Selby Dam at Selby

EA name: SELBY DAM AT SELBY
Environment Agency sampling point NE-49100528 · 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
12 May 2026, 12:375 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 30 Sep 2026 and had nothing newer.
Samples banked
22 since 17 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 461370, 432539As published, to the nearest 1 m. Open in a map
River, by its own name
Selby Dam
River, by the map
Selby DamPlaced on the river its name gives, 5 m from the line.
Next gauge downstream
Selby Dam Pumping Station On the Selby Dam · 0.1 km along the river
Why it was sampled
Monitoring (national agency policy) (22 samples)

Main measurements, river water

Dissolved oxygen

% saturation · code 9901 · %

147.3%

Sampled 12 May 2026, 5 months ago · 22 results banked

5075100125150%20242025202617 Oct 2023, 09:16: 62.7%7 Dec 2023, 10:10: 73.1%18 Jan 2024, 10:44: 74%22 Feb 2024, 11:43: 81.7%19 Mar 2024, 08:27: 81.6%26 Apr 2024, 09:39: 88.6%17 Jun 2024, 14:08: 122.2%18 Jul 2024, 09:18: 104.8%29 Jul 2024, 12:06: 113.5%21 Aug 2024, 10:44: 79.5%16 Sep 2024, 09:59: 87.6%15 Oct 2024, 11:38: 56.9%20 Nov 2024, 13:37: 92.7%6 Dec 2024, 13:25: 78.4%30 Jan 2025, 13:31: 81.8%21 Feb 2025, 13:27: 82.4%14 Mar 2025, 14:41: 104.7%8 Jan 2026, 10:44: 71.6%3 Feb 2026, 10:07: 74.8%4 Mar 2026, 17:39: 81.1%10 Apr 2026, 11:17: 78.8%12 May 2026, 12:37: 147.3%
Every result (22)
SampledResult as publishedReads as
12 May 2026, 12:37147.3 147.3%
10 Apr 2026, 11:1778.8 78.8%
4 Mar 2026, 17:3981.1 81.1%
3 Feb 2026, 10:0774.8 74.8%
8 Jan 2026, 10:4471.6 71.6%
14 Mar 2025, 14:41104.7 104.7%
21 Feb 2025, 13:2782.4 82.4%
30 Jan 2025, 13:3181.8 81.8%
6 Dec 2024, 13:2578.4 78.4%
20 Nov 2024, 13:3792.7 92.7%
15 Oct 2024, 11:3856.9 56.9%
16 Sep 2024, 09:5987.6 87.6%
21 Aug 2024, 10:4479.5 79.5%
29 Jul 2024, 12:06113.5 113.5%
18 Jul 2024, 09:18104.8 104.8%
17 Jun 2024, 14:08122.2 122.2%
26 Apr 2024, 09:3988.6 88.6%
19 Mar 2024, 08:2781.6 81.6%
22 Feb 2024, 11:4381.7 81.7%
18 Jan 2024, 10:4474 74%
7 Dec 2023, 10:1073.1 73.1%
17 Oct 2023, 09:1662.7 62.7%

