Walthamstow Reservoir No 4 Water Body
Moderate ecological status
Get Walthamstow Reservoir No 4 data
Attributes
- Water Body IDGB30641922
- Water Body TypeLake
- Hydromorphological designationartificial
- NGRTQ3538688910
- Altitude12 m
- Mean depth4.925 m
- Surveillance Water BodyNo
- Surface area0.276 km2
- Surface area27.602 ha
- Catchment area136294 ha
Classifications
| Classification Item | 2019 | 2022 |
|---|---|---|
| Ecological | Moderate | Moderate |
| Biological quality elements | Moderate | Moderate |
| Phytoplankton | Moderate | Moderate |
| Physico-chemical quality elements | Moderate | Moderate |
| Salinity | High | High |
| Total Nitrogen | Bad | Bad |
| Total Phosphorus | Bad | Bad |
| Supporting elements (Surface Water) | Moderate | Moderate |
| Expert Judgement | Moderate | Moderate |
| Mitigation Measures Assessment | Moderate or less | Good |
| 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 |
| 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 | Physical modification | Other (not in list, must add details in comments) | Water Industry | Mitigation Measures Assessment | Details |
| 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 | Point source | Sewage discharge (continuous) | Water Industry | Total Phosphorus | Details |
| RNAG | Point source | Sewage discharge (continuous) | Water Industry | Phytoplankton | 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 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Water Industry | 0 | 2 | 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 | 2 | 0 | 0 | 0 | 0 | 0 |
Objectives
| Classification Item | Status | Year | Reasons |
|---|---|---|---|
| Ecological | Poor | 2015 | Disproportionately expensive: Disproportionate burdens; Disproportionately expensive: Unfavourable balance of costs and benefits; Technically infeasible: Cause of adverse impact unknown; Technically infeasible: No known technical solution is available |
| Biological quality elements | Poor | 2015 | Disproportionately expensive: Unfavourable balance of costs and benefits; Technically infeasible: No known technical solution is available |
| Phytoplankton | Poor | 2015 | Disproportionately expensive: Unfavourable balance of costs and benefits; Technically infeasible: No known technical solution is available |
| Physico-chemical quality elements | Moderate | 2015 | Disproportionately expensive: Unfavourable balance of costs and benefits; Technically infeasible: Cause of adverse impact unknown; Technically infeasible: No known technical solution is available |
| Salinity | Good | 2015 | |
| Total Nitrogen | Good | 2027 - Low confidence | Technically infeasible: Cause of adverse impact unknown |
| Total Phosphorus | Bad | 2015 | Disproportionately expensive: Unfavourable balance of costs and benefits; Technically infeasible: No known technical solution is available |
| Hydromorphological Supporting Elements | Not assessed | 2015 | |
| Supporting elements (Surface Water) | Good | 2027 - Low confidence | Disproportionately expensive: Disproportionate burdens |
| Expert Judgement | Good | 2027 - Low confidence | Disproportionately expensive: Disproportionate burdens |
| Mitigation Measures Assessment | Good | 2021 | Disproportionately expensive: Disproportionate burdens |
| 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 | |
| Fluoranthene | Good | 2015 | |
| Other Pollutants | Does not require assessment | 2015 |
Protected areas
| PA Name | Id | Directive | More information |
|---|---|---|---|
| LEE NVZ | S443 | Nitrates Directive | |
| Lee Valley | UK9012111 | Special Protection Area | Natural England |
| Lee Valley | UK11034 | Ramsar Site | Natural England |
| Reservoir No 4 | UKGB30641922 | Drinking Water Protected Area |
Monitoring sites which have been used to classify this water body
Shows which sites were used for classification for which years within each cycle.