Len upstream of Harrietsham sewage treatment works
EA name: LEN U/S HARRIETSHAM STW (also listed as “RSN1189 LEN U/S HARRIETSHAM STW”)
Environment Agency sampling point SO-RSN1189 · 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
- 3 Dec 2024, 12:5422 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
- 12 since 9 Jan 2024 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 587080, 151824As published, to the nearest 1 m. Open in a map
- River, by its own name
- Len
- River, by the map
- River LenPlaced on the river its name gives, 1 m from the line.
- Next gauge downstream
- Maidstone On the River Medway · 16 km along the river
- Why it was sampled
- Monitoring (national agency policy) (12 samples)
Main measurements, river water
Dissolved oxygen
% saturation · code 9901 · %
90.6%
Sampled 3 Dec 2024, 22 months ago · 12 results banked
Every result (12)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Dec 2024, 12:54 | 90.6 | 90.6% |
| 1 Nov 2024, 10:47 | 82.4 | 82.4% |
| 8 Oct 2024, 11:59 | 90.9 | 90.9% |
| 5 Sep 2024, 11:47 | 85.6 | 85.6% |
| 9 Aug 2024, 13:40 | 90.2 | 90.2% |
| 8 Jul 2024, 08:06 | 93.1 | 93.1% |
| 13 Jun 2024, 09:17 | 91.2 | 91.2% |
| 9 May 2024, 14:24 | 92 | 92% |
| 25 Apr 2024, 10:30 | 99.2 | 99.2% |
| 7 Mar 2024, 12:19 | 93.5 | 93.5% |
| 5 Feb 2024, 11:58 | 92.6 | 92.6% |
| 9 Jan 2024, 08:48 | 93.2 | 93.2% |
Dissolved oxygen
as O2 · code 9924 · mg/l
10.7 mg/l
Sampled 3 Dec 2024, 22 months ago · 12 results banked
Every result (12)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Dec 2024, 12:54 | 10.7 | 10.7 mg/l |
| 1 Nov 2024, 10:47 | 8.76 | 8.76 mg/l |
| 8 Oct 2024, 11:59 | 9.32 | 9.32 mg/l |
| 5 Sep 2024, 11:47 | 8.34 | 8.34 mg/l |
| 9 Aug 2024, 13:40 | 8.48 | 8.48 mg/l |
| 8 Jul 2024, 08:06 | 9.53 | 9.53 mg/l |
| 13 Jun 2024, 09:17 | 9.58 | 9.58 mg/l |
| 9 May 2024, 14:24 | 8.83 | 8.83 mg/l |
| 25 Apr 2024, 10:30 | 11.3 | 11.3 mg/l |
| 7 Mar 2024, 12:19 | 10.8 | 10.8 mg/l |
| 5 Feb 2024, 11:58 | 10.7 | 10.7 mg/l |
| 9 Jan 2024, 08:48 | 12.5 | 12.5 mg/l |
Water temperature
code 0076 · °C
8.2 °C
Sampled 3 Dec 2024, 22 months ago · 12 results banked
Every result (12)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Dec 2024, 12:54 | 8.2 | 8.2 °C |
| 1 Nov 2024, 10:47 | 12.5 | 12.5 °C |
| 8 Oct 2024, 11:59 | 14.1 | 14.1 °C |
| 5 Sep 2024, 11:47 | 16.5 | 16.5 °C |
| 9 Aug 2024, 13:40 | 18.2 | 18.2 °C |
| 8 Jul 2024, 08:06 | 14.2 | 14.2 °C |
| 13 Jun 2024, 09:17 | 13 | 13 °C |
| 9 May 2024, 14:24 | 17.2 | 17.2 °C |
| 25 Apr 2024, 10:30 | 9.6 | 9.6 °C |
| 7 Mar 2024, 12:19 | 8.9 | 8.9 °C |
| 5 Feb 2024, 11:58 | 9.1 | 9.1 °C |
| 9 Jan 2024, 08:48 | 3 | 3 °C |
pH
