Gade (from confluence with Bulbourne to Chess) Water Body

Poor ecological status

Attributes

  • Water Body IDGB106039029860
  • Water Body TypeRiver
  • Hydromorphological designationheavily modified
  • NGRTQ0833395244
  • Catchment area7247.056 ha
  • Length15.021 km
  • Catchment area72.471 km2
  • Surveillance Water BodyNo

Classifications

Classification Item20192022
EcologicalModeratePoor
Biological quality elementsModeratePoor
InvertebratesHighHigh
Macrophytes and Phytobenthos CombinedModeratePoor
Macrophytes Sub ElementModeratePoor
Physico-chemical quality elementsModerateGood
Ammonia (Phys-Chem)HighHigh
Biochemical Oxygen Demand (BOD)High
Dissolved oxygenHighHigh
PhosphateModerateGood
TemperatureHighHigh
pHHighHigh
Hydromorphological Supporting ElementsSupports goodSupports good
Hydrological RegimeDoes not support goodDoes not support good
Supporting elements (Surface Water)ModerateModerate
Mitigation Measures AssessmentModerate or lessModerate or less
ChemicalFailDoes not require assessment
Priority hazardous substancesFailDoes not require assessment
Benzo(a)pyreneGood
Cadmium and Its CompoundsGood
Dioxins and dioxin-like compoundsGood
Heptachlor and cis-Heptachlor epoxideGood
Hexabromocyclododecane (HBCDD)Good
HexachlorobenzeneGood
HexachlorobutadieneGood
Mercury and Its CompoundsGood
Perfluorooctane sulphonate (PFOS)Fail
Polybrominated diphenyl ethers (PBDE)Fail
Priority substancesGoodDoes not require assessment
Cypermethrin (Priority)Good
FluorantheneGood
Other PollutantsDoes not require assessmentDoes not require assessment

Why do all water bodies have a chemical status of fail?

Investigations into classification status

No data to show

Reasons for not achieving good (RNAG) and reasons for deterioration (RFD)

All reasons (RFDs and RNAGs) attributed to the classification elements in this water body.

Reason TypeSWMIActivityCategoryClassification ElementMore information
RNAGPoint sourceSewage discharge (continuous)Water IndustryPhosphateDetails
RNAGPoint sourcePrivate Sewage TreatmentNavigationPhosphateDetails
RNAGDiffuse sourceUrbanisation - urban developmentUrban and transportPhosphateDetails
RNAGDiffuse sourcePoor Livestock ManagementAgriculture and rural land managementPhosphateDetails
RNAGFlowGroundwater abstractionWater IndustryHydrological RegimeDetails
RNAGPhysical modificationOther (not in list, must add details in comments)Urban and transportMitigation Measures AssessmentDetails
RNAGPhysical modificationUrbanisation - urban developmentUrban and transportMacrophytes and Phytobenthos CombinedDetails
RNAGPhysical modificationOther (not in list, must add details in comments)RecreationMitigation Measures AssessmentDetails
RNAGPhysical modificationInland boating and structuresNavigationMacrophytes and Phytobenthos CombinedDetails
RNAGUnknown (pending investigation)Unknown (pending investigation)Sector under investigationPerfluorooctane sulphonate (PFOS)Details
RNAGmeasures delivered to address reason, awaiting recoveryNot applicableNo sector responsiblePolybrominated diphenyl ethers (PBDE)Details

Reasons for not achieving good status by business sector

The issues preventing waters reaching good status and the sectors identified as contributing to them. The numbers in the table are individual counts of the reasons for not achieving good status with a confidence status of 'confirmed' and 'probable', where the latest classification is less than good status. There may be more than one reason in a single water body. Note, table does not include reasons for deterioration.

