River Cober at St Johns Bridge
EA name: RIVER COBER AT ST JOHNS BRIDGE
Environment Agency sampling point SW-82010152 · Freshwater - rivers · listed as open (“open” does not mean it is sampled now)
These are samples taken on a date, not live readings of the river. Results reach the Environment Agency's archive days to months after the sample is taken, so the newest here may be weeks or months old. FloodRadar does not grade them.
Where and when
- Last sampled
- 29 Sep 2026, 11:489 days ago · time as the Environment Agency records it (UK clock time; the source gives no time zone)
- Samples banked
- 10 since 14 Jun 2024 Imported periods: 1 Oct 2023 – 8 Oct 2026. Samples outside them are not shown here.
- Latest sample
- River / running surface water Environmental monitoring statutory (EU directives) · results completed 1 Oct 2026
- Where
- National Grid 165456, 27604As published, to the nearest 1 m. Open in a map
- River, by its own name
- Cober
- River, by the map
- River CoberPlaced on the river its name gives, 1 m from the line.
- Next gauge downstream
- Helston County Bridge On the River Cober · 0.3 km along the riverHELSTON COUNTY BRIDGE 0.3 km along the river
- Nearest gauge upstream
- Boscadjack On the River Cober · 4.4 km along the river
- Why it was sampled
- Environmental monitoring statutory (EU directives) (6 samples)
Planned investigation (local monitoring) (4 samples)
Results here were completed a median of 9 days after the sample was taken (2 to 10 days, 4 samples).
Main measurements, river water
Dissolved oxygen
% saturation · code 9901 · %
98.1%
Sampled 29 Sep 2026, 9 days ago · 10 results banked
Every result (10)
| Sampled | Result as published | Reads as |
|---|---|---|
| 29 Sep 2026, 11:48 | 98.1 | 98.1% |
| 3 Aug 2026, 10:06 | 100 | 100% |
| 7 Jul 2026, 14:29 | 99.6 | 99.6% |
| 9 Jun 2026, 09:58 | 97.8 | 97.8% |
| 21 May 2026, 12:26 | 100.2 | 100.2% |
| 13 Apr 2026, 10:30 | 101.3 | 101.3% |
| 24 Jul 2024, 10:04 | 96.7 | 96.7% |
| 12 Jul 2024, 09:43 | 101.6 | 101.6% |
| 27 Jun 2024, 11:00 | 97.4 | 97.4% |
| 14 Jun 2024, 11:57 | 97.6 | 97.6% |
Dissolved oxygen
as O2 · code 9924 · mg/l
9.7 mg/l
Sampled 29 Sep 2026, 9 days ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 29 Sep 2026, 11:48 | 9.7 | 9.7 mg/l |
| 3 Aug 2026, 10:06 | 10.2 | 10.2 mg/l |
| 7 Jul 2026, 14:29 | 9.5 | 9.5 mg/l |
| 9 Jun 2026, 09:58 | 10.4 | 10.4 mg/l |
| 21 May 2026, 12:26 | 10.4 | 10.4 mg/l |
| 13 Apr 2026, 10:30 | 11.7 | 11.7 mg/l |
Water temperature
code 0076 · °C
15.8 °C
Sampled 29 Sep 2026, 9 days ago · 10 results banked
Every result (10)
| Sampled | Result as published | Reads as |
|---|---|---|
| 29 Sep 2026, 11:48 | 15.8 | 15.8 °C |
| 3 Aug 2026, 10:06 | 14.5 | 14.5 °C |
| 7 Jul 2026, 14:29 | 17.5 | 17.5 °C |
| 9 Jun 2026, 09:58 | 12.5 | 12.5 °C |
| 21 May 2026, 12:26 | 13.4 | 13.4 °C |
| 13 Apr 2026, 10:30 | 9.1 | 9.1 °C |
