Knepp Mill Stream at Pondtail Farm

EA name: KNEPP MILL STREAM AT PONDTAIL FARM (also listed as “RSN1281 KNEPP MILL STREAM AT PONDTAIL FARM”)
Environment Agency sampling point SO-RSN1281 · 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 Dec 2024, 10:4222 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 8 Oct 2026 and had nothing newer.
Samples banked
12 since 17 Jan 2024 Imported periods: 1 Oct 2023 – 8 Oct 2026. Samples outside them are not shown here.
Latest sample
River / running surface water Monitoring (national agency policy)
Where
National Grid 515803, 123151As published, to the nearest 1 m. Open in a map
River, by its own name
Knepp Mill Stream
River, by the map
An unnamed streamPlaced by position alone (the only river line close by), 9 m from the line.
Next gauge downstream
Beeding Bridge On the River Adur · 18 km along the river
Why it was sampled
Monitoring (national agency policy) (12 samples)

1 visit found no water to sample (recorded as “No flow”).

Main measurements, river water

Dissolved oxygen

% saturation · code 9901 · %

67%

Sampled 6 Dec 2024, 22 months ago · 11 results banked

50100150200250%202420252026no sample published after Dec 202417 Jan 2024, 11:28: 62%15 Feb 2024, 11:35: 91.5%7 Mar 2024, 11:21: 102.4%25 Apr 2024, 12:51: 132.4%9 May 2024, 10:49: 85.3%17 Jun 2024, 11:21: 70.2%4 Jul 2024, 13:44: 81.4%9 Sep 2024, 12:12: 149.1%9 Oct 2024, 13:02: 224%13 Nov 2024, 10:28: 65%6 Dec 2024, 10:42: 67%
Every result (11)
SampledResult as publishedReads as
6 Dec 2024, 10:4267 67%
13 Nov 2024, 10:2865 65%
9 Oct 2024, 13:02224 224%
9 Sep 2024, 12:12149.1 149.1%
4 Jul 2024, 13:4481.4 81.4%
17 Jun 2024, 11:2170.2 70.2%
9 May 2024, 10:4985.3 85.3%
25 Apr 2024, 12:51132.4 132.4%
7 Mar 2024, 11:21102.4 102.4%
15 Feb 2024, 11:3591.5 91.5%
17 Jan 2024, 11:2862 62%

Dissolved oxygen

as O2 · code 9924 · mg/l

7.98 mg/l

Sampled 6 Dec 2024, 22 months ago · 11 results banked

510152025mg/l202420252026no sample published after Dec 202417 Jan 2024, 11:28: 8.7 mg/l15 Feb 2024, 11:35: 10 mg/l7 Mar 2024, 11:21: 12.2 mg/l25 Apr 2024, 12:51: 14.3 mg/l9 May 2024, 10:49: 9.11 mg/l17 Jun 2024, 11:21: 6.78 mg/l4 Jul 2024, 13:44: 7.82 mg/l9 Sep 2024, 12:12: 14.3 mg/l9 Oct 2024, 13:02: 22.1 mg/l13 Nov 2024, 10:28: 7.5 mg/l6 Dec 2024, 10:42: 7.98 mg/l
Every result (11)
SampledResult as publishedReads as
6 Dec 2024, 10:427.98 7.98 mg/l
13 Nov 2024, 10:287.5 7.5 mg/l
9 Oct 2024, 13:0222.1 22.1 mg/l
9 Sep 2024, 12:1214.3 14.3 mg/l
4 Jul 2024, 13:447.82 7.82 mg/l
17 Jun 2024, 11:216.78 6.78 mg/l
9 May 2024, 10:499.11 9.11 mg/l
25 Apr 2024, 12:5114.3 14.3 mg/l
7 Mar 2024, 11:2112.2 12.2 mg/l
15 Feb 2024, 11:3510 10 mg/l
17 Jan 2024, 11:288.7 8.7 mg/l

Water temperature

code 0076 · °C

7.7 °C

Sampled 6 Dec 2024, 22 months ago · 11 results banked

05101520°C202420252026no sample published after Dec 202417 Jan 2024, 11:28: 1.4 °C15 Feb 2024, 11:35: 11.3 °C7 Mar 2024, 11:21: 7.8 °C25 Apr 2024, 12:51: 11.7 °C9 May 2024, 10:49: 12.3 °C17 Jun 2024, 11:21: 16.9 °C4 Jul 2024, 13:44: 17.1 °C9 Sep 2024, 12:12: 17.3 °C9 Oct 2024, 13:02: 15.8 °C13 Nov 2024, 10:28: 9 °C6 Dec 2024, 10:42: 7.7 °C
Every result (11)
SampledResult as publishedReads as
6 Dec 2024, 10:427.7 7.7 °C
13 Nov 2024, 10:289 9 °C
9 Oct 2024, 13:0215.8 15.8 °C
9 Sep 2024, 12:1217.3 17.3 °C
4 Jul 2024, 13:4417.1 17.1 °C
17 Jun 2024, 11:2116.9 16.9 °C
9 May 2024, 10:4912.3 12.3 °C
25 Apr 2024, 12:5111.7 11.7 °C
7 Mar 2024, 11:217.8 7.8 °C
15 Feb 2024, 11:3511.3 11.3 °C
17 Jan 2024, 11:281.4 1.4 °C

