Stondon Brook A600 Road Bridge Holwellbury
EA name: STONDON BK. A600 RD.BR. HOLWELLBURY
Environment Agency sampling point AN-13M31 · 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, 10:4327 days ago · time as the Environment Agency records it (UK clock time; the source gives no time zone)
- Samples banked
- 23 since 6 Jun 2024 Imported periods: 1 Oct 2023 – 30 Sep 2026. Samples outside them are not shown here.
- Latest sample
- River / running surface water Planned investigation (local monitoring)
- Where
- National Grid 516795, 234950As published, to the nearest 1 m. Open in a map
- River, by its own name
- Its name does not give one
- River, by the map
- An unnamed streamPlaced by position alone (the only river line close by), 5 m from the line.
- Next gauge downstream
- Arlesey On the River Hiz · 4.9 km along the riverARLESEY GS 4.9 km along the river
- Why it was sampled
- Environmental monitoring statutory (EU directives) (17 samples)
Planned investigation (local monitoring) (6 samples)
2 visits found no water to sample (recorded as “No flow”).
Main measurements, river water
Dissolved oxygen
% saturation · code 9901 · %
28.4%
Sampled 4 Sep 2026, 27 days ago · 21 results banked
Every result (21)
| Sampled | Result as published | Reads as |
|---|---|---|
| 4 Sep 2026, 10:43 | 28.4 | 28.4% |
| 4 Jun 2026, 12:05 | 88.1 | 88.1% |
| 5 May 2026, 11:55 | 109.7 | 109.7% |
| 1 Apr 2026, 09:09 | 93 | 93% |
| 4 Mar 2026, 10:19 | 102.4 | 102.4% |
| 3 Feb 2026, 08:54 | 94.8 | 94.8% |
| 14 Jan 2026, 08:17 | 86.2 | 86.2% |
| 1 Dec 2025, 13:13 | 83 | 83% |
| 3 Nov 2025, 12:06 | 17.3 | 17.3% |
| 21 Oct 2025, 09:48 | 24.8 | 24.8% |
| 10 Apr 2025, 09:04 | 84 | 84% |
| 18 Mar 2025, 10:20 | 102.3 | 102.3% |
| 17 Feb 2025, 09:29 | 94.7 | 94.7% |
| 24 Jan 2025, 11:02 | 91.9 | 91.9% |
| 2 Dec 2024, 09:22 | 83.8 | 83.8% |
| 7 Nov 2024, 10:19 | 89.7 | 89.7% |
| 7 Oct 2024, 11:23 | 90.7 | 90.7% |
| 2 Sep 2024, 11:05 | 37.6 | 37.6% |
| 7 Aug 2024, 10:31 | 60.2 | 60.2% |
| 1 Jul 2024, 13:33 | 52.9 | 52.9% |
| 6 Jun 2024, 12:39 | 91.4 | 91.4% |
Dissolved oxygen
as O2 · code 9924 · mg/l
2.7 mg/l
Sampled 4 Sep 2026, 27 days ago · 21 results banked
Every result (21)
| Sampled | Result as published | Reads as |
|---|---|---|
| 4 Sep 2026, 10:43 | 2.7 | 2.7 mg/l |
