Bristol Avon at Monkton House
EA name: BRISTOL AVON AT MONKTON HOUSE (also listed as “D/S CHALFIELD BROOK”)
Environment Agency sampling point SW-Z1011701 · 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
- 18 May 2026, 11:534 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
- 25 since 24 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 388435, 162334As published, to the nearest 1 m. Open in a map
- River, by its own name
- Bristol Avon
- River, by the map
- River AvonPlaced on a river whose name partly matches its own, 19 m from the line.
- Next gauge downstream
- Bradford on Avon On the River Avon · 11 km along the river
- Nearest gauge upstream
- Melksham Clackers On the Clackers Brook · 5.3 km along the riverMelksham Shaw On the South Brook · 5.7 km along the riverStanley On the River Marden · 24 km along the river
- Why it was sampled
- Monitoring (national agency policy) (25 samples)
Main measurements, river water
Dissolved oxygen
% saturation · code 9901 · %
83.7%
Sampled 18 May 2026, 4 months ago · 25 results banked
Every result (25)
| Sampled | Result as published | Reads as |
|---|---|---|
| 18 May 2026, 11:53 | 83.7 | 83.7% |
| 10 Apr 2026, 10:34 | 105.9 | 105.9% |
| 2 Mar 2026, 13:08 | 104.9 | 104.9% |
| 2 Feb 2026, 12:17 | 93.6 | 93.6% |
| 13 Jan 2026, 11:31 | 91.7 | 91.7% |
| 17 Dec 2025, 14:46 | 92.8 | 92.8% |
| 13 Mar 2025, 11:39 | 102.8 | 102.8% |
| 14 Feb 2025, 12:50 | 97.7 | 97.7% |
| 29 Jan 2025, 10:38 | 95 | 95% |
| 4 Dec 2024, 14:54 | 97.7 | 97.7% |
| 18 Nov 2024, 09:08 | 90.6 | 90.6% |
| 14 Oct 2024, 10:38 | 89.2 | 89.2% |
| 18 Sep 2024, 13:55 | 88.2 | 88.2% |
| 22 Aug 2024, 12:38 | 80.6 | 80.6% |
| 15 Jul 2024, 14:04 | 85.6 | 85.6% |
| 28 Jun 2024, 13:38 | 103.7 | 103.7% |
| 17 May 2024, 10:38 | 99.7 | 99.7% |
| 24 Apr 2024, 09:03 | 96.2 | 96.2% |
| 21 Mar 2024, 11:09 | 97.3 | 97.3% |
| 20 Feb 2024, 09:39 | 90 | 90% |
| 24 Jan 2024, 10:31 | 92.2 | 92.2% |
| 13 Dec 2023, 08:15 | 80.6 | 80.6% |
| 29 Nov 2023, 12:14 | 98.1 | 98.1% |
| 14 Nov 2023, 10:33 | 81.9 | 81.9% |
| 24 Oct 2023, 10:48 | 85.6 | 85.6% |
Dissolved oxygen
as O2 · code 9924 · mg/l
8.9 mg/l
Sampled 18 May 2026, 4 months ago · 25 results banked
Every result (25)
| Sampled | Result as published | Reads as |
|---|---|---|
| 18 May 2026, 11:53 | 8.9 | 8.9 mg/l |
| 10 Apr 2026, 10:34 | 11.4 | 11.4 mg/l |
| 2 Mar 2026, 13:08 | 11.8 | 11.8 mg/l |
