River Walkham upstream of Horrabridge sewage treatment works
EA name: RIVER WALKHAM U/S HORRABRIDGE STW (also listed as “RIVER WALKHAM ABOVE HORRABRIDGE STW”)
Environment Agency sampling point SW-81241119 · 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 Mar 2024, 13:132.6 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
- 7 since 16 Oct 2023 Imported periods: 1 Oct 2023 – 8 Oct 2026. Samples outside them are not shown here.
- Latest sample
- River / running surface water Planned investigation (local monitoring)
- Where
- National Grid 249950, 70450As published, to the nearest 10 m. Open in a map
- River, by its own name
- Walkham
- River, by the map
- River WalkhamPlaced on the river its name gives, 15 m from the line.
- Next gauge downstream
- Ludbrook On the River Tavy · 6.9 km along the river
- Nearest gauge upstream
- Horrabridge On the River Walkham · 1.7 km along the river
- Why it was sampled
- Planned investigation (local monitoring) (7 samples)
Main measurements, river water
Dissolved oxygen
% saturation · code 9901 · %
101.7%
Sampled 6 Mar 2024, 2.6 years ago · 7 results banked
Every result (7)
| Sampled | Result as published | Reads as |
|---|---|---|
| 6 Mar 2024, 13:13 | 101.7 | 101.7% |
| 16 Feb 2024, 09:36 | 99.5 | 99.5% |
| 18 Jan 2024, 12:59 | 101.4 | 101.4% |
| 19 Dec 2023, 13:03 | 100.9 | 100.9% |
| 8 Dec 2023, 13:14 | 99.7 | 99.7% |
| 6 Nov 2023, 14:01 | 102.1 | 102.1% |
| 16 Oct 2023, 12:54 | 101.4 | 101.4% |
Dissolved oxygen
as O2 · code 9924 · mg/l
11.8 mg/l
Sampled 6 Mar 2024, 2.6 years ago · 7 results banked
Every result (7)
| Sampled | Result as published | Reads as |
|---|---|---|
| 6 Mar 2024, 13:13 | 11.8 | 11.8 mg/l |
| 16 Feb 2024, 09:36 | 11.2 | 11.2 mg/l |
| 18 Jan 2024, 12:59 | 13 | 13 mg/l |
| 19 Dec 2023, 13:03 | 11.2 | 11.2 mg/l |
| 8 Dec 2023, 13:14 | 11.3 | 11.3 mg/l |
| 6 Nov 2023, 14:01 | 11.3 | 11.3 mg/l |
| 16 Oct 2023, 12:54 | 11.2 | 11.2 mg/l |
Water temperature
code 0076 · °C
8.7 °C
Sampled 6 Mar 2024, 2.6 years ago · 7 results banked
Every result (7)
| Sampled | Result as published | Reads as |
|---|---|---|
| 6 Mar 2024, 13:13 | 8.7 | 8.7 °C |
| 16 Feb 2024, 09:36 | 10.1 | 10.1 °C |
| 18 Jan 2024, 12:59 | 4.7 | 4.7 °C |
| 19 Dec 2023, 13:03 | 10.7 | 10.7 °C |
| 8 Dec 2023, 13:14 | 9.9 | 9.9 °C |
| 6 Nov 2023, 14:01 | 10.7 | 10.7 °C |
| 16 Oct 2023, 12:54 | 10.9 | 10.9 °C |
pH
code 0061
6.93
Sampled 6 Mar 2024, 2.6 years ago · 7 results banked
Every result (7)
| Sampled | Result as published | Reads as |
|---|---|---|
| 6 Mar 2024, 13:13 | 6.93 | 6.93 |
| 16 Feb 2024, 09:36 | 7.26 | 7.26 |
| 18 Jan 2024, 12:59 | 7.37 | 7.37 |
| 19 Dec 2023, 13:03 | 6.89 | 6.89 |
| 8 Dec 2023, 13:14 | 6.9 | 6.9 |
| 6 Nov 2023, 14:01 | 6.8 | 6.8 |
| 16 Oct 2023, 12:54 | 6.84 | 6.84 |
Ammonia
ammoniacal nitrogen as N · code 0111 · mg/l
below 0.03 mg/l (not detected above this)
Sampled 6 Mar 2024, 2.6 years ago · 7 results banked
Every result (7)
| Sampled | Result as published | Reads as |
|---|---|---|
| 6 Mar 2024, 13:13 | <0.03 | below 0.03 mg/l (not detected above this) |
| 16 Feb 2024, 09:36 | <0.03 | below 0.03 mg/l (not detected above this) |
