River Yealm at Yealm Bridge

EA name: RIVER YEALM AT YEALM BRIDGE
Environment Agency sampling point SW-81020118 · 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, 13:2829 days ago · time as the Environment Agency records it (UK clock time; the source gives no time zone)
Samples banked
18 since 1 Apr 2025 Imported periods: 1 Oct 2023 – 8 Oct 2026. Samples outside them are not shown here.
Latest sample
River / running surface water Planned investigation (local monitoring) · results completed 16 Sep 2026
Where
National Grid 259042, 52002As published, to the nearest 1 m. Open in a map
River, by its own name
Yealm
River, by the map
River YealmPlaced on the river its name gives, 1 m from the line.
Next gauge downstream
PUSLINCH 2.2 km along the river
Nearest gauge upstream
Cornwood On the River Yealm · 9.3 km along the river
Why it was sampled
Planned investigation (local monitoring) (18 samples)

Results here were completed a median of 5 days after the sample was taken (4 to 7 days, 3 samples).

Main measurements, river water

Dissolved oxygen

% saturation · code 9901 · %

98.7%

Sampled 9 Sep 2026, 29 days ago · 18 results banked

90100110120%2024202520261 Apr 2025, 12:21: 118.2%14 May 2025, 12:25: 102.9%27 Jun 2025, 12:36: 100%24 Jul 2025, 11:03: 101%19 Aug 2025, 11:10: 93.3%10 Sep 2025, 13:04: 99.1%2 Oct 2025, 10:57: 95.1%13 Nov 2025, 11:04: 100%17 Dec 2025, 11:53: 101.5%19 Jan 2026, 11:22: 99.3%11 Feb 2026, 12:07: 99%19 Mar 2026, 12:07: 100.8%10 Apr 2026, 12:10: 102.1%14 May 2026, 12:12: 101.2%4 Jun 2026, 12:48: 98.4%16 Jul 2026, 13:53: 101.2%7 Aug 2026, 12:56: 102.4%9 Sep 2026, 13:28: 98.7%
Every result (18)
SampledResult as publishedReads as
9 Sep 2026, 13:2898.7 98.7%
7 Aug 2026, 12:56102.4 102.4%
16 Jul 2026, 13:53101.2 101.2%
4 Jun 2026, 12:4898.4 98.4%
14 May 2026, 12:12101.2 101.2%
10 Apr 2026, 12:10102.1 102.1%
19 Mar 2026, 12:07100.8 100.8%
11 Feb 2026, 12:0799 99%
19 Jan 2026, 11:2299.3 99.3%
17 Dec 2025, 11:53101.5 101.5%
13 Nov 2025, 11:04100 100%
2 Oct 2025, 10:5795.1 95.1%
10 Sep 2025, 13:0499.1 99.1%
19 Aug 2025, 11:1093.3 93.3%
24 Jul 2025, 11:03101 101%
27 Jun 2025, 12:36100 100%
14 May 2025, 12:25102.9 102.9%
1 Apr 2025, 12:21118.2 118.2%

