River Tamar at Greystone Bridge
EA name: RIVER TAMAR AT GREYSTONE BRIDGE
Environment Agency sampling point SW-81250277 · 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
- 6 Oct 2026, 14:0519 days ago · time as the Environment Agency records it (UK clock time; the source gives no time zone)
- Samples banked
- 14 since 10 Oct 2023 Imported periods: 1 Oct 2023 – 25 Oct 2026. Samples outside them are not shown here.
- Latest sample
- River / running surface water Environmental monitoring statutory (EU directives) · results completed 8 Oct 2026
- Where
- National Grid 236838, 80363As published, to the nearest 1 m. Open in a map
- River, by its own name
- Tamar
- River, by the map
- River TamarPlaced on the river its name gives, 4 m from the line.
- Next gauge downstream
- Gunnislake On the River Tamar · 19 km along the riverBeside Greystone Bridge: too close to say above or below.
- Nearest gauge upstream
- Lifton Park On the River Lyd · 5.8 km along the riverPolson Bridge On the River Tamar · 7.0 km along the river
- Why it was sampled
- Monitoring (national agency policy) (7 samples)
Environmental monitoring statutory (EU directives) (7 samples)
Results here were completed a median of 2 days after the sample was taken (2 to 9 days, 5 samples).
Main measurements, river water
Dissolved oxygen
% saturation · code 9901 · %
98.8%
Sampled 6 Oct 2026, 19 days ago · 14 results banked
Every result (14)
| Sampled | Result as published | Reads as |
|---|---|---|
| 6 Oct 2026, 14:05 | 98.8 | 98.8% |
| 7 Sep 2026, 09:33 | 90.1 | 90.1% |
| 10 Aug 2026, 12:21 | 99.2 | 99.2% |
| 10 Jul 2026, 10:37 | 99.3 | 99.3% |
| 16 Jun 2026, 11:56 | 98.6 | 98.6% |
| 12 May 2026, 11:17 | 97.8 | 97.8% |
| 14 Apr 2026, 14:34 | 112.8 | 112.8% |
| 21 Mar 2024, 13:24 | 95.7 | 95.7% |
| 1 Feb 2024, 11:36 | 96.9 | 96.9% |
| 31 Jan 2024, 14:26 | 98.8 | 98.8% |
| 4 Jan 2024, 13:29 | 96.6 | 96.6% |
| 7 Dec 2023, 14:02 | 96.9 | 96.9% |
| 16 Nov 2023, 09:53 | 95.5 | 95.5% |
| 10 Oct 2023, 13:50 | 101.4 | 101.4% |
Dissolved oxygen
as O2 · code 9924 · mg/l
9.73 mg/l
Sampled 6 Oct 2026, 19 days ago · 14 results banked
Every result (14)
| Sampled | Result as published | Reads as |
|---|---|---|
| 6 Oct 2026, 14:05 | 9.73 | 9.73 mg/l |
| 7 Sep 2026, 09:33 | 8.42 | 8.42 mg/l |
| 10 Aug 2026, 12:21 | 9.02 | 9.02 mg/l |
| 10 Jul 2026, 10:37 | 8.9 | 8.9 mg/l |
| 16 Jun 2026, 11:56 | 9.58 | 9.58 mg/l |
| 12 May 2026, 11:17 | 10.6 | 10.6 mg/l |
| 14 Apr 2026, 14:34 | 12.4 | 12.4 mg/l |
| 21 Mar 2024, 13:24 | 10.4 | 10.4 mg/l |
| 1 Feb 2024, 11:36 | 11.4 | 11.4 mg/l |
| 31 Jan 2024, 14:26 | 11.8 | 11.8 mg/l |
| 4 Jan 2024, 13:29 | 11.2 | 11.2 mg/l |
| 7 Dec 2023, 14:02 | 11 | 11 mg/l |
| 16 Nov 2023, 09:53 | 10.8 | 10.8 mg/l |
| 10 Oct 2023, 13:50 | 10.3 | 10.3 mg/l |
Water temperature
code 0076 · °C
16 °C
Sampled 6 Oct 2026, 19 days ago · 14 results banked
Every result (14)
| Sampled | Result as published | Reads as |
|---|---|---|
| 6 Oct 2026, 14:05 | 16 | 16 °C |
| 7 Sep 2026, 09:33 | 18.5 | 18.5 °C |
| 10 Aug 2026, 12:21 | 19.9 | 19.9 °C |