| 4 Jun 2026, 12:05 | 8.74 | 8.74 mg/l |
| 5 May 2026, 11:55 | 11.3 | 11.3 mg/l |
| 1 Apr 2026, 09:09 | 10.7 | 10.7 mg/l |
| 4 Mar 2026, 10:19 | 12.2 | 12.2 mg/l |
| 3 Feb 2026, 08:54 | 11.7 | 11.7 mg/l |
| 14 Jan 2026, 08:17 | 11.3 | 11.3 mg/l |
| 1 Dec 2025, 13:13 | 9.6 | 9.6 mg/l |
| 3 Nov 2025, 12:06 | 1.89 | 1.89 mg/l |
| 21 Oct 2025, 09:48 | 2.67 | 2.67 mg/l |
| 10 Apr 2025, 09:04 | 10 | 10 mg/l |
| 18 Mar 2025, 10:20 | 13.3 | 13.3 mg/l |
| 17 Feb 2025, 09:29 | 12.8 | 12.8 mg/l |
| 24 Jan 2025, 11:02 | 11.1 | 11.1 mg/l |
| 2 Dec 2024, 09:22 | 9.55 | 9.55 mg/l |
| 7 Nov 2024, 10:19 | 9.92 | 9.92 mg/l |
| 7 Oct 2024, 11:23 | 9.41 | 9.41 mg/l |
| 2 Sep 2024, 11:05 | 3.56 | 3.56 mg/l |
| 7 Aug 2024, 10:31 | 6.02 | 6.02 mg/l |
| 1 Jul 2024, 13:33 | 5.31 | 5.31 mg/l |
| 6 Jun 2024, 12:39 | 9.87 | 9.87 mg/l |
Water temperature
code 0076 · °C
17.6 °C
Sampled 4 Sep 2026, 27 days ago · 21 results banked
Every result (21)
| Sampled | Result as published | Reads as |
|---|---|---|
| 4 Sep 2026, 10:43 | 17.6 | 17.6 °C |
| 4 Jun 2026, 12:05 | 15.6 | 15.6 °C |
| 5 May 2026, 11:55 | 13.9 | 13.9 °C |
| 1 Apr 2026, 09:09 | 9.2 | 9.2 °C |
| 4 Mar 2026, 10:19 | 7.6 | 7.6 °C |
| 3 Feb 2026, 08:54 | 6.3 | 6.3 °C |
| 14 Jan 2026, 08:17 | 4 | 4 °C |
| 1 Dec 2025, 13:13 | 8.9 | 8.9 °C |
| 3 Nov 2025, 12:06 | 11.2 | 11.2 °C |
| 21 Oct 2025, 09:48 | 12 | 12 °C |
| 10 Apr 2025, 09:04 | 7.6 | 7.6 °C |
| 18 Mar 2025, 10:20 | 4.4 | 4.4 °C |
| 17 Feb 2025, 09:29 | 2.9 | 2.9 °C |
| 24 Jan 2025, 11:02 | 7.1 | 7.1 °C |
| 2 Dec 2024, 09:22 | 9.5 | 9.5 °C |
| 7 Nov 2024, 10:19 | 10.8 | 10.8 °C |
| 7 Oct 2024, 11:23 | 13.6 | 13.6 °C |
| 2 Sep 2024, 11:05 | 17.8 | 17.8 °C |
| 7 Aug 2024, 10:31 | 15.3 | 15.3 °C |
| 1 Jul 2024, 13:33 | 15.1 | 15.1 °C |
| 6 Jun 2024, 12:39 | 11.8 | 11.8 °C |
pH
code 0061
8.21
Sampled 4 Mar 2026, 7 months ago · 17 results banked
Every result (17)
| Sampled | Result as published | Reads as |
|---|---|---|
| 4 Mar 2026, 10:19 | 8.21 | 8.21 |
| 3 Feb 2026, 08:54 | 8.04 | 8.04 |
| 14 Jan 2026, 08:17 | 8.1 | 8.1 |
| 1 Dec 2025, 13:13 | 7.94 | 7.94 |
| 3 Nov 2025, 12:06 | 7.42 | 7.42 |
| 21 Oct 2025, 09:48 | 7.42 | 7.42 |
| 10 Apr 2025, 09:04 | 8.01 | 8.01 |
| 18 Mar 2025, 10:20 | 8.18 | 8.18 |
| 17 Feb 2025, 09:29 | 8.24 | 8.24 |
| 24 Jan 2025, 11:02 | 8.19 | 8.19 |