code 0061
7.69
Sampled 3 Dec 2024, 22 months ago · 12 results banked
Every result (12)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Dec 2024, 12:54 | 7.69 | 7.69 |
| 1 Nov 2024, 10:47 | 7.46 | 7.46 |
| 8 Oct 2024, 11:59 | 7.72 | 7.72 |
| 5 Sep 2024, 11:47 | 7.69 | 7.69 |
| 9 Aug 2024, 13:40 | 8.06 | 8.06 |
| 8 Jul 2024, 08:06 | 7.74 | 7.74 |
| 13 Jun 2024, 09:17 | 7.83 | 7.83 |
| 9 May 2024, 14:24 | 7.92 | 7.92 |
| 25 Apr 2024, 10:30 | 7.73 | 7.73 |
| 7 Mar 2024, 12:19 | 7.8 | 7.8 |
| 5 Feb 2024, 11:58 | 7.88 | 7.88 |
| 9 Jan 2024, 08:48 | 7.87 | 7.87 |
Ammonia
ammoniacal nitrogen as N · code 0111 · mg/l
0.038 mg/l
Sampled 3 Dec 2024, 22 months ago · 12 results banked
Every result (12)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Dec 2024, 12:54 | 0.038 | 0.038 mg/l |
| 1 Nov 2024, 10:47 | 0.038 | 0.038 mg/l |
| 8 Oct 2024, 11:59 | 0.091 | 0.091 mg/l |
| 5 Sep 2024, 11:47 | 0.052 | 0.052 mg/l |
| 9 Aug 2024, 13:40 | <0.03 | below 0.03 mg/l (not detected above this) |
| 8 Jul 2024, 08:06 | 0.043 | 0.043 mg/l |
| 13 Jun 2024, 09:17 | 0.067 | 0.067 mg/l |
| 9 May 2024, 14:24 | 0.034 | 0.034 mg/l |
| 25 Apr 2024, 10:30 | 0.047 | 0.047 mg/l |
| 7 Mar 2024, 12:19 | 0.036 | 0.036 mg/l |
| 5 Feb 2024, 11:58 | 0.033 | 0.033 mg/l |
| 9 Jan 2024, 08:48 | 0.036 | 0.036 mg/l |
Nitrate
as nitrogen (N) · code 0117 · mg/l
4.46 mg/l
Sampled 1 Nov 2024, 23 months ago · 11 results banked
Every result (11)
| Sampled | Result as published | Reads as |
|---|---|---|
| 1 Nov 2024, 10:47 | 4.46 | 4.46 mg/l |
| 8 Oct 2024, 11:59 | 4.06 | 4.06 mg/l |
| 5 Sep 2024, 11:47 | 5.26 | 5.26 mg/l |
| 9 Aug 2024, 13:40 | 5.77 | 5.77 mg/l |
| 8 Jul 2024, 08:06 | 5.66 | 5.66 mg/l |
| 13 Jun 2024, 09:17 | 7.02 | 7.02 mg/l |
| 9 May 2024, 14:24 | 6.17 | 6.17 mg/l |
| 25 Apr 2024, 10:30 | 6.78 | 6.78 mg/l |
| 7 Mar 2024, 12:19 | 5.39 | 5.39 mg/l |
| 5 Feb 2024, 11:58 | 6.48 | 6.48 mg/l |
| 9 Jan 2024, 08:48 | 4.78 | 4.78 mg/l |
Phosphate
orthophosphate, reactive, as P · code 0180 · mg/l
0.035 mg/l
Sampled 3 Dec 2024, 22 months ago · 12 results banked
Every result (12)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Dec 2024, 12:54 | 0.035 | 0.035 mg/l |
| 1 Nov 2024, 10:47 | 0.014 | 0.014 mg/l |
| 8 Oct 2024, 11:59 | 0.014 | 0.014 mg/l |
| 5 Sep 2024, 11:47 | 0.038 | 0.038 mg/l |
| 9 Aug 2024, 13:40 | 0.023 | 0.023 mg/l |
| 8 Jul 2024, 08:06 | 0.024 | 0.024 mg/l |
| 13 Jun 2024, 09:17 | 0.032 | 0.032 mg/l |
| 9 May 2024, 14:24 | <0.01 | below 0.01 mg/l (not detected above this) |
| 25 Apr 2024, 10:30 | <0.01 | below 0.01 mg/l (not detected above this) |
| 7 Mar 2024, 12:19 | 0.016 | 0.016 mg/l |
| 5 Feb 2024, 11:58 | 0.021 | 0.021 mg/l |
