing water body.
notAReservoir	Not a reservoir	The artificial or heavily modified lake is not a reservoir.
inapplicable	Inapplicable	The water body is not a lake, or is a natural lake.

Table 58 Codelist - 4th cycle - HMWBWaterUse#
Notation	Label	Definition
widerEnvironment_natureProtection	Nature protection	See Article 4(3)(a)(i) of the WFD.
widerEnvironment_culturalHeritageProtection	Cultural heritage protection	Archaeological sites and patrimony. See Article 4(3)(a)(i) of the WFD.
transport_navigation	Transport - Navigation and Ports	See Article 4(3)(a)(ii) of the WFD.
tourism	Tourism and recreation	See Article 4(3)(a)(ii) of the WFD.
urban_drinkingWaterSupply	Urban development - drinking water supply	Water storage for domestic public water supply (mostly drinking water supply). See Article 4(3)(a)(iii) of the WFD.
agriculture_irrigation	Agriculture - irrigation	Water storage for irrigation. See Article 4(3)(a)(iii) of the WFD.
aquaculture	Aquaculture, fisheries, fish farms	Water storage for aquaculture, fisheries, fish farms. See Article 4(3)(a)(iii) of the WFD.
industry_waterSupply	Industry - water supply	Water storage for industry. See Article 4(3)(a)(iii) of the WFD.
energy_hydropower	Energy – hydropower	Water storage for hydropower generation. See Article 4(3)(a)(iii) of the WFD.
energy_nonHydropower	Energy – non-hydropower	Water storage for power generation. See Article 4(3)(a)(iii) of the WFD. Applicable to cooling activities for thermal and nuclear plants.
floodProtection	Flood protection	See Article 4(3)(a)(iv) of the WFD.
agriculture_landDrainage	Agriculture - land drainage	See Article 4(3)(a)(iv) of the WFD.
urban_other	Urban development - other use	«to be provided»
otherSustainableHumanDevelopmentActivities	Other sustainable human development activities	See Article 4(3)(a)(v) of the WFD.
unknown	Unknown	Unknown use. The selection of this option will trigger an ERROR.

Click to see the mapping table between 3rd cycle and 4th cycle codes

Table 59 Mapping table - 4th cycle - HMWBWaterUse#
3rd cycle	4th cycle
“Wider environment - nature protection and other ecological uses”	widerEnvironment_natureProtection
“Wider environment - nature protection and other ecological uses”	widerEnvironment_culturalHeritageProtection
“Transport - navigation / ports”	transport
“Tourism and recreation”	tourism
“Urban development - drinking water supply”	urban_drinkingWaterSupply
“Agriculture - irrigation”	agriculture_irrigation
“Storage for fisheries/aquaculture/fish farms”	aquaculture
“Industry supply”	industry_waterSupply
“Energy - hydropower”	energy_hydropower
“Energy - non-hydropower”	energy_nonHydropower
“Flood protection”	floodProtection
“Agriculture - land drainage”	agriculture_landDrainage
“Urban development - other use”	urban_other
“Other”	otherSustainableHumanDevelopmentActivities
“Unknown”	unknown

Table 60 Codelist - 4th cycle - HMWBPhysicalAlteration#
Notation	Label	Definition [1]
locks	locks	Locks: devices for raising and lowering boats between stretches of water of different levels on river and canal waterways.
transversalBarrier	Transversal barrier	Includes: Weirs / dam / reservoir: transversal barriers constructed across a river or a lake discharge for the purpose of creating a water impoundment.
longitudinalBarrier	Longitudinal barrier	Includes: Channelisation / straightening / bed stabilisation: any permanent modification which longitudinally affects river banks and/or river bed, including changing direction, reducing meandering, stabilisation of river banks, etc.
dredging	Dredging	Includes: Dredging / channel maintenance: modifications due to regular maintenance of rivers through dredging for any given purpose, usually navigation or flood protection.
landReclamation	Land reclamation	Includes: Land reclamation / coastal modifications / ports: modifications of a water body as a result of the creation of new land from ocean, riverbeds, or lakes (e.g. for the purpose of expanding or creating a port).
landDrainage	Land drainage	Modification of a water body as a result of an artificial change to the water level intended to make available existing land for a particular purpose (often for agricultural production or for urbanisation).
other	Other	Other alteration not included in any of the categories above.

