Warleggan River at Merrifield
EA name: WARLEGGAN RIVER AT MERRIFIELD (also listed as “RSN0915 WARLEGGAN RIVER AT MERRIFIELD”)
Environment Agency sampling point SW-RSN0915 · 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
- 7 Dec 2023, 13:452.8 years 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 8 Oct 2026 and had nothing newer.
- Samples banked
- 3 since 11 Oct 2023 Imported periods: 1 Oct 2023 – 8 Oct 2026. Samples outside them are not shown here.
- Latest sample
- River / running surface water Monitoring (national agency policy)
- Where
- National Grid 214432, 72716As published, to the nearest 1 m. Open in a map
- River, by its own name
- Warleggan
- River, by the map
- Warleggan RiverPlaced on the river its name gives, 4 m from the line.
- Next gauge downstream
- Trengoffe On the Warleggan River · 7.2 km along the river
- Why it was sampled
- Monitoring (national agency policy) (3 samples)
Main measurements, river water
Dissolved oxygen
% saturation · code 9901 · %
93.7%
Sampled 7 Dec 2023, 2.8 years ago · 3 results banked
Every result (3)
| Sampled | Result as published | Reads as |
|---|---|---|
| 7 Dec 2023, 13:45 | 93.7 | 93.7% |
| 1 Nov 2023, 12:17 | 96.3 | 96.3% |
| 11 Oct 2023, 10:51 | 97.5 | 97.5% |
Dissolved oxygen
as O2 · code 9924 · mg/l
10.8 mg/l
Sampled 7 Dec 2023, 2.8 years ago · 3 results banked
Every result (3)
| Sampled | Result as published | Reads as |
|---|---|---|
| 7 Dec 2023, 13:45 | 10.8 | 10.8 mg/l |
| 1 Nov 2023, 12:17 | 10.5 | 10.5 mg/l |
| 11 Oct 2023, 10:51 | 9.87 | 9.87 mg/l |
Water temperature
code 0076 · °C
9.2 °C
Sampled 7 Dec 2023, 2.8 years ago · 3 results banked
Every result (3)
| Sampled | Result as published | Reads as |
|---|---|---|
| 7 Dec 2023, 13:45 | 9.2 | 9.2 °C |
| 1 Nov 2023, 12:17 | 11.4 | 11.4 °C |
| 11 Oct 2023, 10:51 | 14.7 | 14.7 °C |
pH
code 0061
5.56
Sampled 7 Dec 2023, 2.8 years ago · 3 results banked
Every result (3)
| Sampled | Result as published | Reads as |
|---|---|---|
| 7 Dec 2023, 13:45 | 5.56 | 5.56 |
| 1 Nov 2023, 12:17 | 6.03 | 6.03 |
| 11 Oct 2023, 10:51 | 5.96 | 5.96 |
Ammonia
ammoniacal nitrogen as N · code 0111 · mg/l
0.02 mg/l
Sampled 7 Dec 2023, 2.8 years ago · 3 results banked
Every result (3)
| Sampled | Result as published | Reads as |
|---|---|---|
| 7 Dec 2023, 13:45 | 0.02 | 0.02 mg/l |
| 1 Nov 2023, 12:17 | 0.0042 | 0.0042 mg/l |
| 11 Oct 2023, 10:51 | 0.015 | 0.015 mg/l |
Nitrate
as nitrogen (N) · code 0117 · mg/l
0.179 mg/l
Sampled 7 Dec 2023, 2.8 years ago · 3 results banked
Every result (3)
| Sampled | Result as published | Reads as |
|---|---|---|
| 7 Dec 2023, 13:45 | 0.179 | 0.179 mg/l |
| 1 Nov 2023, 12:17 | 0.249 | 0.249 mg/l |
| 11 Oct 2023, 10:51 | 0.359 | 0.359 mg/l |
Phosphate
orthophosphate, reactive, as P · code 0180 · mg/l
0.015 mg/l
Sampled 7 Dec 2023, 2.8 years ago · 3 results banked
Every result (3)
| Sampled | Result as published | Reads as |
|---|---|---|
| 7 Dec 2023, 13:45 | 0.015 | 0.015 mg/l |
| 1 Nov 2023, 12:17 | 0.005 | 0.005 mg/l |
| 11 Oct 2023, 10:51 | 0.0053 | 0.0053 mg/l |
Conductivity
at 25 °C · code 0077 · µS/cm
46 µS/cm
Sampled 7 Dec 2023, 2.8 years ago · 3 results banked
Every result (3)
| Sampled | Result as published | Reads as |
|---|---|---|
| 7 Dec 2023, 13:45 | 46 | 46 µS/cm |
| 1 Nov 2023, 12:17 | 71 | 71 µS/cm |
| 11 Oct 2023, 10:51 | 79 | 79 µS/cm |
Everything measured here
15 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 15 rows
| Determinand | Material | Results | First – last | Latest result |
|---|---|---|---|---|
| Oxygen, Dissolved, % Saturation 9901 | River water | 3 | Oct 2023 – Dec 2023 | 93.7% 7 Dec 2023 |
| Oxygen, Dissolved as O2 9924 | River water | 3 | Oct 2023 – Dec 2023 | 10.8 mg/l 7 Dec 2023 |
| Temperature of Water 0076 | River water | 3 | Oct 2023 – Dec 2023 | 9.2 °C 7 Dec 2023 |
| pH 0061 | River water | 3 | Oct 2023 – Dec 2023 | 5.56 7 Dec 2023 |
| Ammoniacal Nitrogen as N 0111 | River water | 3 | Oct 2023 – Dec 2023 | 0.02 mg/l 7 Dec 2023 |
| Nitrate as N 0117 | River water | 3 | Oct 2023 – Dec 2023 | 0.179 mg/l 7 Dec 2023 |
| Orthophosphate, reactive as P 0180 | River water | 3 | Oct 2023 – Dec 2023 | 0.015 mg/l 7 Dec 2023 |
| Conductivity at 25 C 0077 | River water | 3 | Oct 2023 – Dec 2023 | 46 µS/cm 7 Dec 2023 |
| Alkalinity to pH 4.5 : Grans Plot 7610 | River water | 3 | Oct 2023 – Dec 2023 | 0.75 mg/l 7 Dec 2023 |
| Ammonia un-ionised as N 0119 | River water | 3 | Oct 2023 – Dec 2023 | below 0.00001 mg/l 7 Dec 2023 |
| Carbon, Organic, Dissolved as C :- {DOC} 0301 | River water | 3 | Oct 2023 – Dec 2023 | 7.4 mg/l 7 Dec 2023 |
| Nitrite as N 0118 | River water | 3 | Oct 2023 – Dec 2023 | below 0.001 mg/l 7 Dec 2023 |
| Nitrogen, Total Oxidised as N 0116 | River water | 3 | Oct 2023 – Dec 2023 | 0.18 mg/l 7 Dec 2023 |
| Phosphorus, Total as P 0348 | River water | 3 | Oct 2023 – Dec 2023 | 0.063 mg/l 7 Dec 2023 |
| Silica, reactive as SiO2 0182 | River water | 3 | Oct 2023 – Dec 2023 | 2.3 mg/l 7 Dec 2023 |
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.