Hampshire Avon upstream of Salisbury sewage treatment works
EA name: HAMPSHIRE AVON U/S SALISBURY STW (also listed as “HAMPSHIRE AVON UPSTREAM OF SALISBURY STW”)
Environment Agency sampling point SW-50260521 · 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 Aug 2025, 10:3615 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 26 Oct 2026 and had nothing newer.
- Samples banked
- 7 since 10 Oct 2023 Imported periods: 1 Oct 2023 – 26 Oct 2026. Samples outside them are not shown here.
- Latest sample
- River / running surface water Monitoring (national agency policy)
- Where
- National Grid 415857, 128713As published, to the nearest 1 m. Open in a map
- River, by its own name
- Hampshire Avon
- River, by the map
- River AvonPlaced on a river whose name partly matches its own, 18 m from the line.
- Next gauge downstream
- Downton Iron Bridge On the River Avon · 10.0 km along the river
- Nearest gauge upstream
- Salisbury Bourne On the River Bourne · 0.8 km along the river
- Why it was sampled
- Monitoring (national agency policy) (5 samples)
Planned investigation (local monitoring) (2 samples)
1 visit found no water to sample (recorded as “No flow”).
Main measurements, river water
Dissolved oxygen
% saturation · code 9901 · %
95.3%
Sampled 14 Feb 2024, 2.7 years ago · 4 results banked
Every result (4)
| Sampled | Result as published | Reads as |
|---|---|---|
| 14 Feb 2024, 11:07 | 95.3 | 95.3% |
| 31 Jan 2024, 11:38 | 94.4 | 94.4% |
| 9 Nov 2023, 11:54 | 87.7 | 87.7% |
| 10 Oct 2023, 12:17 | 88.8 | 88.8% |
Dissolved oxygen
as O2 · code 9924 · mg/l
10.7 mg/l
Sampled 14 Feb 2024, 2.7 years ago · 4 results banked
Every result (4)
| Sampled | Result as published | Reads as |
|---|---|---|
| 14 Feb 2024, 11:07 | 10.7 | 10.7 mg/l |
| 31 Jan 2024, 11:38 | 10.9 | 10.9 mg/l |
| 9 Nov 2023, 11:54 | 9.9 | 9.9 mg/l |
| 10 Oct 2023, 12:17 | 9.25 | 9.25 mg/l |
Water temperature
code 0076 · °C
10.2 °C
Sampled 14 Feb 2024, 2.7 years ago · 4 results banked
Every result (4)
| Sampled | Result as published | Reads as |
|---|---|---|
| 14 Feb 2024, 11:07 | 10.2 | 10.2 °C |
| 31 Jan 2024, 11:38 | 8.9 | 8.9 °C |
| 9 Nov 2023, 11:54 | 9.9 | 9.9 °C |
| 10 Oct 2023, 12:17 | 13.4 | 13.4 °C |
pH
code 0061
8.07
Sampled 14 Feb 2024, 2.7 years ago · 4 results banked
Every result (4)
| Sampled | Result as published | Reads as |
|---|---|---|
| 14 Feb 2024, 11:07 | 8.07 | 8.07 |
| 31 Jan 2024, 11:38 | 8.05 | 8.05 |
| 9 Nov 2023, 11:54 | 7.89 | 7.89 |
| 10 Oct 2023, 12:17 | 7.85 | 7.85 |
Ammonia
ammoniacal nitrogen as N · code 0111 · mg/l
0.03 mg/l
Sampled 14 Feb 2024, 2.7 years ago · 4 results banked
Every result (4)
| Sampled | Result as published | Reads as |
|---|---|---|
| 14 Feb 2024, 11:07 | 0.03 | 0.03 mg/l |
| 31 Jan 2024, 11:38 | <0.03 | below 0.03 mg/l (not detected above this) |
| 9 Nov 2023, 11:54 | <0.03 | below 0.03 mg/l (not detected above this) |
| 10 Oct 2023, 12:17 | <0.03 | below 0.03 mg/l (not detected above this) |
Nitrate
as nitrogen (N) · code 0117 · mg/l
6.79 mg/l
Sampled 14 Feb 2024, 2.7 years ago · 4 results banked
Every result (4)