Click to see the mapping table between 3rd cycle and 4th cycle codes

Table 61 Mapping table - 4th cycle - HMWBPhysicalAlteration#
3rd cycle	4th cycle
“Locks”	locks
“Weirs / dam / reservoir”	transversalBarrier
“Channelisation / straightening / bed stabilisation / bank reinforcement”	longitudinalBarrier
“Dredging / channel maintenance”	dredging
“Land reclamation / coastal modifications / ports”	landReclamation
“Land drainage”	landDrainage
“Other”	other

Ecological status and potential#

The diagram below, adapted from Figure 1 in the CIS Guidance Document 13, illustrates the assessment criteria for ecological status (Figure 66).

        ---
config:
  layout: dagre
---

flowchart LR

title@{ shape: braces, label: "CIS Guidance document 13, Figure 1" }

    %% Defining the nodes

    initial([start])
    final([end])
    
    High["High status"]:::Blue
    Good["Good status"]:::Green
    Moderate["Moderate status"]:::Yellow
    Poor["Poor status"]:::Orange
    Bad["Bad status"]:::Red    
 
    is_BQE_High{"Do the <br/>estimated values <br/>for the biological quality elements <br/>meet reference conditions?"}
    is_BQE_Good{"Do the <br/>estimated values <br/>for the biological quality elements <br/>deviate only slightly <br/>from reference condition values?"}

    is_PhysChemQE_High{"Do the <br/>physico-chemical conditions <br/>meet high status?"}
    is_PhysChemQE_Good{"Do the <br/>physico-chemical conditions <br/>ensure ecosystem functioning?"}
    
    is_HyMoQE_High{"Do the <br/>hydro-morphological conditions<br/> meet high status?"}

    ClassifyUsingBQEOnly["Classify <br/>on the basis of the <br/>biological deviation <br/>from reference conditions"]
    is_BQE_Moderate{"Is the <br/>deviation moderate?"}
    is_BQE_Poor{"Is the <br/>deviation large?"}

    %% Flow 

    initial --> is_BQE_High
    
    is_BQE_High ====> |Yes|is_PhysChemQE_High
    is_PhysChemQE_High ==>|Yes|is_HyMoQE_High
    is_HyMoQE_High ==>|Yes| High
    High --> final

    is_HyMoQE_High ==> |No|Good
    is_PhysChemQE_High ==>|No|is_PhysChemQE_Good

    is_BQE_High ==>|No|is_BQE_Good
    is_BQE_Good ==>|Yes|is_PhysChemQE_Good
    is_BQE_Good ==>|No|ClassifyUsingBQEOnly
    is_PhysChemQE_Good ==>|Yes|Good
    Good --> final
    
    is_PhysChemQE_Good ==>|No|ClassifyUsingBQEOnly
    ClassifyUsingBQEOnly ==> is_BQE_Moderate
    is_BQE_Moderate ==>|Yes|Moderate
    Moderate --> final
    
    is_BQE_Moderate ==>|No|is_BQE_Poor
    is_BQE_Poor ==>|Yes|Poor
    Poor --> final
    
    is_BQE_Poor ==>|Extreme deviation|Bad
    Bad --> final

    %% styling
    classDef state stroke-width:4px,fill:transparent
    classDef Blue fill:#5893A9,stroke:black;
    classDef Green fill:#6FB22C,stroke:black;
    classDef Yellow fill:#FFF6A6,stroke:black;
    classDef Orange fill:#F6A800,black;
    classDef Red fill:#E63D5C,black;

Figure 66 Surface Water Body - Ecological status assessment#

The diagram below, adapted from Figure 2 in the CIS Guidance document 13, illustrates the assessment criteria for ecological potential (Figure 67).

        ---
config:
  layout: dagre
---

flowchart LR

title@{ shape: braces, label: "CIS Guidance document 13, Figure 2" }

    %% Defining the nodes

    initial([start])
    final([end])
    
    Good["Good and above potential"]:::Green
    Moderate["Moderate potential"]:::Yellow
    Poor["Poor potential"]:::Orange
    Bad["Bad potential"]:::Red    

    is_HyMoQE_Good{"Do the <br/>hydro-morphological conditions <br/>meet maximum ecological potential?"}
    is_BQE_High{"Do the <br/>estimated values <br/>for the biological quality elements <br/>meet maximum ecological potential conditions?"}
    is_BQE_Good{"Do the <br/>estimated values <br/>for the biological quality elements <br/>deviate only slightly from maximum ecological potential values?"}

    is_PhysChemQE_High{"Do the <br/>physico-chemical conditions <br/>meet maximum ecological potential?"}
    is_PhysChemQE_Good{"Do the <br/>physico-chemical conditions <br/>ensure ecosystem functioning?"}
    
