Knowl Water at Old Railway Bridge Velator

EA name: KNOWL WATER AT OLD RAILWAY BR VELATOR (also listed as “KNOWL WATER AT OLD RAILWAY BRIDGE VELATOR”)
Environment Agency sampling point SW-73011002 · 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
9 Sep 2026, 11:2522 days ago · time as the Environment Agency records it (UK clock time; the source gives no time zone)
Samples banked
6 since 22 Apr 2026 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 249030, 135600As published, to the nearest 10 m. Open in a map
River, by its own name
Knowl Water
River, by the map
Knowl WaterPlaced on the river its name gives, 3 m from the line.
Next gauge downstream
None tracedIts water reaches the sea without passing a gauge.
Why it was sampled
Environmental monitoring statutory (EU directives) (6 samples)

Main measurements, river water

Dissolved oxygen

% saturation · code 9901 · %

97.3%

Sampled 9 Sep 2026, 22 days ago · 6 results banked

859095100105110%20242025202622 Apr 2026, 12:23: 106.1%11 May 2026, 12:55: 102.1%16 Jun 2026, 13:10: 96.3%6 Jul 2026, 09:23: 89.5%17 Aug 2026, 12:16: 96.1%9 Sep 2026, 11:25: 97.3%
Every result (6)
SampledResult as publishedReads as
9 Sep 2026, 11:2597.3 97.3%
17 Aug 2026, 12:1696.1 96.1%
6 Jul 2026, 09:2389.5 89.5%
16 Jun 2026, 13:1096.3 96.3%
11 May 2026, 12:55102.1 102.1%
22 Apr 2026, 12:23106.1 106.1%

Dissolved oxygen

as O2 · code 9924 · mg/l

9.87 mg/l

Sampled 9 Sep 2026, 22 days ago · 6 results banked

89101112mg/l20242025202622 Apr 2026, 12:23: 11.8 mg/l11 May 2026, 12:55: 11.2 mg/l16 Jun 2026, 13:10: 9.58 mg/l6 Jul 2026, 09:23: 8.92 mg/l17 Aug 2026, 12:16: 9.04 mg/l9 Sep 2026, 11:25: 9.87 mg/l
Every result (6)
SampledResult as publishedReads as
9 Sep 2026, 11:259.87 9.87 mg/l
17 Aug 2026, 12:169.04 9.04 mg/l
6 Jul 2026, 09:238.92 8.92 mg/l
16 Jun 2026, 13:109.58 9.58 mg/l
11 May 2026, 12:5511.2 11.2 mg/l
22 Apr 2026, 12:2311.8 11.8 mg/l

Water temperature

code 0076 · °C

14.6 °C

Sampled 9 Sep 2026, 22 days ago · 6 results banked

101214161820°C20242025202622 Apr 2026, 12:23: 10.6 °C11 May 2026, 12:55: 11 °C16 Jun 2026, 13:10: 15.5 °C6 Jul 2026, 09:23: 15.4 °C17 Aug 2026, 12:16: 18.2 °C9 Sep 2026, 11:25: 14.6 °C
Every result (6)
SampledResult as publishedReads as
9 Sep 2026, 11:2514.6 14.6 °C
17 Aug 2026, 12:1618.2 18.2 °C
6 Jul 2026, 09:2315.4 15.4 °C
16 Jun 2026, 13:1015.5 15.5 °C
11 May 2026, 12:5511 11 °C
22 Apr 2026, 12:2310.6 10.6 °C

pH

code 0061

6.37

Sampled 9 Sep 2026, 22 days ago · 6 results banked

66.577.588.520242025202622 Apr 2026, 12:23: 8.1711 May 2026, 12:55: 8.0716 Jun 2026, 13:10: 7.986 Jul 2026, 09:23: 7.7517 Aug 2026, 12:16: 7.819 Sep 2026, 11:25: 6.37
Every result (6)
SampledResult as publishedReads as
9 Sep 2026, 11:256.37 6.37
17 Aug 2026, 12:167.81 7.81
6 Jul 2026, 09:237.75 7.75
16 Jun 2026, 13:107.98 7.98
11 May 2026, 12:558.07 8.07
22 Apr 2026, 12:238.17 8.17

Ammonia

ammoniacal nitrogen as N · code 0111 · mg/l

below 0.03 mg/l (not detected above this)

Sampled 9 Sep 2026, 22 days ago · 6 results banked

-0.500.51mg/l20242025202622 Apr 2026, 12:23: below 0.03 mg/l (not detected above this)11 May 2026, 12:55: below 0.03 mg/l (not detected above this)16 Jun 2026, 13:10: below 0.03 mg/l (not detected above this)6 Jul 2026, 09:23: below 0.03 mg/l (not detected above this)17 Aug 2026, 12:16: below 0.03 mg/l (not detected above this)9 Sep 2026, 11:25: below 0.03 mg/l (not detected above this)
Every result (6)
SampledResult as publishedReads as
9 Sep 2026, 11:25<0.03 below 0.03 mg/l (not detected above this)
17 Aug 2026, 12:16<0.03 below 0.03 mg/l (not detected above this)
6 Jul 2026, 09:23<0.03 below 0.03 mg/l (not detected above this)
16 Jun 2026, 13:10<0.03 below 0.03 mg/l (not detected above this)
11 May 2026, 12:55<0.03 below 0.03 mg/l (not detected above this)
22 Apr 2026, 12:23<0.03 below 0.03 mg/l (not detected above this)

