Siston Bk - source to conf R Avon (Brist) Water Body

Moderate ecological status

Attributes

  • Water Body IDGB109053027450
  • Water Body TypeRiver
  • Hydromorphological designationheavily modified
  • NGRST6684072692
  • Catchment area23.128 km2
  • Surveillance Water BodyNo
  • Length8.428 km
  • Catchment area2312.77 ha

Classifications

Classification Item20192022
EcologicalModerateModerate
Biological quality elementsGoodGood
InvertebratesGoodGood
Macrophytes and Phytobenthos Combined
Macrophytes Sub ElementModerateGood
Physico-chemical quality elementsModerateModerate
Ammonia (Phys-Chem)HighHigh
Dissolved oxygenHighHigh
PhosphateModerateModerate
TemperatureHighHigh
pHHighHigh
Hydromorphological Supporting ElementsSupports goodSupports good
Hydrological RegimeSupports goodSupports good
Supporting elements (Surface Water)ModerateModerate
Mitigation Measures AssessmentModerate or lessModerate or less
Specific pollutantsHighHigh
CopperHighHigh
IronHighHigh
ManganeseHighHigh
TriclosanHighHigh
ZincHighHigh
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 CompoundsFail
NonylphenolGood
Perfluorooctane sulphonate (PFOS)Good
Polybrominated diphenyl ethers (PBDE)Fail
Tributyltin CompoundsGood
Priority substancesGoodDoes not require assessment
Cypermethrin (Priority)Good
FluorantheneGood
Lead and Its CompoundsGood
Nickel and Its CompoundsGood
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
RNAGPhysical modificationOther (not in list, must add details in comments)Urban and transportMitigation Measures AssessmentDetails
RNAGPhysical modificationOther (not in list, must add details in comments)Local and Central GovernmentMitigation Measures AssessmentDetails
RNAGDiffuse sourcePoor Livestock ManagementAgriculture and rural land managementPhosphateDetails
RNAGPoint sourceTrade/Industry dischargeIndustryPhosphateDetails
RNAGPoint sourceUrbanisation - urban developmentUrban and transportPhosphateDetails
RNAGmeasures delivered to address reason, awaiting recoveryNot applicableNo sector responsiblePolybrominated diphenyl ethers (PBDE)Details
RNAGmeasures delivered to address reason, awaiting recoveryNot applicableNo sector responsibleMercury and Its CompoundsDetails

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 management0000010
Industry0010000
Mining and quarrying0000000
Navigation0000000
Urban and transport1010000
Water Industry0000000
Local & central government1000000
Domestic general public0000000
Recreation0000000
Waste treatment and disposal0000000
Other0000000
No sector responsible0000000
Sector under investigation0000000
Total2020010

Objectives

Classification ItemStatusYearReasons
EcologicalGood2027 - Low confidenceDisproportionately expensive: Disproportionate burdens
Biological quality elementsGood2015
InvertebratesGood2015
Macrophytes and Phytobenthos CombinedNot assessed2015
Physico-chemical quality elementsGood2027 - Low confidenceDisproportionately expensive: Disproportionate burdens
Ammonia (Phys-Chem)Good2015
Dissolved oxygenGood2015
PhosphateGood2027 - Low confidenceDisproportionately expensive: Disproportionate burdens
TemperatureGood2015
pHGood2015
Hydromorphological Supporting ElementsSupports good2015
Hydrological RegimeSupports good2015
Supporting elements (Surface Water)Good2027 - Low confidenceDisproportionately expensive: Disproportionate burdens
Mitigation Measures AssessmentGood2027 - Low confidenceDisproportionately expensive: Disproportionate burdens
Specific pollutantsHigh2015
CopperHigh2015
IronHigh2015
ManganeseHigh2015
TriclosanHigh2015
ZincHigh2015
ChemicalGood2063Disproportionately expensive: Disproportionate burdens;
Natural conditions: Chemical status recovery time
Priority hazardous substancesGood2063Disproportionately expensive: Disproportionate burdens;
Natural conditions: Chemical status recovery time
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 CompoundsGood2040Natural conditions: Chemical status recovery time
NonylphenolGood2015
Perfluorooctane sulphonate (PFOS)Good2015
Polybrominated diphenyl ethers (PBDE)Good2063Natural conditions: Chemical status recovery time
Tributyltin CompoundsGood2021Disproportionately expensive: Disproportionate burdens
Priority substancesGood2015
Cypermethrin (Priority)Good2015
FluorantheneGood2015
Lead and Its CompoundsGood2015
Nickel and Its CompoundsGood2015
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
SISTON BK. WILLSBDGE Z10601052010, 2011, 2009, 20122016, 2015, 20192019
7753 77532009, 20142016, 2014, 2015
SISTON BROOK A420 Z106010320092015, 2016
206391 2063912022
159982 1599822013, 20142014, 2013, 2016, 2015

Upstream water bodies