Headwaters upstream of Old Somerby sewage treatment works
EA name: HEADWATERS U/S OLD SOMERBY STW
Environment Agency sampling point AN-USODSMBY · 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 May 2026, 10:254 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
- 46 since 16 Oct 2023 Imported periods: 1 Oct 2023 – 30 Sep 2026. Samples outside them are not shown here.
- Latest sample
- River / running surface water Monitoring (national agency policy)
- Where
- National Grid 496280, 333466As published, to the nearest 1 m. Open in a map
- River, by its own name
- Headwaters
- River, by the map
- Not placedNo mapped watercourse within 500 m. The river map cannot say which watercourse this is.
- Next gauge downstream
- Not known
- Why it was sampled
- Monitoring (national agency policy) (46 samples)
33 visits found no water to sample (recorded as “No flow”).
Main measurements, river water
Dissolved oxygen
% saturation · code 9901 · %
92.1%
Sampled 2 Mar 2026, 7 months ago · 13 results banked
Every result (13)
| Sampled | Result as published | Reads as |
|---|---|---|
| 2 Mar 2026, 10:52 | 92.1 | 92.1% |
| 16 Feb 2026, 10:12 | 95.2 | 95.2% |
| 21 Jan 2026, 11:28 | 84.6 | 84.6% |
| 18 Dec 2025, 11:09 | 82.1 | 82.1% |
| 9 Dec 2025, 11:06 | 90 | 90% |
| 25 Nov 2025, 11:21 | 90.2 | 90.2% |
| 14 Nov 2025, 11:43 | 74.3 | 74.3% |
| 28 Jan 2025, 11:14 | 94.9 | 94.9% |
| 10 Dec 2024, 11:43 | 88.6 | 88.6% |
| 19 Nov 2024, 11:28 | 91.8 | 91.8% |
| 19 Mar 2024, 11:59 | 115.3 | 115.3% |
| 19 Feb 2024, 12:21 | 96.1 | 96.1% |
| 4 Dec 2023, 10:44 | 94.5 | 94.5% |
Dissolved oxygen
as O2 · code 9924 · mg/l
10.8 mg/l
Sampled 2 Mar 2026, 7 months ago · 13 results banked
Every result (13)
| Sampled | Result as published | Reads as |
|---|---|---|
| 2 Mar 2026, 10:52 | 10.8 | 10.8 mg/l |
| 16 Feb 2026, 10:12 | 12.1 | 12.1 mg/l |
| 21 Jan 2026, 11:28 | 10.7 | 10.7 mg/l |
| 18 Dec 2025, 11:09 | 9.68 | 9.68 mg/l |
| 9 Dec 2025, 11:06 | 10.3 | 10.3 mg/l |
| 25 Nov 2025, 11:21 | 11.3 | 11.3 mg/l |
| 14 Nov 2025, 11:43 | 8.35 | 8.35 mg/l |
| 28 Jan 2025, 11:14 | 11.9 | 11.9 mg/l |
| 10 Dec 2024, 11:43 | 10.7 | 10.7 mg/l |
| 19 Nov 2024, 11:28 | 13.1 | 13.1 mg/l |
| 19 Mar 2024, 11:59 | 12.8 | 12.8 mg/l |
| 19 Feb 2024, 12:21 | 11.2 | 11.2 mg/l |
| 4 Dec 2023, 10:44 | 12.4 | 12.4 mg/l |
Water temperature
code 0076 · °C
8.2 °C
Sampled 2 Mar 2026, 7 months ago · 13 results banked
Every result (13)
| Sampled | Result as published | Reads as |
|---|---|---|
| 2 Mar 2026, 10:52 | 8.2 | 8.2 °C |
| 16 Feb 2026, 10:12 | 5.1 | 5.1 °C |
| 21 Jan 2026, 11:28 | 5.3 | 5.3 °C |
| 18 Dec 2025, 11:09 | 8.1 | 8.1 °C |
| 9 Dec 2025, 11:06 | 9.2 | 9.2 °C |
| 25 Nov 2025, 11:21 | 5.6 | 5.6 °C |
| 14 Nov 2025, 11:43 | 10.1 | 10.1 °C |
| 28 Jan 2025, 11:14 | 5.7 | 5.7 °C |
| 10 Dec 2024, 11:43 | 7 | 7 °C |
| 19 Nov 2024, 11:28 | 0.9 | 0.9 °C |
