Siston Brook at Chiltern Close

EA name: SISTON BROOK AT CHILTERN CLOSE (also listed as “RSN1890 SISTON BROOK AT CHILTERN CLOSE”)
Environment Agency sampling point SW-RSN1890 · 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
13 Dec 2023, 10:462.8 years 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
3 since 13 Oct 2023 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 367097, 172393As published, to the nearest 1 m. Open in a map
River, by its own name
Siston Brook
River, by the map
Siston BrookPlaced on the river its name gives, 0 m from the line.
Next gauge downstream
Bristol Netham Lock On the River Avon · 12 km along the riverNetham Weir On the River Avon · 12 km along the river
Why it was sampled
Monitoring (national agency policy) (3 samples)

Main measurements, river water

Dissolved oxygen

% saturation · code 9901 · %

99.2%

Sampled 13 Dec 2023, 2.8 years ago · 3 results banked

9797.59898.59999.5%202420252026no sample published after Dec 202313 Oct 2023, 10:29: 97.2%9 Nov 2023, 12:28: 97.9%13 Dec 2023, 10:46: 99.2%
Every result (3)
SampledResult as publishedReads as
13 Dec 2023, 10:4699.2 99.2%
9 Nov 2023, 12:2897.9 97.9%
13 Oct 2023, 10:2997.2 97.2%

Dissolved oxygen

as O2 · code 9924 · mg/l

11.3 mg/l

Sampled 13 Dec 2023, 2.8 years ago · 3 results banked

9.51010.51111.5mg/l202420252026no sample published after Dec 202313 Oct 2023, 10:29: 9.63 mg/l9 Nov 2023, 12:28: 10.8 mg/l13 Dec 2023, 10:46: 11.3 mg/l
Every result (3)
SampledResult as publishedReads as
13 Dec 2023, 10:4611.3 11.3 mg/l
9 Nov 2023, 12:2810.8 10.8 mg/l
13 Oct 2023, 10:299.63 9.63 mg/l

Water temperature

code 0076 · °C

9.4 °C

Sampled 13 Dec 2023, 2.8 years ago · 3 results banked

810121416°C202420252026no sample published after Dec 202313 Oct 2023, 10:29: 15.7 °C9 Nov 2023, 12:28: 11 °C13 Dec 2023, 10:46: 9.4 °C
Every result (3)
SampledResult as publishedReads as
13 Dec 2023, 10:469.4 9.4 °C
9 Nov 2023, 12:2811 11 °C
13 Oct 2023, 10:2915.7 15.7 °C

pH

code 0061

8.06

Sampled 13 Dec 2023, 2.8 years ago · 3 results banked

7.77.87.988.1202420252026no sample published after Dec 202313 Oct 2023, 10:29: 7.779 Nov 2023, 12:28: 8.0513 Dec 2023, 10:46: 8.06
Every result (3)
SampledResult as publishedReads as
13 Dec 2023, 10:468.06 8.06
9 Nov 2023, 12:288.05 8.05
13 Oct 2023, 10:297.77 7.77

Ammonia

ammoniacal nitrogen as N · code 0111 · mg/l

0.09 mg/l

Sampled 13 Dec 2023, 2.8 years ago · 3 results banked

0.080.10.120.14mg/l202420252026no sample published after Dec 202313 Oct 2023, 10:29: 0.13 mg/l9 Nov 2023, 12:28: 0.099 mg/l13 Dec 2023, 10:46: 0.09 mg/l
Every result (3)
SampledResult as publishedReads as
13 Dec 2023, 10:460.09 0.09 mg/l
9 Nov 2023, 12:280.099 0.099 mg/l
13 Oct 2023, 10:290.13 0.13 mg/l