    ClassifyUsingBQEOnly["Classify <br/>on the basis of the <br/>biological deviation <br/>from maximum ecological potential conditions"]
    is_BQE_Moderate{"Is the <br/>deviation moderate?"}
    is_BQE_Poor{"Is the <br/>deviation large?"}

    %% Flow 

    initial --> is_HyMoQE_Good
    
    is_HyMoQE_Good ==> |Yes|is_BQE_High
    is_BQE_High ====> |Yes|is_PhysChemQE_High
    is_PhysChemQE_High ==>|Yes|Good

    is_PhysChemQE_High ==>|No|is_PhysChemQE_Good
    is_PhysChemQE_Good ==>|Yes|Good

    is_HyMoQE_Good ==> |No|is_BQE_Good
    is_BQE_High ==>|No|is_BQE_Good
    is_BQE_Good ==>|Yes|is_PhysChemQE_Good
    
    Good --> final
    
    is_PhysChemQE_Good ==>|No|Moderate
    
    is_BQE_Good ==>|No|ClassifyUsingBQEOnly
    ClassifyUsingBQEOnly ==> is_BQE_Moderate
    is_BQE_Moderate ==>|Yes|Moderate
    Moderate --> final
    
    is_BQE_Moderate ==>|No|is_BQE_Poor
    is_BQE_Poor ==>|Yes|Poor
    Poor --> final
    
    is_BQE_Poor ==>|Extreme deviation|Bad
    Bad --> final

    %% styling
    classDef state stroke-width:4px,fill:transparent
    classDef Blue fill:#5893A9,stroke:black;
    classDef Green fill:#6FB22C,stroke:black;
    classDef Yellow fill:#FFF6A6,stroke:black;
    classDef Orange fill:#F6A800,black;
    classDef Red fill:#E63D5C,black;

Figure 67 Surface Water Body - Ecological potential assessment#

Annexes - Data analysis - 3rd cycle#

Changes to the quality check during the 3rd cycle reporting phase

Several data quality issues where detected while the 3rd cycle was ongoing (i.e. after the testing phase).

That required the implementation of additional quality checks, or the correction of existing quality checks.

For example, the reporting guidance was not always clear in the distinction between conditions in the form “if A then B” versus conditions in the form if and only if A then B.

On a case-by-case decision, resubmissions may have been requested or not. Therefore the database may contain inconsistencies (e.g. in early submissions) that were only detected and blocked in later submissions.

Quality element status (3rd, 2nd and 1st RBMP), by category#

The following dashboard shows the number of quality elements used in the assessment of the ecological status or potential:

Click to open an interactive dashboard — Figure 68 Surface water bodies: Quality element status (3rd, 2nd and 1st RBMP), by category#

Number of quality elements used#

The following dashboard shows the number of quality elements used in the assessment of the ecological status or potential:

Status calculated from the quality elements#

The following dashboard shows the reported ecological status vs. calculated ecological status (based on the quality elements):

Quality element status#

In the 3rd cycle reporting, the quality element status value was reported using the following values:

‘1’ meaning ‘high’ status or potential
‘2’ meaning ‘good’ status or potential
‘Unknown’ meaning ‘unknown’ status or potential
“Not applicable” meaning the quality element is not applicable in the surface water category or water body national type to which the water body in question belongs.

For biological quality elements only, the following values were also used:

‘3’ meaning ‘moderate’ status or potential
‘4’ meaning ‘poor’ status or potential
‘5’ meaning ‘bad’ status or potential

For hydro-morphological and physico-chemical quality elements only, the following values were also used:

‘3’ meaning ‘less than good’ status or potential
“Monitored but not used” meaning than the QE was monitored but no standard has been developed and/or the QE is not used for status assessment

Show technical detail: encoding quality element status

To harmonise the data in different codelists and reporting cycles, the reported values were recoded in the published [WISE_WFD].
Table 62 shows the original codes (id) and the published codes (mappingId).

Table 62 Encoding quality element status in the [WISE_WFD] database.#
tableName	id	label	mappingTable	mappingId
QEStatusCode	-1	Not a value(NULL).	NilReasonType	unpopulated
QEStatusCode	1	1	WFDStatus	1
QEStatusCode	2	2	WFDStatus	2
QEStatusCode	3	3	WFDStatus	3
QEStatusCode	4	4	WFDStatus	4
QEStatusCode	5	5	WFDStatus	5
QEStatusCode	6	MonitoredButNotUsed	NilReasonType	none
QEStatusCode	7	Unknown	NilReasonType	unknown
QEStatusCode	8	NotApplicable	NilReasonType	inapplicable

“Monitored but not used”#

The option “Monitored but not used” was inherently ambiguous, because it could be applied to signify that the quality element was being monitored although it was in fact not applicable to a specific water category or water body national type.

