River Wensum Alderford off Marriott Way
EA name: R.WENSUM ALDERFORD OFF MARRIOTT WAY
Environment Agency sampling point AN-WEN219 · 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
- 11 Mar 2026, 08:477 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 8 Oct 2026 and had nothing newer.
- Samples banked
- 17 since 3 Jun 2024 Imported periods: 1 Oct 2023 – 8 Oct 2026. Samples outside them are not shown here.
- Latest sample
- River / running surface water Planned investigation (local monitoring)
- Where
- National Grid 612214, 317773As published, to the nearest 1 m. Open in a map
- River, by its own name
- Wensum
- River, by the map
- River WensumPlaced on the river its name gives, 6 m from the line.
- Next gauge downstream
- COSTESSEY MILL SLUICE 14 km along the riverCOSTESSEY MILL SLUICE 14 km along the riverCostessey Mill On the River Wensum · 14 km along the river
- Nearest gauge upstream
- Swanton Morley On the River Wensum · 16 km along the river
- Why it was sampled
- Planned investigation (local monitoring) (17 samples)
Main measurements, river water
Dissolved oxygen
% saturation · code 9901 · %
97.4%
Sampled 11 Mar 2026, 7 months ago · 17 results banked
Every result (17)
| Sampled | Result as published | Reads as |
|---|---|---|
| 11 Mar 2026, 08:47 | 97.4 | 97.4% |
| 4 Feb 2026, 09:41 | 93.6 | 93.6% |
| 9 Jan 2026, 14:37 | 94.1 | 94.1% |
| 2 Dec 2025, 13:01 | 92.7 | 92.7% |
| 13 Nov 2025, 12:04 | 85.4 | 85.4% |
| 9 Oct 2025, 14:38 | 93.7 | 93.7% |
| 2 Apr 2025, 09:23 | 88.8 | 88.8% |
| 3 Mar 2025, 10:06 | 95 | 95% |
| 11 Feb 2025, 10:23 | 95.5 | 95.5% |
| 7 Jan 2025, 11:20 | 95.6 | 95.6% |
| 3 Dec 2024, 13:37 | 93.7 | 93.7% |
| 1 Nov 2024, 12:09 | 92.6 | 92.6% |
| 8 Oct 2024, 13:36 | 96.5 | 96.5% |
| 3 Sep 2024, 09:13 | 80 | 80% |
| 9 Aug 2024, 09:15 | 80.9 | 80.9% |
| 26 Jul 2024, 12:10 | 90.9 | 90.9% |
| 3 Jun 2024, 17:12 | 94.3 | 94.3% |
Dissolved oxygen
as O2 · code 9924 · mg/l
11.2 mg/l
Sampled 11 Mar 2026, 7 months ago · 17 results banked
Every result (17)
| Sampled | Result as published | Reads as |
|---|---|---|
| 11 Mar 2026, 08:47 | 11.2 | 11.2 mg/l |
| 4 Feb 2026, 09:41 | 11.7 | 11.7 mg/l |
| 9 Jan 2026, 14:37 | 12.5 | 12.5 mg/l |
| 2 Dec 2025, 13:01 | 11 | 11 mg/l |
| 13 Nov 2025, 12:04 | 9.31 | 9.31 mg/l |
| 9 Oct 2025, 14:38 | 9.89 | 9.89 mg/l |
| 2 Apr 2025, 09:23 | 9.98 | 9.98 mg/l |
