Dollis Brook and Upper Brent Water Body
Moderate ecological status
Get Dollis Brook and Upper Brent data
Attributes
- Water Body IDGB106039022980
- Water Body TypeRiver
- Hydromorphological designationheavily modified
- NGRTQ2555092799
- Catchment area4308.27 ha
- Length16.986 km
- Catchment area43.083 km2
- Surveillance Water BodyNo
Classifications
| Classification Item | 2019 | 2022 |
|---|---|---|
| Ecological | Moderate | Moderate |
| Biological quality elements | Poor | Poor |
| Invertebrates | Poor | Poor |
| Macrophytes and Phytobenthos Combined | ||
| Macrophytes Sub Element | Poor | Poor |
| Physico-chemical quality elements | Moderate | Moderate |
| Ammonia (Phys-Chem) | Moderate | Moderate |
| Dissolved oxygen | Bad | Bad |
| Phosphate | Poor | Poor |
| 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 |
| Specific pollutants | High | High |
| Triclosan | High | High |
| Chemical | Fail | Does not require assessment |
| Priority hazardous substances | Fail | Does not require assessment |
| Benzo(a)pyrene | Good | |
| Benzo(b)fluoranthene | Good | |
| Benzo(g-h-i)perylene | Fail | |
| Benzo(k)fluoranthene | 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 | |
| Nonylphenol | Good | |
| Perfluorooctane sulphonate (PFOS) | Good | |
| 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
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 Type | SWMI | Activity | Category | Classification Element | More information |
|---|---|---|---|---|---|
| RNAG | Unknown (pending investigation) | Unknown (pending investigation) | Sector under investigation | Benzo(g-h-i)perylene | Details |
| RNAG | measures delivered to address reason, awaiting recovery | Not applicable | No sector responsible | Polybrominated diphenyl ethers (PBDE) | Details |
| RNAG | Diffuse source | Urbanisation - urban development | Urban and transport | Invertebrates | Details |
| RNAG | Point source | Incidents | Other | Invertebrates | Details |
| RNAG | Point source | Sewage discharge (intermittent) | Water Industry | Invertebrates | Details |
| RNAG | Diffuse source | Urbanisation - urban development | Urban and transport | Invertebrates | Details |
| RNAG | Point source | Sewage discharge (intermittent) | Water Industry | Dissolved oxygen | Details |
| RNAG | Point source | Misconnections | Domestic General Public | Invertebrates | Details |
| RNAG | Diffuse source | Urbanisation - urban development | Urban and transport | Ammonia (Phys-Chem) | Details |
| RNAG | Point source | Misconnections | Domestic General Public | Ammonia (Phys-Chem) | Details |
| RNAG | Point source | Sewage discharge (intermittent) | Water Industry | Invertebrates | Details |
| RNAG | Physical modification | Other (not in list, must add details in comments) | Urban and transport | Mitigation Measures Assessment | Details |
| RNAG | Point source | Sewage discharge (intermittent) | Water Industry | Ammonia (Phys-Chem) | Details |
| RNAG | Physical modification | Flood protection - structures | Urban and transport | Invertebrates | Details |
| RNAG | Physical modification | Urbanisation - urban development | Urban and transport | Invertebrates | Details |
| RNAG | Physical modification | Other (not in list, must add details in comments) | Local and Central Government | Mitigation Measures Assessment | Details |
| RNAG | Diffuse source | Urbanisation - urban development | Urban and transport | Phosphate | Details |
| RNAG | Point source | Misconnections | Domestic General Public | Phosphate | Details |
| RNAG | Point source | Sewage discharge (intermittent) | Water Industry | Phosphate | Details |
| RNAG | Diffuse source | Urbanisation - urban development | Urban and transport | Dissolved oxygen | Details |
| RNAG | Point source | Incidents | Other | Dissolved oxygen | 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 | 0 | 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 | 3 | 0 | 1 | 0 | 0 | 0 | 0 |
| Water Industry | 0 | 5 | 0 | 0 | 0 | 0 | 0 |
| Local & central government | 1 | 0 | 0 | 0 | 0 | 0 | 0 |
| Domestic general public | 0 | 0 | 3 | 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 | 4 | 5 | 4 | 0 | 0 | 0 | 0 |
Objectives
| Classification Item | Status | Year | Reasons |
|---|---|---|---|
| Ecological | Good | 2027 - Low confidence | Disproportionately expensive: Disproportionate burdens |
| Biological quality elements | Good | 2027 - Low confidence | Disproportionately expensive: Disproportionate burdens |
| Invertebrates | Good | 2027 - Low confidence | Disproportionately expensive: Disproportionate burdens |
| Macrophytes and Phytobenthos Combined | Not assessed | 2015 | Disproportionately expensive: Disproportionate burdens |
| Physico-chemical quality elements | Good | 2027 - Low confidence | Disproportionately expensive: Disproportionate burdens |
| Ammonia (Phys-Chem) | Good | 2027 - Low confidence | Disproportionately expensive: Disproportionate burdens |
| Dissolved oxygen | Good | 2027 - Low confidence | Disproportionately expensive: Disproportionate burdens |
| 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 | 2027 - Low confidence | Disproportionately expensive: Disproportionate burdens |
| Mitigation Measures Assessment | Good | 2027 - Low confidence | Disproportionately expensive: Disproportionate burdens |
| Specific pollutants | High | 2015 | |
| Triclosan | High | 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 | |
| Benzo(b)fluoranthene | Good | 2015 | |
| Benzo(g-h-i)perylene | Good | 2033 | Technically infeasible: No known technical solution is available |
| Benzo(k)fluoranthene | 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 | |
| Nonylphenol | Good | 2015 | |
| Perfluorooctane sulphonate (PFOS) | Good | 2015 | |
| 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
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.