Dissolved oxygen

as O2 · code 9924 · mg/l

15.6 mg/l

Sampled 12 May 2026, 5 months ago · 22 results banked

57.51012.51517.5mg/l20242025202617 Oct 2023, 09:16: 7.47 mg/l7 Dec 2023, 10:10: 9.35 mg/l18 Jan 2024, 10:44: 10.2 mg/l22 Feb 2024, 11:43: 9.66 mg/l19 Mar 2024, 08:27: 9.19 mg/l26 Apr 2024, 09:39: 10.4 mg/l17 Jun 2024, 14:08: 12.2 mg/l18 Jul 2024, 09:18: 10 mg/l29 Jul 2024, 12:06: 10.4 mg/l21 Aug 2024, 10:44: 7.78 mg/l16 Sep 2024, 09:59: 9.19 mg/l15 Oct 2024, 11:38: 6.44 mg/l20 Nov 2024, 13:37: 11.8 mg/l6 Dec 2024, 13:25: 9.5 mg/l30 Jan 2025, 13:31: 10.6 mg/l21 Feb 2025, 13:27: 9.31 mg/l14 Mar 2025, 14:41: 12.7 mg/l8 Jan 2026, 10:44: 9.83 mg/l3 Feb 2026, 10:07: 9.37 mg/l4 Mar 2026, 17:39: 9.4 mg/l10 Apr 2026, 11:17: 8.9 mg/l12 May 2026, 12:37: 15.6 mg/l
Every result (22)
SampledResult as publishedReads as
12 May 2026, 12:3715.6 15.6 mg/l
10 Apr 2026, 11:178.9 8.9 mg/l
4 Mar 2026, 17:399.4 9.4 mg/l
3 Feb 2026, 10:079.37 9.37 mg/l
8 Jan 2026, 10:449.83 9.83 mg/l
14 Mar 2025, 14:4112.7 12.7 mg/l
21 Feb 2025, 13:279.31 9.31 mg/l
30 Jan 2025, 13:3110.6 10.6 mg/l
6 Dec 2024, 13:259.5 9.5 mg/l
20 Nov 2024, 13:3711.8 11.8 mg/l
15 Oct 2024, 11:386.44 6.44 mg/l
16 Sep 2024, 09:599.19 9.19 mg/l
21 Aug 2024, 10:447.78 7.78 mg/l
29 Jul 2024, 12:0610.4 10.4 mg/l
18 Jul 2024, 09:1810 10 mg/l
17 Jun 2024, 14:0812.2 12.2 mg/l
26 Apr 2024, 09:3910.4 10.4 mg/l
19 Mar 2024, 08:279.19 9.19 mg/l
22 Feb 2024, 11:439.66 9.66 mg/l
18 Jan 2024, 10:4410.2 10.2 mg/l
7 Dec 2023, 10:109.35 9.35 mg/l
17 Oct 2023, 09:167.47 7.47 mg/l

Water temperature

code 0076 · °C

12.6 °C

Sampled 12 May 2026, 5 months ago · 22 results banked

05101520°C20242025202617 Oct 2023, 09:16: 7.7 °C7 Dec 2023, 10:10: 4.9 °C18 Jan 2024, 10:44: 2.2 °C22 Feb 2024, 11:43: 8 °C19 Mar 2024, 08:27: 10 °C26 Apr 2024, 09:39: 8.3 °C17 Jun 2024, 14:08: 15.5 °C18 Jul 2024, 09:18: 17.5 °C29 Jul 2024, 12:06: 19.5 °C21 Aug 2024, 10:44: 16.3 °C16 Sep 2024, 09:59: 13.1 °C15 Oct 2024, 11:38: 9.8 °C20 Nov 2024, 13:37: 5.2 °C6 Dec 2024, 13:25: 7 °C30 Jan 2025, 13:31: 4.3 °C21 Feb 2025, 13:27: 9.9 °C14 Mar 2025, 14:41: 7.1 °C8 Jan 2026, 10:44: 2.2 °C3 Feb 2026, 10:07: 5.7 °C4 Mar 2026, 17:39: 8.8 °C10 Apr 2026, 11:17: 9.9 °C12 May 2026, 12:37: 12.6 °C
Every result (22)
SampledResult as publishedReads as
12 May 2026, 12:3712.6 12.6 °C
10 Apr 2026, 11:179.9 9.9 °C
4 Mar 2026, 17:398.8 8.8 °C
3 Feb 2026, 10:075.7 5.7 °C
8 Jan 2026, 10:442.2 2.2 °C
14 Mar 2025, 14:417.1 7.1 °C
21 Feb 2025, 13:279.9 9.9 °C
30 Jan 2025, 13:314.3 4.3 °C
6 Dec 2024, 13:257 7 °C
20 Nov 2024, 13:375.2 5.2 °C
15 Oct 2024, 11:389.8 9.8 °C
16 Sep 2024, 09:5913.1 13.1 °C
21 Aug 2024, 10:4416.3 16.3 °C
29 Jul 2024, 12:0619.5 19.5 °C
18 Jul 2024, 09:1817.5 17.5 °C
17 Jun 2024, 14:0815.5 15.5 °C
26 Apr 2024, 09:398.3 8.3 °C
19 Mar 2024, 08:2710 10 °C
22 Feb 2024, 11:438 8 °C
18 Jan 2024, 10:442.2 2.2 °C
7 Dec 2023, 10:104.9 4.9 °C
17 Oct 2023, 09:167.7 7.7 °C