| 3 Mar 2025, 10:06 | 12.2 | 12.2 mg/l |
| 11 Feb 2025, 10:23 | 12.2 | 12.2 mg/l |
| 7 Jan 2025, 11:20 | 12.4 | 12.4 mg/l |
| 3 Dec 2024, 13:37 | 11.2 | 11.2 mg/l |
| 1 Nov 2024, 12:09 | 10.1 | 10.1 mg/l |
| 8 Oct 2024, 13:36 | 9.99 | 9.99 mg/l |
| 3 Sep 2024, 09:13 | 7.62 | 7.62 mg/l |
| 9 Aug 2024, 09:15 | 7.67 | 7.67 mg/l |
| 26 Jul 2024, 12:10 | 8.62 | 8.62 mg/l |
| 3 Jun 2024, 17:12 | 9.28 | 9.28 mg/l |
Water temperature
code 0076 · °C
9.3 °C
Sampled 11 Mar 2026, 7 months ago · 17 results banked
Every result (17)
| Sampled | Result as published | Reads as |
|---|---|---|
| 11 Mar 2026, 08:47 | 9.3 | 9.3 °C |
| 4 Feb 2026, 09:41 | 5.8 | 5.8 °C |
| 9 Jan 2026, 14:37 | 3.4 | 3.4 °C |
| 2 Dec 2025, 13:01 | 7.7 | 7.7 °C |
| 13 Nov 2025, 12:04 | 11.4 | 11.4 °C |
| 9 Oct 2025, 14:38 | 12.8 | 12.8 °C |
| 2 Apr 2025, 09:23 | 10.1 | 10.1 °C |
| 3 Mar 2025, 10:06 | 4.8 | 4.8 °C |
| 11 Feb 2025, 10:23 | 5 | 5 °C |
| 7 Jan 2025, 11:20 | 4.5 | 4.5 °C |
| 3 Dec 2024, 13:37 | 7.4 | 7.4 °C |
| 1 Nov 2024, 12:09 | 11.2 | 11.2 °C |
| 8 Oct 2024, 13:36 | 13.7 | 13.7 °C |
| 3 Sep 2024, 09:13 | 17.6 | 17.6 °C |
| 9 Aug 2024, 09:15 | 17.8 | 17.8 °C |
| 26 Jul 2024, 12:10 | 17.8 | 17.8 °C |
| 3 Jun 2024, 17:12 | 16 | 16 °C |
pH
code 0061
8.11
Sampled 11 Mar 2026, 7 months ago · 17 results banked
Every result (17)
| Sampled | Result as published | Reads as |
|---|---|---|
| 11 Mar 2026, 08:47 | 8.11 | 8.11 |
| 4 Feb 2026, 09:41 | 8.08 | 8.08 |
| 9 Jan 2026, 14:37 | 7.91 | 7.91 |
| 2 Dec 2025, 13:01 | 7.96 | 7.96 |
| 13 Nov 2025, 12:04 | 7.99 | 7.99 |
| 9 Oct 2025, 14:38 | 8.35 | 8.35 |
| 2 Apr 2025, 09:23 | 8.15 | 8.15 |
| 3 Mar 2025, 10:06 | 8.28 | 8.28 |
| 11 Feb 2025, 10:23 | 8.32 | 8.32 |
| 7 Jan 2025, 11:20 | 8.07 | 8.07 |
| 3 Dec 2024, 13:37 | 8 | 8 |
| 1 Nov 2024, 12:09 | 8 | 8 |
| 8 Oct 2024, 13:36 | 8.09 | 8.09 |
| 3 Sep 2024, 09:13 | 7.97 | 7.97 |
| 9 Aug 2024, 09:15 | 7.91 | 7.91 |
| 26 Jul 2024, 12:10 | 8.24 | 8.24 |
| 3 Jun 2024, 17:12 | 8.17 | 8.17 |
Ammonia
ammoniacal nitrogen as N · code 0111 · mg/l
below 0.03 mg/l (not detected above this)
Sampled 11 Mar 2026, 7 months ago · 16 results banked
Every result (16)
| Sampled | Result as published | Reads as |
|---|---|---|
| 11 Mar 2026, 08:47 | <0.03 | below 0.03 mg/l (not detected above this) |
| 4 Feb 2026, 09:41 | 0.031 | 0.031 mg/l |
| 9 Jan 2026, 14:37 | 0.16 | 0.16 mg/l |
| 2 Dec 2025, 13:01 | 0.04 | 0.04 mg/l |
