Lyonshall WwTW Overflow
Storm overflow run by Dwr Cymru Welsh Water, discharging into Curl Brook.
"Not discharging" means the company's monitor reports no discharge right now — not that the water is clean. The feed publishes status only; no discharge volume is measured.
Year by year
Dŵr Cymru Welsh Water's annual Event Duration Monitoring return to Natural Resources Wales (12/24-hour spill count), as compiled by The Rivers Trust. 2026 is our own running count, the same way, from the live feed since 28 February (when we began keeping every discharge it reports) — so it can only be lower than the full year. The official figure is published next spring.
"No data" means the monitor was not working or not required to report that year — not zero.
Downstream of this overflow
The next gauge downstream that the river map places is Eardisland (River Arrow), 11.9 km along the river.
Water-sampling points downstream
The nearest Environment Agency sampling points the river map places below Eardisland. Points between this overflow and that gauge cannot be put in order with it on the map, so they are not listed.
- Arrow downstream of Arrow Green
14 km along the river, below Eardisland · No sample published 1 Oct 2023 – 30 Sep 2026 - Lugg Marden
46 km along the river · Last sampled 30 Jul 2026 · 2 months ago - Lugg, downstream of Moreton on Lugg
48 km along the river · No sample published 1 Oct 2023 – 30 Sep 2026
A sample is dated: it is not the river now, and its results are on its own page. A sample taken after a discharge does not show that the discharge caused what was measured. Samples: Environment Agency Water Quality Archive, © Environment Agency and/or database right 2026, Open Government Licence v3.0.
A river gauge measures the level of the river; it does not measure this overflow's discharge, and a spill does not by itself explain a change there. Traced on OS Open Rivers (edition 2026-04), which leaves out many small channels.
Contains OS data © Crown copyright and database rights 2026.
Discharges we have recorded
65 discharge periods since 20 Jan 2021. 63 of them come from Dwr Cymru Welsh Water's own event-duration-monitoring records (published by the company, Jan 2021 – Dec 2025); the live feed adds anything after that. The official annual count is the figure to quote.
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Wed 30 Sep 2026, 06:1530 min
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Thu 27 Aug 2026, 08:0045 min
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Thu 18 Dec 2025, 12:157 h 0 min
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Wed 17 Dec 2025, 20:1515 min
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Mon 15 Dec 2025, 06:3015 min
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Tue 9 Dec 2025, 14:4515 min
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Tue 9 Dec 2025, 10:453 h 15 min
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Sat 15 Nov 2025, 01:3030 min
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Fri 14 Nov 2025, 10:0013 h 45 min
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Tue 4 Nov 2025, 17:301 h 30 min
Show 30 earlier (of 65)
| Started (UK time) | Ended | Discharge time |
|---|---|---|
| 4 Nov 2025, 16:00 | 16:15 | 15 min |
| 20 Sep 2025, 15:30 | 15:45 | 15 min |
| 14 Sep 2025, 16:30 | 16:45 | 15 min |
| 14 Sep 2025, 15:30 | 16:00 | 30 min |
| 4 Sep 2025, 11:00 | 11:15 | 15 min |
| 22 Mar 2025, 23:30 | 00:45 | 1 h 15 min |
| 16 Jan 2025, 18:15 | 18:30 | 15 min |
| 6 Jan 2025, 17:15 | 17:30 | 15 min |
| 5 Jan 2025, 20:15 | 14:45 | 18 h 30 min |
| 27 Dec 2023, 14:00 | 15:15 | 1 h 15 min |
| 27 Dec 2023, 12:15 | 13:15 | 1 h 0 min |
| 27 Dec 2023, 07:15 | 08:30 | 1 h 15 min |
| 9 Dec 2023, 07:15 | 08:15 | 1 h 0 min |
| 25 Oct 2023, 13:30 | 13:45 | 15 min |
| 20 Oct 2023, 09:00 | 12:15 | 3 h 15 min |
| 18 Aug 2023, 10:45 | 11:00 | 15 min |
| 13 Mar 2023, 08:45 | 09:15 | 30 min |
| 26 Feb 2023, 16:15 | 16:45 | 30 min |
| 23 Feb 2023, 16:15 | 16:45 | 30 min |
| 14 Jan 2023, 04:30 | 09:30 | 5 h 0 min |
| 11 Jan 2023, 22:45 | 11:45 | 12 h 45 min |
| 11 Jan 2023, 15:45 | 21:15 | 5 h 30 min |
| 23 Dec 2022, 09:30 | 09:45 | 15 min |
| 2 Nov 2022, 16:45 | 17:30 | 45 min |
| 8 Sep 2022, 14:45 | 15:30 | 45 min |
| 30 Jun 2022, 14:00 | 14:45 | 45 min |
| 26 Mar 2022, 11:00 | 11:15 | 15 min |
| 26 Mar 2022, 06:45 | 07:15 | 30 min |
| 26 Mar 2022, 01:15 | 01:30 | 15 min |
| 26 Mar 2022, 00:30 | 00:45 | 15 min |
The year figures above use the EA's 12/24-hour counting method, so they are comparable with the official figures; the monitor log's 70 raw blocks were merged into 65 continuous discharge periods (gaps under 15 min joined).
Rain nearby last 30 days
Nearest live rain gauge: Rainfall gauge nr Titley, 3.1 km away. Brown shading = when this overflow was discharging; ▼ = a discharge start.
Overflow shading is a timing match, not proof of cause — heavy rain and spills share a trigger. Times come from the water company’s event-duration monitor (site status only; no discharge volume is published).
Where it is
Concerned about this overflow?
Report pollution you can see or smell to the regulator straight away; the company handles complaints about the overflow itself.
Live status: © Dŵr Cymru Welsh Water, from its Storm Overflow Map. Spill-event history: © Dŵr Cymru Welsh Water's published EDM start/stop records. Annual figures: The Rivers Trust EDM compilation, © Dŵr Cymru/Welsh Water, Open Government Licence. Times are shown in UK local time. FloodRadar republishes the monitor's status; it does not measure discharges itself.