River Gannel at Trerice Mill
EA name: RIVER GANNEL AT TRERICE MILL
Environment Agency sampling point SW-82410255 · 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
- 28 Sep 2026, 10:3610 days ago · time as the Environment Agency records it (UK clock time; the source gives no time zone)
- Samples banked
- 6 since 1 Apr 2026 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 183700, 59350As published, to the nearest 10 m. Open in a map
- River, by its own name
- Gannel
- River, by the map
- River GannelPlaced on the river its name gives, 1 m from the line.
- Next gauge downstream
- Gwills On the River Gannel · 1.0 km along the riverGWILLS 1.0 km along the river
- Why it was sampled
- Environmental monitoring statutory (EU directives) (6 samples)
Results here were completed a median of 4 days after the sample was taken (3 to 5 days, 4 samples).
Main measurements, river water
Dissolved oxygen
% saturation · code 9901 · %
96.5%
Sampled 28 Sep 2026, 10 days ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 28 Sep 2026, 10:36 | 96.5 | 96.5% |
| 11 Aug 2026, 09:33 | 92.4 | 92.4% |
| 1 Jul 2026, 09:18 | 96.4 | 96.4% |
| 16 Jun 2026, 10:09 | 98.5 | 98.5% |
| 11 May 2026, 09:32 | 99 | 99% |
| 1 Apr 2026, 09:57 | 98.6 | 98.6% |
Dissolved oxygen
as O2 · code 9924 · mg/l
10.2 mg/l
Sampled 28 Sep 2026, 10 days ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 28 Sep 2026, 10:36 | 10.2 | 10.2 mg/l |
| 11 Aug 2026, 09:33 | 9.33 | 9.33 mg/l |
| 1 Jul 2026, 09:18 | 9.55 | 9.55 mg/l |
| 16 Jun 2026, 10:09 | 10.1 | 10.1 mg/l |
| 11 May 2026, 09:32 | 11 | 11 mg/l |
| 1 Apr 2026, 09:57 | 11 | 11 mg/l |
Water temperature
code 0076 · °C
12.8 °C
Sampled 28 Sep 2026, 10 days ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 28 Sep 2026, 10:36 | 12.8 | 12.8 °C |
| 11 Aug 2026, 09:33 | 14.8 | 14.8 °C |
| 1 Jul 2026, 09:18 | 15.7 | 15.7 °C |
| 16 Jun 2026, 10:09 | 14.2 | 14.2 °C |
| 11 May 2026, 09:32 | 10.7 | 10.7 °C |
| 1 Apr 2026, 09:57 | 10.4 | 10.4 °C |
pH
code 0061
7.92
Sampled 28 Sep 2026, 10 days ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 28 Sep 2026, 10:36 | 7.92 | 7.92 |
| 11 Aug 2026, 09:33 | 7.8 | 7.8 |
| 1 Jul 2026, 09:18 | 7.81 | 7.81 |
| 16 Jun 2026, 10:09 | 7.93 | 7.93 |
| 11 May 2026, 09:32 | 7.77 | 7.77 |
| 1 Apr 2026, 09:57 | 7.78 | 7.78 |
Ammonia
ammoniacal nitrogen as N · code 0111 · mg/l
below 0.03 mg/l (not detected above this)
Sampled 28 Sep 2026, 10 days ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 28 Sep 2026, 10:36 | <0.03 | below 0.03 mg/l (not detected above this) |
| 11 Aug 2026, 09:33 | 0.19 | 0.19 mg/l |
| 1 Jul 2026, 09:18 | <0.03 | below 0.03 mg/l (not detected above this) |
| 16 Jun 2026, 10:09 | <0.03 | below 0.03 mg/l (not detected above this) |
| 11 May 2026, 09:32 | <0.03 | below 0.03 mg/l (not detected above this) |
| 1 Apr 2026, 09:57 | <0.03 | below 0.03 mg/l (not detected above this) |
Nitrate
as nitrogen (N) · code 0117 · mg/l
5.9 mg/l
Sampled 28 Sep 2026, 10 days ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 28 Sep 2026, 10:36 | 5.9 | 5.9 mg/l |
| 11 Aug 2026, 09:33 | 6.19 | 6.19 mg/l |
| 1 Jul 2026, 09:18 | 5.4 | 5.4 mg/l |
| 16 Jun 2026, 10:09 | 4.4 | 4.4 mg/l |
| 11 May 2026, 09:32 | 5.09 | 5.09 mg/l |
| 1 Apr 2026, 09:57 | 4.7 | 4.7 mg/l |
Phosphate
orthophosphate, reactive, as P · code 0180 · mg/l
0.095 mg/l
Sampled 28 Sep 2026, 10 days ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 28 Sep 2026, 10:36 | 0.095 | 0.095 mg/l |
| 11 Aug 2026, 09:33 | 0.089 | 0.089 mg/l |
| 1 Jul 2026, 09:18 | 0.087 | 0.087 mg/l |
| 16 Jun 2026, 10:09 | 0.039 | 0.039 mg/l |
| 11 May 2026, 09:32 | 0.034 | 0.034 mg/l |
| 1 Apr 2026, 09:57 | 0.032 | 0.032 mg/l |
Conductivity
at 25 °C · code 0077 · µS/cm
431 µS/cm
Sampled 28 Sep 2026, 10 days ago · 6 results banked
Every result (6)
| Sampled | Result as published | Reads as |
|---|---|---|
| 28 Sep 2026, 10:36 | 431 | 431 µS/cm |
| 11 Aug 2026, 09:33 | 406 | 406 µS/cm |
| 1 Jul 2026, 09:18 | 283 | 283 µS/cm |
| 16 Jun 2026, 10:09 | 325 | 325 µS/cm |
| 11 May 2026, 09:32 | 324 | 324 µS/cm |
| 1 Apr 2026, 09:57 | 303 | 303 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 | 6 | Apr 2026 – Sep 2026 | 96.5% 28 Sep 2026 |
| Oxygen, Dissolved as O2 9924 | River water | 6 | Apr 2026 – Sep 2026 | 10.2 mg/l 28 Sep 2026 |
| Temperature of Water 0076 | River water | 6 | Apr 2026 – Sep 2026 | 12.8 °C 28 Sep 2026 |
| pH 0061 | River water | 6 | Apr 2026 – Sep 2026 | 7.92 28 Sep 2026 |
| Ammoniacal Nitrogen as N 0111 | River water | 6 | Apr 2026 – Sep 2026 | below 0.03 mg/l 28 Sep 2026 |
| Nitrate as N 0117 | River water | 6 | Apr 2026 – Sep 2026 | 5.9 mg/l 28 Sep 2026 |
| Orthophosphate, reactive as P 0180 | River water | 6 | Apr 2026 – Sep 2026 | 0.095 mg/l 28 Sep 2026 |
| Conductivity at 25 C 0077 | River water | 6 | Apr 2026 – Sep 2026 | 431 µS/cm 28 Sep 2026 |
| Alkalinity to pH 4.5 as CaCO3 0162 | River water | 6 | Apr 2026 – Sep 2026 | 94 mg/l 28 Sep 2026 |
| Ammonia un-ionised as N 0119 | River water | 6 | Apr 2026 – Sep 2026 | below 0.00056 mg/l 28 Sep 2026 |
| Nitrite as N 0118 | River water | 6 | Apr 2026 – Sep 2026 | 0.0045 mg/l 28 Sep 2026 |
| Nitrogen, Total Oxidised as N 0116 | River water | 6 | Apr 2026 – Sep 2026 | 5.9 mg/l 28 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.