Todo

The option “Monitored but not used” should be removed, because it does not convey concrete information about the status.
Member States can report monitoring results under the WISE-6 Water Quality dataflow: that provides concrete information about what is being monitored beyond the requirements of the ecological status assessment.

“Not applicable”#

The 3rd cycle reporting guidance provided a clear definition of the option “Not applicable”.

If the QE is not applicable in the surface water category or type to which the water body in question belongs, then select ‘Not applicable’ from the enumeration list.

Theoretically, it should be possible to derive the applicability of the quality elements to a given type or category.

For 77% of the 3384 reported national types, the applicability of the quality elements can indeed be derived.
Unfortunately, for the remaining 772 national types (23% of the total) the information is inconsistent, and a given quality element is simultaneously reported as applicable (because it has a reported status) and not applicable to the assessment of ecological status.

It is possible that the inconsistencies are due to an interchangeable use or interpretation of the options ‘unknown’ and ‘inapplicable’, or are due to a mistake in the reporting of some water bodies only.

Nevertheless, the inconsistencies reveal a flaw in the reporting model, and an opportunity for both improvement and simplification. the applicability of the quality elements should be reported in the surface water methodologies and only the applicable quality elements should be reported in the quality elements table.

Proposed changes#

The removal of the options “Not applicable” and “Monitored but not used” reduces the reported data by 25% and provides a clearer and consistent overview of the assessment criteria.

Table 63 Number of records per QE status#
qeStatusOrPotentialValue	number of records	% of records
1,2,3,4,5	636,742	25%
Unknown	1,208,667	48%
“Not applicable”	541,637	21%
“Monitored but not used”	136,743	5%

Todo

The applicability of the quality elements should be reported in the surface water methodologies and only the applicable quality elements should be reported in the quality elements table.

Ecological status and BQE status#

If a biological quality element fails to achieve ‘good’ or ‘high’ status, then the ecological status or potential cannot be ‘good’ or ‘high’.

The majority of reported data complies with this rule.

A total of 216 water bodies does not comply with this rule. The question is, can the reported ecological status or potential be ‘unknown’?

From a logical (mathematical) perspective, the ecological status can be ‘indeterminate’, if not all the relevant biological quality elements were assessed, and therefore it could be ‘moderate’, ‘poor’ or ‘bad’. But the ecological status is known to fail to achieve good status.

Furthermore, the analysis of the 216 water bodies shows that:

in 71 cases, the ecological status should have been reported as ‘bad’
in 69 cases, the ecological status could never be ‘moderate’.

Table 64 Unknown ecological status of water bodies with failing BQEs.#
worstBQE	numberOfWB	numberOfCountries
3	76	5
4	69	3
5	71	3
	216	5

The low frequency of these cases suggests a reporting error, that must be captured in the quality control during the 4th cycle.

Proposed change#

If at least one biological quality element has ‘moderate’, ‘poor’ or ‘bad’ status or potential, then the ecological status cannot be ‘unknown’.

Todo

If at least one biological quality element has ‘moderate’, ‘poor’ or ‘bad’ status or potential, then the ecological status cannot be ‘unknown’.

Clearer guidance must be provided to MS with regard to these cases.
The quality control must enforce the adopted guidance.

One-out-all-out: ecological status#

Todo

Include the CIS Guidance flowcharts for the ecological status assessment.

According to the WFD Annex V and as clarified in the CIS Guidance document 13, the ecological status is assessed using biological quality elements (QE1 a.k.a. BQE).

The physico-chemical quality elements (QE3) act as modifiers of the BQE assessment:

all applicable QE3 statuses must be ‘high’, for the ecological status to be ‘high’,
if any applicable QE3 status is ‘less than good’, then the ecological status cannot be ‘good’.

Likewise, the hydromorphological quality elements (QE2) act as modifiers of the BQE assessment:

all applicable QE2 statuses must be ‘high’, for the ecological status to be ‘high’,
if any applicable QE3 status is ‘less than good’, then the ecological status cannot be ‘good’.

In the 3rd cycle reporting, the quality control checks enforced the interpretation above. Pending: confirm whether if changes are required.