Dissolved oxygen

as O2 · code 9924 · mg/l

9.97 mg/l

Sampled 9 Sep 2026, 29 days ago · 18 results banked

91011121314mg/l2024202520261 Apr 2025, 12:21: 13.1 mg/l14 May 2025, 12:25: 10.6 mg/l27 Jun 2025, 12:36: 9.7 mg/l24 Jul 2025, 11:03: 9.92 mg/l19 Aug 2025, 11:10: 9.18 mg/l10 Sep 2025, 13:04: 10 mg/l2 Oct 2025, 10:57: 10.1 mg/l13 Nov 2025, 11:04: 10.5 mg/l17 Dec 2025, 11:53: 11.4 mg/l19 Jan 2026, 11:22: 11.6 mg/l11 Feb 2026, 12:07: 11.1 mg/l19 Mar 2026, 12:07: 11.3 mg/l10 Apr 2026, 12:10: 11.4 mg/l14 May 2026, 12:12: 11.3 mg/l4 Jun 2026, 12:48: 10.2 mg/l16 Jul 2026, 13:53: 9.25 mg/l7 Aug 2026, 12:56: 10.2 mg/l9 Sep 2026, 13:28: 9.97 mg/l
Every result (18)
SampledResult as publishedReads as
9 Sep 2026, 13:289.97 9.97 mg/l
7 Aug 2026, 12:5610.2 10.2 mg/l
16 Jul 2026, 13:539.25 9.25 mg/l
4 Jun 2026, 12:4810.2 10.2 mg/l
14 May 2026, 12:1211.3 11.3 mg/l
10 Apr 2026, 12:1011.4 11.4 mg/l
19 Mar 2026, 12:0711.3 11.3 mg/l
11 Feb 2026, 12:0711.1 11.1 mg/l
19 Jan 2026, 11:2211.6 11.6 mg/l
17 Dec 2025, 11:5311.4 11.4 mg/l
13 Nov 2025, 11:0410.5 10.5 mg/l
2 Oct 2025, 10:5710.1 10.1 mg/l
10 Sep 2025, 13:0410 10 mg/l
19 Aug 2025, 11:109.18 9.18 mg/l
24 Jul 2025, 11:039.92 9.92 mg/l
27 Jun 2025, 12:369.7 9.7 mg/l
14 May 2025, 12:2510.6 10.6 mg/l
1 Apr 2025, 12:2113.1 13.1 mg/l

Water temperature

code 0076 · °C

14.8 °C

Sampled 9 Sep 2026, 29 days ago · 18 results banked

5101520°C2024202520261 Apr 2025, 12:21: 10.7 °C14 May 2025, 12:25: 13.9 °C27 Jun 2025, 12:36: 16.7 °C24 Jul 2025, 11:03: 16.1 °C19 Aug 2025, 11:10: 16 °C10 Sep 2025, 13:04: 14.7 °C2 Oct 2025, 10:57: 12.7 °C13 Nov 2025, 11:04: 13.2 °C17 Dec 2025, 11:53: 10.3 °C19 Jan 2026, 11:22: 8.5 °C11 Feb 2026, 12:07: 10.3 °C19 Mar 2026, 12:07: 10.1 °C10 Apr 2026, 12:10: 10.3 °C14 May 2026, 12:12: 10.5 °C4 Jun 2026, 12:48: 13.7 °C16 Jul 2026, 13:53: 19.6 °C7 Aug 2026, 12:56: 15.5 °C9 Sep 2026, 13:28: 14.8 °C
Every result (18)
SampledResult as publishedReads as
9 Sep 2026, 13:2814.8 14.8 °C
7 Aug 2026, 12:5615.5 15.5 °C
16 Jul 2026, 13:5319.6 19.6 °C
4 Jun 2026, 12:4813.7 13.7 °C
14 May 2026, 12:1210.5 10.5 °C
10 Apr 2026, 12:1010.3 10.3 °C
19 Mar 2026, 12:0710.1 10.1 °C
11 Feb 2026, 12:0710.3 10.3 °C
19 Jan 2026, 11:228.5 8.5 °C
17 Dec 2025, 11:5310.3 10.3 °C
13 Nov 2025, 11:0413.2 13.2 °C
2 Oct 2025, 10:5712.7 12.7 °C
10 Sep 2025, 13:0414.7 14.7 °C
19 Aug 2025, 11:1016 16 °C
24 Jul 2025, 11:0316.1 16.1 °C
27 Jun 2025, 12:3616.7 16.7 °C
14 May 2025, 12:2513.9 13.9 °C
1 Apr 2025, 12:2110.7 10.7 °C