pH

code 0061

8.33

Sampled 12 May 2026, 5 months ago · 22 results banked

7.257.57.7588.258.520242025202617 Oct 2023, 09:16: 7.597 Dec 2023, 10:10: 7.5918 Jan 2024, 10:44: 7.7322 Feb 2024, 11:43: 7.4719 Mar 2024, 08:27: 7.5626 Apr 2024, 09:39: 7.7317 Jun 2024, 14:08: 8.0418 Jul 2024, 09:18: 7.7929 Jul 2024, 12:06: 7.8621 Aug 2024, 10:44: 7.8416 Sep 2024, 09:59: 7.815 Oct 2024, 11:38: 7.9520 Nov 2024, 13:37: 8.016 Dec 2024, 13:25: 7.5430 Jan 2025, 13:31: 7.5721 Feb 2025, 13:27: 7.714 Mar 2025, 14:41: 7.898 Jan 2026, 10:44: 7.813 Feb 2026, 10:07: 7.754 Mar 2026, 17:39: 7.6210 Apr 2026, 11:17: 7.6712 May 2026, 12:37: 8.33
Every result (22)
SampledResult as publishedReads as
12 May 2026, 12:378.33 8.33
10 Apr 2026, 11:177.67 7.67
4 Mar 2026, 17:397.62 7.62
3 Feb 2026, 10:077.75 7.75
8 Jan 2026, 10:447.81 7.81
14 Mar 2025, 14:417.89 7.89
21 Feb 2025, 13:277.7 7.7
30 Jan 2025, 13:317.57 7.57
6 Dec 2024, 13:257.54 7.54
20 Nov 2024, 13:378.01 8.01
15 Oct 2024, 11:387.95 7.95
16 Sep 2024, 09:597.8 7.8
21 Aug 2024, 10:447.84 7.84
29 Jul 2024, 12:067.86 7.86
18 Jul 2024, 09:187.79 7.79
17 Jun 2024, 14:088.04 8.04
26 Apr 2024, 09:397.73 7.73
19 Mar 2024, 08:277.56 7.56
22 Feb 2024, 11:437.47 7.47
18 Jan 2024, 10:447.73 7.73
7 Dec 2023, 10:107.59 7.59
17 Oct 2023, 09:167.59 7.59

Ammonia

ammoniacal nitrogen as N · code 0111 · mg/l

below 0.03 mg/l (not detected above this)