| 19 Mar 2024, 11:59 | 10.6 | 10.6 °C |
| 19 Feb 2024, 12:21 | 8.6 | 8.6 °C |
| 4 Dec 2023, 10:44 | 4 | 4 °C |
pH
code 0061
8.03
Sampled 2 Mar 2026, 7 months ago · 13 results banked
Every result (13)
| Sampled | Result as published | Reads as |
|---|---|---|
| 2 Mar 2026, 10:52 | 8.03 | 8.03 |
| 16 Feb 2026, 10:12 | 8.01 | 8.01 |
| 21 Jan 2026, 11:28 | 7.92 | 7.92 |
| 18 Dec 2025, 11:09 | 7.81 | 7.81 |
| 9 Dec 2025, 11:06 | 7.78 | 7.78 |
| 25 Nov 2025, 11:21 | 8.03 | 8.03 |
| 14 Nov 2025, 11:43 | 7.73 | 7.73 |
| 28 Jan 2025, 11:14 | 7.95 | 7.95 |
| 10 Dec 2024, 11:43 | 7.88 | 7.88 |
| 19 Nov 2024, 11:28 | 8.25 | 8.25 |
| 19 Mar 2024, 11:59 | 8.23 | 8.23 |
| 19 Feb 2024, 12:21 | 7.95 | 7.95 |
| 4 Dec 2023, 10:44 | 7.87 | 7.87 |
Ammonia
ammoniacal nitrogen as N · code 0111 · mg/l
below 0.03 mg/l (not detected above this)
Sampled 2 Mar 2026, 7 months ago · 13 results banked
Every result (13)
| Sampled | Result as published | Reads as |
|---|---|---|
| 2 Mar 2026, 10:52 | <0.03 | below 0.03 mg/l (not detected above this) |
| 16 Feb 2026, 10:12 | <0.03 | below 0.03 mg/l (not detected above this) |
| 21 Jan 2026, 11:28 | 0.051 | 0.051 mg/l |
| 18 Dec 2025, 11:09 | <0.03 | below 0.03 mg/l (not detected above this) |
| 9 Dec 2025, 11:06 | <0.03 | below 0.03 mg/l (not detected above this) |
| 25 Nov 2025, 11:21 | <0.03 | below 0.03 mg/l (not detected above this) |
| 14 Nov 2025, 11:43 | <0.03 | below 0.03 mg/l (not detected above this) |
| 28 Jan 2025, 11:14 | <0.03 | below 0.03 mg/l (not detected above this) |
| 10 Dec 2024, 11:43 | <0.03 | below 0.03 mg/l (not detected above this) |
| 19 Nov 2024, 11:28 | 0.078 | 0.078 mg/l |
| 19 Mar 2024, 11:59 | <0.03 | below 0.03 mg/l (not detected above this) |
| 19 Feb 2024, 12:21 | <0.03 | below 0.03 mg/l (not detected above this) |
| 4 Dec 2023, 10:44 | <0.03 | below 0.03 mg/l (not detected above this) |
Nitrate
as nitrogen (N) · code 0117 · mg/l
3.79 mg/l
Sampled 2 Mar 2026, 7 months ago · 13 results banked
Every result (13)
| Sampled | Result as published | Reads as |
|---|---|---|
| 2 Mar 2026, 10:52 | 3.79 | 3.79 mg/l |
| 16 Feb 2026, 10:12 | 3.99 | 3.99 mg/l |
| 21 Jan 2026, 11:28 | 7.08 | 7.08 mg/l |
| 18 Dec 2025, 11:09 | 8.49 | 8.49 mg/l |
| 9 Dec 2025, 11:06 | 8.09 | 8.09 mg/l |
| 25 Nov 2025, 11:21 | 15 | 15 mg/l |
| 14 Nov 2025, 11:43 | <0.196 | below 0.196 mg/l (not detected above this) |
| 28 Jan 2025, 11:14 | 5.09 | 5.09 mg/l |
| 10 Dec 2024, 11:43 | 7.68 | 7.68 mg/l |
| 19 Nov 2024, 11:28 | 0.345 | 0.345 mg/l |
| 19 Mar 2024, 11:59 | 4.69 | 4.69 mg/l |
| 19 Feb 2024, 12:21 | 5.09 | 5.09 mg/l |
| 4 Dec 2023, 10:44 | 3.09 | 3.09 mg/l |
Phosphate
orthophosphate, reactive, as P · code 0180 · mg/l
0.24 mg/l
Sampled 2 Mar 2026, 7 months ago · 13 results banked
Every result (13)
| Sampled | Result as published | Reads as |
|---|---|---|