| 10 Jul 2026, 10:37 | 20.6 | 20.6 °C |
| 16 Jun 2026, 11:56 | 16.6 | 16.6 °C |
| 12 May 2026, 11:17 | 11.7 | 11.7 °C |
| 14 Apr 2026, 14:34 | 11 | 11 °C |
| 21 Mar 2024, 13:24 | 11.5 | 11.5 °C |
| 1 Feb 2024, 11:36 | 8.1 | 8.1 °C |
| 31 Jan 2024, 14:26 | 7.5 | 7.5 °C |
| 4 Jan 2024, 13:29 | 8.8 | 8.8 °C |
| 7 Dec 2023, 14:02 | 9.6 | 9.6 °C |
| 16 Nov 2023, 09:53 | 9.8 | 9.8 °C |
| 10 Oct 2023, 13:50 | 14.6 | 14.6 °C |
pH
code 0061
7.68
Sampled 6 Oct 2026, 19 days ago · 14 results banked
Every result (14)
| Sampled | Result as published | Reads as |
|---|---|---|
| 6 Oct 2026, 14:05 | 7.68 | 7.68 |
| 7 Sep 2026, 09:33 | 7.44 | 7.44 |
| 10 Aug 2026, 12:21 | 7.82 | 7.82 |
| 10 Jul 2026, 10:37 | 8.12 | 8.12 |
| 16 Jun 2026, 11:56 | 7.58 | 7.58 |
| 12 May 2026, 11:17 | 7.69 | 7.69 |
| 14 Apr 2026, 14:34 | 8.28 | 8.28 |
| 21 Mar 2024, 13:24 | 7.45 | 7.45 |
| 1 Feb 2024, 11:36 | 7.33 | 7.33 |
| 31 Jan 2024, 14:26 | 7.44 | 7.44 |
| 4 Jan 2024, 13:29 | 7.26 | 7.26 |
| 7 Dec 2023, 14:02 | 7.11 | 7.11 |
| 16 Nov 2023, 09:53 | 6.94 | 6.94 |
| 10 Oct 2023, 13:50 | 7.43 | 7.43 |
Ammonia
ammoniacal nitrogen as N · code 0111 · mg/l
below 0.03 mg/l (not detected above this)
Sampled 6 Oct 2026, 19 days ago · 14 results banked
Every result (14)
| Sampled | Result as published | Reads as |
|---|---|---|
| 6 Oct 2026, 14:05 | <0.03 | below 0.03 mg/l (not detected above this) |
| 7 Sep 2026, 09:33 | <0.03 | below 0.03 mg/l (not detected above this) |
| 10 Aug 2026, 12:21 | <0.03 | below 0.03 mg/l (not detected above this) |
| 10 Jul 2026, 10:37 | <0.03 | below 0.03 mg/l (not detected above this) |
| 16 Jun 2026, 11:56 | <0.03 | below 0.03 mg/l (not detected above this) |
| 12 May 2026, 11:17 | <0.03 | below 0.03 mg/l (not detected above this) |
| 14 Apr 2026, 14:34 | <0.03 | below 0.03 mg/l (not detected above this) |
| 21 Mar 2024, 13:24 | <0.03 | below 0.03 mg/l (not detected above this) |
| 1 Feb 2024, 11:36 | <0.03 | below 0.03 mg/l (not detected above this) |
| 31 Jan 2024, 14:26 | <0.03 | below 0.03 mg/l (not detected above this) |
| 4 Jan 2024, 13:29 | 0.045 | 0.045 mg/l |
| 7 Dec 2023, 14:02 | 0.087 | 0.087 mg/l |
| 16 Nov 2023, 09:53 | 0.08 | 0.08 mg/l |
| 10 Oct 2023, 13:50 | <0.03 | below 0.03 mg/l (not detected above this) |
Nitrate
as nitrogen (N) · code 0117 · mg/l
0.866 mg/l
Sampled 6 Oct 2026, 19 days ago · 14 results banked
Every result (14)
| Sampled | Result as published | Reads as |
|---|---|---|
| 6 Oct 2026, 14:05 | 0.866 | 0.866 mg/l |
| 7 Sep 2026, 09:33 | 0.846 | 0.846 mg/l |
| 10 Aug 2026, 12:21 | 0.586 | 0.586 mg/l |
| 10 Jul 2026, 10:37 | 0.816 | 0.816 mg/l |
| 16 Jun 2026, 11:56 | 1.29 | 1.29 mg/l |
| 12 May 2026, 11:17 | 1.19 | 1.19 mg/l |
| 14 Apr 2026, 14:34 | 1.2 | 1.2 mg/l |
| 21 Mar 2024, 13:24 | 1.89 | 1.89 mg/l |
| 1 Feb 2024, 11:36 | 2.19 | 2.19 mg/l |
| 31 Jan 2024, 14:26 | 2.19 | 2.19 mg/l |
| 4 Jan 2024, 13:29 | 2.19 | 2.19 mg/l |
| 7 Dec 2023, 14:02 | 1.39 | 1.39 mg/l |
| 16 Nov 2023, 09:53 | 1.59 | 1.59 mg/l |
| 10 Oct 2023, 13:50 | 1.7 | 1.7 mg/l |