Significant water management issuePhysical modificationsPollution from waste waterPollution from towns, cities and transportChanges to the natural flow and level of waterInvasive non-native speciesPollution from rural areasPollution from abandoned mines
Agriculture and rural land management0000000
Industry0000000
Mining and quarrying0000000
Navigation1000000
Urban and transport2000000
Water Industry0001000
Local & central government0000000
Domestic general public0000000
Recreation1000000
Waste treatment and disposal0000000
Other0000000
No sector responsible0000000
Sector under investigation0000000
Total4001000

Objectives

Classification ItemStatusYearReasons
EcologicalModerate2027 - Low confidenceDisproportionately expensive: Disproportionate burdens;
Good status prevented by A/HMWB designated use: Action to get biological element to good would have significant adverse impact on use;
Technically infeasible: No known technical solution is available
Biological quality elementsGood2027 - Low confidenceGood status prevented by A/HMWB designated use: Action to get biological element to good would have significant adverse impact on use
InvertebratesGood2015
Macrophytes and Phytobenthos CombinedNot assessed2027 - Low confidenceGood status prevented by A/HMWB designated use: Action to get biological element to good would have significant adverse impact on use
Physico-chemical quality elementsModerate2015Technically infeasible: No known technical solution is available
Ammonia (Phys-Chem)Good2015
Dissolved oxygenGood2015
PhosphateModerate2021Technically infeasible: No known technical solution is available
TemperatureGood2015
pHGood2015
Hydromorphological Supporting ElementsSupports good2015
Hydrological RegimeSupports good2027 - Low confidenceDisproportionately expensive: Disproportionate burdens
Supporting elements (Surface Water)Good2027 - Low confidenceDisproportionately expensive: Disproportionate burdens
Mitigation Measures AssessmentGood2027 - Low confidenceDisproportionately expensive: Disproportionate burdens
Specific pollutantsNot assessed2015
ChemicalGood2063Natural conditions: Chemical status recovery time;
Technically infeasible: No known technical solution is available
Priority hazardous substancesGood2063Natural conditions: Chemical status recovery time;
Technically infeasible: No known technical solution is available
Benzo(a)pyreneGood2015
Cadmium and Its CompoundsGood2015
Dioxins and dioxin-like compoundsGood2015
Heptachlor and cis-Heptachlor epoxideGood2015
Hexabromocyclododecane (HBCDD)Good2015
HexachlorobenzeneGood2015
HexachlorobutadieneGood2015
Mercury and Its CompoundsGood2015
Perfluorooctane sulphonate (PFOS)Good2039Technically infeasible: No known technical solution is available
Polybrominated diphenyl ethers (PBDE)Good2063Natural conditions: Chemical status recovery time
Priority substancesGood2015
Cypermethrin (Priority)Good2015
FluorantheneGood2015
Other PollutantsDoes not require assessment2015

Protected areas

No data to show

Monitoring sites which have been used to classify this water body

Shows which sites were used for classification for which years within each cycle.

Monitoring SiteCycle 1Cycle 2Cycle 3
GADE / G.U.C. AT HUNTON BRIDGE PCNR00602011, 2012, 2010, 2009
COLNE/GADE/CASSIOBURY PARK/ 102452009
G.U.C. AT GADEBANK, CROXLEY PCNR01922009
157845 1578452014, 2012, 2013
G.U.C. ABOVE LOCK 74, HUNTON BRIDGE PCNR02092009
34025 340252009
34024 340242009
GADE AT CROXLEY CENTRE, WATFORD PCNR00542009
G.U.C. 200M BELOW STATION FOOTPATH, KING PCNR02112009
34082 3408220142016, 2015, 2019, 20142022, 2019
G.U.C. AT LOT MEAD LOCK PCNR01872009
33897 338972009
34264 342642014, 2012, 2011, 2013, 2010, 2009
COLNE/GADE/KINGS LANGLEY/ 127522014, 2010, 2009
34315 343152013, 2012, 2011, 20142013, 2015, 2016, 2014, 20192022, 2019
33899 338992009
G.U.C. AT DURRANTS HILL ROAD, HEMEL HEMP PCNR01852009
GADE ABOVE G.U.C., RICKMANSWORTH PCNR00552011, 2012, 2013, 2009, 20102016, 20192022, 2019