Caerhays Stream at Tubbs Mill
EA name: CAERHAYS STREAM AT TUBBS MILL
Environment Agency sampling point SW-81811127 · 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
- 21 Sep 2026, 14:1510 days ago · time as the Environment Agency records it (UK clock time; the source gives no time zone)
- Samples banked
- 72 since 4 Apr 2024 Imported periods: 1 Oct 2023 – 30 Sep 2026. Samples outside them are not shown here.
- Latest sample
- River / running surface water Planned investigation (local monitoring) · results completed 25 Sep 2026
- Where
- National Grid 196090, 43290As published, to the nearest 10 m. Open in a map
- River, by its own name
- Caerhays Stream
- River, by the map
- An unnamed streamPlaced by position alone (the only river line close by), 7 m from the line.
- Next gauge downstream
- None tracedThe map stops before any gauge.
- Why it was sampled
- Planned investigation (local monitoring) (70 samples)
Unplanned reactive monitoring (pollution incidents) (2 samples)
Results here were completed a median of 4 days after the sample was taken (2 to 41 days, 33 samples).
Main measurements, river water
Dissolved oxygen
% saturation · code 9901 · %
102.3%
Sampled 3 Sep 2026, 28 days ago · 20 results banked
Every result (20)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Sep 2026, 13:07 | 102.3 | 102.3% |
| 26 Aug 2026, 14:15 | 98.1 | 98.1% |
| 30 Jul 2026, 14:07 | 100.3 | 100.3% |
| 14 Jul 2026, 12:19 | 98.9 | 98.9% |
| 1 Jun 2026, 12:23 | 97.3 | 97.3% |
| 8 May 2026, 10:48 | 100.8 | 100.8% |
| 24 Apr 2026, 09:19 | 99.6 | 99.6% |
| 19 Mar 2026, 10:58 | 98.6 | 98.6% |
| 4 Feb 2026, 11:28 | 97.6 | 97.6% |
| 5 Jan 2026, 14:00 | 96.4 | 96.4% |
| 2 Dec 2025, 10:45 | 95 | 95% |
| 12 Nov 2025, 10:35 | 92.5 | 92.5% |
| 7 Oct 2025, 11:59 | 105.1 | 105.1% |
| 4 Sep 2025, 11:55 | 100.8 | 100.8% |
| 1 Aug 2025, 10:50 | 98.4 | 98.4% |
| 2 Jul 2025, 12:00 | 100.1 | 100.1% |
| 3 Jun 2025, 10:53 | 99.5 | 99.5% |
| 27 May 2025, 13:35 | 97.4 | 97.4% |
| 8 Apr 2025, 11:27 | 98.3 | 98.3% |
| 4 Apr 2024, 13:22 | 97.5 | 97.5% |
Dissolved oxygen
as O2 · code 9924 · mg/l
9.66 mg/l
Sampled 3 Sep 2026, 28 days ago · 18 results banked
Every result (18)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Sep 2026, 13:07 | 9.66 | 9.66 mg/l |
| 26 Aug 2026, 14:15 | 9.42 | 9.42 mg/l |
| 14 Jul 2026, 12:19 | 9.3 | 9.3 mg/l |
| 1 Jun 2026, 12:23 | 9.85 | 9.85 mg/l |
| 8 May 2026, 10:48 | 10.9 | 10.9 mg/l |
| 24 Apr 2026, 09:19 | 11 | 11 mg/l |
| 19 Mar 2026, 10:58 | 11.1 | 11.1 mg/l |
| 4 Feb 2026, 11:28 | 11 | 11 mg/l |