pH

code 0061

7.4

Sampled 9 Sep 2026, 29 days ago · 18 results banked

77.588.592024202520261 Apr 2025, 12:21: 8.5514 May 2025, 12:25: 7.6627 Jun 2025, 12:36: 7.8224 Jul 2025, 11:03: 7.6819 Aug 2025, 11:10: 7.5210 Sep 2025, 13:04: 7.842 Oct 2025, 10:57: 7.5113 Nov 2025, 11:04: 7.3317 Dec 2025, 11:53: 7.4219 Jan 2026, 11:22: 7.6411 Feb 2026, 12:07: 7.719 Mar 2026, 12:07: 7.5710 Apr 2026, 12:10: 8.0314 May 2026, 12:12: 7.54 Jun 2026, 12:48: 7.1116 Jul 2026, 13:53: 7.537 Aug 2026, 12:56: 7.639 Sep 2026, 13:28: 7.4
Every result (18)
SampledResult as publishedReads as
9 Sep 2026, 13:287.4 7.4
7 Aug 2026, 12:567.63 7.63
16 Jul 2026, 13:537.53 7.53
4 Jun 2026, 12:487.11 7.11
14 May 2026, 12:127.5 7.5
10 Apr 2026, 12:108.03 8.03
19 Mar 2026, 12:077.57 7.57
11 Feb 2026, 12:077.7 7.7
19 Jan 2026, 11:227.64 7.64
17 Dec 2025, 11:537.42 7.42
13 Nov 2025, 11:047.33 7.33
2 Oct 2025, 10:577.51 7.51
10 Sep 2025, 13:047.84 7.84
19 Aug 2025, 11:107.52 7.52
24 Jul 2025, 11:037.68 7.68
27 Jun 2025, 12:367.82 7.82
14 May 2025, 12:257.66 7.66
1 Apr 2025, 12:218.55 8.55

Ammonia

ammoniacal nitrogen as N · code 0111 · mg/l

below 0.03 mg/l (not detected above this)

Sampled 9 Sep 2026, 29 days ago · 18 results banked

-0.500.51mg/l2024202520261 Apr 2025, 12:21: below 0.03 mg/l (not detected above this)14 May 2025, 12:25: below 0.03 mg/l (not detected above this)27 Jun 2025, 12:36: below 0.03 mg/l (not detected above this)24 Jul 2025, 11:03: below 0.03 mg/l (not detected above this)19 Aug 2025, 11:10: below 0.03 mg/l (not detected above this)10 Sep 2025, 13:04: below 0.03 mg/l (not detected above this)2 Oct 2025, 10:57: below 0.03 mg/l (not detected above this)13 Nov 2025, 11:04: below 0.03 mg/l (not detected above this)17 Dec 2025, 11:53: below 0.03 mg/l (not detected above this)19 Jan 2026, 11:22: below 0.03 mg/l (not detected above this)11 Feb 2026, 12:07: below 0.03 mg/l (not detected above this)19 Mar 2026, 12:07: below 0.03 mg/l (not detected above this)10 Apr 2026, 12:10: below 0.03 mg/l (not detected above this)14 May 2026, 12:12: below 0.03 mg/l (not detected above this)4 Jun 2026, 12:48: below 0.03 mg/l (not detected above this)16 Jul 2026, 13:53: below 0.03 mg/l (not detected above this)7 Aug 2026, 12:56: below 0.03 mg/l (not detected above this)9 Sep 2026, 13:28: below 0.03 mg/l (not detected above this)
Every result (18)
SampledResult as publishedReads as
9 Sep 2026, 13:28<0.03 below 0.03 mg/l (not detected above this)
7 Aug 2026, 12:56<0.03 below 0.03 mg/l (not detected above this)
16 Jul 2026, 13:53<0.03 below 0.03 mg/l (not detected above this)
4 Jun 2026, 12:48<0.03 below 0.03 mg/l (not detected above this)
14 May 2026, 12:12<0.03 below 0.03 mg/l (not detected above this)
10 Apr 2026, 12:10<0.03 below 0.03 mg/l (not detected above this)
19 Mar 2026, 12:07<0.03 below 0.03 mg/l (not detected above this)
11 Feb 2026, 12:07<0.03 below 0.03 mg/l (not detected above this)
19 Jan 2026, 11:22<0.03 below 0.03 mg/l (not detected above this)
17 Dec 2025, 11:53<0.03 below 0.03 mg/l (not detected above this)
13 Nov 2025, 11:04<0.03 below 0.03 mg/l (not detected above this)
2 Oct 2025, 10:57<0.03 below 0.03 mg/l (not detected above this)
10 Sep 2025, 13:04<0.03 below 0.03 mg/l (not detected above this)
19 Aug 2025, 11:10<0.03 below 0.03 mg/l (not detected above this)
24 Jul 2025, 11:03<0.03 below 0.03 mg/l (not detected above this)
27 Jun 2025, 12:36<0.03 below 0.03 mg/l (not detected above this)
14 May 2025, 12:25<0.03 below 0.03 mg/l (not detected above this)
1 Apr 2025, 12:21<0.03 below 0.03 mg/l (not detected above this)