Sampled 12 May 2026, 5 months ago · 21 results banked

00.250.50.751mg/l20242025202617 Oct 2023, 09:16: 0.35 mg/l7 Dec 2023, 10:10: 0.21 mg/l18 Jan 2024, 10:44: 0.68 mg/l22 Feb 2024, 11:43: 0.21 mg/l19 Mar 2024, 08:27: 0.25 mg/l26 Apr 2024, 09:39: 0.42 mg/l17 Jun 2024, 14:08: below 0.03 mg/l (not detected above this)18 Jul 2024, 09:18: below 0.03 mg/l (not detected above this)29 Jul 2024, 12:06: 0.031 mg/l21 Aug 2024, 10:44: below 0.03 mg/l (not detected above this)16 Sep 2024, 09:59: 0.075 mg/l15 Oct 2024, 11:38: 0.28 mg/l20 Nov 2024, 13:37: 0.096 mg/l30 Jan 2025, 13:31: 0.31 mg/l21 Feb 2025, 13:27: 0.81 mg/l14 Mar 2025, 14:41: 0.5 mg/l8 Jan 2026, 10:44: 0.94 mg/l3 Feb 2026, 10:07: 0.24 mg/l4 Mar 2026, 17:39: 0.23 mg/l10 Apr 2026, 11:17: 0.41 mg/l12 May 2026, 12:37: below 0.03 mg/l (not detected above this)
Every result (21)
SampledResult as publishedReads as
12 May 2026, 12:37<0.03 below 0.03 mg/l (not detected above this)
10 Apr 2026, 11:170.41 0.41 mg/l
4 Mar 2026, 17:390.23 0.23 mg/l
3 Feb 2026, 10:070.24 0.24 mg/l
8 Jan 2026, 10:440.94 0.94 mg/l
14 Mar 2025, 14:410.5 0.5 mg/l
21 Feb 2025, 13:270.81 0.81 mg/l
30 Jan 2025, 13:310.31 0.31 mg/l
20 Nov 2024, 13:370.096 0.096 mg/l
15 Oct 2024, 11:380.28 0.28 mg/l
16 Sep 2024, 09:590.075 0.075 mg/l
21 Aug 2024, 10:44<0.03 below 0.03 mg/l (not detected above this)
29 Jul 2024, 12:060.031 0.031 mg/l
18 Jul 2024, 09:18<0.03 below 0.03 mg/l (not detected above this)
17 Jun 2024, 14:08<0.03 below 0.03 mg/l (not detected above this)
26 Apr 2024, 09:390.42 0.42 mg/l
19 Mar 2024, 08:270.25 0.25 mg/l
22 Feb 2024, 11:430.21 0.21 mg/l
18 Jan 2024, 10:440.68 0.68 mg/l
7 Dec 2023, 10:100.21 0.21 mg/l
17 Oct 2023, 09:160.35 0.35 mg/l

Nitrate

as nitrogen (N) · code 0117 · mg/l

9.47 mg/l

Sampled 12 May 2026, 5 months ago · 21 results banked

24681012mg/l20242025202617 Oct 2023, 09:16: 7.29 mg/l7 Dec 2023, 10:10: 8.05 mg/l18 Jan 2024, 10:44: 8.92 mg/l22 Feb 2024, 11:43: 5.66 mg/l19 Mar 2024, 08:27: 7.64 mg/l26 Apr 2024, 09:39: 8.89 mg/l17 Jun 2024, 14:08: 7.87 mg/l18 Jul 2024, 09:18: 8.89 mg/l29 Jul 2024, 12:06: 10.8 mg/l21 Aug 2024, 10:44: 4.49 mg/l16 Sep 2024, 09:59: 3.28 mg/l15 Oct 2024, 11:38: 7.16 mg/l20 Nov 2024, 13:37: 4.47 mg/l30 Jan 2025, 13:31: 8.05 mg/l21 Feb 2025, 13:27: 7.09 mg/l14 Mar 2025, 14:41: 9.13 mg/l8 Jan 2026, 10:44: 10.9 mg/l3 Feb 2026, 10:07: 8.75 mg/l4 Mar 2026, 17:39: 8.92 mg/l10 Apr 2026, 11:17: 10.7 mg/l12 May 2026, 12:37: 9.47 mg/l
Every result (21)
SampledResult as publishedReads as
12 May 2026, 12:379.47 9.47 mg/l
10 Apr 2026, 11:1710.7 10.7 mg/l
4 Mar 2026, 17:398.92 8.92 mg/l
3 Feb 2026, 10:078.75 8.75 mg/l
8 Jan 2026, 10:4410.9 10.9 mg/l
14 Mar 2025, 14:419.13 9.13 mg/l
21 Feb 2025, 13:277.09 7.09 mg/l
30 Jan 2025, 13:318.05 8.05 mg/l
20 Nov 2024, 13:374.47 4.47 mg/l
15 Oct 2024, 11:387.16 7.16 mg/l
16 Sep 2024, 09:593.28 3.28 mg/l
21 Aug 2024, 10:444.49 4.49 mg/l
29 Jul 2024, 12:0610.8 10.8 mg/l
18 Jul 2024, 09:188.89 8.89 mg/l
17 Jun 2024, 14:087.87 7.87 mg/l
26 Apr 2024, 09:398.89 8.89 mg/l
19 Mar 2024, 08:277.64 7.64 mg/l
22 Feb 2024, 11:435.66 5.66 mg/l
18 Jan 2024, 10:448.92 8.92 mg/l
7 Dec 2023, 10:108.05 8.05 mg/l
17 Oct 2023, 09:167.29 7.29 mg/l