| 5 Jan 2026, 14:00 | 11.8 | 11.8 mg/l |
| 2 Dec 2025, 10:45 | 10.8 | 10.8 mg/l |
| 12 Nov 2025, 10:35 | 9.7 | 9.7 mg/l |
| 7 Oct 2025, 11:59 | 11 | 11 mg/l |
| 4 Sep 2025, 11:55 | 10.2 | 10.2 mg/l |
| 1 Aug 2025, 10:50 | 9.75 | 9.75 mg/l |
| 2 Jul 2025, 12:00 | 9.75 | 9.75 mg/l |
| 3 Jun 2025, 10:53 | 10.4 | 10.4 mg/l |
| 27 May 2025, 13:35 | 10.1 | 10.1 mg/l |
| 8 Apr 2025, 11:27 | 11.4 | 11.4 mg/l |
Water temperature
code 0076 · °C
18 °C
Sampled 3 Sep 2026, 28 days ago · 20 results banked
Every result (20)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Sep 2026, 13:07 | 18 | 18 °C |
| 26 Aug 2026, 14:15 | 17.2 | 17.2 °C |
| 30 Jul 2026, 14:07 | 17.1 | 17.1 °C |
| 14 Jul 2026, 12:19 | 18.2 | 18.2 °C |
| 1 Jun 2026, 12:23 | 14.7 | 14.7 °C |
| 8 May 2026, 10:48 | 11.7 | 11.7 °C |
| 24 Apr 2026, 09:19 | 10.7 | 10.7 °C |
| 19 Mar 2026, 10:58 | 10.1 | 10.1 °C |
| 4 Feb 2026, 11:28 | 9.9 | 9.9 °C |
| 5 Jan 2026, 14:00 | 6.5 | 6.5 °C |
| 2 Dec 2025, 10:45 | 9.5 | 9.5 °C |
| 12 Nov 2025, 10:35 | 13.1 | 13.1 °C |
| 7 Oct 2025, 11:59 | 13.1 | 13.1 °C |
| 4 Sep 2025, 11:55 | 14.6 | 14.6 °C |
| 1 Aug 2025, 10:50 | 15.7 | 15.7 °C |
| 2 Jul 2025, 12:00 | 16.5 | 16.5 °C |
| 3 Jun 2025, 10:53 | 13.4 | 13.4 °C |
| 27 May 2025, 13:35 | 13.4 | 13.4 °C |
| 8 Apr 2025, 11:27 | 8.9 | 8.9 °C |
| 4 Apr 2024, 13:22 | 11.8 | 11.8 °C |
pH
code 0061
8.22
Sampled 3 Sep 2026, 28 days ago · 20 results banked
Every result (20)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Sep 2026, 13:07 | 8.22 | 8.22 |
| 26 Aug 2026, 14:15 | 8.14 | 8.14 |
| 30 Jul 2026, 14:07 | 7.93 | 7.93 |
| 14 Jul 2026, 12:19 | 8.3 | 8.3 |
| 1 Jun 2026, 12:23 | 8.24 | 8.24 |
| 8 May 2026, 10:48 | 7.84 | 7.84 |
| 24 Apr 2026, 09:19 | 8.08 | 8.08 |
| 19 Mar 2026, 10:58 | 7.75 | 7.75 |
| 4 Feb 2026, 11:28 | 7.51 | 7.51 |
| 5 Jan 2026, 14:00 | 7.54 | 7.54 |
| 2 Dec 2025, 10:45 | 7.39 | 7.39 |
| 12 Nov 2025, 10:35 | 7.3 | 7.3 |
| 7 Oct 2025, 11:59 | 7.71 | 7.71 |
| 4 Sep 2025, 11:55 | 7.98 | 7.98 |
| 1 Aug 2025, 10:50 | 8.2 | 8.2 |
| 2 Jul 2025, 12:00 | 8.2 | 8.2 |
| 3 Jun 2025, 10:53 | 7.83 | 7.83 |
| 27 May 2025, 13:35 | 7.73 | 7.73 |
| 8 Apr 2025, 11:27 | 7.85 | 7.85 |
| 4 Apr 2024, 13:22 | 7.25 | 7.25 |
Ammonia
ammoniacal nitrogen as N · code 0111 · mg/l
below 0.03 mg/l (not detected above this)
Sampled 3 Sep 2026, 28 days ago · 18 results banked
Every result (18)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Sep 2026, 13:07 | <0.03 | below 0.03 mg/l (not detected above this) |
| 26 Aug 2026, 14:15 | <0.03 | below 0.03 mg/l (not detected above this) |
