Tilgate Brook and Gatwick Stream at Crawley Water Body
Moderate ecological status
Get Tilgate Brook and Gatwick Stream at Crawley data
Attributes
- Water Body IDGB106039017500
- Water Body TypeRiver
- Hydromorphological designationheavily modified
- NGRTQ2917739654
- Catchment area14.176 km2
- Surveillance Water BodyNo
- Length8.017 km
- Catchment area1417.62 ha
Classifications
| Classification Item | 2019 | 2022 |
|---|---|---|
| Ecological | Moderate | Moderate |
| Biological quality elements | Bad | Poor |
| Fish | Bad | Moderate |
| Invertebrates | Poor | Poor |
| Macrophytes and Phytobenthos Combined | High | High |
| Phytobenthos Sub Element | High | High |
| Physico-chemical quality elements | Good | Good |
| Acid Neutralising Capacity | High | High |
| Ammonia (Phys-Chem) | High | High |
| Dissolved oxygen | High | High |
| Phosphate | Good | Good |
| 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 |
| Copper | High | High |
| Iron | High | High |
| Manganese | High | High |
| Triclosan | High | High |
| Zinc | 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 | Good | |
| Benzo(k)fluoranthene | Good | |
| Cadmium and Its Compounds | Good | |
| Di(2-ethylhexyl)phthalate (Priority hazardous) | Good | |
| Dioxins and dioxin-like compounds | Fail | |
| Heptachlor and cis-Heptachlor epoxide | Good | |
| Hexabromocyclododecane (HBCDD) | Good | |
| Hexachlorobenzene | Good | |
| Hexachlorobutadiene | Good | |
| Mercury and Its Compounds | Fail | |
| Nonylphenol | Good | |
| Perfluorooctane sulphonate (PFOS) | Fail | |
| Polybrominated diphenyl ethers (PBDE) | Fail | |
| Tributyltin Compounds | Good | |
| Priority substances | Good | Does not require assessment |
| Cypermethrin (Priority) | Good | |
| Fluoranthene | Good | |
| Lead and Its Compounds | Good | |
| Nickel and Its Compounds | 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 | Urbanisation - transport | Urban and transport | Invertebrates | Details |
| RNAG | Physical modification | Other (not in list, must add details in comments) | Urban and transport | Mitigation Measures Assessment | Details |
| RNAG | Physical modification | Other (not in list, must add details in comments) | Local and Central Government | Mitigation Measures Assessment | Details |
| RNAG | Invasive non-native species | North american signal crayfish | No sector responsible | Fish | Details |
| RNAG | Physical modification | Flood protection - structures | Local and Central Government | Fish | Details |
| RNAG | Physical modification | Other (not in list, must add details in comments) | Recreation | Mitigation Measures Assessment | Details |
| RNAG | Physical modification | Barriers - ecological discontinuity | Urban and transport | Fish | Details |
| RNAG | Diffuse source | Transport Drainage | Urban and transport | Invertebrates | Details |
| RNAG | Diffuse source | Transport Drainage | Urban and transport | Fish | Details |
| RNAG | Invasive non-native species | North american signal crayfish | No sector responsible | Invertebrates | Details |
| RNAG | Point source | Sewage discharge (continuous) | Water Industry | Fish | Details |
| RNAG | Point source | Sewage discharge (continuous) | Water Industry | Invertebrates | Details |
| RNAG | Physical modification | Urbanisation - transport | Urban and transport | Fish | Details |
| RNAG | Diffuse source | Urbanisation - urban development | Urban and transport | Invertebrates | 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 | measures delivered to address reason, awaiting recovery | Not applicable | No sector responsible | Mercury and Its Compounds | 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 | 4 | 0 | 3 | 0 | 0 | 0 | 0 |
| Water Industry | 0 | 1 | 0 | 0 | 0 | 0 | 0 |
| Local & central government | 2 | 0 | 0 | 0 | 0 | 0 | 0 |
| Domestic general public | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Recreation | 1 | 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 | 1 | 0 | 0 |
