River Grom confluence with Medway
EA name: R GROM CONFLUENCE WITH MEDWAY (also listed as “CONFLUENCE WITH RIVER MEDWAY RIVER GROM”)
Environment Agency sampling point SO-E0000934 · 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
- 6 Aug 2026, 09:2356 days ago · time as the Environment Agency records it (UK clock time; the source gives no time zone)
- Samples banked
- 17 since 23 Apr 2025 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 551278, 137539As published, to the nearest 1 m. Open in a map
- River, by its own name
- Grom
- River, by the map
- River GromPlaced on the river its name gives, 10 m from the line.
- Next gauge downstream
- Chafford On the River Medway · 5.1 km along the river
- Why it was sampled
- Environmental monitoring statutory (EU directives) (17 samples)
Main measurements, river water
Dissolved oxygen
% saturation · code 9901 · %
80.8%
Sampled 6 Aug 2026, 56 days ago · 17 results banked
Every result (17)
| Sampled | Result as published | Reads as |
|---|---|---|
| 6 Aug 2026, 09:23 | 80.8 | 80.8% |
| 9 Jul 2026, 10:01 | 85.1 | 85.1% |
| 17 Jun 2026, 11:11 | 89.2 | 89.2% |
| 26 May 2026, 08:10 | 84.8 | 84.8% |
| 13 Apr 2026, 10:35 | 102.6 | 102.6% |
| 10 Mar 2026, 08:56 | 97.2 | 97.2% |
| 19 Feb 2026, 12:30 | 94.1 | 94.1% |
| 6 Jan 2026, 13:27 | 98.1 | 98.1% |
| 5 Dec 2025, 13:44 | 98.1 | 98.1% |
| 5 Nov 2025, 09:24 | 90.9 | 90.9% |
| 6 Oct 2025, 10:14 | 88.8 | 88.8% |
| 2 Sep 2025, 09:06 | 78.7 | 78.7% |
| 11 Aug 2025, 11:35 | 100.1 | 100.1% |
| 4 Jul 2025, 09:23 | 85.7 | 85.7% |
| 6 Jun 2025, 14:36 | 93 | 93% |
| 9 May 2025, 08:29 | 95 | 95% |
| 23 Apr 2025, 16:45 | 98.2 | 98.2% |
Dissolved oxygen
as O2 · code 9924 · mg/l
7.77 mg/l
Sampled 6 Aug 2026, 56 days ago · 17 results banked
Every result (17)
| Sampled | Result as published | Reads as |
|---|---|---|
| 6 Aug 2026, 09:23 | 7.77 | 7.77 mg/l |
| 9 Jul 2026, 10:01 | 7.63 | 7.63 mg/l |
| 17 Jun 2026, 11:11 | 8.47 | 8.47 mg/l |
| 26 May 2026, 08:10 | 8.11 | 8.11 mg/l |
| 13 Apr 2026, 10:35 | 11.6 | 11.6 mg/l |
| 10 Mar 2026, 08:56 | 10.9 | 10.9 mg/l |
| 19 Feb 2026, 12:30 | 11.3 | 11.3 mg/l |
| 6 Jan 2026, 13:27 | 12.6 | 12.6 mg/l |
| 5 Dec 2025, 13:44 | 11.5 | 11.5 mg/l |
| 5 Nov 2025, 09:24 | 9.47 | 9.47 mg/l |
| 6 Oct 2025, 10:14 | 9.21 | 9.21 mg/l |
| 2 Sep 2025, 09:06 | 7.63 | 7.63 mg/l |
| 11 Aug 2025, 11:35 | 9.34 | 9.34 mg/l |
| 4 Jul 2025, 09:23 | 8.28 | 8.28 mg/l |
| 6 Jun 2025, 14:36 | 9 | 9 mg/l |
| 9 May 2025, 08:29 | 10.1 | 10.1 mg/l |
| 23 Apr 2025, 16:45 | 10.5 | 10.5 mg/l |
Water temperature
code 0076 · °C
17.1 °C
Sampled 6 Aug 2026, 56 days ago · 17 results banked
Every result (17)
| Sampled | Result as published | Reads as |
|---|---|---|
| 6 Aug 2026, 09:23 | 17.1 | 17.1 °C |
| 9 Jul 2026, 10:01 | 20.6 | 20.6 °C |
| 17 Jun 2026, 11:11 | 17.7 | 17.7 °C |
| 26 May 2026, 08:10 | 17.4 | 17.4 °C |
| 13 Apr 2026, 10:35 | 9.7 | 9.7 °C |
| 10 Mar 2026, 08:56 | 10.2 | 10.2 °C |
| 19 Feb 2026, 12:30 | 7.4 | 7.4 °C |
| 6 Jan 2026, 13:27 | 4.6 | 4.6 °C |