| 2 Feb 2026, 12:17 | 11.1 | 11.1 mg/l |
| 13 Jan 2026, 11:31 | 11 | 11 mg/l |
| 17 Dec 2025, 14:46 | 10.9 | 10.9 mg/l |
| 13 Mar 2025, 11:39 | 12.1 | 12.1 mg/l |
| 14 Feb 2025, 12:50 | 12.1 | 12.1 mg/l |
| 29 Jan 2025, 10:38 | 11.8 | 11.8 mg/l |
| 4 Dec 2024, 14:54 | 11.3 | 11.3 mg/l |
| 18 Nov 2024, 09:08 | 10.5 | 10.5 mg/l |
| 14 Oct 2024, 10:38 | 9.86 | 9.86 mg/l |
| 18 Sep 2024, 13:55 | 8.89 | 8.89 mg/l |
| 22 Aug 2024, 12:38 | 7.69 | 7.69 mg/l |
| 15 Jul 2024, 14:04 | 8.3 | 8.3 mg/l |
| 28 Jun 2024, 13:38 | 9.69 | 9.69 mg/l |
| 17 May 2024, 10:38 | 9.98 | 9.98 mg/l |
| 24 Apr 2024, 09:03 | 10.9 | 10.9 mg/l |
| 21 Mar 2024, 11:09 | 10.6 | 10.6 mg/l |
| 20 Feb 2024, 09:39 | 10.2 | 10.2 mg/l |
| 24 Jan 2024, 10:31 | 10.9 | 10.9 mg/l |
| 13 Dec 2023, 08:15 | 9.39 | 9.39 mg/l |
| 29 Nov 2023, 12:14 | 11.7 | 11.7 mg/l |
| 14 Nov 2023, 10:33 | 9.12 | 9.12 mg/l |
| 24 Oct 2023, 10:48 | 9.23 | 9.23 mg/l |
Water temperature
code 0076 · °C
12.5 °C
Sampled 18 May 2026, 4 months ago · 25 results banked
Every result (25)
| Sampled | Result as published | Reads as |
|---|---|---|
| 18 May 2026, 11:53 | 12.5 | 12.5 °C |
| 10 Apr 2026, 10:34 | 12.1 | 12.1 °C |
| 2 Mar 2026, 13:08 | 9.9 | 9.9 °C |
| 2 Feb 2026, 12:17 | 7.9 | 7.9 °C |
| 13 Jan 2026, 11:31 | 7.6 | 7.6 °C |
| 17 Dec 2025, 14:46 | 8.1 | 8.1 °C |
| 13 Mar 2025, 11:39 | 8.2 | 8.2 °C |
| 14 Feb 2025, 12:50 | 6.2 | 6.2 °C |
| 29 Jan 2025, 10:38 | 6.1 | 6.1 °C |
| 4 Dec 2024, 14:54 | 8.9 | 8.9 °C |
| 18 Nov 2024, 09:08 | 8.8 | 8.8 °C |
| 14 Oct 2024, 10:38 | 10.8 | 10.8 °C |
| 18 Sep 2024, 13:55 | 14.9 | 14.9 °C |
| 22 Aug 2024, 12:38 | 17.5 | 17.5 °C |
| 15 Jul 2024, 14:04 | 16.7 | 16.7 °C |
| 28 Jun 2024, 13:38 | 18.5 | 18.5 °C |
| 17 May 2024, 10:38 | 15.2 | 15.2 °C |
| 24 Apr 2024, 09:03 | 9.6 | 9.6 °C |
| 21 Mar 2024, 11:09 | 11.3 | 11.3 °C |
| 20 Feb 2024, 09:39 | 9.6 | 9.6 °C |
| 24 Jan 2024, 10:31 | 7.9 | 7.9 °C |
| 13 Dec 2023, 08:15 | 8.6 | 8.6 °C |
| 29 Nov 2023, 12:14 | 7.7 | 7.7 °C |
| 14 Nov 2023, 10:33 | 10.5 | 10.5 °C |
| 24 Oct 2023, 10:48 | 11.9 | 11.9 °C |
pH
code 0061
7.89
Sampled 18 May 2026, 4 months ago · 25 results banked
Every result (25)
| Sampled | Result as published | Reads as |
|---|---|---|
| 18 May 2026, 11:53 | 7.89 | 7.89 |
| 10 Apr 2026, 10:34 | 8.43 | 8.43 |
| 2 Mar 2026, 13:08 | 8.26 | 8.26 |
| 2 Feb 2026, 12:17 | 7.96 | 7.96 |