| 9 Jan 2024, 08:48 | 0.023 | 0.023 mg/l |
Conductivity
at 25 °C · code 0077 · µS/cm
604 µS/cm
Sampled 3 Dec 2024, 22 months ago · 12 results banked
Every result (12)
| Sampled | Result as published | Reads as |
|---|---|---|
| 3 Dec 2024, 12:54 | 604 | 604 µS/cm |
| 1 Nov 2024, 10:47 | 607 | 607 µS/cm |
| 8 Oct 2024, 11:59 | 536 | 536 µS/cm |
| 5 Sep 2024, 11:47 | 601 | 601 µS/cm |
| 9 Aug 2024, 13:40 | 581 | 581 µS/cm |
| 8 Jul 2024, 08:06 | 575 | 575 µS/cm |
| 13 Jun 2024, 09:17 | 674 | 674 µS/cm |
| 9 May 2024, 14:24 | 629 | 629 µS/cm |
| 25 Apr 2024, 10:30 | 654 | 654 µS/cm |
| 7 Mar 2024, 12:19 | 604 | 604 µS/cm |
| 5 Feb 2024, 11:58 | 697 | 697 µS/cm |
| 9 Jan 2024, 08:48 | 558 | 558 µS/cm |
Everything measured here
18 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 18 rows
| Determinand | Material | Results | First – last | Latest result |
|---|---|---|---|---|
| Oxygen, Dissolved, % Saturation 9901 | River water | 12 | Jan 2024 – Dec 2024 | 90.6% 3 Dec 2024 |
| Oxygen, Dissolved as O2 9924 | River water | 12 | Jan 2024 – Dec 2024 | 10.7 mg/l 3 Dec 2024 |
| Temperature of Water 0076 | River water | 12 | Jan 2024 – Dec 2024 | 8.2 °C 3 Dec 2024 |
| pH 0061 | River water | 12 | Jan 2024 – Dec 2024 | 7.69 3 Dec 2024 |
| Ammoniacal Nitrogen as N 0111 | River water | 12 | Jan 2024 – Dec 2024 | 0.038 mg/l 3 Dec 2024 |
| Nitrate as N 0117 | River water | 11 | Jan 2024 – Nov 2024 | 4.46 mg/l 1 Nov 2024 |
| Orthophosphate, reactive as P 0180 | River water | 12 | Jan 2024 – Dec 2024 | 0.035 mg/l 3 Dec 2024 |
| Conductivity at 25 C 0077 | River water | 12 | Jan 2024 – Dec 2024 | 604 µS/cm 3 Dec 2024 |
| Alkalinity to pH 4.5 as CaCO3 0162 | River water | 12 | Jan 2024 – Dec 2024 | 210 mg/l 3 Dec 2024 |
| Ammonia un-ionised as N 0119 | River water | 12 | Jan 2024 – Dec 2024 | 0.0003 mg/l 3 Dec 2024 |
| Carbon, Organic, Dissolved as C :- {DOC} 0301 | River water | 12 | Jan 2024 – Dec 2024 | 5 mg/l 3 Dec 2024 |
| Chloride 0172 | River water | 12 | Jan 2024 – Dec 2024 | 41 mg/l 3 Dec 2024 |
| Flow Type 2896 | River water | 6 | Jul 2024 – Dec 2024 | Moderate Flow 3 Dec 2024 |
| Nitrite as N 0118 | River water | 12 | Jan 2024 – Dec 2024 | 0.019 mg/l 3 Dec 2024 |
| Nitrogen, Total as N 9686 | River water | 12 | Jan 2024 – Dec 2024 | 4.9 mg/l 3 Dec 2024 |
| Nitrogen, Total Oxidised as N 0116 | River water | 11 | Jan 2024 – Nov 2024 | 4.5 mg/l 1 Nov 2024 |
| Phosphorus, Total as P 0348 | River water | 12 | Jan 2024 – Dec 2024 | 0.077 mg/l 3 Dec 2024 |
| Silica, reactive as SiO2 0182 | River water | 12 | Jan 2024 – Dec 2024 | 10 mg/l 3 Dec 2024 |
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.