| 5 Dec 2025, 13:44 | 8.3 | 8.3 °C |
| 5 Nov 2025, 09:24 | 13.4 | 13.4 °C |
| 6 Oct 2025, 10:14 | 13.6 | 13.6 °C |
| 2 Sep 2025, 09:06 | 16.7 | 16.7 °C |
| 11 Aug 2025, 11:35 | 18.6 | 18.6 °C |
| 4 Jul 2025, 09:23 | 16.9 | 16.9 °C |
| 6 Jun 2025, 14:36 | 16.8 | 16.8 °C |
| 9 May 2025, 08:29 | 12.4 | 12.4 °C |
| 23 Apr 2025, 16:45 | 12.1 | 12.1 °C |
pH
code 0061
7.76
Sampled 6 Aug 2026, 56 days ago · 17 results banked
Every result (17)
| Sampled | Result as published | Reads as |
|---|---|---|
| 6 Aug 2026, 09:23 | 7.76 | 7.76 |
| 9 Jul 2026, 10:01 | 7.55 | 7.55 |
| 17 Jun 2026, 11:11 | 7.63 | 7.63 |
| 26 May 2026, 08:10 | 7.34 | 7.34 |
| 13 Apr 2026, 10:35 | 7.66 | 7.66 |
| 10 Mar 2026, 08:56 | 7.22 | 7.22 |
| 19 Feb 2026, 12:30 | 7.23 | 7.23 |
| 6 Jan 2026, 13:27 | 7.54 | 7.54 |
| 5 Dec 2025, 13:44 | 7.28 | 7.28 |
| 5 Nov 2025, 09:24 | 7.43 | 7.43 |
| 6 Oct 2025, 10:14 | 7.7 | 7.7 |
| 2 Sep 2025, 09:06 | 7.51 | 7.51 |
| 11 Aug 2025, 11:35 | 7.78 | 7.78 |
| 4 Jul 2025, 09:23 | 7.56 | 7.56 |
| 6 Jun 2025, 14:36 | 7.55 | 7.55 |
| 9 May 2025, 08:29 | 7.52 | 7.52 |
| 23 Apr 2025, 16:45 | 7.5 | 7.5 |
Ammonia
ammoniacal nitrogen as N · code 0111 · mg/l
below 0.03 mg/l (not detected above this)
Sampled 6 Aug 2026, 56 days ago · 15 results banked
Every result (15)
| Sampled | Result as published | Reads as |
|---|---|---|
| 6 Aug 2026, 09:23 | <0.03 | below 0.03 mg/l (not detected above this) |
| 9 Jul 2026, 10:01 | <0.03 | below 0.03 mg/l (not detected above this) |
| 26 May 2026, 08:10 | <0.03 | below 0.03 mg/l (not detected above this) |
| 13 Apr 2026, 10:35 | <0.03 | below 0.03 mg/l (not detected above this) |
| 10 Mar 2026, 08:56 | <0.03 | below 0.03 mg/l (not detected above this) |
| 19 Feb 2026, 12:30 | 0.12 | 0.12 mg/l |
| 6 Jan 2026, 13:27 | <0.03 | below 0.03 mg/l (not detected above this) |
| 5 Dec 2025, 13:44 | <0.03 | below 0.03 mg/l (not detected above this) |
| 5 Nov 2025, 09:24 | <0.03 | below 0.03 mg/l (not detected above this) |
| 6 Oct 2025, 10:14 | <0.03 | below 0.03 mg/l (not detected above this) |
| 2 Sep 2025, 09:06 | 0.15 | 0.15 mg/l |
| 11 Aug 2025, 11:35 | <0.03 | below 0.03 mg/l (not detected above this) |
| 4 Jul 2025, 09:23 | 0.032 | 0.032 mg/l |
| 6 Jun 2025, 14:36 | <0.03 | below 0.03 mg/l (not detected above this) |
| 9 May 2025, 08:29 | <0.03 | below 0.03 mg/l (not detected above this) |
Nitrate
as nitrogen (N) · code 0117 · mg/l
21 mg/l
Sampled 6 Aug 2026, 56 days ago · 15 results banked
Every result (15)
| Sampled | Result as published | Reads as |
|---|---|---|
| 6 Aug 2026, 09:23 | 21 | 21 mg/l |
| 9 Jul 2026, 10:01 | 21 | 21 mg/l |
| 26 May 2026, 08:10 | 19 | 19 mg/l |
| 13 Apr 2026, 10:35 | 9.99 | 9.99 mg/l |
| 10 Mar 2026, 08:56 | 7.29 | 7.29 mg/l |
| 19 Feb 2026, 12:30 | 2.6 | 2.6 mg/l |
| 6 Jan 2026, 13:27 | 16 | 16 mg/l |
| 5 Dec 2025, 13:44 | 7.1 | 7.1 mg/l |
| 5 Nov 2025, 09:24 | 9.99 | 9.99 mg/l |
| 6 Oct 2025, 10:14 | 14 | 14 mg/l |
| 2 Sep 2025, 09:06 | 13 | 13 mg/l |