| 14 Jul 2026, 12:19 | <0.03 | below 0.03 mg/l (not detected above this) |
| 1 Jun 2026, 12:23 | <0.03 | below 0.03 mg/l (not detected above this) |
| 8 May 2026, 10:48 | <0.03 | below 0.03 mg/l (not detected above this) |
| 24 Apr 2026, 09:19 | <0.03 | below 0.03 mg/l (not detected above this) |
| 19 Mar 2026, 10:58 | <0.03 | below 0.03 mg/l (not detected above this) |
| 4 Feb 2026, 11:28 | 0.034 | 0.034 mg/l |
| 5 Jan 2026, 14:00 | 0.088 | 0.088 mg/l |
| 2 Dec 2025, 10:45 | 0.037 | 0.037 mg/l |
| 12 Nov 2025, 10:35 | 0.066 | 0.066 mg/l |
| 7 Oct 2025, 11:59 | <0.03 | below 0.03 mg/l (not detected above this) |
| 4 Sep 2025, 11:55 | <0.03 | below 0.03 mg/l (not detected above this) |
| 1 Aug 2025, 10:50 | <0.03 | below 0.03 mg/l (not detected above this) |
| 2 Jul 2025, 12:00 | <0.03 | below 0.03 mg/l (not detected above this) |
| 3 Jun 2025, 10:53 | <0.03 | below 0.03 mg/l (not detected above this) |
| 27 May 2025, 13:35 | <0.03 | below 0.03 mg/l (not detected above this) |
| 8 Apr 2025, 11:27 | <0.03 | below 0.03 mg/l (not detected above this) |
Nitrate
as nitrogen (N) · code 0117 · mg/l
5.2 mg/l
Sampled 3 Sep 2026, 28 days ago · 18 results banked
Every result (18)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Sep 2026, 13:07 | 5.2 | 5.2 mg/l |
| 26 Aug 2026, 14:15 | 6.3 | 6.3 mg/l |
| 14 Jul 2026, 12:19 | 6.3 | 6.3 mg/l |
| 1 Jun 2026, 12:23 | 6.8 | 6.8 mg/l |
| 8 May 2026, 10:48 | 6.39 | 6.39 mg/l |
| 24 Apr 2026, 09:19 | 6.49 | 6.49 mg/l |
| 19 Mar 2026, 10:58 | 6.59 | 6.59 mg/l |
| 4 Feb 2026, 11:28 | 6.99 | 6.99 mg/l |
| 5 Jan 2026, 14:00 | 6.37 | 6.37 mg/l |
| 2 Dec 2025, 10:45 | 6.19 | 6.19 mg/l |
| 12 Nov 2025, 10:35 | 3.29 | 3.29 mg/l |
| 7 Oct 2025, 11:59 | 4.9 | 4.9 mg/l |
| 4 Sep 2025, 11:55 | 3.6 | 3.6 mg/l |
| 1 Aug 2025, 10:50 | 6.9 | 6.9 mg/l |
| 2 Jul 2025, 12:00 | 7.19 | 7.19 mg/l |
| 3 Jun 2025, 10:53 | 7.39 | 7.39 mg/l |
| 27 May 2025, 13:35 | 6.69 | 6.69 mg/l |
| 8 Apr 2025, 11:27 | 7.7 | 7.7 mg/l |
Phosphate
orthophosphate, reactive, as P · code 0180 · mg/l
0.062 mg/l
Sampled 3 Sep 2026, 28 days ago · 18 results banked
Every result (18)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Sep 2026, 13:07 | 0.062 | 0.062 mg/l |
| 26 Aug 2026, 14:15 | 0.061 | 0.061 mg/l |
| 14 Jul 2026, 12:19 | 0.054 | 0.054 mg/l |
| 1 Jun 2026, 12:23 | 0.04 | 0.04 mg/l |
| 8 May 2026, 10:48 | 0.025 | 0.025 mg/l |
| 24 Apr 2026, 09:19 | 0.016 | 0.016 mg/l |
| 19 Mar 2026, 10:58 | 0.024 | 0.024 mg/l |
| 4 Feb 2026, 11:28 | 0.022 | 0.022 mg/l |
| 5 Jan 2026, 14:00 | 0.049 | 0.049 mg/l |