| 2 Dec 2024, 09:22 | 7.96 | 7.96 |
| 7 Nov 2024, 10:19 | 8.06 | 8.06 |
| 7 Oct 2024, 11:23 | 7.95 | 7.95 |
| 2 Sep 2024, 11:05 | 7.37 | 7.37 |
| 7 Aug 2024, 10:31 | 7.7 | 7.7 |
| 1 Jul 2024, 13:33 | 7.9 | 7.9 |
| 6 Jun 2024, 12:39 | 8.17 | 8.17 |
Ammonia
ammoniacal nitrogen as N · code 0111 · mg/l
0.062 mg/l
Sampled 4 Sep 2026, 27 days ago · 21 results banked
Every result (21)
| Sampled | Result as published | Reads as |
|---|---|---|
| 4 Sep 2026, 10:43 | 0.062 | 0.062 mg/l |
| 4 Jun 2026, 12:05 | 0.049 | 0.049 mg/l |
| 5 May 2026, 11:55 | 0.11 | 0.11 mg/l |
| 1 Apr 2026, 09:09 | <0.03 | below 0.03 mg/l (not detected above this) |
| 4 Mar 2026, 10:19 | <0.03 | below 0.03 mg/l (not detected above this) |
| 3 Feb 2026, 08:54 | <0.03 | below 0.03 mg/l (not detected above this) |
| 14 Jan 2026, 08:17 | 0.032 | 0.032 mg/l |
| 1 Dec 2025, 13:13 | 0.049 | 0.049 mg/l |
| 3 Nov 2025, 12:06 | <0.03 | below 0.03 mg/l (not detected above this) |
| 21 Oct 2025, 09:48 | <0.03 | below 0.03 mg/l (not detected above this) |
| 10 Apr 2025, 09:04 | 0.039 | 0.039 mg/l |
| 18 Mar 2025, 10:20 | 0.031 | 0.031 mg/l |
| 17 Feb 2025, 09:29 | <0.03 | below 0.03 mg/l (not detected above this) |
| 24 Jan 2025, 11:02 | 0.047 | 0.047 mg/l |
| 2 Dec 2024, 09:22 | <0.03 | below 0.03 mg/l (not detected above this) |
| 7 Nov 2024, 10:19 | <0.03 | below 0.03 mg/l (not detected above this) |
| 7 Oct 2024, 11:23 | <0.03 | below 0.03 mg/l (not detected above this) |
| 2 Sep 2024, 11:05 | 0.04 | 0.04 mg/l |
| 7 Aug 2024, 10:31 | 0.059 | 0.059 mg/l |
| 1 Jul 2024, 13:33 | 0.24 | 0.24 mg/l |
| 6 Jun 2024, 12:39 | 0.051 | 0.051 mg/l |
Nitrate
as nitrogen (N) · code 0117 · mg/l
0.281 mg/l
Sampled 4 Sep 2026, 27 days ago · 21 results banked
Every result (21)
| Sampled | Result as published | Reads as |
|---|---|---|
| 4 Sep 2026, 10:43 | 0.281 | 0.281 mg/l |
| 4 Jun 2026, 12:05 | 0.789 | 0.789 mg/l |
| 5 May 2026, 11:55 | 3.62 | 3.62 mg/l |
| 1 Apr 2026, 09:09 | 7.96 | 7.96 mg/l |
| 4 Mar 2026, 10:19 | 11 | 11 mg/l |
| 3 Feb 2026, 08:54 | 15 | 15 mg/l |
| 14 Jan 2026, 08:17 | 13 | 13 mg/l |
| 1 Dec 2025, 13:13 | 3.97 | 3.97 mg/l |
| 3 Nov 2025, 12:06 | <0.196 | below 0.196 mg/l (not detected above this) |
| 21 Oct 2025, 09:48 | <0.196 | below 0.196 mg/l (not detected above this) |
| 10 Apr 2025, 09:04 | 6.57 | 6.57 mg/l |