Nitrate

as nitrogen (N) · code 0117 · mg/l

1.99 mg/l

Sampled 13 Dec 2023, 2.8 years ago · 3 results banked

1.522.533.5mg/l202420252026no sample published after Dec 202313 Oct 2023, 10:29: 3.27 mg/l9 Nov 2023, 12:28: 1.89 mg/l13 Dec 2023, 10:46: 1.99 mg/l
Every result (3)
SampledResult as publishedReads as
13 Dec 2023, 10:461.99 1.99 mg/l
9 Nov 2023, 12:281.89 1.89 mg/l
13 Oct 2023, 10:293.27 3.27 mg/l

Phosphate

orthophosphate, reactive, as P · code 0180 · mg/l

0.11 mg/l

Sampled 13 Dec 2023, 2.8 years ago · 3 results banked

0.10.120.140.160.18mg/l202420252026no sample published after Dec 202313 Oct 2023, 10:29: 0.18 mg/l9 Nov 2023, 12:28: 0.1 mg/l13 Dec 2023, 10:46: 0.11 mg/l
Every result (3)
SampledResult as publishedReads as
13 Dec 2023, 10:460.11 0.11 mg/l
9 Nov 2023, 12:280.1 0.1 mg/l
13 Oct 2023, 10:290.18 0.18 mg/l

Conductivity

at 25 °C · code 0077 · µS/cm

595 µS/cm

Sampled 13 Dec 2023, 2.8 years ago · 3 results banked

520540560580600620µS/cm202420252026no sample published after Dec 202313 Oct 2023, 10:29: 528 µS/cm9 Nov 2023, 12:28: 604 µS/cm13 Dec 2023, 10:46: 595 µS/cm
Every result (3)
SampledResult as publishedReads as
13 Dec 2023, 10:46595 595 µS/cm
9 Nov 2023, 12:28604 604 µS/cm
13 Oct 2023, 10:29528 528 µS/cm

Everything measured here

17 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 17 rows
DeterminandMaterialResults First – lastLatest result
Oxygen, Dissolved, % Saturation 9901 River water 3 Oct 2023 – Dec 2023 99.2% 13 Dec 2023
Oxygen, Dissolved as O2 9924 River water 3 Oct 2023 – Dec 2023 11.3 mg/l 13 Dec 2023
Temperature of Water 0076 River water 3 Oct 2023 – Dec 2023 9.4 °C 13 Dec 2023
pH 0061 River water 3 Oct 2023 – Dec 2023 8.06 13 Dec 2023
Ammoniacal Nitrogen as N 0111 River water 3 Oct 2023 – Dec 2023 0.09 mg/l 13 Dec 2023
Nitrate as N 0117 River water 3 Oct 2023 – Dec 2023 1.99 mg/l 13 Dec 2023
Orthophosphate, reactive as P 0180 River water 3 Oct 2023 – Dec 2023 0.11 mg/l 13 Dec 2023
Conductivity at 25 C 0077 River water 3 Oct 2023 – Dec 2023 595 µS/cm 13 Dec 2023
Alkalinity to pH 4.5 as CaCO3 0162 River water 3 Oct 2023 – Dec 2023 240 mg/l 13 Dec 2023
Ammonia un-ionised as N 0119 River water 3 Oct 2023 – Dec 2023 0.00157 mg/l 13 Dec 2023
Carbon, Organic, Dissolved as C :- {DOC} 0301 River water 3 Oct 2023 – Dec 2023 6.3 mg/l 13 Dec 2023
Chloride 0172 River water 3 Oct 2023 – Dec 2023 25 mg/l 13 Dec 2023
Nitrite as N 0118 River water 3 Oct 2023 – Dec 2023 0.011 mg/l 13 Dec 2023
Nitrogen, Total as N 9686 River water 3 Oct 2023 – Dec 2023 2.6 mg/l 13 Dec 2023
Nitrogen, Total Oxidised as N 0116 River water 3 Oct 2023 – Dec 2023 2 mg/l 13 Dec 2023
Phosphorus, Total as P 0348 River water 3 Oct 2023 – Dec 2023 0.14 mg/l 13 Dec 2023
Silica, reactive as SiO2 0182 River water 3 Oct 2023 – Dec 2023 10 mg/l 13 Dec 2023

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.