| 2 Dec 2025, 10:45 | 0.034 | 0.034 mg/l |
| 12 Nov 2025, 10:35 | 0.057 | 0.057 mg/l |
| 7 Oct 2025, 11:59 | 0.021 | 0.021 mg/l |
| 4 Sep 2025, 11:55 | 0.039 | 0.039 mg/l |
| 1 Aug 2025, 10:50 | 0.052 | 0.052 mg/l |
| 2 Jul 2025, 12:00 | 0.044 | 0.044 mg/l |
| 3 Jun 2025, 10:53 | 0.028 | 0.028 mg/l |
| 27 May 2025, 13:35 | 0.023 | 0.023 mg/l |
| 8 Apr 2025, 11:27 | <0.01 | below 0.01 mg/l (not detected above this) |
Conductivity
at 25 °C · code 0077 · µS/cm
346 µS/cm
Sampled 3 Sep 2026, 28 days ago · 20 results banked
Every result (20)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Sep 2026, 13:07 | 346 | 346 µS/cm |
| 26 Aug 2026, 14:15 | 309 | 309 µS/cm |
| 30 Jul 2026, 14:07 | 306 | 306 µS/cm |
| 14 Jul 2026, 12:19 | 302 | 302 µS/cm |
| 1 Jun 2026, 12:23 | 423 | 423 µS/cm |
| 8 May 2026, 10:48 | 279 | 279 µS/cm |
| 24 Apr 2026, 09:19 | 273 | 273 µS/cm |
| 19 Mar 2026, 10:58 | 263 | 263 µS/cm |
| 4 Feb 2026, 11:28 | 263 | 263 µS/cm |
| 5 Jan 2026, 14:00 | 334 | 334 µS/cm |
| 2 Dec 2025, 10:45 | 261 | 261 µS/cm |
| 12 Nov 2025, 10:35 | 228 | 228 µS/cm |
| 7 Oct 2025, 11:59 | 292 | 292 µS/cm |
| 4 Sep 2025, 11:55 | 308 | 308 µS/cm |
| 1 Aug 2025, 10:50 | 309 | 309 µS/cm |
| 2 Jul 2025, 12:00 | 302 | 302 µS/cm |
| 3 Jun 2025, 10:53 | 330 | 330 µS/cm |
| 27 May 2025, 13:35 | 287 | 287 µS/cm |
| 8 Apr 2025, 11:27 | 283 | 283 µS/cm |
| 4 Apr 2024, 13:22 | 246 | 246 µS/cm |
E. coli
confirmed, membrane filtration · code 2348 · per 100 ml
640 per 100 ml
Sampled 21 Sep 2026, 10 days ago · 62 results banked
Every result (62)
| Sampled | Result as published | Reads as |
|---|---|---|
| 21 Sep 2026, 14:15 | 640 | 640 per 100 ml |
| 16 Sep 2026, 14:15 | 1200 | 1200 per 100 ml |
| 9 Sep 2026, 11:29 | 6300 | 6300 per 100 ml |
| 3 Sep 2026, 13:07 | 780 | 780 per 100 ml |
| 26 Aug 2026, 14:15 | 1600 | 1600 per 100 ml |
| 18 Aug 2026, 13:38 | 3900 | 3900 per 100 ml |
| 14 Aug 2026, 10:50 | 5500 | 5500 per 100 ml |
| 6 Aug 2026, 14:52 | 1900 | 1900 per 100 ml |
| 30 Jul 2026, 14:07 | 2700 | 2700 per 100 ml |
| 26 Jul 2026, 11:52 | 2100 | 2100 per 100 ml |
| 20 Jul 2026, 14:47 | 4100 | 4100 per 100 ml |
| 14 Jul 2026, 12:19 | 14000 | 14000 per 100 ml |
| 10 Jul 2026, 12:50 | 1600 | 1600 per 100 ml |
| 30 Jun 2026, 11:42 | 2900 | 2900 per 100 ml |
| 23 Jun 2026, 11:05 | 1500 | 1500 per 100 ml |
| 18 Jun 2026, 13:25 | 1500 | 1500 per 100 ml |
| 8 Jun 2026, 14:51 | 1600 | 1600 per 100 ml |
| 1 Jun 2026, 12:23 | 2300 | 2300 per 100 ml |
| 27 May 2026, 13:16 | 1600 | 1600 per 100 ml |
| 21 May 2026, 11:20 | 430 | 430 per 100 ml |