Nitrate

as nitrogen (N) · code 0117 · mg/l

0.876 mg/l

Sampled 9 Sep 2026, 29 days ago · 18 results banked

0.511.522.5mg/l2024202520261 Apr 2025, 12:21: 1.7 mg/l14 May 2025, 12:25: 1.8 mg/l27 Jun 2025, 12:36: 1.5 mg/l24 Jul 2025, 11:03: 1.4 mg/l19 Aug 2025, 11:10: 1.4 mg/l10 Sep 2025, 13:04: 0.926 mg/l2 Oct 2025, 10:57: 1.3 mg/l13 Nov 2025, 11:04: 1.8 mg/l17 Dec 2025, 11:53: 2.3 mg/l19 Jan 2026, 11:22: 2.1 mg/l11 Feb 2026, 12:07: 1.7 mg/l19 Mar 2026, 12:07: 1.6 mg/l10 Apr 2026, 12:10: 1.4 mg/l14 May 2026, 12:12: 1.3 mg/l4 Jun 2026, 12:48: 0.536 mg/l16 Jul 2026, 13:53: 0.966 mg/l7 Aug 2026, 12:56: 0.996 mg/l9 Sep 2026, 13:28: 0.876 mg/l
Every result (18)
SampledResult as publishedReads as
9 Sep 2026, 13:280.876 0.876 mg/l
7 Aug 2026, 12:560.996 0.996 mg/l
16 Jul 2026, 13:530.966 0.966 mg/l
4 Jun 2026, 12:480.536 0.536 mg/l
14 May 2026, 12:121.3 1.3 mg/l
10 Apr 2026, 12:101.4 1.4 mg/l
19 Mar 2026, 12:071.6 1.6 mg/l
11 Feb 2026, 12:071.7 1.7 mg/l
19 Jan 2026, 11:222.1 2.1 mg/l
17 Dec 2025, 11:532.3 2.3 mg/l
13 Nov 2025, 11:041.8 1.8 mg/l
2 Oct 2025, 10:571.3 1.3 mg/l
10 Sep 2025, 13:040.926 0.926 mg/l
19 Aug 2025, 11:101.4 1.4 mg/l
24 Jul 2025, 11:031.4 1.4 mg/l
27 Jun 2025, 12:361.5 1.5 mg/l
14 May 2025, 12:251.8 1.8 mg/l
1 Apr 2025, 12:211.7 1.7 mg/l

Phosphate

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

0.038 mg/l

Sampled 9 Sep 2026, 29 days ago · 18 results banked

0.020.040.060.08mg/l2024202520261 Apr 2025, 12:21: 0.023 mg/l14 May 2025, 12:25: 0.04 mg/l27 Jun 2025, 12:36: 0.042 mg/l24 Jul 2025, 11:03: 0.053 mg/l19 Aug 2025, 11:10: 0.079 mg/l10 Sep 2025, 13:04: 0.026 mg/l2 Oct 2025, 10:57: 0.027 mg/l13 Nov 2025, 11:04: 0.022 mg/l17 Dec 2025, 11:53: 0.033 mg/l19 Jan 2026, 11:22: 0.035 mg/l11 Feb 2026, 12:07: 0.026 mg/l19 Mar 2026, 12:07: 0.027 mg/l10 Apr 2026, 12:10: 0.028 mg/l14 May 2026, 12:12: 0.039 mg/l4 Jun 2026, 12:48: 0.022 mg/l16 Jul 2026, 13:53: 0.058 mg/l7 Aug 2026, 12:56: 0.078 mg/l9 Sep 2026, 13:28: 0.038 mg/l
Every result (18)
SampledResult as publishedReads as
9 Sep 2026, 13:280.038 0.038 mg/l
7 Aug 2026, 12:560.078 0.078 mg/l
16 Jul 2026, 13:530.058 0.058 mg/l
4 Jun 2026, 12:480.022 0.022 mg/l
14 May 2026, 12:120.039 0.039 mg/l
10 Apr 2026, 12:100.028 0.028 mg/l
19 Mar 2026, 12:070.027 0.027 mg/l
11 Feb 2026, 12:070.026 0.026 mg/l
19 Jan 2026, 11:220.035 0.035 mg/l
17 Dec 2025, 11:530.033 0.033 mg/l
13 Nov 2025, 11:040.022 0.022 mg/l
2 Oct 2025, 10:570.027 0.027 mg/l
10 Sep 2025, 13:040.026 0.026 mg/l
19 Aug 2025, 11:100.079 0.079 mg/l
24 Jul 2025, 11:030.053 0.053 mg/l
27 Jun 2025, 12:360.042 0.042 mg/l
14 May 2025, 12:250.04 0.04 mg/l
1 Apr 2025, 12:210.023 0.023 mg/l