| 13 Jan 2026, 11:31 | 7.95 | 7.95 |
| 17 Dec 2025, 14:46 | 8.03 | 8.03 |
| 13 Mar 2025, 11:39 | 8.31 | 8.31 |
| 14 Feb 2025, 12:50 | 8.24 | 8.24 |
| 29 Jan 2025, 10:38 | 8.1 | 8.1 |
| 4 Dec 2024, 14:54 | 8.11 | 8.11 |
| 18 Nov 2024, 09:08 | 8.13 | 8.13 |
| 14 Oct 2024, 10:38 | 7.96 | 7.96 |
| 18 Sep 2024, 13:55 | 7.92 | 7.92 |
| 22 Aug 2024, 12:38 | 7.91 | 7.91 |
| 15 Jul 2024, 14:04 | 7.99 | 7.99 |
| 28 Jun 2024, 13:38 | 8.3 | 8.3 |
| 17 May 2024, 10:38 | 8.25 | 8.25 |
| 24 Apr 2024, 09:03 | 8.23 | 8.23 |
| 21 Mar 2024, 11:09 | 8.22 | 8.22 |
| 20 Feb 2024, 09:39 | 8.05 | 8.05 |
| 24 Jan 2024, 10:31 | 8.05 | 8.05 |
| 13 Dec 2023, 08:15 | 7.84 | 7.84 |
| 29 Nov 2023, 12:14 | 8.15 | 8.15 |
| 14 Nov 2023, 10:33 | 8.01 | 8.01 |
| 24 Oct 2023, 10:48 | 7.86 | 7.86 |
Ammonia
ammoniacal nitrogen as N · code 0111 · mg/l
0.23 mg/l
Sampled 18 May 2026, 4 months ago · 25 results banked
Every result (25)
| Sampled | Result as published | Reads as |
|---|---|---|
| 18 May 2026, 11:53 | 0.23 | 0.23 mg/l |
| 10 Apr 2026, 10:34 | 0.039 | 0.039 mg/l |
| 2 Mar 2026, 13:08 | 0.039 | 0.039 mg/l |
| 2 Feb 2026, 12:17 | 0.063 | 0.063 mg/l |
| 13 Jan 2026, 11:31 | 0.089 | 0.089 mg/l |
| 17 Dec 2025, 14:46 | <0.03 | below 0.03 mg/l (not detected above this) |
| 13 Mar 2025, 11:39 | 0.085 | 0.085 mg/l |
| 14 Feb 2025, 12:50 | 0.13 | 0.13 mg/l |
| 29 Jan 2025, 10:38 | <0.03 | below 0.03 mg/l (not detected above this) |
| 4 Dec 2024, 14:54 | 0.07 | 0.07 mg/l |
| 18 Nov 2024, 09:08 | 0.2 | 0.2 mg/l |
| 14 Oct 2024, 10:38 | 0.13 | 0.13 mg/l |
| 18 Sep 2024, 13:55 | 0.062 | 0.062 mg/l |
| 22 Aug 2024, 12:38 | 0.083 | 0.083 mg/l |
| 15 Jul 2024, 14:04 | 0.054 | 0.054 mg/l |
| 28 Jun 2024, 13:38 | <0.03 | below 0.03 mg/l (not detected above this) |
| 17 May 2024, 10:38 | 0.041 | 0.041 mg/l |
| 24 Apr 2024, 09:03 | 0.034 | 0.034 mg/l |
| 21 Mar 2024, 11:09 | 0.061 | 0.061 mg/l |
| 20 Feb 2024, 09:39 | 0.055 | 0.055 mg/l |
| 24 Jan 2024, 10:31 | 0.12 | 0.12 mg/l |
| 13 Dec 2023, 08:15 | 0.068 | 0.068 mg/l |
| 29 Nov 2023, 12:14 | 0.067 | 0.067 mg/l |
| 14 Nov 2023, 10:33 | <0.03 | below 0.03 mg/l (not detected above this) |
| 24 Oct 2023, 10:48 | 0.061 | 0.061 mg/l |
Nitrate
as nitrogen (N) · code 0117 · mg/l
7.39 mg/l
Sampled 18 May 2026, 4 months ago · 24 results banked
Every result (24)
| Sampled | Result as published | Reads as |
|---|---|---|