| 13 Nov 2025, 12:04 | <0.03 | below 0.03 mg/l (not detected above this) |
| 9 Oct 2025, 14:38 | <0.03 | below 0.03 mg/l (not detected above this) |
| 3 Mar 2025, 10:06 | <0.03 | below 0.03 mg/l (not detected above this) |
| 11 Feb 2025, 10:23 | 0.049 | 0.049 mg/l |
| 7 Jan 2025, 11:20 | 0.16 | 0.16 mg/l |
| 3 Dec 2024, 13:37 | 0.079 | 0.079 mg/l |
| 1 Nov 2024, 12:09 | <0.03 | below 0.03 mg/l (not detected above this) |
| 8 Oct 2024, 13:36 | <0.03 | below 0.03 mg/l (not detected above this) |
| 3 Sep 2024, 09:13 | <0.03 | below 0.03 mg/l (not detected above this) |
| 9 Aug 2024, 09:15 | <0.03 | below 0.03 mg/l (not detected above this) |
| 26 Jul 2024, 12:10 | <0.03 | below 0.03 mg/l (not detected above this) |
| 3 Jun 2024, 17:12 | <0.03 | below 0.03 mg/l (not detected above this) |
Nitrate
as nitrogen (N) · code 0117 · mg/l
6.48 mg/l
Sampled 11 Mar 2026, 7 months ago · 15 results banked
Every result (15)
| Sampled | Result as published | Reads as |
|---|---|---|
| 11 Mar 2026, 08:47 | 6.48 | 6.48 mg/l |
| 4 Feb 2026, 09:41 | 7.07 | 7.07 mg/l |
| 9 Jan 2026, 14:37 | 5.66 | 5.66 mg/l |
| 2 Dec 2025, 13:01 | 6.46 | 6.46 mg/l |
| 13 Nov 2025, 12:04 | 5.58 | 5.58 mg/l |
| 9 Oct 2025, 14:38 | 5.19 | 5.19 mg/l |
| 3 Mar 2025, 10:06 | 7.28 | 7.28 mg/l |
| 11 Feb 2025, 10:23 | 7.17 | 7.17 mg/l |
| 7 Jan 2025, 11:20 | 6.97 | 6.97 mg/l |
| 1 Nov 2024, 12:09 | 6.09 | 6.09 mg/l |
| 8 Oct 2024, 13:36 | 5.29 | 5.29 mg/l |
| 3 Sep 2024, 09:13 | 6.69 | 6.69 mg/l |
| 9 Aug 2024, 09:15 | 6.09 | 6.09 mg/l |
| 26 Jul 2024, 12:10 | 4.99 | 4.99 mg/l |
| 3 Jun 2024, 17:12 | 4.48 | 4.48 mg/l |
Phosphate
orthophosphate, reactive, as P · code 0180 · mg/l
0.043 mg/l
Sampled 11 Mar 2026, 7 months ago · 16 results banked
Every result (16)
| Sampled | Result as published | Reads as |
|---|---|---|
| 11 Mar 2026, 08:47 | 0.043 | 0.043 mg/l |
| 4 Feb 2026, 09:41 | 0.048 | 0.048 mg/l |
| 9 Jan 2026, 14:37 | 0.067 | 0.067 mg/l |
| 2 Dec 2025, 13:01 | 0.055 | 0.055 mg/l |
| 13 Nov 2025, 12:04 | 0.058 | 0.058 mg/l |
| 9 Oct 2025, 14:38 | 0.063 | 0.063 mg/l |
| 3 Mar 2025, 10:06 | 0.031 | 0.031 mg/l |
| 11 Feb 2025, 10:23 | 0.047 | 0.047 mg/l |
| 7 Jan 2025, 11:20 | 0.062 | 0.062 mg/l |
| 3 Dec 2024, 13:37 | 0.051 | 0.051 mg/l |
| 1 Nov 2024, 12:09 | 0.052 | 0.052 mg/l |
| 8 Oct 2024, 13:36 | 0.062 | 0.062 mg/l |
| 3 Sep 2024, 09:13 | 0.054 | 0.054 mg/l |
