Heligan Stream at Heligan
EA name: HELIGAN STREAM AT HELIGAN (also listed as “RSN0163 HELIGAN STREAM AT HELIGAN”)
Environment Agency sampling point SW-RSN0163 · 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
- 19 Mar 2026, 11:416 months ago · time as the Environment Agency records it (UK clock time; the source gives no time zone). Not sampled since, as far as the archive shows: the Environment Agency was asked up to 30 Sep 2026 and had nothing newer.
- Samples banked
- 24 since 6 Oct 2023 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)
- Where
- National Grid 200086, 45764As published, to the nearest 1 m. Open in a map
- River, by its own name
- Heligan Stream
- River, by the map
- An unnamed streamPlaced by position alone (the only river line close by), 1 m from the line.
- Next gauge downstream
- Mevagissey On the Mevagissey Stream · 1.5 km along the river
- Why it was sampled
- Planned investigation (local monitoring) (21 samples)
Monitoring (national agency policy) (3 samples)
Main measurements, river water
Dissolved oxygen
% saturation · code 9901 · %
99.1%
Sampled 19 Mar 2026, 6 months ago · 22 results banked
Every result (22)
| Sampled | Result as published | Reads as |
|---|---|---|
| 19 Mar 2026, 11:41 | 99.1 | 99.1% |
| 4 Feb 2026, 12:16 | 99 | 99% |
| 5 Jan 2026, 13:08 | 97.9 | 97.9% |
| 3 Dec 2025, 11:40 | 98.2 | 98.2% |
| 12 Nov 2025, 09:52 | 98.2 | 98.2% |
| 7 Oct 2025, 13:20 | 96.1 | 96.1% |
| 9 Sep 2025, 13:55 | 94.4 | 94.4% |
| 15 Apr 2025, 12:51 | 98.5 | 98.5% |
| 8 Apr 2025, 12:15 | 95.5 | 95.5% |
| 13 Mar 2025, 12:30 | 100.7 | 100.7% |
| 25 Feb 2025, 11:04 | 100 | 100% |
| 16 Jan 2025, 08:50 | 100 | 100% |
| 10 Dec 2024, 13:10 | 100 | 100% |
| 13 Nov 2024, 09:44 | 99 | 99% |
| 29 Oct 2024, 12:19 | 98.4 | 98.4% |
| 7 Oct 2024, 11:47 | 97.6 | 97.6% |
| 25 Sep 2024, 10:16 | 98 | 98% |
| 14 Aug 2024, 11:57 | 96.4 | 96.4% |
| 18 Jul 2024, 11:32 | 99.1 | 99.1% |
| 5 Dec 2023, 10:51 | 98 | 98% |
| 8 Nov 2023, 12:20 | 97.5 | 97.5% |
| 6 Oct 2023, 11:55 | 93.7 | 93.7% |
Dissolved oxygen
as O2 · code 9924 · mg/l
11 mg/l
Sampled 19 Mar 2026, 6 months ago · 22 results banked
Every result (22)
| Sampled | Result as published | Reads as |
|---|---|---|
| 19 Mar 2026, 11:41 | 11 | 11 mg/l |
| 4 Feb 2026, 12:16 | 11 | 11 mg/l |
| 5 Jan 2026, 13:08 | 12.1 | 12.1 mg/l |
| 3 Dec 2025, 11:40 | 11.1 | 11.1 mg/l |
| 12 Nov 2025, 09:52 | 10.3 | 10.3 mg/l |
| 7 Oct 2025, 13:20 | 10.1 | 10.1 mg/l |
| 9 Sep 2025, 13:55 | 9.73 | 9.73 mg/l |
| 15 Apr 2025, 12:51 | 11.3 | 11.3 mg/l |
| 8 Apr 2025, 12:15 | 10.8 | 10.8 mg/l |