Phosphate

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

0.35 mg/l

Sampled 12 May 2026, 5 months ago · 21 results banked

00.20.40.6mg/l20242025202617 Oct 2023, 09:16: 0.5 mg/l7 Dec 2023, 10:10: 0.082 mg/l18 Jan 2024, 10:44: 0.15 mg/l22 Feb 2024, 11:43: 0.092 mg/l19 Mar 2024, 08:27: 0.11 mg/l26 Apr 2024, 09:39: 0.12 mg/l17 Jun 2024, 14:08: 0.21 mg/l18 Jul 2024, 09:18: 0.24 mg/l29 Jul 2024, 12:06: 0.41 mg/l21 Aug 2024, 10:44: 0.24 mg/l16 Sep 2024, 09:59: 0.18 mg/l15 Oct 2024, 11:38: 0.23 mg/l20 Nov 2024, 13:37: 0.23 mg/l30 Jan 2025, 13:31: 0.097 mg/l21 Feb 2025, 13:27: 0.16 mg/l14 Mar 2025, 14:41: 0.23 mg/l8 Jan 2026, 10:44: 0.079 mg/l3 Feb 2026, 10:07: 0.067 mg/l4 Mar 2026, 17:39: 0.085 mg/l10 Apr 2026, 11:17: 0.11 mg/l12 May 2026, 12:37: 0.35 mg/l
Every result (21)
SampledResult as publishedReads as
12 May 2026, 12:370.35 0.35 mg/l
10 Apr 2026, 11:170.11 0.11 mg/l
4 Mar 2026, 17:390.085 0.085 mg/l
3 Feb 2026, 10:070.067 0.067 mg/l
8 Jan 2026, 10:440.079 0.079 mg/l
14 Mar 2025, 14:410.23 0.23 mg/l
21 Feb 2025, 13:270.16 0.16 mg/l
30 Jan 2025, 13:310.097 0.097 mg/l
20 Nov 2024, 13:370.23 0.23 mg/l
15 Oct 2024, 11:380.23 0.23 mg/l
16 Sep 2024, 09:590.18 0.18 mg/l
21 Aug 2024, 10:440.24 0.24 mg/l
29 Jul 2024, 12:060.41 0.41 mg/l
18 Jul 2024, 09:180.24 0.24 mg/l
17 Jun 2024, 14:080.21 0.21 mg/l
26 Apr 2024, 09:390.12 0.12 mg/l
19 Mar 2024, 08:270.11 0.11 mg/l
22 Feb 2024, 11:430.092 0.092 mg/l
18 Jan 2024, 10:440.15 0.15 mg/l
7 Dec 2023, 10:100.082 0.082 mg/l
17 Oct 2023, 09:160.5 0.5 mg/l