| 18 Mar 2025, 10:20 | 8.59 | 8.59 mg/l |
| 17 Feb 2025, 09:29 | 9.49 | 9.49 mg/l |
| 24 Jan 2025, 11:02 | 7.78 | 7.78 mg/l |
| 2 Dec 2024, 09:22 | 8.97 | 8.97 mg/l |
| 7 Nov 2024, 10:19 | 6.48 | 6.48 mg/l |
| 7 Oct 2024, 11:23 | 8.67 | 8.67 mg/l |
| 2 Sep 2024, 11:05 | 0.331 | 0.331 mg/l |
| 7 Aug 2024, 10:31 | 1.93 | 1.93 mg/l |
| 1 Jul 2024, 13:33 | 2.76 | 2.76 mg/l |
| 6 Jun 2024, 12:39 | 4.87 | 4.87 mg/l |
Phosphate
orthophosphate, reactive, as P · code 0180 · mg/l
0.21 mg/l
Sampled 4 Sep 2026, 27 days ago · 21 results banked
Every result (21)
| Sampled | Result as published | Reads as |
|---|---|---|
| 4 Sep 2026, 10:43 | 0.21 | 0.21 mg/l |
| 4 Jun 2026, 12:05 | 0.098 | 0.098 mg/l |
| 5 May 2026, 11:55 | 0.048 | 0.048 mg/l |
| 1 Apr 2026, 09:09 | 0.03 | 0.03 mg/l |
| 4 Mar 2026, 10:19 | 0.034 | 0.034 mg/l |
| 3 Feb 2026, 08:54 | 0.031 | 0.031 mg/l |
| 14 Jan 2026, 08:17 | 0.037 | 0.037 mg/l |
| 1 Dec 2025, 13:13 | 0.058 | 0.058 mg/l |
| 3 Nov 2025, 12:06 | 0.97 | 0.97 mg/l |
| 21 Oct 2025, 09:48 | 0.34 | 0.34 mg/l |
| 10 Apr 2025, 09:04 | 0.049 | 0.049 mg/l |
| 18 Mar 2025, 10:20 | 0.043 | 0.043 mg/l |
| 17 Feb 2025, 09:29 | 0.03 | 0.03 mg/l |
| 24 Jan 2025, 11:02 | 0.052 | 0.052 mg/l |
| 2 Dec 2024, 09:22 | 0.036 | 0.036 mg/l |
| 7 Nov 2024, 10:19 | 0.078 | 0.078 mg/l |
| 7 Oct 2024, 11:23 | 0.049 | 0.049 mg/l |
| 2 Sep 2024, 11:05 | 0.17 | 0.17 mg/l |
| 7 Aug 2024, 10:31 | 0.11 | 0.11 mg/l |
| 1 Jul 2024, 13:33 | 0.17 | 0.17 mg/l |
| 6 Jun 2024, 12:39 | 0.079 | 0.079 mg/l |
Conductivity
at 25 °C · code 0077 · µS/cm
1049 µS/cm
Sampled 4 Sep 2026, 27 days ago · 21 results banked
Every result (21)
| Sampled | Result as published | Reads as |
|---|---|---|
| 4 Sep 2026, 10:43 | 1049 | 1049 µS/cm |
| 4 Jun 2026, 12:05 | 676 | 676 µS/cm |
| 5 May 2026, 11:55 | 855 | 855 µS/cm |
| 1 Apr 2026, 09:09 | 881 | 881 µS/cm |
| 4 Mar 2026, 10:19 | 849 | 849 µS/cm |
| 3 Feb 2026, 08:54 | 812 | 812 µS/cm |
| 14 Jan 2026, 08:17 | 827 | 827 µS/cm |
| 1 Dec 2025, 13:13 | 858 | 858 µS/cm |
| 3 Nov 2025, 12:06 | 859 | 859 µS/cm |
| 21 Oct 2025, 09:48 | 728 | 728 µS/cm |
| 10 Apr 2025, 09:04 | 875 | 875 µS/cm |
| 18 Mar 2025, 10:20 | 875 | 875 µS/cm |
| 17 Feb 2025, 09:29 | 845 | 845 µS/cm |
| 24 Jan 2025, 11:02 | 852 | 852 µS/cm |