| 13 Mar 2025, 12:30 | 11.9 | 11.9 mg/l |
| 25 Feb 2025, 11:04 | 11.2 | 11.2 mg/l |
| 16 Jan 2025, 08:50 | 11.5 | 11.5 mg/l |
| 10 Dec 2024, 13:10 | 11.4 | 11.4 mg/l |
| 13 Nov 2024, 09:44 | 11.2 | 11.2 mg/l |
| 29 Oct 2024, 12:19 | 10.3 | 10.3 mg/l |
| 7 Oct 2024, 11:47 | 10.1 | 10.1 mg/l |
| 25 Sep 2024, 10:16 | 10.3 | 10.3 mg/l |
| 14 Aug 2024, 11:57 | 9.55 | 9.55 mg/l |
| 18 Jul 2024, 11:32 | 9.97 | 9.97 mg/l |
| 5 Dec 2023, 10:51 | 11.1 | 11.1 mg/l |
| 8 Nov 2023, 12:20 | 10.5 | 10.5 mg/l |
| 6 Oct 2023, 11:55 | 9.52 | 9.52 mg/l |
Water temperature
code 0076 · °C
10.7 °C
Sampled 19 Mar 2026, 6 months ago · 22 results banked
Every result (22)
| Sampled | Result as published | Reads as |
|---|---|---|
| 19 Mar 2026, 11:41 | 10.7 | 10.7 °C |
| 4 Feb 2026, 12:16 | 10.4 | 10.4 °C |
| 5 Jan 2026, 13:08 | 6.2 | 6.2 °C |
| 3 Dec 2025, 11:40 | 9.7 | 9.7 °C |
| 12 Nov 2025, 09:52 | 13.3 | 13.3 °C |
| 7 Oct 2025, 13:20 | 13.2 | 13.2 °C |
| 9 Sep 2025, 13:55 | 13.9 | 13.9 °C |
| 15 Apr 2025, 12:51 | 9.3 | 9.3 °C |
| 8 Apr 2025, 12:15 | 10 | 10 °C |
| 13 Mar 2025, 12:30 | 8.1 | 8.1 °C |
| 25 Feb 2025, 11:04 | 10.1 | 10.1 °C |
| 16 Jan 2025, 08:50 | 9.2 | 9.2 °C |
| 10 Dec 2024, 13:10 | 9.5 | 9.5 °C |
| 13 Nov 2024, 09:44 | 9.8 | 9.8 °C |
| 29 Oct 2024, 12:19 | 13 | 13 °C |
| 7 Oct 2024, 11:47 | 13.7 | 13.7 °C |
| 25 Sep 2024, 10:16 | 13.1 | 13.1 °C |
| 14 Aug 2024, 11:57 | 15.7 | 15.7 °C |
| 18 Jul 2024, 11:32 | 15 | 15 °C |
| 5 Dec 2023, 10:51 | 9.7 | 9.7 °C |
| 8 Nov 2023, 12:20 | 12.1 | 12.1 °C |
| 6 Oct 2023, 11:55 | 14.5 | 14.5 °C |
pH
code 0061
7.87
Sampled 19 Mar 2026, 6 months ago · 22 results banked
Every result (22)
| Sampled | Result as published | Reads as |
|---|---|---|
| 19 Mar 2026, 11:41 | 7.87 | 7.87 |
| 4 Feb 2026, 12:16 | 7.66 | 7.66 |
| 5 Jan 2026, 13:08 | 7.7 | 7.7 |
| 3 Dec 2025, 11:40 | 7.52 | 7.52 |
| 12 Nov 2025, 09:52 | 7.64 | 7.64 |
| 7 Oct 2025, 13:20 | 7.7 | 7.7 |
| 9 Sep 2025, 13:55 | 7.92 | 7.92 |
| 15 Apr 2025, 12:51 | 7.7 | 7.7 |
| 8 Apr 2025, 12:15 | 7.93 | 7.93 |
| 13 Mar 2025, 12:30 | 7.85 | 7.85 |
| 25 Feb 2025, 11:04 | 7.44 | 7.44 |
| 16 Jan 2025, 08:50 | 7.78 | 7.78 |
| 10 Dec 2024, 13:10 | 7.72 | 7.72 |
| 13 Nov 2024, 09:44 | 7.87 | 7.87 |
| 29 Oct 2024, 12:19 | 7.75 | 7.75 |
| 7 Oct 2024, 11:47 | 7.75 | 7.75 |
| 25 Sep 2024, 10:16 | 7.64 | 7.64 |
| 14 Aug 2024, 11:57 | 8 | 8 |
| 18 Jul 2024, 11:32 | 7.88 | 7.88 |
| 5 Dec 2023, 10:51 | 7.63 | 7.63 |
| 8 Nov 2023, 12:20 | 7.34 | 7.34 |
| 6 Oct 2023, 11:55 | 7.73 | 7.73 |
Ammonia
ammoniacal nitrogen as N · code 0111 · mg/l
below 0.03 mg/l (not detected above this)
