River Yeo at Lake
EA name: RIVER YEO AT LAKE (also listed as “RSN1637 RIVER YEO AT LAKE”)
Environment Agency sampling point SW-RSN1637 · 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
- 16 Sep 2026, 11:4640 days ago · time as the Environment Agency records it (UK clock time; the source gives no time zone)
- Samples banked
- 9 since 9 Jan 2026 Imported periods: 1 Oct 2023 – 26 Oct 2026. Samples outside them are not shown here.
- Latest sample
- River / running surface water Monitoring (national agency policy) · results completed 22 Sep 2026
- Where
- National Grid 360922, 114151As published, to the nearest 1 m. Open in a map
- River, by its own name
- Yeo
- River, by the map
- River IvelPlaced on the river its name gives, 1 m from the line.
- Next gauge downstream
- Pen Mill On the River Yeo · 8.8 km along the river
- Nearest gauge upstream
- Sherborne Lake On the River Yeo · 4.9 km along the river
- Why it was sampled
- Monitoring (national agency policy) (9 samples)
Results here were completed a median of 9 days after the sample was taken (4 to 43 days, 9 samples).
Main measurements, river water
Dissolved oxygen
% saturation · code 9901 · %
79.4%
Sampled 16 Sep 2026, 40 days ago · 9 results banked
Every result (9)
| Sampled | Result as published | Reads as |
|---|---|---|
| 16 Sep 2026, 11:46 | 79.4 | 79.4% |
| 11 Aug 2026, 10:26 | 77.5 | 77.5% |
| 3 Jul 2026, 10:05 | 85.1 | 85.1% |
| 4 Jun 2026, 10:24 | 97.3 | 97.3% |
| 13 May 2026, 11:43 | 91.3 | 91.3% |
| 27 Apr 2026, 09:37 | 86.9 | 86.9% |
| 9 Mar 2026, 12:26 | 93.4 | 93.4% |
| 13 Feb 2026, 08:38 | 93.8 | 93.8% |
| 9 Jan 2026, 11:31 | 96.8 | 96.8% |
Dissolved oxygen
as O2 · code 9924 · mg/l
7.88 mg/l
Sampled 16 Sep 2026, 40 days ago · 9 results banked
Every result (9)
| Sampled | Result as published | Reads as |
|---|---|---|
| 16 Sep 2026, 11:46 | 7.88 | 7.88 mg/l |
| 11 Aug 2026, 10:26 | 7.36 | 7.36 mg/l |
| 3 Jul 2026, 10:05 | 8.11 | 8.11 mg/l |
| 4 Jun 2026, 10:24 | 9.93 | 9.93 mg/l |
| 13 May 2026, 11:43 | 9.7 | 9.7 mg/l |
| 27 Apr 2026, 09:37 | 9.3 | 9.3 mg/l |
| 9 Mar 2026, 12:26 | 10.7 | 10.7 mg/l |
| 13 Feb 2026, 08:38 | 11.2 | 11.2 mg/l |
| 9 Jan 2026, 11:31 | 12.3 | 12.3 mg/l |
Water temperature
code 0076 · °C
15.6 °C
Sampled 16 Sep 2026, 40 days ago · 9 results banked
Every result (9)
| Sampled | Result as published | Reads as |
|---|---|---|
| 16 Sep 2026, 11:46 | 15.6 | 15.6 °C |
| 11 Aug 2026, 10:26 | 17.7 | 17.7 °C |
| 3 Jul 2026, 10:05 | 17.5 | 17.5 °C |
| 4 Jun 2026, 10:24 | 14.3 | 14.3 °C |
| 13 May 2026, 11:43 | 12.5 | 12.5 °C |
| 27 Apr 2026, 09:37 | 12.2 | 12.2 °C |