Phosphate
orthophosphate, reactive, as P · code 0180 · mg/l
0.014 mg/l
Sampled 6 Oct 2026, 19 days ago · 14 results banked
Every result (14)
| Sampled | Result as published | Reads as |
|---|---|---|
| 6 Oct 2026, 14:05 | 0.014 | 0.014 mg/l |
| 7 Sep 2026, 09:33 | <0.01 | below 0.01 mg/l (not detected above this) |
| 10 Aug 2026, 12:21 | <0.01 | below 0.01 mg/l (not detected above this) |
| 10 Jul 2026, 10:37 | <0.01 | below 0.01 mg/l (not detected above this) |
| 16 Jun 2026, 11:56 | 0.036 | 0.036 mg/l |
| 12 May 2026, 11:17 | 0.016 | 0.016 mg/l |
| 14 Apr 2026, 14:34 | 0.017 | 0.017 mg/l |
| 21 Mar 2024, 13:24 | 0.024 | 0.024 mg/l |
| 1 Feb 2024, 11:36 | 0.025 | 0.025 mg/l |
| 31 Jan 2024, 14:26 | 0.026 | 0.026 mg/l |
| 4 Jan 2024, 13:29 | 0.033 | 0.033 mg/l |
| 7 Dec 2023, 14:02 | 0.036 | 0.036 mg/l |
| 16 Nov 2023, 09:53 | 0.035 | 0.035 mg/l |
| 10 Oct 2023, 13:50 | 0.026 | 0.026 mg/l |
Conductivity
at 25 °C · code 0077 · µS/cm
189 µS/cm
Sampled 6 Oct 2026, 19 days ago · 14 results banked
Every result (14)
| Sampled | Result as published | Reads as |
|---|---|---|
| 6 Oct 2026, 14:05 | 189 | 189 µS/cm |
| 7 Sep 2026, 09:33 | 188 | 188 µS/cm |
| 10 Aug 2026, 12:21 | 162 | 162 µS/cm |
| 10 Jul 2026, 10:37 | 187 | 187 µS/cm |
| 16 Jun 2026, 11:56 | 201 | 201 µS/cm |
| 12 May 2026, 11:17 | 200 | 200 µS/cm |
| 14 Apr 2026, 14:34 | 184 | 184 µS/cm |
| 21 Mar 2024, 13:24 | 170 | 170 µS/cm |
| 1 Feb 2024, 11:36 | 195 | 195 µS/cm |
| 31 Jan 2024, 14:26 | 195 | 195 µS/cm |
| 4 Jan 2024, 13:29 | 168 | 168 µS/cm |
| 7 Dec 2023, 14:02 | 141 | 141 µS/cm |
| 16 Nov 2023, 09:53 | 154 | 154 µS/cm |
| 10 Oct 2023, 13:50 | 196 | 196 µS/cm |
Everything measured here
12 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 12 rows
| Determinand | Material | Results | First – last | Latest result |
|---|---|---|---|---|
| Oxygen, Dissolved, % Saturation 9901 | River water | 14 | Oct 2023 – Oct 2026 | 98.8% 6 Oct 2026 |
| Oxygen, Dissolved as O2 9924 | River water | 14 | Oct 2023 – Oct 2026 | 9.73 mg/l 6 Oct 2026 |
| Temperature of Water 0076 | River water | 14 | Oct 2023 – Oct 2026 | 16 °C 6 Oct 2026 |
| pH 0061 | River water | 14 | Oct 2023 – Oct 2026 | 7.68 6 Oct 2026 |
| Ammoniacal Nitrogen as N 0111 | River water | 14 | Oct 2023 – Oct 2026 | below 0.03 mg/l 6 Oct 2026 |
| Nitrate as N 0117 | River water | 14 | Oct 2023 – Oct 2026 | 0.866 mg/l 6 Oct 2026 |
| Orthophosphate, reactive as P 0180 | River water | 14 | Oct 2023 – Oct 2026 | 0.014 mg/l 6 Oct 2026 |
| Conductivity at 25 C 0077 | River water | 14 | Oct 2023 – Oct 2026 | 189 µS/cm 6 Oct 2026 |
| Alkalinity to pH 4.5 as CaCO3 0162 | River water | 14 | Oct 2023 – Oct 2026 | 38 mg/l 6 Oct 2026 |
| Ammonia un-ionised as N 0119 | River water | 14 | Oct 2023 – Oct 2026 | below 0.00041 mg/l 6 Oct 2026 |
| Nitrite as N 0118 | River water | 14 | Oct 2023 – Oct 2026 | below 0.004 mg/l 6 Oct 2026 |
| Nitrogen, Total Oxidised as N 0116 | River water | 14 | Oct 2023 – Oct 2026 | 0.87 mg/l 6 Oct 2026 |
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.