High Maynard Reservoir Water Body
Moderate ecological status
Get High Maynard Reservoir data
Attributes
- Water Body IDGB30641884
- Water Body TypeLake
- Hydromorphological designationartificial
- NGRTQ3543789754
- Surface area14.868 ha
- Mean depth4.435 m
- Surface area0.149 km2
- Altitude12 m
- Surveillance Water BodyNo
- Catchment area136239.5 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 |
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 | Diffuse source | Urbanisation - urban development | Urban and transport | Total Phosphorus | Details |
RNAG | Diffuse source | Poor nutrient management | Agriculture and rural land management | Total Phosphorus | 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 | Phytoplankton | Details |
RNAG | Point source | Sewage discharge (continuous) | Water Industry | Total Phosphorus | Details |
RNAG | Physical modification | Other (not in list, must add details in comments) | Water Industry | Mitigation Measures Assessment | Details |
RNAG | Point source | Sewage discharge (intermittent) | Water Industry | Total Phosphorus | 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 | 1 | 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 | 1 | 0 | 0 | 0 | 0 |
Water Industry | 0 | 3 | 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 | 3 | 1 | 0 | 0 | 1 | 0 |
Objectives
Classification Item | Status | Year | Reasons |
---|---|---|---|
Ecological | Poor | 2015 | Disproportionately expensive: Disproportionate burdens; Technically infeasible: Cause of adverse impact unknown; Technically infeasible: No known technical solution is available |
Biological quality elements | Poor | 2015 | Technically infeasible: No known technical solution is available |
Phytoplankton | Poor | 2015 | Technically infeasible: No known technical solution is available |
Physico-chemical quality elements | Moderate | 2015 | 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 | 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 |
Walthamstow Reservoirs - GB30641884 | UKGB30641884 | 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.