River Ray upstream of Tetchwick Brook tributary
EA name: RIVER RAY U/S OF TETCHWICK BROOK TRIB (also listed as “RIVER RAY UPSTREAM OF TETCHWICK BROOK TRIBUTARY”)
Environment Agency sampling point TH-PCHR0269 · 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
- 4 Sep 2026, 12:0627 days ago · time as the Environment Agency records it (UK clock time; the source gives no time zone)
- Samples banked
- 22 since 28 Jun 2024 Imported periods: 1 Oct 2023 – 30 Sep 2026. Samples outside them are not shown here.
- Latest sample
- River / running surface water Environmental monitoring statutory (EU directives)
- Where
- National Grid 465950, 220391As published, to the nearest 1 m. Open in a map
- River, by its own name
- Ray
- River, by the map
- River RayPlaced on the river its name gives, 93 m from the line.
- Next gauge downstream
- Lower Arncott On the River Ray · 8.0 km along the river
- Nearest gauge upstream
- Grendon Underwood On the River Ray · 3.1 km along the river
- Why it was sampled
- Environmental monitoring statutory (EU directives) (22 samples)
Main measurements, river water
Dissolved oxygen
% saturation · code 9901 · %
74.8%
Sampled 4 Sep 2026, 27 days ago · 22 results banked
Every result (22)
| Sampled | Result as published | Reads as |
|---|---|---|
| 4 Sep 2026, 12:06 | 74.8 | 74.8% |
| 4 Aug 2026, 11:47 | 83.8 | 83.8% |
| 14 Jul 2026, 11:06 | 85.4 | 85.4% |
| 29 Jun 2026, 15:14 | 74.9 | 74.9% |
| 29 May 2026, 11:22 | 53.7 | 53.7% |
| 22 Apr 2026, 12:07 | 89.2 | 89.2% |
| 3 Mar 2026, 13:41 | 85.8 | 85.8% |
| 2 Feb 2026, 13:31 | 80.6 | 80.6% |
| 13 Jan 2026, 12:34 | 83.9 | 83.9% |
| 18 Dec 2025, 12:01 | 79.4 | 79.4% |
| 24 Nov 2025, 12:21 | 77.8 | 77.8% |
| 31 Oct 2025, 14:49 | 53.3 | 53.3% |
| 16 Jul 2025, 13:52 | 88 | 88% |
| 9 Apr 2025, 13:26 | 95.4 | 95.4% |
| 14 Mar 2025, 11:24 | 90.3 | 90.3% |
| 25 Feb 2025, 11:53 | 86.8 | 86.8% |
| 21 Nov 2024, 12:21 | 83.3 | 83.3% |
| 7 Oct 2024, 12:35 | 68.5 | 68.5% |
| 4 Sep 2024, 12:57 | 85.3 | 85.3% |
| 7 Aug 2024, 12:49 | 86.9 | 86.9% |
| 22 Jul 2024, 12:35 | 87.3 | 87.3% |
| 28 Jun 2024, 12:21 | 90.6 | 90.6% |
Dissolved oxygen
as O2 · code 9924 · mg/l
7.2 mg/l
Sampled 4 Sep 2026, 27 days ago · 22 results banked
Every result (22)