The hydromorphological quality elements

According to the 3rd cycle reporting guidance:

Rule 1: “If SWB/SurfaceWaterBody/swEcologicalStatusOrPotentialValue = 1 Then it cannot be lower than the highest of the values reported under SWB/SurfaceWaterBody/QualityElement/qeStatusOrPotentialValue”
Rule 2: “If SWB/SurfaceWaterBody/swEcologicalStatusOrPotentialValue in (2,3,4,5) Then it cannot be lower than the highest of the values reported under SWB/SurfaceWaterBody/QualityElement/qeStatusOrPotentialValue for the set of quality elements where qeCode starts with QE1 or qeCode starts with QE3.”
Rule 3: “If SWB/SurfaceWaterBody/swEcologicalStatusOrPotentialValue = 1 Then at least one hydromorphological quality element (QE2%) must be assessed.”
Rule 4: “If the surface water body has a known status (1,2,3,4 or 5) the status of all Quality Elements cannot be ‘Unknown’, ‘Not Applicable’ or ‘Monitored but not used’.”

Preliminary comments:

Rule 3 requires that a QE2 be assessed, but does not explicitly mention the QE2 status, which should also be taken into account.
Rule 4 requires that at least one QE be assessed, but it should also require that at least at least one QE1 be assessed.
According to the CIS Guidance documents, the QE2 status should also be assessed if the ecological status is ‘1’ and the worst QE3 status is also ‘1’.
According to the CIS Guidance documents, the QE2 status should also be assessed for the artificial and highly modified water bodies.

Checking the rule 2 (the ecological status cannot be worse than the worst QE1 or QE3):

As expected: 114204 surface water bodies with ecological status equal to the status of the worst known QE1 or QE3
NOT as expected: 309 surface water bodies with ecological status better than the status of the worst known QE1 or QE3. All the cases where due QE3-3 status (River Basin Specific Pollutants).
NOT as expected: 5665 surface water bodies with ecological status worse than the status of the worst known QE1 or QE3.
- of which 1717 surface water bodies failing to achieve good ecological status, when none of the QE1 or or QE3 status is failing.

Repeating the analysis without ‘QE3-3 - River Basin Specific Pollutants’, the values are similar.

As expected: 112315 surface water bodies with ecological status equal to the status of the worst known QE1, QE3-1 or QE3-2
As expected: zero surface water bodies with ecological status better than the status of the worst known QE1, QE3-1 or QE3-2
NOT as expected: 7015 surface water bodies with ecological status worse than the status of the worst known QE1, QE3-1 or QE3-2
- of which 2535 surface water bodies failing to achieve good ecological status, when none of the QE1, QE3-1 or QE3-2 status is failing

This raises the question of how to compare the ecological status reported in the 3rd cycle, with the ecological status that will be reported in the 4th cycle.

Deriving the ecological status from the reported quality elements statuses might somewhat reduce the problem (in the visualisations).

River basin specific pollutants#

According to the rules in the 3rd cycle of reporting,
if the status or potential of ‘QE3-3 - River Basin Specific Pollutants’ is less than good, than the failing RBSP must be reported.

This rule was enforced by the quality control.

The following table should that 2588 of those water bodies were reported as being in good or unknown chemical status. Incorporating the RBSPs into the chemical status assessment changes the percentage of water bodies not achieving good chemical status from 38% to 40%.

Table 65 Chemical status of water bodies with failing QE3-3.#
swChemicalStatusValue	numberOfCountries	numberOfWB	numberOfRBSP
2	18	2453	110
3	25	5192	167
Unknown	10	135	21
Total	25	7780	177

Heavily modified water bodies#

For 60% of the heavily modified water bodies, only one physical alteration and only one water use is reported. It doesn’t make sense to keep the two separate tables used in the 3rd cycle: it complicates the reporting and does not allow a link to be made between the alteration and the use.

../_images/HMWB_NumberOfAlteration_NumberOfUses.png — Figure 71 Heavily modified water bodies - Number of different physical alterations per water use.#

Surface water bodies#

Purpose and overview#

Current structure - 3rd cycle#

SWB_2022 schema - 3rd cycle#

Surface water - descriptive data - 4th cycle#

Surface water - codelists - 4th cycle#

Ecological status and potential#

Annexes - Data analysis - 3rd cycle#

Quality element status (3rd, 2nd and 1st RBMP), by category#

Number of quality elements used#

Status calculated from the quality elements#

Quality element status#

“Monitored but not used”#

“Not applicable”#

Proposed changes#

Ecological status and BQE status#

Proposed change#

One-out-all-out: ecological status#

River basin specific pollutants#

Heavily modified water bodies#

References#