| 16 May 2026, 13:25 | 1500 | 1500 per 100 ml |
| 17 Sep 2025, 10:35 | 6000 | 6000 per 100 ml |
| 8 Sep 2025, 14:21 | 910 | 910 per 100 ml |
| 4 Sep 2025, 11:55 | 1300 | 1300 per 100 ml |
| 28 Aug 2025, 11:27 | 1500 | 1500 per 100 ml |
| 19 Aug 2025, 15:02 | 1000 | 1000 per 100 ml |
| 15 Aug 2025, 10:00 | 1600 | 1600 per 100 ml |
| 5 Aug 2025, 14:25 | 2500 | 2500 per 100 ml |
| 1 Aug 2025, 10:50 | 1500 | 1500 per 100 ml |
| 21 Jul 2025, 13:17 | 1500 | 1500 per 100 ml |
| 15 Jul 2025, 13:07 | 820 | 820 per 100 ml |
| 11 Jul 2025, 10:40 | 2900 | 2900 per 100 ml |
| 2 Jul 2025, 12:00 | 1600 | 1600 per 100 ml |
| 27 Jun 2025, 10:50 | 3600 | 3600 per 100 ml |
| 22 Jun 2025, 12:56 | 2100 | 2100 per 100 ml |
| 9 Jun 2025, 13:23 | 7900 | 7900 per 100 ml |
| 3 Jun 2025, 10:53 | 4500 | 4500 per 100 ml |
| 28 May 2025, 11:31 | 1300 | 1300 per 100 ml |
| 23 May 2025, 13:32 | 580 | 580 per 100 ml |
| 18 May 2025, 10:30 | 330 | 330 per 100 ml |
| 3 May 2025, 12:55 | 2000 | 2000 per 100 ml |
| 20 Sep 2024, 13:00 | 870 | 870 per 100 ml |
| 10 Sep 2024, 13:17 | 2300 | 2300 per 100 ml |
| 3 Sep 2024, 14:05 | 1600 | 1600 per 100 ml |
| 26 Aug 2024, 12:37 | 1400 | 1400 per 100 ml |
| 23 Aug 2024, 11:50 | 2200 | 2200 per 100 ml |
| 13 Aug 2024, 14:14 | 2500 | 2500 per 100 ml |
| 8 Aug 2024, 13:20 | 5200 | 5200 per 100 ml |
| 29 Jul 2024, 15:13 | 2300 | 2300 per 100 ml |
| 24 Jul 2024, 10:40 | 950 | 950 per 100 ml |
| 21 Jul 2024, 15:10 | 2700 | 2700 per 100 ml |
| 8 Jul 2024, 11:00 | 3100 | 3100 per 100 ml |
| 3 Jul 2024, 13:42 | 1400 | 1400 per 100 ml |
| 24 Jun 2024, 12:39 | 1100 | 1100 per 100 ml |
| 17 Jun 2024, 12:01 | 800 | 800 per 100 ml |
| 11 Jun 2024, 12:00 | 1800 | 1800 per 100 ml |
| 4 Jun 2024, 13:36 | 750 | 750 per 100 ml |
| 31 May 2024, 12:00 | 300 | 300 per 100 ml |
| 25 May 2024, 13:17 | 360 | 360 per 100 ml |
| 17 May 2024, 12:49 | 740 | 740 per 100 ml |
| 3 May 2024, 14:18 | 1400 | 1400 per 100 ml |
| 4 Apr 2024, 13:22 | 4400 | 4400 per 100 ml |
Everything measured here
27 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 27 rows
| Determinand | Material | Results | First – last | Latest result |
|---|---|---|---|---|
| Oxygen, Dissolved, % Saturation 9901 | River water | 20 | Apr 2024 – Sep 2026 | 102.3% 3 Sep 2026 |
| Oxygen, Dissolved as O2 9924 | River water | 18 | Apr 2025 – Sep 2026 | 9.66 mg/l 3 Sep 2026 |
| Temperature of Water 0076 | River water | 20 | Apr 2024 – Sep 2026 | 18 °C 3 Sep 2026 |
| pH 0061 | River water | 20 | Apr 2024 – Sep 2026 | 8.22 3 Sep 2026 |