| 2 Mar 2026, 10:52 | 0.24 | 0.24 mg/l |
| 16 Feb 2026, 10:12 | 0.098 | 0.098 mg/l |
| 21 Jan 2026, 11:28 | 0.24 | 0.24 mg/l |
| 18 Dec 2025, 11:09 | 0.076 | 0.076 mg/l |
| 9 Dec 2025, 11:06 | 0.14 | 0.14 mg/l |
| 25 Nov 2025, 11:21 | 0.052 | 0.052 mg/l |
| 14 Nov 2025, 11:43 | 0.39 | 0.39 mg/l |
| 28 Jan 2025, 11:14 | 0.068 | 0.068 mg/l |
| 10 Dec 2024, 11:43 | 0.05 | 0.05 mg/l |
| 19 Nov 2024, 11:28 | 0.3 | 0.3 mg/l |
| 19 Mar 2024, 11:59 | 0.023 | 0.023 mg/l |
| 19 Feb 2024, 12:21 | 0.066 | 0.066 mg/l |
| 4 Dec 2023, 10:44 | 0.14 | 0.14 mg/l |
Conductivity
at 25 °C · code 0077 · µS/cm
546 µS/cm
Sampled 2 Mar 2026, 7 months ago · 13 results banked
Every result (13)
| Sampled | Result as published | Reads as |
|---|---|---|
| 2 Mar 2026, 10:52 | 546 | 546 µS/cm |
| 16 Feb 2026, 10:12 | 464 | 464 µS/cm |
| 21 Jan 2026, 11:28 | 576 | 576 µS/cm |
| 18 Dec 2025, 11:09 | 551 | 551 µS/cm |
| 9 Dec 2025, 11:06 | 456 | 456 µS/cm |
| 25 Nov 2025, 11:21 | 627 | 627 µS/cm |
| 14 Nov 2025, 11:43 | 178 | 178 µS/cm |
| 28 Jan 2025, 11:14 | 577 | 577 µS/cm |
| 10 Dec 2024, 11:43 | 605 | 605 µS/cm |
| 19 Nov 2024, 11:28 | 1694 | 1694 µS/cm |
| 19 Mar 2024, 11:59 | 632 | 632 µS/cm |
| 19 Feb 2024, 12:21 | 562 | 562 µS/cm |
| 4 Dec 2023, 10:44 | 229 | 229 µS/cm |
Everything measured here
14 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 14 rows
| Determinand | Material | Results | First – last | Latest result |
|---|---|---|---|---|
| Oxygen, Dissolved, % Saturation 9901 | River water | 13 | Dec 2023 – Mar 2026 | 92.1% 2 Mar 2026 |
| Oxygen, Dissolved as O2 9924 | River water | 13 | Dec 2023 – Mar 2026 | 10.8 mg/l 2 Mar 2026 |
| Temperature of Water 0076 | River water | 13 | Dec 2023 – Mar 2026 | 8.2 °C 2 Mar 2026 |
| pH 0061 | River water | 13 | Dec 2023 – Mar 2026 | 8.03 2 Mar 2026 |
| Ammoniacal Nitrogen as N 0111 | River water | 13 | Dec 2023 – Mar 2026 | below 0.03 mg/l 2 Mar 2026 |
| Nitrate as N 0117 | River water | 13 | Dec 2023 – Mar 2026 | 3.79 mg/l 2 Mar 2026 |
| Orthophosphate, reactive as P 0180 | River water | 13 | Dec 2023 – Mar 2026 | 0.24 mg/l 2 Mar 2026 |
| Conductivity at 25 C 0077 | River water | 13 | Dec 2023 – Mar 2026 | 546 µS/cm 2 Mar 2026 |
| Alkalinity to pH 4.5 as CaCO3 0162 | River water | 13 | Dec 2023 – Mar 2026 | 220 mg/l 2 Mar 2026 |
| Ammonia un-ionised as N 0119 | River water | 13 | Dec 2023 – Mar 2026 | below 0.00048 mg/l 2 Mar 2026 |
| BOD : 5 Day ATU 0085 | River water | 11 | Feb 2024 – Mar 2026 | below 1 mg/l 2 Mar 2026 |
| Nitrite as N 0118 | River water | 13 | Dec 2023 – Mar 2026 | 0.0099 mg/l 2 Mar 2026 |
| Nitrogen, Total Oxidised as N 0116 | River water | 13 | Dec 2023 – Mar 2026 | 3.8 mg/l 2 Mar 2026 |
| No flow /No sample 7668 | River water | 33 | Oct 2023 – May 2026 | No flow/discharge at sampling point 21 May 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.