| 9 Aug 2024, 09:15 | 0.062 | 0.062 mg/l |
| 26 Jul 2024, 12:10 | 0.066 | 0.066 mg/l |
| 3 Jun 2024, 17:12 | 0.053 | 0.053 mg/l |
Conductivity
at 25 °C · code 0077 · µS/cm
724 µS/cm
Sampled 11 Mar 2026, 7 months ago · 17 results banked
Every result (17)
| Sampled | Result as published | Reads as |
|---|---|---|
| 11 Mar 2026, 08:47 | 724 | 724 µS/cm |
| 4 Feb 2026, 09:41 | 736 | 736 µS/cm |
| 9 Jan 2026, 14:37 | 736 | 736 µS/cm |
| 2 Dec 2025, 13:01 | 764 | 764 µS/cm |
| 13 Nov 2025, 12:04 | 790 | 790 µS/cm |
| 9 Oct 2025, 14:38 | 751 | 751 µS/cm |
| 2 Apr 2025, 09:23 | 743 | 743 µS/cm |
| 3 Mar 2025, 10:06 | 713 | 713 µS/cm |
| 11 Feb 2025, 10:23 | 764 | 764 µS/cm |
| 7 Jan 2025, 11:20 | 684 | 684 µS/cm |
| 3 Dec 2024, 13:37 | 734 | 734 µS/cm |
| 1 Nov 2024, 12:09 | 757 | 757 µS/cm |
| 8 Oct 2024, 13:36 | 734 | 734 µS/cm |
| 3 Sep 2024, 09:13 | 753 | 753 µS/cm |
| 9 Aug 2024, 09:15 | 742 | 742 µS/cm |
| 26 Jul 2024, 12:10 | 716 | 716 µS/cm |
| 3 Jun 2024, 17:12 | 750 | 750 µS/cm |
Everything measured here
12 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 12 rows
| Determinand | Material | Results | First – last | Latest result |
|---|---|---|---|---|
| Oxygen, Dissolved, % Saturation 9901 | River water | 17 | Jun 2024 – Mar 2026 | 97.4% 11 Mar 2026 |
| Oxygen, Dissolved as O2 9924 | River water | 17 | Jun 2024 – Mar 2026 | 11.2 mg/l 11 Mar 2026 |
| Temperature of Water 0076 | River water | 17 | Jun 2024 – Mar 2026 | 9.3 °C 11 Mar 2026 |
| pH 0061 | River water | 17 | Jun 2024 – Mar 2026 | 8.11 11 Mar 2026 |
| Ammoniacal Nitrogen as N 0111 | River water | 16 | Jun 2024 – Mar 2026 | below 0.03 mg/l 11 Mar 2026 |
| Nitrate as N 0117 | River water | 15 | Jun 2024 – Mar 2026 | 6.48 mg/l 11 Mar 2026 |
| Orthophosphate, reactive as P 0180 | River water | 16 | Jun 2024 – Mar 2026 | 0.043 mg/l 11 Mar 2026 |
| Conductivity at 25 C 0077 | River water | 17 | Jun 2024 – Mar 2026 | 724 µS/cm 11 Mar 2026 |
| Alkalinity to pH 4.5 as CaCO3 0162 | River water | 16 | Jun 2024 – Mar 2026 | 270 mg/l 11 Mar 2026 |
| Ammonia un-ionised as N 0119 | River water | 16 | Jun 2024 – Mar 2026 | below 0.00052 mg/l 11 Mar 2026 |
| Nitrite as N 0118 | River water | 15 | Jun 2024 – Mar 2026 | 0.018 mg/l 11 Mar 2026 |
| Nitrogen, Total Oxidised as N 0116 | River water | 16 | Jun 2024 – Mar 2026 | 6.5 mg/l 11 Mar 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.