| 9 Mar 2026, 12:26 | 9.4 | 9.4 °C |
| 13 Feb 2026, 08:38 | 7.7 | 7.7 °C |
| 9 Jan 2026, 11:31 | 5 | 5 °C |
pH
code 0061
7.91
Sampled 16 Sep 2026, 40 days ago · 9 results banked
Every result (9)
| Sampled | Result as published | Reads as |
|---|---|---|
| 16 Sep 2026, 11:46 | 7.91 | 7.91 |
| 11 Aug 2026, 10:26 | 7.76 | 7.76 |
| 3 Jul 2026, 10:05 | 8.09 | 8.09 |
| 4 Jun 2026, 10:24 | 8.11 | 8.11 |
| 13 May 2026, 11:43 | 8.37 | 8.37 |
| 27 Apr 2026, 09:37 | 8.14 | 8.14 |
| 9 Mar 2026, 12:26 | 8.03 | 8.03 |
| 13 Feb 2026, 08:38 | 8.09 | 8.09 |
| 9 Jan 2026, 11:31 | 8.06 | 8.06 |
Ammonia
ammoniacal nitrogen as N · code 0111 · mg/l
below 0.03 mg/l (not detected above this)
Sampled 16 Sep 2026, 40 days ago · 9 results banked
Every result (9)
| Sampled | Result as published | Reads as |
|---|---|---|
| 16 Sep 2026, 11:46 | <0.03 | below 0.03 mg/l (not detected above this) |
| 11 Aug 2026, 10:26 | 0.25 | 0.25 mg/l |
| 3 Jul 2026, 10:05 | <0.03 | below 0.03 mg/l (not detected above this) |
| 4 Jun 2026, 10:24 | 0.12 | 0.12 mg/l |
| 13 May 2026, 11:43 | <0.03 | below 0.03 mg/l (not detected above this) |
| 27 Apr 2026, 09:37 | 0.036 | 0.036 mg/l |
| 9 Mar 2026, 12:26 | 0.045 | 0.045 mg/l |
| 13 Feb 2026, 08:38 | 0.072 | 0.072 mg/l |
| 9 Jan 2026, 11:31 | 0.12 | 0.12 mg/l |
Nitrate
as nitrogen (N) · code 0117 · mg/l
7.85 mg/l
Sampled 16 Sep 2026, 40 days ago · 9 results banked
Every result (9)
| Sampled | Result as published | Reads as |
|---|---|---|
| 16 Sep 2026, 11:46 | 7.85 | 7.85 mg/l |
| 11 Aug 2026, 10:26 | 6.34 | 6.34 mg/l |
| 3 Jul 2026, 10:05 | 7.68 | 7.68 mg/l |
| 4 Jun 2026, 10:24 | 3.66 | 3.66 mg/l |
| 13 May 2026, 11:43 | 6.47 | 6.47 mg/l |
| 27 Apr 2026, 09:37 | 6.87 | 6.87 mg/l |
| 9 Mar 2026, 12:26 | 1.78 | 1.78 mg/l |
| 13 Feb 2026, 08:38 | 3.47 | 3.47 mg/l |
| 9 Jan 2026, 11:31 | 6.95 | 6.95 mg/l |
Phosphate
orthophosphate, reactive, as P · code 0180 · mg/l
0.11 mg/l
Sampled 16 Sep 2026, 40 days ago · 9 results banked
Every result (9)
| Sampled | Result as published | Reads as |
|---|---|---|
| 16 Sep 2026, 11:46 | 0.11 | 0.11 mg/l |
| 11 Aug 2026, 10:26 | 0.12 | 0.12 mg/l |
| 3 Jul 2026, 10:05 | 0.14 | 0.14 mg/l |
| 4 Jun 2026, 10:24 | 0.15 | 0.15 mg/l |
| 13 May 2026, 11:43 | 0.071 | 0.071 mg/l |
| 27 Apr 2026, 09:37 | 0.056 | 0.056 mg/l |
| 9 Mar 2026, 12:26 | 0.14 | 0.14 mg/l |
| 13 Feb 2026, 08:38 | 0.093 | 0.093 mg/l |
| 9 Jan 2026, 11:31 | 0.085 | 0.085 mg/l |
Conductivity
at 25 °C · code 0077 · µS/cm
726 µS/cm
Sampled 16 Sep 2026, 40 days ago · 9 results banked
Every result (9)
| Sampled | Result as published | Reads as |
