Thet (DS Swangey Fen) Water Body
Moderate ecological status
Get Thet (DS Swangey Fen) data
Attributes
- Water Body IDGB105033043190
- Water Body TypeRiver
- Hydromorphological designationheavily modified
- NGRTL9889586665
- Catchment area9197.356 ha
- Length27.802 km
- Surveillance Water BodyNo
- Catchment area91.974 km2
Classifications
Classification Item | 2019 | 2022 |
---|---|---|
Ecological | Moderate | Moderate |
Biological quality elements | Moderate | Poor |
Fish | Moderate | Poor |
Invertebrates | High | High |
Macrophytes and Phytobenthos Combined | ||
Macrophytes Sub Element | Good | Good |
Physico-chemical quality elements | Moderate | Moderate |
Ammonia (Phys-Chem) | High | High |
Biochemical Oxygen Demand (BOD) | High | |
Dissolved oxygen | Good | High |
Phosphate | Moderate | Moderate |
Temperature | High | High |
pH | High | High |
Hydromorphological Supporting Elements | Supports good | Supports good |
Hydrological Regime | Supports good | Supports good |
Supporting elements (Surface Water) | Moderate | Moderate |
Mitigation Measures Assessment | Moderate or less | Moderate or less |
Chemical | Fail | Does not require assessment |
Priority hazardous substances | Fail | Does not require assessment |
Benzo(a)pyrene | Good | |
Dioxins and dioxin-like compounds | Good | |
Heptachlor and cis-Heptachlor epoxide | Good | |
Hexabromocyclododecane (HBCDD) | Good | |
Hexachlorobenzene | Good | |
Hexachlorobutadiene | Good | |
Mercury and Its Compounds | Good | |
Perfluorooctane sulphonate (PFOS) | Fail | |
Polybrominated diphenyl ethers (PBDE) | Fail | |
Priority substances | Good | Does not require assessment |
Cypermethrin (Priority) | Good | |
Fluoranthene | Good | |
Other Pollutants | Does not require assessment | Does not require assessment |
Investigations into classification status
Classification Element | Cycle | Year | Status | Outcome |
---|---|---|---|---|
Phosphate | 2 | 2013 | Moderate | Very certain there is a problem |
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 Type | SWMI | Activity | Category | Classification Element | More information |
---|---|---|---|---|---|
RNAG | Unknown (pending investigation) | Unknown (pending investigation) | Sector under investigation | Perfluorooctane sulphonate (PFOS) | Details |
RNAG | measures delivered to address reason, awaiting recovery | Not applicable | No sector responsible | Polybrominated diphenyl ethers (PBDE) | Details |
RNAG | Diffuse source | Poor nutrient management | Agriculture and rural land management | Phosphate | Details |
RNAG | Diffuse source | Poor nutrient management | Agriculture and rural land management | Phosphate | Details |
RNAG | Point source | Sewage discharge (continuous) | Water Industry | Phosphate | 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 issue | Physical modifications | Pollution from waste water | Pollution from towns, cities and transport | Changes to the natural flow and level of water | Invasive non-native species | Pollution from rural areas | Pollution from abandoned mines |
---|---|---|---|---|---|---|---|
Agriculture and rural land management | 0 | 0 | 0 | 0 | 0 | 2 | 0 |
Industry | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Mining and quarrying | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Navigation | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Urban and transport | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Water Industry | 0 | 1 | 0 | 0 | 0 | 0 | 0 |
Local & central government | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Domestic general public | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Recreation | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Waste treatment and disposal | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Other | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
No sector responsible | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Sector under investigation | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
Total | 0 | 1 | 0 | 0 | 0 | 2 | 0 |
Objectives
Classification Item | Status | Year | Reasons |
---|---|---|---|
Ecological | Good | 2027 - Low confidence | Disproportionately expensive: Disproportionate burdens |
Biological quality elements | Good | 2015 | |
Fish | Good | 2015 | |
Invertebrates | Good | 2015 | |
Macrophytes and Phytobenthos Combined | Not assessed | 2015 | |
Physico-chemical quality elements | Good | 2027 - Low confidence | Disproportionately expensive: Disproportionate burdens |
Ammonia (Phys-Chem) | Good | 2015 | |
Dissolved oxygen | Good | 2015 | |
Phosphate | Good | 2027 - Low confidence | Disproportionately expensive: Disproportionate burdens |
Temperature | Good | 2015 | |
pH | Good | 2015 | |
Hydromorphological Supporting Elements | Supports good | 2015 | |
Hydrological Regime | Supports good | 2015 | |
Supporting elements (Surface Water) | Good | 2015 | |
Mitigation Measures Assessment | Good | 2015 | |
Specific pollutants | Not assessed | 2015 | |
Chemical | Good | 2063 | Natural conditions: Chemical status recovery time; Technically infeasible: No known technical solution is available |
Priority hazardous substances | Good | 2063 | Natural conditions: Chemical status recovery time; Technically infeasible: No known technical solution is available |
Benzo(a)pyrene | Good | 2015 | |
Dioxins and dioxin-like compounds | Good | 2015 | |
Heptachlor and cis-Heptachlor epoxide | Good | 2015 | |
Hexabromocyclododecane (HBCDD) | Good | 2015 | |
Hexachlorobenzene | Good | 2015 | |
Hexachlorobutadiene | Good | 2015 | |
Mercury and Its Compounds | Good | 2015 | |
Perfluorooctane sulphonate (PFOS) | Good | 2039 | Technically infeasible: No known technical solution is available |
Polybrominated diphenyl ethers (PBDE) | Good | 2063 | Natural conditions: Chemical status recovery time |
Priority substances | Good | 2015 | |
Cypermethrin (Priority) | Good | 2015 | |
Fluoranthene | Good | 2015 | |
Other Pollutants | Does not require assessment | 2015 |
Protected areas
PA Name | Id | Directive | More information |
---|---|---|---|
Ely Ouse and Cut-off channel NVZ | S390 | Nitrates Directive | |
Anglian Chalk | G71 | Nitrates Directive | |
Breckland | UK0019865 | Special Area of Conservation | Natural England |
Monitoring sites which have been used to classify this water body
Shows which sites were used for classification for which years within each cycle.