| Sampled | Result as published | Reads as |
|---|---|---|
| 4 Sep 2026, 12:06 | 7.2 | 7.2 mg/l |
| 4 Aug 2026, 11:47 | 7.79 | 7.79 mg/l |
| 14 Jul 2026, 11:06 | 8.34 | 8.34 mg/l |
| 29 Jun 2026, 15:14 | 7.27 | 7.27 mg/l |
| 29 May 2026, 11:22 | 5.12 | 5.12 mg/l |
| 22 Apr 2026, 12:07 | 10.2 | 10.2 mg/l |
| 3 Mar 2026, 13:41 | 9.83 | 9.83 mg/l |
| 2 Feb 2026, 13:31 | 9.79 | 9.79 mg/l |
| 13 Jan 2026, 12:34 | 10.2 | 10.2 mg/l |
| 18 Dec 2025, 12:01 | 9.16 | 9.16 mg/l |
| 24 Nov 2025, 12:21 | 9.5 | 9.5 mg/l |
| 31 Oct 2025, 14:49 | 5.73 | 5.73 mg/l |
| 16 Jul 2025, 13:52 | 8.5 | 8.5 mg/l |
| 9 Apr 2025, 13:26 | 11 | 11 mg/l |
| 14 Mar 2025, 11:24 | 11.6 | 11.6 mg/l |
| 25 Feb 2025, 11:53 | 10.4 | 10.4 mg/l |
| 21 Nov 2024, 12:21 | 10.7 | 10.7 mg/l |
| 7 Oct 2024, 12:35 | 7.25 | 7.25 mg/l |
| 4 Sep 2024, 12:57 | 8.71 | 8.71 mg/l |
| 7 Aug 2024, 12:49 | 8.5 | 8.5 mg/l |
| 22 Jul 2024, 12:35 | 8.35 | 8.35 mg/l |
| 28 Jun 2024, 12:21 | 9.19 | 9.19 mg/l |
Water temperature
code 0076 · °C
17.1 °C
Sampled 4 Sep 2026, 27 days ago · 22 results banked
Every result (22)
| Sampled | Result as published | Reads as |
|---|---|---|
| 4 Sep 2026, 12:06 | 17.1 | 17.1 °C |
| 4 Aug 2026, 11:47 | 18.8 | 18.8 °C |
| 14 Jul 2026, 11:06 | 16.4 | 16.4 °C |
| 29 Jun 2026, 15:14 | 16.7 | 16.7 °C |
| 29 May 2026, 11:22 | 17.5 | 17.5 °C |
| 22 Apr 2026, 12:07 | 9.3 | 9.3 °C |
| 3 Mar 2026, 13:41 | 9.3 | 9.3 °C |
| 2 Feb 2026, 13:31 | 6.9 | 6.9 °C |
| 13 Jan 2026, 12:34 | 6.9 | 6.9 °C |
| 18 Dec 2025, 12:01 | 9 | 9 °C |
| 24 Nov 2025, 12:21 | 6.7 | 6.7 °C |
| 31 Oct 2025, 14:49 | 12 | 12 °C |
| 16 Jul 2025, 13:52 | 16.9 | 16.9 °C |
| 9 Apr 2025, 13:26 | 9.2 | 9.2 °C |
| 14 Mar 2025, 11:24 | 4.6 | 4.6 °C |
| 25 Feb 2025, 11:53 | 7.6 | 7.6 °C |
| 21 Nov 2024, 12:21 | 4.7 | 4.7 °C |
| 7 Oct 2024, 12:35 | 12.7 | 12.7 °C |
| 4 Sep 2024, 12:57 | 14.3 | 14.3 °C |
| 7 Aug 2024, 12:49 | 16.3 | 16.3 °C |
| 22 Jul 2024, 12:35 | 17.4 | 17.4 °C |
| 28 Jun 2024, 12:21 | 14.6 | 14.6 °C |
pH
code 0061
7.79
Sampled 4 Sep 2026, 27 days ago · 22 results banked
Every result (22)
| Sampled | Result as published | Reads as |
|---|---|---|
| 4 Sep 2026, 12:06 | 7.79 | 7.79 |
| 4 Aug 2026, 11:47 | 7.95 | 7.95 |
| 14 Jul 2026, 11:06 | 8.12 | 8.12 |