Sampled 19 Mar 2026, 6 months ago · 22 results banked
Every result (22)
| Sampled | Result as published | Reads as |
|---|---|---|
| 19 Mar 2026, 11:41 | <0.03 | below 0.03 mg/l (not detected above this) |
| 4 Feb 2026, 12:16 | <0.03 | below 0.03 mg/l (not detected above this) |
| 5 Jan 2026, 13:08 | <0.03 | below 0.03 mg/l (not detected above this) |
| 3 Dec 2025, 11:40 | <0.03 | below 0.03 mg/l (not detected above this) |
| 12 Nov 2025, 09:52 | <0.03 | below 0.03 mg/l (not detected above this) |
| 7 Oct 2025, 13:20 | <0.03 | below 0.03 mg/l (not detected above this) |
| 9 Sep 2025, 13:55 | <0.03 | below 0.03 mg/l (not detected above this) |
| 15 Apr 2025, 12:51 | <0.03 | below 0.03 mg/l (not detected above this) |
| 8 Apr 2025, 12:15 | <0.03 | below 0.03 mg/l (not detected above this) |
| 13 Mar 2025, 12:30 | <0.03 | below 0.03 mg/l (not detected above this) |
| 25 Feb 2025, 11:04 | <0.03 | below 0.03 mg/l (not detected above this) |
| 16 Jan 2025, 08:50 | <0.03 | below 0.03 mg/l (not detected above this) |
| 10 Dec 2024, 13:10 | <0.03 | below 0.03 mg/l (not detected above this) |
| 13 Nov 2024, 09:44 | <0.03 | below 0.03 mg/l (not detected above this) |
| 29 Oct 2024, 12:19 | <0.03 | below 0.03 mg/l (not detected above this) |
| 7 Oct 2024, 11:47 | <0.03 | below 0.03 mg/l (not detected above this) |
| 25 Sep 2024, 10:16 | <0.03 | below 0.03 mg/l (not detected above this) |
| 14 Aug 2024, 11:57 | <0.03 | below 0.03 mg/l (not detected above this) |
| 18 Jul 2024, 11:32 | 0.031 | 0.031 mg/l |
| 5 Dec 2023, 10:51 | 0.011 | 0.011 mg/l |
| 8 Nov 2023, 12:20 | 0.0075 | 0.0075 mg/l |
| 6 Oct 2023, 11:55 | 0.0055 | 0.0055 mg/l |
Nitrate
as nitrogen (N) · code 0117 · mg/l
6.2 mg/l
Sampled 19 Mar 2026, 6 months ago · 22 results banked
Every result (22)
| Sampled | Result as published | Reads as |
|---|---|---|
| 19 Mar 2026, 11:41 | 6.2 | 6.2 mg/l |
| 4 Feb 2026, 12:16 | 6.8 | 6.8 mg/l |
| 5 Jan 2026, 13:08 | 6.6 | 6.6 mg/l |
| 3 Dec 2025, 11:40 | 6.5 | 6.5 mg/l |
| 12 Nov 2025, 09:52 | 4.6 | 4.6 mg/l |
| 7 Oct 2025, 13:20 | 4.2 | 4.2 mg/l |
| 9 Sep 2025, 13:55 | 3.4 | 3.4 mg/l |
| 15 Apr 2025, 12:51 | 3.5 | 3.5 mg/l |
| 8 Apr 2025, 12:15 | 5.6 | 5.6 mg/l |
| 13 Mar 2025, 12:30 | 6.2 | 6.2 mg/l |
| 25 Feb 2025, 11:04 | 5.4 | 5.4 mg/l |
| 16 Jan 2025, 08:50 | 6.5 | 6.5 mg/l |
| 10 Dec 2024, 13:10 | 6.6 | 6.6 mg/l |
| 13 Nov 2024, 09:44 | 5.9 | 5.9 mg/l |
| 29 Oct 2024, 12:19 | 6.3 | 6.3 mg/l |
| 7 Oct 2024, 11:47 | 4.4 | 4.4 mg/l |
| 25 Sep 2024, 10:16 | 4.1 | 4.1 mg/l |
| 14 Aug 2024, 11:57 | 4.9 | 4.9 mg/l |
| 18 Jul 2024, 11:32 | 5.09 | 5.09 mg/l |