Nitrate

as nitrogen (N) · code 0117 · mg/l

3.4 mg/l

Sampled 9 Sep 2026, 22 days ago · 6 results banked

33.544.55mg/l20242025202622 Apr 2026, 12:23: 4.89 mg/l11 May 2026, 12:55: 4.69 mg/l16 Jun 2026, 13:10: 4.59 mg/l6 Jul 2026, 09:23: 4.29 mg/l17 Aug 2026, 12:16: 3.4 mg/l9 Sep 2026, 11:25: 3.4 mg/l
Every result (6)
SampledResult as publishedReads as
9 Sep 2026, 11:253.4 3.4 mg/l
17 Aug 2026, 12:163.4 3.4 mg/l
6 Jul 2026, 09:234.29 4.29 mg/l
16 Jun 2026, 13:104.59 4.59 mg/l
11 May 2026, 12:554.69 4.69 mg/l
22 Apr 2026, 12:234.89 4.89 mg/l

Phosphate

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

0.15 mg/l

Sampled 9 Sep 2026, 22 days ago · 6 results banked

0.050.0750.10.1250.15mg/l20242025202622 Apr 2026, 12:23: 0.061 mg/l11 May 2026, 12:55: 0.093 mg/l16 Jun 2026, 13:10: 0.12 mg/l6 Jul 2026, 09:23: 0.13 mg/l17 Aug 2026, 12:16: 0.15 mg/l9 Sep 2026, 11:25: 0.15 mg/l
Every result (6)
SampledResult as publishedReads as
9 Sep 2026, 11:250.15 0.15 mg/l
17 Aug 2026, 12:160.15 0.15 mg/l
6 Jul 2026, 09:230.13 0.13 mg/l
16 Jun 2026, 13:100.12 0.12 mg/l
11 May 2026, 12:550.093 0.093 mg/l
22 Apr 2026, 12:230.061 0.061 mg/l

Conductivity

at 25 °C · code 0077 · µS/cm

311 µS/cm

Sampled 9 Sep 2026, 22 days ago · 6 results banked

280290300310320µS/cm20242025202622 Apr 2026, 12:23: 283 µS/cm11 May 2026, 12:55: 294 µS/cm16 Jun 2026, 13:10: 318 µS/cm6 Jul 2026, 09:23: 288 µS/cm17 Aug 2026, 12:16: 304 µS/cm9 Sep 2026, 11:25: 311 µS/cm
Every result (6)
SampledResult as publishedReads as
9 Sep 2026, 11:25311 311 µS/cm
17 Aug 2026, 12:16304 304 µS/cm
6 Jul 2026, 09:23288 288 µS/cm
16 Jun 2026, 13:10318 318 µS/cm
11 May 2026, 12:55294 294 µS/cm
22 Apr 2026, 12:23283 283 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
DeterminandMaterialResults First – lastLatest result
Oxygen, Dissolved, % Saturation 9901 River water 6 Apr 2026 – Sep 2026 97.3% 9 Sep 2026
Oxygen, Dissolved as O2 9924 River water 6 Apr 2026 – Sep 2026 9.87 mg/l 9 Sep 2026
Temperature of Water 0076 River water 6 Apr 2026 – Sep 2026 14.6 °C 9 Sep 2026
pH 0061 River water 6 Apr 2026 – Sep 2026 6.37 9 Sep 2026
Ammoniacal Nitrogen as N 0111 River water 6 Apr 2026 – Sep 2026 below 0.03 mg/l 9 Sep 2026
Nitrate as N 0117 River water 6 Apr 2026 – Sep 2026 3.4 mg/l 9 Sep 2026
Orthophosphate, reactive as P 0180 River water 6 Apr 2026 – Sep 2026 0.15 mg/l 9 Sep 2026
Conductivity at 25 C 0077 River water 6 Apr 2026 – Sep 2026 311 µS/cm 9 Sep 2026
Alkalinity to pH 4.5 as CaCO3 0162 River water 6 Apr 2026 – Sep 2026 73 mg/l 9 Sep 2026
Ammonia un-ionised as N 0119 River water 6 Apr 2026 – Sep 2026 below 0.00002 mg/l 9 Sep 2026
Nitrite as N 0118 River water 6 Apr 2026 – Sep 2026 below 0.004 mg/l 9 Sep 2026
Nitrogen, Total Oxidised as N 0116 River water 6 Apr 2026 – Sep 2026 3.4 mg/l 9 Sep 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.