| 29 Jun 2026, 15:14 | 7.94 | 7.94 |
| 29 May 2026, 11:22 | 7.67 | 7.67 |
| 22 Apr 2026, 12:07 | 7.85 | 7.85 |
| 3 Mar 2026, 13:41 | 7.87 | 7.87 |
| 2 Feb 2026, 13:31 | 7.68 | 7.68 |
| 13 Jan 2026, 12:34 | 7.77 | 7.77 |
| 18 Dec 2025, 12:01 | 7.71 | 7.71 |
| 24 Nov 2025, 12:21 | 7.75 | 7.75 |
| 31 Oct 2025, 14:49 | 7.96 | 7.96 |
| 16 Jul 2025, 13:52 | 7.89 | 7.89 |
| 9 Apr 2025, 13:26 | 8.1 | 8.1 |
| 14 Mar 2025, 11:24 | 8.06 | 8.06 |
| 25 Feb 2025, 11:53 | 7.81 | 7.81 |
| 21 Nov 2024, 12:21 | 7.81 | 7.81 |
| 7 Oct 2024, 12:35 | 7.57 | 7.57 |
| 4 Sep 2024, 12:57 | 7.95 | 7.95 |
| 7 Aug 2024, 12:49 | 8.04 | 8.04 |
| 22 Jul 2024, 12:35 | 8.14 | 8.14 |
| 28 Jun 2024, 12:21 | 8.09 | 8.09 |
Ammonia
ammoniacal nitrogen as N · code 0111 · mg/l
below 0.03 mg/l (not detected above this)
Sampled 4 Sep 2026, 27 days ago · 22 results banked
Every result (22)
| Sampled | Result as published | Reads as |
|---|---|---|
| 4 Sep 2026, 12:06 | <0.03 | below 0.03 mg/l (not detected above this) |
| 4 Aug 2026, 11:47 | <0.03 | below 0.03 mg/l (not detected above this) |
| 14 Jul 2026, 11:06 | 0.035 | 0.035 mg/l |
| 29 Jun 2026, 15:14 | 0.052 | 0.052 mg/l |
| 29 May 2026, 11:22 | 0.59 | 0.59 mg/l |
| 22 Apr 2026, 12:07 | 0.09 | 0.09 mg/l |
| 3 Mar 2026, 13:41 | 0.07 | 0.07 mg/l |
| 2 Feb 2026, 13:31 | 0.073 | 0.073 mg/l |
| 13 Jan 2026, 12:34 | 0.086 | 0.086 mg/l |
| 18 Dec 2025, 12:01 | 0.061 | 0.061 mg/l |
| 24 Nov 2025, 12:21 | 0.034 | 0.034 mg/l |
| 31 Oct 2025, 14:49 | <0.03 | below 0.03 mg/l (not detected above this) |
| 16 Jul 2025, 13:52 | <0.03 | below 0.03 mg/l (not detected above this) |
| 9 Apr 2025, 13:26 | 0.076 | 0.076 mg/l |
| 14 Mar 2025, 11:24 | 0.28 | 0.28 mg/l |
| 25 Feb 2025, 11:53 | 0.06 | 0.06 mg/l |
| 21 Nov 2024, 12:21 | 0.059 | 0.059 mg/l |
| 7 Oct 2024, 12:35 | 0.076 | 0.076 mg/l |
| 4 Sep 2024, 12:57 | 0.031 | 0.031 mg/l |
| 7 Aug 2024, 12:49 | <0.03 | below 0.03 mg/l (not detected above this) |
| 22 Jul 2024, 12:35 | 0.047 | 0.047 mg/l |
| 28 Jun 2024, 12:21 | 0.042 | 0.042 mg/l |
Nitrate
as nitrogen (N) · code 0117 · mg/l
13 mg/l
Sampled 4 Sep 2026, 27 days ago · 22 results banked
Every result (22)
| Sampled | Result as published | Reads as |
|---|---|---|
| 4 Sep 2026, 12:06 | 13 | 13 mg/l |