| 5 Dec 2023, 10:51 | 5.9 | 5.9 mg/l |
| 8 Nov 2023, 12:20 | 6 | 6 mg/l |
| 6 Oct 2023, 11:55 | 3.6 | 3.6 mg/l |
Phosphate
orthophosphate, reactive, as P · code 0180 · mg/l
0.012 mg/l
Sampled 19 Mar 2026, 6 months ago · 22 results banked
Every result (22)
| Sampled | Result as published | Reads as |
|---|---|---|
| 19 Mar 2026, 11:41 | 0.012 | 0.012 mg/l |
| 4 Feb 2026, 12:16 | 0.01 | 0.01 mg/l |
| 5 Jan 2026, 13:08 | 0.012 | 0.012 mg/l |
| 3 Dec 2025, 11:40 | 0.013 | 0.013 mg/l |
| 12 Nov 2025, 09:52 | 0.016 | 0.016 mg/l |
| 7 Oct 2025, 13:20 | 0.017 | 0.017 mg/l |
| 9 Sep 2025, 13:55 | 0.027 | 0.027 mg/l |
| 15 Apr 2025, 12:51 | 0.016 | 0.016 mg/l |
| 8 Apr 2025, 12:15 | <0.01 | below 0.01 mg/l (not detected above this) |
| 13 Mar 2025, 12:30 | 0.012 | 0.012 mg/l |
| 25 Feb 2025, 11:04 | 0.012 | 0.012 mg/l |
| 16 Jan 2025, 08:50 | 0.015 | 0.015 mg/l |
| 10 Dec 2024, 13:10 | <0.01 | below 0.01 mg/l (not detected above this) |
| 13 Nov 2024, 09:44 | 0.012 | 0.012 mg/l |
| 29 Oct 2024, 12:19 | <0.01 | below 0.01 mg/l (not detected above this) |
| 7 Oct 2024, 11:47 | 0.022 | 0.022 mg/l |
| 25 Sep 2024, 10:16 | 0.035 | 0.035 mg/l |
| 14 Aug 2024, 11:57 | 0.029 | 0.029 mg/l |
| 18 Jul 2024, 11:32 | 0.024 | 0.024 mg/l |
| 5 Dec 2023, 10:51 | 0.01 | 0.01 mg/l |
| 8 Nov 2023, 12:20 | 0.015 | 0.015 mg/l |
| 6 Oct 2023, 11:55 | 0.026 | 0.026 mg/l |
Conductivity
at 25 °C · code 0077 · µS/cm
282 µS/cm
Sampled 19 Mar 2026, 6 months ago · 22 results banked
Every result (22)
| Sampled | Result as published | Reads as |
|---|---|---|
| 19 Mar 2026, 11:41 | 282 | 282 µS/cm |
| 4 Feb 2026, 12:16 | 283 | 283 µS/cm |
| 5 Jan 2026, 13:08 | 301 | 301 µS/cm |
| 3 Dec 2025, 11:40 | 280 | 280 µS/cm |
| 12 Nov 2025, 09:52 | 270 | 270 µS/cm |
| 7 Oct 2025, 13:20 | 292 | 292 µS/cm |
| 9 Sep 2025, 13:55 | 285 | 285 µS/cm |
| 15 Apr 2025, 12:51 | 246 | 246 µS/cm |
| 8 Apr 2025, 12:15 | 293 | 293 µS/cm |
| 13 Mar 2025, 12:30 | 292 | 292 µS/cm |
| 25 Feb 2025, 11:04 | 265 | 265 µS/cm |
| 16 Jan 2025, 08:50 | 249 | 249 µS/cm |
| 10 Dec 2024, 13:10 | 290 | 290 µS/cm |
| 13 Nov 2024, 09:44 | 294 | 294 µS/cm |
| 29 Oct 2024, 12:19 | 288 | 288 µS/cm |
| 7 Oct 2024, 11:47 | 284 | 284 µS/cm |
| 25 Sep 2024, 10:16 | 278 | 278 µS/cm |
| 14 Aug 2024, 11:57 | 310 | 310 µS/cm |
| 18 Jul 2024, 11:32 | 304 | 304 µS/cm |
| 5 Dec 2023, 10:51 | 291 | 291 µS/cm |
| 8 Nov 2023, 12:20 | 279 | 279 µS/cm |
| 6 Oct 2023, 11:55 | 307 | 307 µS/cm |
E. coli
confirmed, membrane filtration · code 2348 · per 100 ml
1200 per 100 ml
Sampled 29 Jan 2025, 20 months ago · 2 results banked