| 24 Jul 2024, 10:04 | 14.7 | 14.7 °C |
| 12 Jul 2024, 09:43 | 13 | 13 °C |
| 27 Jun 2024, 11:00 | 14.5 | 14.5 °C |
| 14 Jun 2024, 11:57 | 12.5 | 12.5 °C |
pH
code 0061
7.32
Sampled 29 Sep 2026, 9 days ago · 10 results banked
Every result (10)
| Sampled | Result as published | Reads as |
|---|---|---|
| 29 Sep 2026, 11:48 | 7.32 | 7.32 |
| 3 Aug 2026, 10:06 | 7.1 | 7.1 |
| 7 Jul 2026, 14:29 | 7.27 | 7.27 |
| 9 Jun 2026, 09:58 | 6.87 | 6.87 |
| 21 May 2026, 12:26 | 7.15 | 7.15 |
| 13 Apr 2026, 10:30 | 7.34 | 7.34 |
| 24 Jul 2024, 10:04 | 6.89 | 6.89 |
| 12 Jul 2024, 09:43 | 7.09 | 7.09 |
| 27 Jun 2024, 11:00 | 7.12 | 7.12 |
| 14 Jun 2024, 11:57 | 7.09 | 7.09 |
Ammonia
ammoniacal nitrogen as N · code 0111 · mg/l
below 0.03 mg/l (not detected above this)
Sampled 29 Sep 2026, 9 days ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 29 Sep 2026, 11:48 | <0.03 | below 0.03 mg/l (not detected above this) |
| 3 Aug 2026, 10:06 | <0.03 | below 0.03 mg/l (not detected above this) |
| 7 Jul 2026, 14:29 | <0.03 | below 0.03 mg/l (not detected above this) |
| 9 Jun 2026, 09:58 | <0.03 | below 0.03 mg/l (not detected above this) |
| 21 May 2026, 12:26 | <0.03 | below 0.03 mg/l (not detected above this) |
| 13 Apr 2026, 10:30 | <0.03 | below 0.03 mg/l (not detected above this) |
Nitrate
as nitrogen (N) · code 0117 · mg/l
2.6 mg/l
Sampled 29 Sep 2026, 9 days ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 29 Sep 2026, 11:48 | 2.6 | 2.6 mg/l |
| 3 Aug 2026, 10:06 | 3 | 3 mg/l |
| 7 Jul 2026, 14:29 | 2.8 | 2.8 mg/l |
| 9 Jun 2026, 09:58 | 2.8 | 2.8 mg/l |
| 21 May 2026, 12:26 | 3.1 | 3.1 mg/l |
| 13 Apr 2026, 10:30 | 3.2 | 3.2 mg/l |
Phosphate
orthophosphate, reactive, as P · code 0180 · mg/l
0.02 mg/l
Sampled 29 Sep 2026, 9 days ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 29 Sep 2026, 11:48 | 0.02 | 0.02 mg/l |
| 3 Aug 2026, 10:06 | 0.015 | 0.015 mg/l |
| 7 Jul 2026, 14:29 | 0.028 | 0.028 mg/l |
| 9 Jun 2026, 09:58 | 0.02 | 0.02 mg/l |
| 21 May 2026, 12:26 | 0.013 | 0.013 mg/l |
| 13 Apr 2026, 10:30 | 0.01 | 0.01 mg/l |
Conductivity
at 25 °C · code 0077 · µS/cm
178 µS/cm
Sampled 29 Sep 2026, 9 days ago · 10 results banked
Every result (10)
| Sampled | Result as published | Reads as |
|---|---|---|
| 29 Sep 2026, 11:48 | 178 | 178 µS/cm |
| 3 Aug 2026, 10:06 | 179 | 179 µS/cm |
| 7 Jul 2026, 14:29 | 171 | 171 µS/cm |
| 9 Jun 2026, 09:58 | 170 | 170 µS/cm |
| 21 May 2026, 12:26 | 172 | 172 µS/cm |
| 13 Apr 2026, 10:30 | 170 | 170 µS/cm |
| 24 Jul 2024, 10:04 | 172 | 172 µS/cm |
| 12 Jul 2024, 09:43 | 174 | 174 µS/cm |
| 27 Jun 2024, 11:00 | 180 | 180 µS/cm |
| 14 Jun 2024, 11:57 | 175 | 175 µS/cm |
Everything measured here
23 determinands, each kept by its code, unit and sample material: results in different units or on different materials are never mixed. A “below” result is under the laboratory's detection limit, not zero.