| 4 Aug 2026, 11:47 | 19 | 19 mg/l |
| 14 Jul 2026, 11:06 | 15 | 15 mg/l |
| 29 Jun 2026, 15:14 | 8.98 | 8.98 mg/l |
| 29 May 2026, 11:22 | 1.56 | 1.56 mg/l |
| 22 Apr 2026, 12:07 | 13.8 | 13.8 mg/l |
| 3 Mar 2026, 13:41 | 3.06 | 3.06 mg/l |
| 2 Feb 2026, 13:31 | 3.78 | 3.78 mg/l |
| 13 Jan 2026, 12:34 | 5.47 | 5.47 mg/l |
| 18 Dec 2025, 12:01 | 7.27 | 7.27 mg/l |
| 24 Nov 2025, 12:21 | 11 | 11 mg/l |
| 31 Oct 2025, 14:49 | 3.94 | 3.94 mg/l |
| 16 Jul 2025, 13:52 | 6.79 | 6.79 mg/l |
| 9 Apr 2025, 13:26 | 9.19 | 9.19 mg/l |
| 14 Mar 2025, 11:24 | 5.71 | 5.71 mg/l |
| 25 Feb 2025, 11:53 | 2.49 | 2.49 mg/l |
| 21 Nov 2024, 12:21 | 4.87 | 4.87 mg/l |
| 7 Oct 2024, 12:35 | 3.84 | 3.84 mg/l |
| 4 Sep 2024, 12:57 | 20 | 20 mg/l |
| 7 Aug 2024, 12:49 | 17.9 | 17.9 mg/l |
| 22 Jul 2024, 12:35 | 6.19 | 6.19 mg/l |
| 28 Jun 2024, 12:21 | 13 | 13 mg/l |
Phosphate
orthophosphate, reactive, as P · code 0180 · mg/l
4.2 mg/l
Sampled 4 Sep 2026, 27 days ago · 22 results banked
Every result (22)
| Sampled | Result as published | Reads as |
|---|---|---|
| 4 Sep 2026, 12:06 | 4.2 | 4.2 mg/l |
| 4 Aug 2026, 11:47 | 5 | 5 mg/l |
| 14 Jul 2026, 11:06 | 4.7 | 4.7 mg/l |
| 29 Jun 2026, 15:14 | 3.2 | 3.2 mg/l |
| 29 May 2026, 11:22 | 2.5 | 2.5 mg/l |
| 22 Apr 2026, 12:07 | 2.5 | 2.5 mg/l |
| 3 Mar 2026, 13:41 | 0.26 | 0.26 mg/l |
| 2 Feb 2026, 13:31 | 0.13 | 0.13 mg/l |
| 13 Jan 2026, 12:34 | 0.11 | 0.11 mg/l |
| 18 Dec 2025, 12:01 | 0.11 | 0.11 mg/l |
| 24 Nov 2025, 12:21 | 0.15 | 0.15 mg/l |
| 31 Oct 2025, 14:49 | 1.9 | 1.9 mg/l |
| 16 Jul 2025, 13:52 | 1.8 | 1.8 mg/l |
| 9 Apr 2025, 13:26 | 1.1 | 1.1 mg/l |
| 14 Mar 2025, 11:24 | 0.51 | 0.51 mg/l |
| 25 Feb 2025, 11:53 | 0.087 | 0.087 mg/l |
| 21 Nov 2024, 12:21 | 0.13 | 0.13 mg/l |
| 7 Oct 2024, 12:35 | 0.25 | 0.25 mg/l |
| 4 Sep 2024, 12:57 | 3.9 | 3.9 mg/l |
| 7 Aug 2024, 12:49 | 2.9 | 2.9 mg/l |
| 22 Jul 2024, 12:35 | 1.1 | 1.1 mg/l |
| 28 Jun 2024, 12:21 | 1.8 | 1.8 mg/l |
Conductivity
at 25 °C · code 0077 · µS/cm
962 µS/cm
Sampled 4 Sep 2026, 27 days ago · 22 results banked
Every result (22)
| Sampled | Result as published | Reads as |
|---|---|---|
| 4 Sep 2026, 12:06 | 962 | 962 µS/cm |
| 4 Aug 2026, 11:47 | 1084 | 1084 µS/cm |
| 14 Jul 2026, 11:06 | 1043 | 1043 µS/cm |
