Chalvey Ditches Water Body
Moderate ecological status
Get Chalvey Ditches data
Attributes
- Water Body IDGB106039023550
- Water Body TypeRiver
- Hydromorphological designationheavily modified
- NGRSU9528279887
- Catchment area20.944 km2
- Surveillance Water BodyNo
- Catchment area2094.434 ha
- Length6.717 km
Classifications
| Classification Item | 2019 |
|---|---|
| Ecological | Moderate |
| Biological quality elements | Poor |
| Fish | Poor |
| Invertebrates | Moderate |
| Macrophytes and Phytobenthos Combined | |
| Macrophytes Sub Element | Good |
| Physico-chemical quality elements | Moderate |
| Ammonia (Phys-Chem) | High |
| Dissolved oxygen | Moderate |
| Phosphate | Moderate |
| Temperature | High |
| pH | High |
| Hydromorphological Supporting Elements | Supports good |
| Hydrological Regime | Supports good |
| Supporting elements (Surface Water) | Moderate |
| Mitigation Measures Assessment | Moderate or less |
| Specific pollutants | High |
| Triclosan | High |
| Chemical | Fail |
| Priority hazardous substances | Fail |
| Benzo(a)pyrene | Good |
| Benzo(b)fluoranthene | Fail |
| Benzo(g-h-i)perylene | Fail |
| Benzo(k)fluoranthene | Fail |
| 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 |
| Cypermethrin (Priority) | Good |
| Fluoranthene | Good |
| Other Pollutants | 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(k)fluoranthene | Details |
| RNAG | Unknown (pending investigation) | Unknown (pending investigation) | Sector under investigation | Benzo(g-h-i)perylene | 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 | Invertebrates | Details |
| RNAG | Unknown (pending investigation) | Unknown (pending investigation) | Sector under investigation | Benzo(b)fluoranthene | Details |
| RNAG | measures delivered to address reason, awaiting recovery | Not applicable | No sector responsible | Polybrominated diphenyl ethers (PBDE) | 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 | Flow | Groundwater abstraction | Water Industry | Fish | Details |
| RNAG | Point source | Sewage discharge (intermittent) | Water Industry | Phosphate | Details |
| RNAG | Point source | Leaking utility sewers | Water Industry | Phosphate | Details |
| RNAG | Flow | Groundwater abstraction | Water Industry | Fish | Details |
| RNAG | Diffuse source | Transport Drainage | Urban and transport | Phosphate | Details |
| RNAG | Point source | Incidents | Water Industry | Phosphate | Details |
| RNAG | Diffuse source | Poor Livestock Management | Agriculture and rural land management | Phosphate | Details |
| RNAG | Point source | Leaking utility sewers | Water Industry | Dissolved oxygen | Details |
| RNAG | Point source | Incidents | Water Industry | Dissolved oxygen | Details |
| RNAG | Physical modification | Urbanisation - transport | Urban and transport | Dissolved oxygen | Details |
| RNAG | Diffuse source | Urbanisation - urban development | Urban and transport | 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 | 2 | 0 | 0 | 0 | 0 | 0 | 0 |
| Water Industry | 0 | 1 | 0 | 0 | 0 | 0 | 0 |
| Local & central government | 1 | 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 | 3 | 1 | 0 | 0 | 0 | 0 | 0 |
Objectives
| Classification Item | Status | Year | Reasons |
|---|---|---|---|
| Ecological | Good | 2027 - Low confidence | Disproportionately expensive: Disproportionate burdens; Technically infeasible: Practical technical constraints prevent implementation of the measure by an earlier deadline |
| Biological quality elements | Moderate | 2027 - Low confidence | Disproportionately expensive: Disproportionate burdens; Technically infeasible: Practical technical constraints prevent implementation of the measure by an earlier deadline |
| Fish | Moderate | 2027 - Low confidence | Technically infeasible: Practical technical constraints prevent implementation of the measure by an earlier deadline |
| Invertebrates | Good | 2027 - Low confidence | Disproportionately expensive: Disproportionate burdens |
| 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 | 2027 - Low confidence | Technically infeasible: Practical technical constraints prevent implementation of the measure by an earlier deadline |
| Mitigation Measures Assessment | Good | 2027 - Low confidence | Technically infeasible: Practical technical constraints prevent implementation of the measure by an earlier deadline |
| 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 | 2033 | Technically infeasible: No known technical solution is available |
| Benzo(g-h-i)perylene | Good | 2033 | Technically infeasible: No known technical solution is available |
| Benzo(k)fluoranthene | Good | 2033 | Technically infeasible: No known technical solution is available |
| 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
| PA Name | Id | Directive | More information |
|---|---|---|---|
| Lower Thames (Cookham Egham Teddington) | SWSGZ4016 | Safeguard Zone |
Monitoring sites which have been used to classify this water body
Shows which sites were used for classification for which years within each cycle.