Conductivity

at 25 °C · code 0077 · µS/cm

167 µS/cm

Sampled 9 Sep 2026, 29 days ago · 18 results banked

50100150200250µS/cm2024202520261 Apr 2025, 12:21: 209 µS/cm14 May 2025, 12:25: 196 µS/cm27 Jun 2025, 12:36: 182 µS/cm24 Jul 2025, 11:03: 189 µS/cm19 Aug 2025, 11:10: 189 µS/cm10 Sep 2025, 13:04: 137 µS/cm2 Oct 2025, 10:57: 163 µS/cm13 Nov 2025, 11:04: 173 µS/cm17 Dec 2025, 11:53: 200 µS/cm19 Jan 2026, 11:22: 197 µS/cm11 Feb 2026, 12:07: 168 µS/cm19 Mar 2026, 12:07: 170 µS/cm10 Apr 2026, 12:10: 176 µS/cm14 May 2026, 12:12: 164 µS/cm4 Jun 2026, 12:48: 97 µS/cm16 Jul 2026, 13:53: 153 µS/cm7 Aug 2026, 12:56: 158 µS/cm9 Sep 2026, 13:28: 167 µS/cm
Every result (18)
SampledResult as publishedReads as
9 Sep 2026, 13:28167 167 µS/cm
7 Aug 2026, 12:56158 158 µS/cm
16 Jul 2026, 13:53153 153 µS/cm
4 Jun 2026, 12:4897 97 µS/cm
14 May 2026, 12:12164 164 µS/cm
10 Apr 2026, 12:10176 176 µS/cm
19 Mar 2026, 12:07170 170 µS/cm
11 Feb 2026, 12:07168 168 µS/cm
19 Jan 2026, 11:22197 197 µS/cm
17 Dec 2025, 11:53200 200 µS/cm
13 Nov 2025, 11:04173 173 µS/cm
2 Oct 2025, 10:57163 163 µS/cm
10 Sep 2025, 13:04137 137 µS/cm
19 Aug 2025, 11:10189 189 µS/cm
24 Jul 2025, 11:03189 189 µS/cm
27 Jun 2025, 12:36182 182 µS/cm
14 May 2025, 12:25196 196 µS/cm
1 Apr 2025, 12:21209 209 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 18 Apr 2025 – Sep 2026 98.7% 9 Sep 2026
Oxygen, Dissolved as O2 9924 River water 18 Apr 2025 – Sep 2026 9.97 mg/l 9 Sep 2026
Temperature of Water 0076 River water 18 Apr 2025 – Sep 2026 14.8 °C 9 Sep 2026
pH 0061 River water 18 Apr 2025 – Sep 2026 7.4 9 Sep 2026
Ammoniacal Nitrogen as N 0111 River water 18 Apr 2025 – Sep 2026 below 0.03 mg/l 9 Sep 2026
Nitrate as N 0117 River water 18 Apr 2025 – Sep 2026 0.876 mg/l 9 Sep 2026
Orthophosphate, reactive as P 0180 River water 18 Apr 2025 – Sep 2026 0.038 mg/l 9 Sep 2026
Conductivity at 25 C 0077 River water 18 Apr 2025 – Sep 2026 167 µS/cm 9 Sep 2026
Alkalinity to pH 4.5 as CaCO3 0162 River water 18 Apr 2025 – Sep 2026 28 mg/l 9 Sep 2026
Ammonia un-ionised as N 0119 River water 18 Apr 2025 – Sep 2026 below 0.0002 mg/l 9 Sep 2026
Nitrite as N 0118 River water 18 Apr 2025 – Sep 2026 below 0.004 mg/l 9 Sep 2026
Nitrogen, Total Oxidised as N 0116 River water 18 Apr 2025 – Sep 2026 0.88 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.