Conductivity

at 25 °C · code 0077 · µS/cm

1349 µS/cm

Sampled 12 May 2026, 5 months ago · 22 results banked

500100015002000µS/cm20242025202617 Oct 2023, 09:16: 1285 µS/cm7 Dec 2023, 10:10: 976 µS/cm18 Jan 2024, 10:44: 1360 µS/cm22 Feb 2024, 11:43: 812 µS/cm19 Mar 2024, 08:27: 1072 µS/cm26 Apr 2024, 09:39: 1319 µS/cm17 Jun 2024, 14:08: 1224 µS/cm18 Jul 2024, 09:18: 1331 µS/cm29 Jul 2024, 12:06: 1565 µS/cm21 Aug 2024, 10:44: 798 µS/cm16 Sep 2024, 09:59: 522 µS/cm15 Oct 2024, 11:38: 1232 µS/cm20 Nov 2024, 13:37: 679 µS/cm6 Dec 2024, 13:25: 666 µS/cm30 Jan 2025, 13:31: 1091 µS/cm21 Feb 2025, 13:27: 1190 µS/cm14 Mar 2025, 14:41: 1300 µS/cm8 Jan 2026, 10:44: 1464 µS/cm3 Feb 2026, 10:07: 982 µS/cm4 Mar 2026, 17:39: 1246 µS/cm10 Apr 2026, 11:17: 1460 µS/cm12 May 2026, 12:37: 1349 µS/cm
Every result (22)
SampledResult as publishedReads as
12 May 2026, 12:371349 1349 µS/cm
10 Apr 2026, 11:171460 1460 µS/cm
4 Mar 2026, 17:391246 1246 µS/cm
3 Feb 2026, 10:07982 982 µS/cm
8 Jan 2026, 10:441464 1464 µS/cm
14 Mar 2025, 14:411300 1300 µS/cm
21 Feb 2025, 13:271190 1190 µS/cm
30 Jan 2025, 13:311091 1091 µS/cm
6 Dec 2024, 13:25666 666 µS/cm
20 Nov 2024, 13:37679 679 µS/cm
15 Oct 2024, 11:381232 1232 µS/cm
16 Sep 2024, 09:59522 522 µS/cm
21 Aug 2024, 10:44798 798 µS/cm
29 Jul 2024, 12:061565 1565 µS/cm
18 Jul 2024, 09:181331 1331 µS/cm
17 Jun 2024, 14:081224 1224 µS/cm
26 Apr 2024, 09:391319 1319 µS/cm
19 Mar 2024, 08:271072 1072 µS/cm
22 Feb 2024, 11:43812 812 µS/cm
18 Jan 2024, 10:441360 1360 µS/cm
7 Dec 2023, 10:10976 976 µS/cm
17 Oct 2023, 09:161285 1285 µS/cm

Everything measured here

13 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 13 rows
DeterminandMaterialResults First – lastLatest result
Oxygen, Dissolved, % Saturation 9901 River water 22 Oct 2023 – May 2026 147.3% 12 May 2026
Oxygen, Dissolved as O2 9924 River water 22 Oct 2023 – May 2026 15.6 mg/l 12 May 2026
Temperature of Water 0076 River water 22 Oct 2023 – May 2026 12.6 °C 12 May 2026
pH 0061 River water 22 Oct 2023 – May 2026 8.33 12 May 2026
Ammoniacal Nitrogen as N 0111 River water 21 Oct 2023 – May 2026 below 0.03 mg/l 12 May 2026
Nitrate as N 0117 River water 21 Oct 2023 – May 2026 9.47 mg/l 12 May 2026
Orthophosphate, reactive as P 0180 River water 21 Oct 2023 – May 2026 0.35 mg/l 12 May 2026
Conductivity at 25 C 0077 River water 22 Oct 2023 – May 2026 1349 µS/cm 12 May 2026
Alkalinity to pH 4.5 as CaCO3 0162 River water 21 Oct 2023 – May 2026 210 mg/l 12 May 2026
Ammonia un-ionised as N 0119 River water 21 Oct 2023 – May 2026 below 0.00066 mg/l 12 May 2026
BOD : 5 Day ATU 0085 River water 14 Feb 2024 – Mar 2025 below 3 mg/l 14 Mar 2025
Nitrite as N 0118 River water 21 Oct 2023 – May 2026 0.13 mg/l 12 May 2026
Nitrogen, Total Oxidised as N 0116 River water 21 Oct 2023 – May 2026 9.6 mg/l 12 May 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.