pH

code 0061

7.08

Sampled 6 Dec 2024, 22 months ago · 11 results banked

7891011202420252026no sample published after Dec 202417 Jan 2024, 11:28: 7.2715 Feb 2024, 11:35: 7.37 Mar 2024, 11:21: 7.1725 Apr 2024, 12:51: 8.269 May 2024, 10:49: 7.5417 Jun 2024, 11:21: 7.434 Jul 2024, 13:44: 7.69 Sep 2024, 12:12: 9.049 Oct 2024, 13:02: 10.2913 Nov 2024, 10:28: 7.426 Dec 2024, 10:42: 7.08
Every result (11)
SampledResult as publishedReads as
6 Dec 2024, 10:427.08 7.08
13 Nov 2024, 10:287.42 7.42
9 Oct 2024, 13:0210.29 10.29
9 Sep 2024, 12:129.04 9.04
4 Jul 2024, 13:447.6 7.6
17 Jun 2024, 11:217.43 7.43
9 May 2024, 10:497.54 7.54
25 Apr 2024, 12:518.26 8.26
7 Mar 2024, 11:217.17 7.17
15 Feb 2024, 11:357.3 7.3
17 Jan 2024, 11:287.27 7.27

Ammonia

ammoniacal nitrogen as N · code 0111 · mg/l

0.51 mg/l

Sampled 13 Nov 2024, 23 months ago · 10 results banked

00.20.40.60.8mg/l202420252026no sample published after Nov 202417 Jan 2024, 11:28: 0.29 mg/l15 Feb 2024, 11:35: 0.092 mg/l7 Mar 2024, 11:21: 0.046 mg/l25 Apr 2024, 12:51: 0.036 mg/l9 May 2024, 10:49: 0.041 mg/l17 Jun 2024, 11:21: 0.54 mg/l4 Jul 2024, 13:44: 0.63 mg/l9 Sep 2024, 12:12: 0.11 mg/l9 Oct 2024, 13:02: below 0.03 mg/l (not detected above this)13 Nov 2024, 10:28: 0.51 mg/l
Every result (10)
SampledResult as publishedReads as
13 Nov 2024, 10:280.51 0.51 mg/l
9 Oct 2024, 13:02<0.03 below 0.03 mg/l (not detected above this)
9 Sep 2024, 12:120.11 0.11 mg/l
4 Jul 2024, 13:440.63 0.63 mg/l
17 Jun 2024, 11:210.54 0.54 mg/l
9 May 2024, 10:490.041 0.041 mg/l
25 Apr 2024, 12:510.036 0.036 mg/l
7 Mar 2024, 11:210.046 0.046 mg/l
15 Feb 2024, 11:350.092 0.092 mg/l
17 Jan 2024, 11:280.29 0.29 mg/l

Nitrate

as nitrogen (N) · code 0117 · mg/l

0.507 mg/l

Sampled 13 Nov 2024, 23 months ago · 10 results banked

00.250.50.7511.25mg/l202420252026no sample published after Nov 202417 Jan 2024, 11:28: 0.392 mg/l15 Feb 2024, 11:35: 0.33 mg/l7 Mar 2024, 11:21: below 0.196 mg/l (not detected above this)25 Apr 2024, 12:51: below 0.196 mg/l (not detected above this)9 May 2024, 10:49: 1.09 mg/l17 Jun 2024, 11:21: 0.196 mg/l4 Jul 2024, 13:44: 0.183 mg/l9 Sep 2024, 12:12: below 0.196 mg/l (not detected above this)9 Oct 2024, 13:02: 0.185 mg/l13 Nov 2024, 10:28: 0.507 mg/l
Every result (10)
SampledResult as publishedReads as
13 Nov 2024, 10:280.507 0.507 mg/l
9 Oct 2024, 13:020.185 0.185 mg/l
9 Sep 2024, 12:12<0.196 below 0.196 mg/l (not detected above this)
4 Jul 2024, 13:440.183 0.183 mg/l
17 Jun 2024, 11:210.196 0.196 mg/l
9 May 2024, 10:491.09 1.09 mg/l
25 Apr 2024, 12:51<0.196 below 0.196 mg/l (not detected above this)
7 Mar 2024, 11:21<0.196 below 0.196 mg/l (not detected above this)
15 Feb 2024, 11:350.33 0.33 mg/l
17 Jan 2024, 11:280.392 0.392 mg/l