| 11 Aug 2025, 11:35 | 20 | 20 mg/l |
| 4 Jul 2025, 09:23 | 23 | 23 mg/l |
| 6 Jun 2025, 14:36 | 15 | 15 mg/l |
| 9 May 2025, 08:29 | 16 | 16 mg/l |
Phosphate
orthophosphate, reactive, as P · code 0180 · mg/l
0.14 mg/l
Sampled 9 Jul 2026, 3 months ago · 14 results banked
Every result (14)
| Sampled | Result as published | Reads as |
|---|---|---|
| 9 Jul 2026, 10:01 | 0.14 | 0.14 mg/l |
| 26 May 2026, 08:10 | 0.072 | 0.072 mg/l |
| 13 Apr 2026, 10:35 | 0.054 | 0.054 mg/l |
| 10 Mar 2026, 08:56 | 0.029 | 0.029 mg/l |
| 19 Feb 2026, 12:30 | 0.046 | 0.046 mg/l |
| 6 Jan 2026, 13:27 | 0.034 | 0.034 mg/l |
| 5 Dec 2025, 13:44 | 0.028 | 0.028 mg/l |
| 5 Nov 2025, 09:24 | 0.035 | 0.035 mg/l |
| 6 Oct 2025, 10:14 | 0.042 | 0.042 mg/l |
| 2 Sep 2025, 09:06 | 0.082 | 0.082 mg/l |
| 11 Aug 2025, 11:35 | 0.12 | 0.12 mg/l |
| 4 Jul 2025, 09:23 | 0.15 | 0.15 mg/l |
| 6 Jun 2025, 14:36 | 0.12 | 0.12 mg/l |
| 9 May 2025, 08:29 | 0.093 | 0.093 mg/l |
Conductivity
at 25 °C · code 0077 · µS/cm
872 µS/cm
Sampled 6 Aug 2026, 56 days ago · 17 results banked
Every result (17)
| Sampled | Result as published | Reads as |
|---|---|---|
| 6 Aug 2026, 09:23 | 872 | 872 µS/cm |
| 9 Jul 2026, 10:01 | 844 | 844 µS/cm |
| 17 Jun 2026, 11:11 | 751 | 751 µS/cm |
| 26 May 2026, 08:10 | 710 | 710 µS/cm |
| 13 Apr 2026, 10:35 | 454 | 454 µS/cm |
| 10 Mar 2026, 08:56 | 363 | 363 µS/cm |
| 19 Feb 2026, 12:30 | 232 | 232 µS/cm |
| 6 Jan 2026, 13:27 | 600 | 600 µS/cm |
| 5 Dec 2025, 13:44 | 395 | 395 µS/cm |
| 5 Nov 2025, 09:24 | 462 | 462 µS/cm |
| 6 Oct 2025, 10:14 | 589 | 589 µS/cm |
| 2 Sep 2025, 09:06 | 570 | 570 µS/cm |
| 11 Aug 2025, 11:35 | 751 | 751 µS/cm |
| 4 Jul 2025, 09:23 | 797 | 797 µS/cm |
| 6 Jun 2025, 14:36 | 608 | 608 µS/cm |
| 9 May 2025, 08:29 | 594 | 594 µS/cm |
| 23 Apr 2025, 16:45 | 516 | 516 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 | Apr 2025 – Aug 2026 | 80.8% 6 Aug 2026 |
| Oxygen, Dissolved as O2 9924 | River water | 17 | Apr 2025 – Aug 2026 | 7.77 mg/l 6 Aug 2026 |
| Temperature of Water 0076 | River water | 17 | Apr 2025 – Aug 2026 | 17.1 °C 6 Aug 2026 |
| pH 0061 | River water | 17 | Apr 2025 – Aug 2026 | 7.76 6 Aug 2026 |
| Ammoniacal Nitrogen as N 0111 | River water | 15 | May 2025 – Aug 2026 | below 0.03 mg/l 6 Aug 2026 |
| Nitrate as N 0117 | River water | 15 | May 2025 – Aug 2026 | 21 mg/l 6 Aug 2026 |
| Orthophosphate, reactive as P 0180 | River water | 14 | May 2025 – Jul 2026 | 0.14 mg/l 9 Jul 2026 |
| Conductivity at 25 C 0077 | River water | 17 | Apr 2025 – Aug 2026 | 872 µS/cm 6 Aug 2026 |
| Alkalinity to pH 4.5 as CaCO3 0162 | River water | 15 | May 2025 – Aug 2026 | 96 mg/l 6 Aug 2026 |
| Ammonia un-ionised as N 0119 | River water | 15 | May 2025 – Aug 2026 | below 0.00053 mg/l 6 Aug 2026 |
| Nitrite as N 0118 | River water | 15 | May 2025 – Aug 2026 | 0.035 mg/l 6 Aug 2026 |
| Nitrogen, Total Oxidised as N 0116 | River water | 15 | May 2025 – Aug 2026 | 21 mg/l 6 Aug 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.