| Sector under investigation | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Total | 7 | 1 | 3 | 0 | 1 | 0 | 0 |
Objectives
| Classification Item | Status | Year | Reasons |
|---|---|---|---|
| Ecological | Good | 2027 - Low confidence | Disproportionately expensive: Disproportionate burdens; Disproportionately expensive: Unfavourable balance of costs and benefits; Good status prevented by A/HMWB designated use: Action to get biological element to good would have significant adverse impact on use; Technically infeasible: No known technical solution is available |
| Biological quality elements | Poor | 2027 - Low confidence | Disproportionately expensive: Disproportionate burdens; Disproportionately expensive: Unfavourable balance of costs and benefits; Good status prevented by A/HMWB designated use: Action to get biological element to good would have significant adverse impact on use; Technically infeasible: No known technical solution is available |
| Fish | Poor | 2027 - Low confidence | Disproportionately expensive: Disproportionate burdens; Disproportionately expensive: Unfavourable balance of costs and benefits; Good status prevented by A/HMWB designated use: Action to get biological element to good would have significant adverse impact on use; Technically infeasible: No known technical solution is available |
| Invertebrates | Moderate | 2027 - Low confidence | Disproportionately expensive: Disproportionate burdens |
| Macrophytes and Phytobenthos Combined | Good | 2015 | |
| Physico-chemical quality elements | Good | 2021 | Disproportionately expensive: Disproportionate burdens |
| Acid Neutralising Capacity | Good | 2015 | |
| Ammonia (Phys-Chem) | Good | 2015 | |
| Dissolved oxygen | Good | 2015 | |
| Phosphate | Good | 2021 | 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 | |
| Copper | High | 2015 | |
| Iron | High | 2015 | |
| Manganese | High | 2015 | |
| Triclosan | High | 2015 | |
| Zinc | High | 2015 | |
| Chemical | Good | 2063 | Disproportionately expensive: Disproportionate burdens; Natural conditions: Chemical status recovery time; Technically infeasible: No known technical solution is available |
| Priority hazardous substances | Good | 2063 | Disproportionately expensive: Disproportionate burdens; Natural conditions: Chemical status recovery time; Technically infeasible: No known technical solution is available |
| Benzo (b) and (k) fluoranthene | Good | 2015 | |
| Benzo (ghi) perelyene and indeno (123-cd) pyrene | Good | 2015 | |
| Benzo(a)pyrene | Good | 2015 | |
| Benzo(b)fluoranthene | Good | 2015 | |
| Benzo(g-h-i)perylene | Good | 2015 | |
| Benzo(k)fluoranthene | Good | 2015 | |
| Cadmium and Its Compounds | Good | 2015 | |
| Di(2-ethylhexyl)phthalate (Priority hazardous) | Good | 2015 | |
| Dioxins and dioxin-like compounds | Good | 2039 | Disproportionately expensive: Disproportionate burdens |
| Heptachlor and cis-Heptachlor epoxide | Good | 2015 | |
| Hexabromocyclododecane (HBCDD) | Good | 2015 | |
| Hexachlorobenzene | Good | 2015 | |
| Hexachlorobutadiene | Good | 2015 | |
| Mercury and Its Compounds | Good | 2040 | Natural conditions: Chemical status recovery time |
| Nonylphenol | 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 |
| Tributyltin Compounds | Good | 2015 | |
| Priority substances | Good | 2015 | |
| Cypermethrin (Priority) | Good | 2015 | |
| Fluoranthene | Good | 2015 | |
| Lead and Its Compounds | Good | 2015 | |
| Nickel and Its Compounds | Good | 2015 | |
| Other Pollutants | Does not require assessment | 2015 |
Protected areas
| PA Name | Id | Directive | More information |
|---|---|---|---|
| River Mole | UKENRI58 | Urban Waste Water Treatment Directive |
Monitoring sites which have been used to classify this water body
Shows which sites were used for classification for which years within each cycle.