Phosphate

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

0.054 mg/l

Sampled 13 Nov 2024, 23 months ago · 10 results banked

00.050.10.150.2mg/l202420252026no sample published after Nov 202417 Jan 2024, 11:28: 0.012 mg/l15 Feb 2024, 11:35: 0.022 mg/l7 Mar 2024, 11:21: 0.013 mg/l25 Apr 2024, 12:51: below 0.01 mg/l (not detected above this)9 May 2024, 10:49: 0.075 mg/l17 Jun 2024, 11:21: 0.19 mg/l4 Jul 2024, 13:44: 0.12 mg/l9 Sep 2024, 12:12: 0.15 mg/l9 Oct 2024, 13:02: 0.071 mg/l13 Nov 2024, 10:28: 0.054 mg/l
Every result (10)
SampledResult as publishedReads as
13 Nov 2024, 10:280.054 0.054 mg/l
9 Oct 2024, 13:020.071 0.071 mg/l
9 Sep 2024, 12:120.15 0.15 mg/l
4 Jul 2024, 13:440.12 0.12 mg/l
17 Jun 2024, 11:210.19 0.19 mg/l
9 May 2024, 10:490.075 0.075 mg/l
25 Apr 2024, 12:51<0.01 below 0.01 mg/l (not detected above this)
7 Mar 2024, 11:210.013 0.013 mg/l
15 Feb 2024, 11:350.022 0.022 mg/l
17 Jan 2024, 11:280.012 0.012 mg/l

Conductivity

at 25 °C · code 0077 · µS/cm

235 µS/cm

Sampled 6 Dec 2024, 22 months ago · 11 results banked

200400600800µS/cm202420252026no sample published after Dec 202417 Jan 2024, 11:28: 331 µS/cm15 Feb 2024, 11:35: 300 µS/cm7 Mar 2024, 11:21: 286 µS/cm25 Apr 2024, 12:51: 345 µS/cm9 May 2024, 10:49: 353 µS/cm17 Jun 2024, 11:21: 320 µS/cm4 Jul 2024, 13:44: 712 µS/cm9 Sep 2024, 12:12: 535 µS/cm9 Oct 2024, 13:02: 242 µS/cm13 Nov 2024, 10:28: 395 µS/cm6 Dec 2024, 10:42: 235 µS/cm
Every result (11)
SampledResult as publishedReads as
6 Dec 2024, 10:42235 235 µS/cm
13 Nov 2024, 10:28395 395 µS/cm
9 Oct 2024, 13:02242 242 µS/cm
9 Sep 2024, 12:12535 535 µS/cm
4 Jul 2024, 13:44712 712 µS/cm
17 Jun 2024, 11:21320 320 µS/cm
9 May 2024, 10:49353 353 µS/cm
25 Apr 2024, 12:51345 345 µS/cm
7 Mar 2024, 11:21286 286 µS/cm
15 Feb 2024, 11:35300 300 µS/cm
17 Jan 2024, 11:28331 331 µS/cm

Everything measured here

19 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 19 rows
DeterminandMaterialResults First – lastLatest result
Oxygen, Dissolved, % Saturation 9901 River water 11 Jan 2024 – Dec 2024 67% 6 Dec 2024
Oxygen, Dissolved as O2 9924 River water 11 Jan 2024 – Dec 2024 7.98 mg/l 6 Dec 2024
Temperature of Water 0076 River water 11 Jan 2024 – Dec 2024 7.7 °C 6 Dec 2024
pH 0061 River water 11 Jan 2024 – Dec 2024 7.08 6 Dec 2024
Ammoniacal Nitrogen as N 0111 River water 10 Jan 2024 – Nov 2024 0.51 mg/l 13 Nov 2024
Nitrate as N 0117 River water 10 Jan 2024 – Nov 2024 0.507 mg/l 13 Nov 2024
Orthophosphate, reactive as P 0180 River water 10 Jan 2024 – Nov 2024 0.054 mg/l 13 Nov 2024
Conductivity at 25 C 0077 River water 11 Jan 2024 – Dec 2024 235 µS/cm 6 Dec 2024
Alkalinity to pH 4.5 as CaCO3 0162 River water 10 Jan 2024 – Nov 2024 150 mg/l 13 Nov 2024
Ammonia un-ionised as N 0119 River water 10 Jan 2024 – Nov 2024 0.0023 mg/l 13 Nov 2024
Carbon, Organic, Dissolved as C :- {DOC} 0301 River water 11 Jan 2024 – Dec 2024 16 mg/l 6 Dec 2024
Chloride 0172 River water 10 Jan 2024 – Nov 2024 27 mg/l 13 Nov 2024
Flow Type 2896 River water 5 Aug 2024 – Dec 2024 High Flow 6 Dec 2024
Nitrite as N 0118 River water 10 Jan 2024 – Nov 2024 0.043 mg/l 13 Nov 2024
Nitrogen, Total as N 9686 River water 11 Jan 2024 – Dec 2024 3.5 mg/l 6 Dec 2024
Nitrogen, Total Oxidised as N 0116 River water 10 Jan 2024 – Nov 2024 0.55 mg/l 13 Nov 2024
No flow /No sample 7668 River water 1 Aug 2024 – Aug 2024 No flow/discharge at sampling point 7 Aug 2024
Phosphorus, Total as P 0348 River water 11 Jan 2024 – Dec 2024 0.37 mg/l 6 Dec 2024
Silica, reactive as SiO2 0182 River water 10 Jan 2024 – Nov 2024 4.7 mg/l 13 Nov 2024

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.