Show all 23 rows
| Determinand | Material | Results | First – last | Latest result |
|---|---|---|---|---|
| Oxygen, Dissolved, % Saturation 9901 | River water | 10 | Jun 2024 – Sep 2026 | 98.1% 29 Sep 2026 |
| Oxygen, Dissolved as O2 9924 | River water | 6 | Apr 2026 – Sep 2026 | 9.7 mg/l 29 Sep 2026 |
| Temperature of Water 0076 | River water | 10 | Jun 2024 – Sep 2026 | 15.8 °C 29 Sep 2026 |
| pH 0061 | River water | 10 | Jun 2024 – Sep 2026 | 7.32 29 Sep 2026 |
| Ammoniacal Nitrogen as N 0111 | River water | 6 | Apr 2026 – Sep 2026 | below 0.03 mg/l 29 Sep 2026 |
| Nitrate as N 0117 | River water | 6 | Apr 2026 – Sep 2026 | 2.6 mg/l 29 Sep 2026 |
| Orthophosphate, reactive as P 0180 | River water | 6 | Apr 2026 – Sep 2026 | 0.02 mg/l 29 Sep 2026 |
| Conductivity at 25 C 0077 | River water | 10 | Jun 2024 – Sep 2026 | 178 µS/cm 29 Sep 2026 |
| Alkalinity to pH 4.5 as CaCO3 0162 | River water | 6 | Apr 2026 – Sep 2026 | 16 mg/l 29 Sep 2026 |
| Aluminium, Dissolved 6037 | River water | 4 | Jun 2024 – Jul 2024 | 55 µg/l 24 Jul 2024 |
| Ammonia un-ionised as N 0119 | River water | 6 | Apr 2026 – Sep 2026 | below 0.00018 mg/l 29 Sep 2026 |
| Cadmium, Dissolved 0106 | River water | 4 | Jun 2024 – Jul 2024 | below 0.1 µg/l 24 Jul 2024 |
| Calcium, Dissolved 0239 | River water | 4 | Jun 2024 – Jul 2024 | 8.4 mg/l 24 Jul 2024 |
| Carbon, Organic, Dissolved as C :- {DOC} 0301 | River water | 4 | Jun 2024 – Jul 2024 | 2.9 mg/l 24 Jul 2024 |
| Chromium, Dissolved 3409 | River water | 4 | Jun 2024 – Jul 2024 | below 0.5 µg/l 24 Jul 2024 |
| Copper, Dissolved 6450 | River water | 4 | Jun 2024 – Jul 2024 | 8.2 µg/l 24 Jul 2024 |
| Hardness, Total as CaCO3 0158 | River water | 4 | Jun 2024 – Jul 2024 | 37 mg/l 24 Jul 2024 |
| Lead, Dissolved 0052 | River water | 4 | Jun 2024 – Jul 2024 | below 2 µg/l 24 Jul 2024 |
| Magnesium, Dissolved 0235 | River water | 4 | Jun 2024 – Jul 2024 | 3.9 mg/l 24 Jul 2024 |
| Nickel, Dissolved 3410 | River water | 4 | Jun 2024 – Jul 2024 | below 1 µg/l 24 Jul 2024 |
| Nitrite as N 0118 | River water | 6 | Apr 2026 – Sep 2026 | below 0.004 mg/l 29 Sep 2026 |
| Nitrogen, Total Oxidised as N 0116 | River water | 6 | Apr 2026 – Sep 2026 | 2.6 mg/l 29 Sep 2026 |
| Zinc, Dissolved 3408 | River water | 4 | Jun 2024 – Jul 2024 | 24 µg/l 24 Jul 2024 |
FloodRadar does not grade these results: there is no overall score, and official river classifications are a separate dataset. A sample taken downstream of an overflow does not by itself show where anything in it came from. River connections and distances are traced on OS Open Rivers (edition 2026-04), which leaves out many small channels.
Water samples: Environment Agency Water Quality Archive, © Environment Agency and/or database right 2026, Open Government Licence v3.0.
Contains OS data © Crown copyright and database rights 2026.