| 2 Dec 2024, 09:22 | 820 | 820 µS/cm |
| 7 Nov 2024, 10:19 | 867 | 867 µS/cm |
| 7 Oct 2024, 11:23 | 796 | 796 µS/cm |
| 2 Sep 2024, 11:05 | 957 | 957 µS/cm |
| 7 Aug 2024, 10:31 | 915 | 915 µS/cm |
| 1 Jul 2024, 13:33 | 918 | 918 µS/cm |
| 6 Jun 2024, 12:39 | 892 | 892 µS/cm |
Everything measured here
19 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 19 rows
| Determinand | Material | Results | First – last | Latest result |
|---|---|---|---|---|
| Oxygen, Dissolved, % Saturation 9901 | River water | 21 | Jun 2024 – Sep 2026 | 28.4% 4 Sep 2026 |
| Oxygen, Dissolved as O2 9924 | River water | 21 | Jun 2024 – Sep 2026 | 2.7 mg/l 4 Sep 2026 |
| Temperature of Water 0076 | River water | 21 | Jun 2024 – Sep 2026 | 17.6 °C 4 Sep 2026 |
| pH 0061 | River water | 17 | Jun 2024 – Mar 2026 | 8.21 4 Mar 2026 |
| Ammoniacal Nitrogen as N 0111 | River water | 21 | Jun 2024 – Sep 2026 | 0.062 mg/l 4 Sep 2026 |
| Nitrate as N 0117 | River water | 21 | Jun 2024 – Sep 2026 | 0.281 mg/l 4 Sep 2026 |
| Orthophosphate, reactive as P 0180 | River water | 21 | Jun 2024 – Sep 2026 | 0.21 mg/l 4 Sep 2026 |
| Conductivity at 25 C 0077 | River water | 21 | Jun 2024 – Sep 2026 | 1049 µS/cm 4 Sep 2026 |
| Alkalinity to pH 4.5 as CaCO3 0162 | River water | 17 | Jun 2024 – Mar 2026 | 290 mg/l 4 Mar 2026 |
| Ammonia un-ionised as N 0119 | River water | 17 | Jun 2024 – Mar 2026 | below 0.00046 mg/l 4 Mar 2026 |
| BOD : 5 Day ATU 0085 | River water | 4 | Apr 2026 – Sep 2026 | 5.4 mg/l 4 Sep 2026 |
| Chemical Oxygen Demand :- {COD} 0092 | River water | 4 | Apr 2026 – Sep 2026 | 52 mg/l 4 Sep 2026 |
| Chloride 0172 | River water | 4 | Apr 2026 – Sep 2026 | 50 mg/l 4 Sep 2026 |
| Chlorophyll : Acetone Extract 7887 | River water | 4 | Apr 2026 – Sep 2026 | 31 µg/l 4 Sep 2026 |
| Nitrite as N 0118 | River water | 21 | Jun 2024 – Sep 2026 | 0.019 mg/l 4 Sep 2026 |
| Nitrogen, Total Oxidised as N 0116 | River water | 21 | Jun 2024 – Sep 2026 | 0.3 mg/l 4 Sep 2026 |
| No flow /No sample 7668 | River water | 2 | Jul 2026 – Aug 2026 | No flow/discharge at sampling point 5 Aug 2026 |
| Silica, reactive as SiO2 0182 | River water | 4 | Apr 2026 – Sep 2026 | 20 mg/l 4 Sep 2026 |
| Solids, Suspended at 105 C 0135 | River water | 4 | Apr 2026 – Sep 2026 | 99 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.