| 18 May 2026, 11:53 | 7.39 | 7.39 mg/l |
| 10 Apr 2026, 10:34 | 6.26 | 6.26 mg/l |
| 2 Mar 2026, 13:08 | 4.77 | 4.77 mg/l |
| 2 Feb 2026, 12:17 | 4.77 | 4.77 mg/l |
| 13 Jan 2026, 11:31 | 5.95 | 5.95 mg/l |
| 17 Dec 2025, 14:46 | 6.09 | 6.09 mg/l |
| 13 Mar 2025, 11:39 | 6.36 | 6.36 mg/l |
| 14 Feb 2025, 12:50 | 5.06 | 5.06 mg/l |
| 29 Jan 2025, 10:38 | 3.39 | 3.39 mg/l |
| 4 Dec 2024, 14:54 | 5.37 | 5.37 mg/l |
| 18 Nov 2024, 09:08 | 6.73 | 6.73 mg/l |
| 14 Oct 2024, 10:38 | 4.87 | 4.87 mg/l |
| 18 Sep 2024, 13:55 | 6.96 | 6.96 mg/l |
| 22 Aug 2024, 12:38 | 7.64 | 7.64 mg/l |
| 15 Jul 2024, 14:04 | 5.95 | 5.95 mg/l |
| 28 Jun 2024, 13:38 | 6.37 | 6.37 mg/l |
| 17 May 2024, 10:38 | 5.67 | 5.67 mg/l |
| 24 Apr 2024, 09:03 | 6.18 | 6.18 mg/l |
| 21 Mar 2024, 11:09 | 4.96 | 4.96 mg/l |
| 20 Feb 2024, 09:39 | 3.78 | 3.78 mg/l |
| 13 Dec 2023, 08:15 | 3.86 | 3.86 mg/l |
| 29 Nov 2023, 12:14 | 5.75 | 5.75 mg/l |
| 14 Nov 2023, 10:33 | 4.09 | 4.09 mg/l |
| 24 Oct 2023, 10:48 | 5.96 | 5.96 mg/l |
Phosphate
orthophosphate, reactive, as P · code 0180 · mg/l
0.17 mg/l
Sampled 18 May 2026, 4 months ago · 25 results banked
Every result (25)
| Sampled | Result as published | Reads as |
|---|---|---|
| 18 May 2026, 11:53 | 0.17 | 0.17 mg/l |
| 10 Apr 2026, 10:34 | 0.048 | 0.048 mg/l |
| 2 Mar 2026, 13:08 | 0.079 | 0.079 mg/l |
| 2 Feb 2026, 12:17 | 0.097 | 0.097 mg/l |
| 13 Jan 2026, 11:31 | 0.086 | 0.086 mg/l |
| 17 Dec 2025, 14:46 | 0.078 | 0.078 mg/l |
| 13 Mar 2025, 11:39 | 0.073 | 0.073 mg/l |
| 14 Feb 2025, 12:50 | 0.089 | 0.089 mg/l |
| 29 Jan 2025, 10:38 | 0.077 | 0.077 mg/l |
| 4 Dec 2024, 14:54 | 0.07 | 0.07 mg/l |
| 18 Nov 2024, 09:08 | 0.092 | 0.092 mg/l |
| 14 Oct 2024, 10:38 | 0.11 | 0.11 mg/l |
| 18 Sep 2024, 13:55 | 0.19 | 0.19 mg/l |
| 22 Aug 2024, 12:38 | 0.27 | 0.27 mg/l |
| 15 Jul 2024, 14:04 | 0.17 | 0.17 mg/l |
| 28 Jun 2024, 13:38 | 0.09 | 0.09 mg/l |
| 17 May 2024, 10:38 | 0.12 | 0.12 mg/l |
| 24 Apr 2024, 09:03 | 0.062 | 0.062 mg/l |
| 21 Mar 2024, 11:09 | 0.096 | 0.096 mg/l |
| 20 Feb 2024, 09:39 | 0.1 | 0.1 mg/l |
| 24 Jan 2024, 10:31 | 0.089 | 0.089 mg/l |
| 13 Dec 2023, 08:15 | 0.092 | 0.092 mg/l |
| 29 Nov 2023, 12:14 | 0.1 | 0.1 mg/l |
| 14 Nov 2023, 10:33 | 0.077 | 0.077 mg/l |
| 24 Oct 2023, 10:48 | 0.13 | 0.13 mg/l |
Conductivity
at 25 °C · code 0077 · µS/cm
728 µS/cm
Sampled 18 May 2026, 4 months ago · 25 results banked