| 18 Jan 2024, 12:59 | <0.03 | below 0.03 mg/l (not detected above this) |
| 19 Dec 2023, 13:03 | <0.03 | below 0.03 mg/l (not detected above this) |
| 8 Dec 2023, 13:14 | <0.03 | below 0.03 mg/l (not detected above this) |
| 6 Nov 2023, 14:01 | <0.03 | below 0.03 mg/l (not detected above this) |
| 16 Oct 2023, 12:54 | <0.03 | below 0.03 mg/l (not detected above this) |
Nitrate
as nitrogen (N) · code 0117 · mg/l
0.896 mg/l
Sampled 6 Mar 2024, 2.6 years ago · 7 results banked
Every result (7)
| Sampled | Result as published | Reads as |
|---|---|---|
| 6 Mar 2024, 13:13 | 0.896 | 0.896 mg/l |
| 16 Feb 2024, 09:36 | 0.826 | 0.826 mg/l |
| 18 Jan 2024, 12:59 | 0.756 | 0.756 mg/l |
| 19 Dec 2023, 13:03 | 0.376 | 0.376 mg/l |
| 8 Dec 2023, 13:14 | 1.1 | 1.1 mg/l |
| 6 Nov 2023, 14:01 | 0.816 | 0.816 mg/l |
| 16 Oct 2023, 12:54 | 0.826 | 0.826 mg/l |
Phosphate
orthophosphate, reactive, as P · code 0180 · mg/l
0.01 mg/l
Sampled 6 Mar 2024, 2.6 years ago · 7 results banked
Every result (7)
| Sampled | Result as published | Reads as |
|---|---|---|
| 6 Mar 2024, 13:13 | 0.01 | 0.01 mg/l |
| 16 Feb 2024, 09:36 | 0.016 | 0.016 mg/l |
| 18 Jan 2024, 12:59 | <0.01 | below 0.01 mg/l (not detected above this) |
| 19 Dec 2023, 13:03 | <0.01 | below 0.01 mg/l (not detected above this) |
| 8 Dec 2023, 13:14 | 0.013 | 0.013 mg/l |
| 6 Nov 2023, 14:01 | <0.01 | below 0.01 mg/l (not detected above this) |
| 16 Oct 2023, 12:54 | 0.011 | 0.011 mg/l |
Conductivity
at 25 °C · code 0077 · µS/cm
73 µS/cm
Sampled 6 Mar 2024, 2.6 years ago · 7 results banked
Every result (7)
| Sampled | Result as published | Reads as |
|---|---|---|
| 6 Mar 2024, 13:13 | 73 | 73 µS/cm |
| 16 Feb 2024, 09:36 | 85 | 85 µS/cm |
| 18 Jan 2024, 12:59 | 70 | 70 µS/cm |
| 19 Dec 2023, 13:03 | 50 | 50 µS/cm |
| 8 Dec 2023, 13:14 | 87 | 87 µS/cm |
| 6 Nov 2023, 14:01 | 74 | 74 µS/cm |
| 16 Oct 2023, 12:54 | 78 | 78 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 | 7 | Oct 2023 – Mar 2024 | 101.7% 6 Mar 2024 |
| Oxygen, Dissolved as O2 9924 | River water | 7 | Oct 2023 – Mar 2024 | 11.8 mg/l 6 Mar 2024 |
| Temperature of Water 0076 | River water | 7 | Oct 2023 – Mar 2024 | 8.7 °C 6 Mar 2024 |
| pH 0061 | River water | 7 | Oct 2023 – Mar 2024 | 6.93 6 Mar 2024 |
| Ammoniacal Nitrogen as N 0111 | River water | 7 | Oct 2023 – Mar 2024 | below 0.03 mg/l 6 Mar 2024 |
| Nitrate as N 0117 | River water | 7 | Oct 2023 – Mar 2024 | 0.896 mg/l 6 Mar 2024 |
| Orthophosphate, reactive as P 0180 | River water | 7 | Oct 2023 – Mar 2024 | 0.01 mg/l 6 Mar 2024 |
| Conductivity at 25 C 0077 | River water | 7 | Oct 2023 – Mar 2024 | 73 µS/cm 6 Mar 2024 |
| Alkalinity to pH 4.5 as CaCO3 0162 | River water | 7 | Oct 2023 – Mar 2024 | 10 mg/l 6 Mar 2024 |
| Ammonia un-ionised as N 0119 | River water | 7 | Oct 2023 – Mar 2024 | below 0.00004 mg/l 6 Mar 2024 |
| Nitrite as N 0118 | River water | 7 | Oct 2023 – Mar 2024 | below 0.004 mg/l 6 Mar 2024 |
| Nitrogen, Total Oxidised as N 0116 | River water | 7 | Oct 2023 – Mar 2024 | 0.9 mg/l 6 Mar 2024 |
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.