| Ammoniacal Nitrogen as N 0111 | River water | 18 | Apr 2025 – Sep 2026 | below 0.03 mg/l 3 Sep 2026 |
| Nitrate as N 0117 | River water | 18 | Apr 2025 – Sep 2026 | 5.2 mg/l 3 Sep 2026 |
| Orthophosphate, reactive as P 0180 | River water | 18 | Apr 2025 – Sep 2026 | 0.062 mg/l 3 Sep 2026 |
| Conductivity at 25 C 0077 | River water | 20 | Apr 2024 – Sep 2026 | 346 µS/cm 3 Sep 2026 |
| Escherichia coli : Confirmed : MF 2348 | River water | 62 | Apr 2024 – Sep 2026 | 640 per 100 ml 21 Sep 2026 |
| Alkalinity to pH 4.5 as CaCO3 0162 | River water | 18 | Apr 2025 – Sep 2026 | 62 mg/l 3 Sep 2026 |
| Ammonia un-ionised as N 0119 | River water | 18 | Apr 2025 – Sep 2026 | below 0.00098 mg/l 3 Sep 2026 |
| Bacteroides HF183 primer 5886 | River water | 4 | Aug 2024 – Jul 2026 | Present / 100ml 30 Jul 2026 |
| Bacteroidetes Marker : Human copy number 3820 | River water | 4 | Aug 2024 – Jul 2026 | 3.9 log (10) gene copies / 100ml 30 Jul 2026 |
| Bacteroidetes Marker : Ruminant 4906 | River water | 4 | Aug 2024 – Jul 2026 | Present 30 Jul 2026 |
| Bacteroidetes Marker : Ruminant copy number 3819 | River water | 4 | Aug 2024 – Jul 2026 | 5 log (10) gene copies / 100ml 30 Jul 2026 |
| Catellicoccus Marker : Seabird 3120 | River water | 2 | Jun 2025 – Jul 2026 | Not found 14 Jul 2026 |
| Catellicoccus Marker : Seabird Copy Number 3116 | River water | 2 | Jun 2025 – Jul 2026 | below 2 log (10) gene copies / 100ml 14 Jul 2026 |
| Enterococci: Intestinal: Confirmed: MF 3723 | River water | 1 | Jul 2026 – Jul 2026 | 520 colony forming units / 100ml 30 Jul 2026 |
| Enterococci: Intestinal: Presumptive: MF 3722 | River water | 62 | Apr 2024 – Sep 2026 | 350 colony forming units / 100ml 21 Sep 2026 |
| Microbial Source Tracking 4876 | River water | 4 | Aug 2024 – Jul 2026 | 1 text result 30 Jul 2026 |
| Mitochondrial Marker : Canine 4870 | River water | 2 | Jun 2025 – Jul 2026 | Present 14 Jul 2026 |
| Mitochrondrial Marker: Canine copy number 3816 | River water | 2 | Jun 2025 – Jul 2026 | 3.1 log (10) gene copies / 100ml 14 Jul 2026 |
| MST Filtration 4926 | River water | 58 | May 2024 – Sep 2026 | DNA Stored 21 Sep 2026 |
| Nitrite as N 0118 | River water | 18 | Apr 2025 – Sep 2026 | below 0.004 mg/l 3 Sep 2026 |
| Nitrogen, Total Oxidised as N 0116 | River water | 18 | Apr 2025 – Sep 2026 | 5.2 mg/l 3 Sep 2026 |
| Preparation: DNA 5923 | River water | 4 | Aug 2024 – Jul 2026 | Done 30 Jul 2026 |
| Volume of Sample Filtered 4865 | River water | 58 | May 2024 – Sep 2026 | 710 millilitre 21 Sep 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.