| Sampled | Result as published | Reads as |
|---|---|---|
| 14 Feb 2024, 11:07 | 6.79 | 6.79 mg/l |
| 31 Jan 2024, 11:38 | 7.08 | 7.08 mg/l |
| 9 Nov 2023, 11:54 | 5.69 | 5.69 mg/l |
| 10 Oct 2023, 12:17 | 6.29 | 6.29 mg/l |
Phosphate
orthophosphate, reactive, as P · code 0180 · mg/l
0.091 mg/l
Sampled 14 Feb 2024, 2.7 years ago · 4 results banked
Every result (4)
| Sampled | Result as published | Reads as |
|---|---|---|
| 14 Feb 2024, 11:07 | 0.091 | 0.091 mg/l |
| 31 Jan 2024, 11:38 | 0.084 | 0.084 mg/l |
| 9 Nov 2023, 11:54 | 0.088 | 0.088 mg/l |
| 10 Oct 2023, 12:17 | 0.067 | 0.067 mg/l |
Conductivity
at 25 °C · code 0077 · µS/cm
576 µS/cm
Sampled 14 Feb 2024, 2.7 years ago · 4 results banked
Every result (4)
| Sampled | Result as published | Reads as |
|---|---|---|
| 14 Feb 2024, 11:07 | 576 | 576 µS/cm |
| 31 Jan 2024, 11:38 | 591 | 591 µS/cm |
| 9 Nov 2023, 11:54 | 561 | 561 µS/cm |
| 10 Oct 2023, 12:17 | 569 | 569 µS/cm |
E. coli
confirmed, membrane filtration · code 2348 · per 100 ml
370 per 100 ml
Sampled 26 Jun 2025, 16 months ago · 2 results banked
Every result (2)
| Sampled | Result as published | Reads as |
|---|---|---|
| 26 Jun 2025, 14:10 | 370 | 370 per 100 ml |
| 29 May 2025, 14:20 | 330 | 330 per 100 ml |
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 | 4 | Oct 2023 – Feb 2024 | 95.3% 14 Feb 2024 |
| Oxygen, Dissolved as O2 9924 | River water | 4 | Oct 2023 – Feb 2024 | 10.7 mg/l 14 Feb 2024 |
| Temperature of Water 0076 | River water | 4 | Oct 2023 – Feb 2024 | 10.2 °C 14 Feb 2024 |
| pH 0061 | River water | 4 | Oct 2023 – Feb 2024 | 8.07 14 Feb 2024 |
| Ammoniacal Nitrogen as N 0111 | River water | 4 | Oct 2023 – Feb 2024 | 0.03 mg/l 14 Feb 2024 |
| Nitrate as N 0117 | River water | 4 | Oct 2023 – Feb 2024 | 6.79 mg/l 14 Feb 2024 |
| Orthophosphate, reactive as P 0180 | River water | 4 | Oct 2023 – Feb 2024 | 0.091 mg/l 14 Feb 2024 |
| Conductivity at 25 C 0077 | River water | 4 | Oct 2023 – Feb 2024 | 576 µS/cm 14 Feb 2024 |
| Escherichia coli : Confirmed : MF 2348 | River water | 2 | May 2025 – Jun 2025 | 370 per 100 ml 26 Jun 2025 |
| Alkalinity to pH 4.5 as CaCO3 0162 | River water | 4 | Oct 2023 – Feb 2024 | 240 mg/l 14 Feb 2024 |
| Ammonia un-ionised as N 0119 | River water | 4 | Oct 2023 – Feb 2024 | 0.00056 mg/l 14 Feb 2024 |
| Enterococci: Intestinal: Presumptive: MF 3722 | River water | 2 | May 2025 – Jun 2025 | 72 colony forming units / 100ml 26 Jun 2025 |
| MST Filtration 4926 | River water | 2 | May 2025 – Jun 2025 | DNA Stored 26 Jun 2025 |
| Nitrite as N 0118 | River water | 4 | Oct 2023 – Feb 2024 | 0.014 mg/l 14 Feb 2024 |
| Nitrogen, Total Oxidised as N 0116 | River water | 4 | Oct 2023 – Feb 2024 | 6.8 mg/l 14 Feb 2024 |
| No flow /No sample 7668 | River water | 1 | Aug 2025 – Aug 2025 | No flow/discharge at sampling point 4 Aug 2025 |
| Solids, Suspended at 105 C 0135 | River water | 4 | Oct 2023 – Feb 2024 | 8.5 mg/l 14 Feb 2024 |
| Volume of Sample Filtered 4865 | River water | 2 | May 2025 – Jun 2025 | 970 millilitre 26 Jun 2025 |
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.