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

868890929496%202420252026no sample published after Feb 202410 Oct 2023, 12:17: 88.8%9 Nov 2023, 11:54: 87.7%31 Jan 2024, 11:38: 94.4%14 Feb 2024, 11:07: 95.3%
Every result (4)
SampledResult as publishedReads as
14 Feb 2024, 11:0795.3 95.3%
31 Jan 2024, 11:3894.4 94.4%
9 Nov 2023, 11:5487.7 87.7%
10 Oct 2023, 12:1788.8 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

99.51010.511mg/l202420252026no sample published after Feb 202410 Oct 2023, 12:17: 9.25 mg/l9 Nov 2023, 11:54: 9.9 mg/l31 Jan 2024, 11:38: 10.9 mg/l14 Feb 2024, 11:07: 10.7 mg/l
Every result (4)
SampledResult as publishedReads as
14 Feb 2024, 11:0710.7 10.7 mg/l
31 Jan 2024, 11:3810.9 10.9 mg/l
9 Nov 2023, 11:549.9 9.9 mg/l
10 Oct 2023, 12:179.25 9.25 mg/l

Water temperature

code 0076 · °C

10.2 °C

Sampled 14 Feb 2024, 2.7 years ago · 4 results banked

8101214°C202420252026no sample published after Feb 202410 Oct 2023, 12:17: 13.4 °C9 Nov 2023, 11:54: 9.9 °C31 Jan 2024, 11:38: 8.9 °C14 Feb 2024, 11:07: 10.2 °C
Every result (4)
SampledResult as publishedReads as
14 Feb 2024, 11:0710.2 10.2 °C
31 Jan 2024, 11:388.9 8.9 °C
9 Nov 2023, 11:549.9 9.9 °C
10 Oct 2023, 12:1713.4 13.4 °C

pH

code 0061

8.07

Sampled 14 Feb 2024, 2.7 years ago · 4 results banked

7.87.988.1202420252026no sample published after Feb 202410 Oct 2023, 12:17: 7.859 Nov 2023, 11:54: 7.8931 Jan 2024, 11:38: 8.0514 Feb 2024, 11:07: 8.07
Every result (4)
SampledResult as publishedReads as
14 Feb 2024, 11:078.07 8.07
31 Jan 2024, 11:388.05 8.05
9 Nov 2023, 11:547.89 7.89
10 Oct 2023, 12:177.85 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

-0.500.51mg/l202420252026no sample published after Feb 202410 Oct 2023, 12:17: below 0.03 mg/l (not detected above this)9 Nov 2023, 11:54: below 0.03 mg/l (not detected above this)31 Jan 2024, 11:38: below 0.03 mg/l (not detected above this)14 Feb 2024, 11:07: 0.03 mg/l
Every result (4)
SampledResult as publishedReads as
14 Feb 2024, 11:070.03 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

5.566.577.5mg/l202420252026no sample published after Feb 202410 Oct 2023, 12:17: 6.29 mg/l9 Nov 2023, 11:54: 5.69 mg/l31 Jan 2024, 11:38: 7.08 mg/l14 Feb 2024, 11:07: 6.79 mg/l
Every result (4)
SampledResult as publishedReads as
14 Feb 2024, 11:076.79 6.79 mg/l
31 Jan 2024, 11:387.08 7.08 mg/l
9 Nov 2023, 11:545.69 5.69 mg/l
10 Oct 2023, 12:176.29 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

0.060.070.080.090.1mg/l202420252026no sample published after Feb 202410 Oct 2023, 12:17: 0.067 mg/l9 Nov 2023, 11:54: 0.088 mg/l31 Jan 2024, 11:38: 0.084 mg/l14 Feb 2024, 11:07: 0.091 mg/l
Every result (4)
SampledResult as publishedReads as
14 Feb 2024, 11:070.091 0.091 mg/l
31 Jan 2024, 11:380.084 0.084 mg/l
9 Nov 2023, 11:540.088 0.088 mg/l
10 Oct 2023, 12:170.067 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

560570580590600µS/cm202420252026no sample published after Feb 202410 Oct 2023, 12:17: 569 µS/cm9 Nov 2023, 11:54: 561 µS/cm31 Jan 2024, 11:38: 591 µS/cm14 Feb 2024, 11:07: 576 µS/cm
Every result (4)
SampledResult as publishedReads as
14 Feb 2024, 11:07576 576 µS/cm
31 Jan 2024, 11:38591 591 µS/cm
9 Nov 2023, 11:54561 561 µS/cm
10 Oct 2023, 12:17569 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

330340350360370per 100 ml202420252026no sample published after Jun 202529 May 2025, 14:20: 330 per 100 ml26 Jun 2025, 14:10: 370 per 100 ml
Every result (2)
SampledResult as publishedReads as
26 Jun 2025, 14:10370 370 per 100 ml
29 May 2025, 14:20330 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
DeterminandMaterialResults First – lastLatest 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.