Every result (25)
| Sampled | Result as published | Reads as |
|---|---|---|
| 18 May 2026, 11:53 | 728 | 728 µS/cm |
| 10 Apr 2026, 10:34 | 669 | 669 µS/cm |
| 2 Mar 2026, 13:08 | 569 | 569 µS/cm |
| 2 Feb 2026, 12:17 | 531 | 531 µS/cm |
| 13 Jan 2026, 11:31 | 582 | 582 µS/cm |
| 17 Dec 2025, 14:46 | 560 | 560 µS/cm |
| 13 Mar 2025, 11:39 | 684 | 684 µS/cm |
| 14 Feb 2025, 12:50 | 631 | 631 µS/cm |
| 29 Jan 2025, 10:38 | 524 | 524 µS/cm |
| 4 Dec 2024, 14:54 | 629 | 629 µS/cm |
| 18 Nov 2024, 09:08 | 702 | 702 µS/cm |
| 14 Oct 2024, 10:38 | 576 | 576 µS/cm |
| 18 Sep 2024, 13:55 | 746 | 746 µS/cm |
| 22 Aug 2024, 12:38 | 812 | 812 µS/cm |
| 15 Jul 2024, 14:04 | 702 | 702 µS/cm |
| 28 Jun 2024, 13:38 | 732 | 732 µS/cm |
| 17 May 2024, 10:38 | 664 | 664 µS/cm |
| 24 Apr 2024, 09:03 | 652 | 652 µS/cm |
| 21 Mar 2024, 11:09 | 620 | 620 µS/cm |
| 20 Feb 2024, 09:39 | 546 | 546 µS/cm |
| 24 Jan 2024, 10:31 | 543 | 543 µS/cm |
| 13 Dec 2023, 08:15 | 519 | 519 µS/cm |
| 29 Nov 2023, 12:14 | 648 | 648 µS/cm |
| 14 Nov 2023, 10:33 | 597 | 597 µS/cm |
| 24 Oct 2023, 10:48 | 624 | 624 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 | 25 | Oct 2023 – May 2026 | 83.7% 18 May 2026 |
| Oxygen, Dissolved as O2 9924 | River water | 25 | Oct 2023 – May 2026 | 8.9 mg/l 18 May 2026 |
| Temperature of Water 0076 | River water | 25 | Oct 2023 – May 2026 | 12.5 °C 18 May 2026 |
| pH 0061 | River water | 25 | Oct 2023 – May 2026 | 7.89 18 May 2026 |
| Ammoniacal Nitrogen as N 0111 | River water | 25 | Oct 2023 – May 2026 | 0.23 mg/l 18 May 2026 |
| Nitrate as N 0117 | River water | 24 | Oct 2023 – May 2026 | 7.39 mg/l 18 May 2026 |
| Orthophosphate, reactive as P 0180 | River water | 25 | Oct 2023 – May 2026 | 0.17 mg/l 18 May 2026 |
| Conductivity at 25 C 0077 | River water | 25 | Oct 2023 – May 2026 | 728 µS/cm 18 May 2026 |
| Alkalinity to pH 4.5 as CaCO3 0162 | River water | 25 | Oct 2023 – May 2026 | 240 mg/l 18 May 2026 |
| Ammonia un-ionised as N 0119 | River water | 25 | Oct 2023 – May 2026 | 0.00393 mg/l 18 May 2026 |
| BOD : 5 Day ATU 0085 | River water | 20 | Feb 2024 – May 2026 | 1.9 mg/l 18 May 2026 |
| Nitrite as N 0118 | River water | 25 | Oct 2023 – May 2026 | 0.11 mg/l 18 May 2026 |
| Nitrogen, Total Oxidised as N 0116 | River water | 24 | Oct 2023 – May 2026 | 7.5 mg/l 18 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.