| 29 Jun 2026, 15:14 | 1086 | 1086 µS/cm |
| 29 May 2026, 11:22 | 4746 | 4746 µS/cm |
| 22 Apr 2026, 12:07 | 1346 | 1346 µS/cm |
| 3 Mar 2026, 13:41 | 922 | 922 µS/cm |
| 2 Feb 2026, 13:31 | 600 | 600 µS/cm |
| 13 Jan 2026, 12:34 | 1212 | 1212 µS/cm |
| 18 Dec 2025, 12:01 | 1146 | 1146 µS/cm |
| 24 Nov 2025, 12:21 | 842 | 842 µS/cm |
| 31 Oct 2025, 14:49 | 1052 | 1052 µS/cm |
| 16 Jul 2025, 13:52 | 736 | 736 µS/cm |
| 9 Apr 2025, 13:26 | 934 | 934 µS/cm |
| 14 Mar 2025, 11:24 | 982 | 982 µS/cm |
| 25 Feb 2025, 11:53 | 583 | 583 µS/cm |
| 21 Nov 2024, 12:21 | 740 | 740 µS/cm |
| 7 Oct 2024, 12:35 | 1414 | 1414 µS/cm |
| 4 Sep 2024, 12:57 | 1194 | 1194 µS/cm |
| 7 Aug 2024, 12:49 | 1368 | 1368 µS/cm |
| 22 Jul 2024, 12:35 | 1023 | 1023 µS/cm |
| 28 Jun 2024, 12:21 | 1115 | 1115 µS/cm |
Everything measured here
13 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 13 rows
| Determinand | Material | Results | First – last | Latest result |
|---|---|---|---|---|
| Oxygen, Dissolved, % Saturation 9901 | River water | 22 | Jun 2024 – Sep 2026 | 74.8% 4 Sep 2026 |
| Oxygen, Dissolved as O2 9924 | River water | 22 | Jun 2024 – Sep 2026 | 7.2 mg/l 4 Sep 2026 |
| Temperature of Water 0076 | River water | 22 | Jun 2024 – Sep 2026 | 17.1 °C 4 Sep 2026 |
| pH 0061 | River water | 22 | Jun 2024 – Sep 2026 | 7.79 4 Sep 2026 |
| Ammoniacal Nitrogen as N 0111 | River water | 22 | Jun 2024 – Sep 2026 | below 0.03 mg/l 4 Sep 2026 |
| Nitrate as N 0117 | River water | 22 | Jun 2024 – Sep 2026 | 13 mg/l 4 Sep 2026 |
| Orthophosphate, reactive as P 0180 | River water | 22 | Jun 2024 – Sep 2026 | 4.2 mg/l 4 Sep 2026 |
| Conductivity at 25 C 0077 | River water | 22 | Jun 2024 – Sep 2026 | 962 µS/cm 4 Sep 2026 |
| Alkalinity to pH 4.5 as CaCO3 0162 | River water | 22 | Jun 2024 – Sep 2026 | 220 mg/l 4 Sep 2026 |
| Ammonia un-ionised as N 0119 | River water | 22 | Jun 2024 – Sep 2026 | below 0.00057 mg/l 4 Sep 2026 |
| BOD : 5 Day ATU 0085 | River water | 22 | Jun 2024 – Sep 2026 | below 4 mg/l 4 Sep 2026 |
| Nitrite as N 0118 | River water | 22 | Jun 2024 – Sep 2026 | 0.03 mg/l 4 Sep 2026 |
| Nitrogen, Total Oxidised as N 0116 | River water | 22 | Jun 2024 – Sep 2026 | 13 mg/l 4 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.