Every result (2)
| Sampled | Result as published | Reads as |
|---|---|---|
| 29 Jan 2025, 13:22 | 1200 | 1200 per 100 ml |
| 29 Jan 2025, 12:18 | 650 | 650 per 100 ml |
Everything measured here
22 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 22 rows
| Determinand | Material | Results | First – last | Latest result |
|---|---|---|---|---|
| Oxygen, Dissolved, % Saturation 9901 | River water | 22 | Oct 2023 – Mar 2026 | 99.1% 19 Mar 2026 |
| Oxygen, Dissolved as O2 9924 | River water | 22 | Oct 2023 – Mar 2026 | 11 mg/l 19 Mar 2026 |
| Temperature of Water 0076 | River water | 22 | Oct 2023 – Mar 2026 | 10.7 °C 19 Mar 2026 |
| pH 0061 | River water | 22 | Oct 2023 – Mar 2026 | 7.87 19 Mar 2026 |
| Ammoniacal Nitrogen as N 0111 | River water | 22 | Oct 2023 – Mar 2026 | below 0.03 mg/l 19 Mar 2026 |
| Nitrate as N 0117 | River water | 22 | Oct 2023 – Mar 2026 | 6.2 mg/l 19 Mar 2026 |
| Orthophosphate, reactive as P 0180 | River water | 22 | Oct 2023 – Mar 2026 | 0.012 mg/l 19 Mar 2026 |
| Conductivity at 25 C 0077 | River water | 22 | Oct 2023 – Mar 2026 | 282 µS/cm 19 Mar 2026 |
| Escherichia coli : Confirmed : MF 2348 | River water | 2 | Jan 2025 – Jan 2025 | 1200 per 100 ml 29 Jan 2025 |
| Alkalinity to pH 4.5 as CaCO3 0162 | River water | 21 | Oct 2023 – Mar 2026 | 52 mg/l 19 Mar 2026 |
| Ammonia un-ionised as N 0119 | River water | 22 | Oct 2023 – Mar 2026 | below 0.00043 mg/l 19 Mar 2026 |
| Carbon, Organic, Dissolved as C :- {DOC} 0301 | River water | 3 | Oct 2023 – Dec 2023 | 1.6 mg/l 5 Dec 2023 |
| Chloride 0172 | River water | 3 | Oct 2023 – Dec 2023 | 32 mg/l 5 Dec 2023 |
| Enterococci: Intestinal: Presumptive: MF 3722 | River water | 2 | Jan 2025 – Jan 2025 | 210 colony forming units / 100ml 29 Jan 2025 |
| MST Filtration 4926 | River water | 2 | Jan 2025 – Jan 2025 | DNA Stored 29 Jan 2025 |
| Nitrite as N 0118 | River water | 22 | Oct 2023 – Mar 2026 | below 0.004 mg/l 19 Mar 2026 |
| Nitrogen, Total as N 9686 | River water | 18 | Jul 2024 – Mar 2026 | 6.5 mg/l 19 Mar 2026 |
| Nitrogen, Total Oxidised as N 0116 | River water | 22 | Oct 2023 – Mar 2026 | 6.2 mg/l 19 Mar 2026 |
| Phosphorus, Total as P 0348 | River water | 21 | Oct 2023 – Mar 2026 | 0.023 mg/l 19 Mar 2026 |
| Silica, reactive as SiO2 0182 | River water | 3 | Oct 2023 – Dec 2023 | 5.2 mg/l 5 Dec 2023 |
| Solids, Suspended at 105 C 0135 | River water | 19 | Jul 2024 – Mar 2026 | 6.8 mg/l 19 Mar 2026 |
| Volume of Sample Filtered 4865 | River water | 2 | Jan 2025 – Jan 2025 | 870 millilitre 29 Jan 2025 |
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.