|---|---|---|
| 16 Sep 2026, 11:46 | 726 | 726 µS/cm |
| 11 Aug 2026, 10:26 | 704 | 704 µS/cm |
| 3 Jul 2026, 10:05 | 756 | 756 µS/cm |
| 4 Jun 2026, 10:24 | 573 | 573 µS/cm |
| 13 May 2026, 11:43 | 705 | 705 µS/cm |
| 27 Apr 2026, 09:37 | 694 | 694 µS/cm |
| 9 Mar 2026, 12:26 | 497 | 497 µS/cm |
| 13 Feb 2026, 08:38 | 401 | 401 µS/cm |
| 9 Jan 2026, 11:31 | 711 | 711 µS/cm |
Everything measured here
20 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 20 rows
| Determinand | Material | Results | First – last | Latest result |
|---|---|---|---|---|
| Oxygen, Dissolved, % Saturation 9901 | River water | 9 | Jan 2026 – Sep 2026 | 79.4% 16 Sep 2026 |
| Oxygen, Dissolved as O2 9924 | River water | 9 | Jan 2026 – Sep 2026 | 7.88 mg/l 16 Sep 2026 |
| Temperature of Water 0076 | River water | 9 | Jan 2026 – Sep 2026 | 15.6 °C 16 Sep 2026 |
| pH 0061 | River water | 9 | Jan 2026 – Sep 2026 | 7.91 16 Sep 2026 |
| Ammoniacal Nitrogen as N 0111 | River water | 9 | Jan 2026 – Sep 2026 | below 0.03 mg/l 16 Sep 2026 |
| Nitrate as N 0117 | River water | 9 | Jan 2026 – Sep 2026 | 7.85 mg/l 16 Sep 2026 |
| Orthophosphate, reactive as P 0180 | River water | 9 | Jan 2026 – Sep 2026 | 0.11 mg/l 16 Sep 2026 |
| Conductivity at 25 C 0077 | River water | 9 | Jan 2026 – Sep 2026 | 726 µS/cm 16 Sep 2026 |
| Alkalinity to pH 4.5 as CaCO3 0162 | River water | 9 | Jan 2026 – Sep 2026 | 200 mg/l 16 Sep 2026 |
| Ammonia un-ionised as N 0119 | River water | 9 | Jan 2026 – Sep 2026 | below 0.00067 mg/l 16 Sep 2026 |
| Carbon, Organic, Dissolved as C :- {DOC} 0301 | River water | 9 | Jan 2026 – Sep 2026 | 4.5 mg/l 16 Sep 2026 |
| Chloride 0172 | River water | 9 | Jan 2026 – Sep 2026 | 61 mg/l 16 Sep 2026 |
| Flow Type 2896 | River water | 9 | Jan 2026 – Sep 2026 | Moderate Flow 16 Sep 2026 |
| GCMS Screen : Target Based multi-residue screening : Semi Quantitative 4994 | River water | 1 | Aug 2026 – Aug 2026 | 1 text result 11 Aug 2026 |
| Nitrite as N 0118 | River water | 9 | Jan 2026 – Sep 2026 | 0.047 mg/l 16 Sep 2026 |
| Nitrogen, Total as N 9686 | River water | 9 | Jan 2026 – Sep 2026 | 8.6 mg/l 16 Sep 2026 |
| Nitrogen, Total Oxidised as N 0116 | River water | 9 | Jan 2026 – Sep 2026 | 7.9 mg/l 16 Sep 2026 |
| Phosphorus, Total as P 0348 | River water | 9 | Jan 2026 – Sep 2026 | 0.16 mg/l 16 Sep 2026 |
| Silica, reactive as SiO2 0182 | River water | 9 | Jan 2026 – Sep 2026 | 6.5 mg/l 16 Sep 2026 |
| Solids, Suspended at 105 C 0135 | River water | 9 | Jan 2026 – Sep 2026 | 6.5 mg/l 16 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.