Tanybryn Risca Pontymister Storm Overflow
Storm overflow run by Dwr Cymru Welsh Water, discharging into River Ebbw.
"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.
Twin outlet
Dwr Cymru Welsh Water runs another overflow within 300 m that also discharges into River Ebbw. They share the sewer and the storm, so one outlet's figures are only part of what reaches the water.
This overflow: 196 spills in 2025. Distances are between the published outlet points.
Discharges we have recorded
210 discharge periods since 2 Jan 2020, 1 still open. 210 of them come from Dwr Cymru Welsh Water's own event-duration-monitoring records (published by the company, Jan 2020 – Dec 2021); the live feed adds anything after that. The official annual count is the figure to quote.
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Fri 31 Dec 2021, 03:45ongoing
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Wed 29 Dec 2021, 21:001 d 5 h
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Wed 29 Dec 2021, 08:158 h 45 min
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Tue 28 Dec 2021, 08:306 h 45 min
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Tue 28 Dec 2021, 06:0030 min
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Mon 27 Dec 2021, 08:3018 h 0 min
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Mon 27 Dec 2021, 00:3030 min
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Sat 25 Dec 2021, 15:001 d 7 h
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Sat 25 Dec 2021, 12:1515 min
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Fri 24 Dec 2021, 14:4515 min
Show 30 earlier (of 210)
| Started (UK time) | Ended | Discharge time |
|---|---|---|
| 7 Dec 2021, 23:15 | 01:00 | 1 h 30 min |
| 7 Dec 2021, 21:45 | 22:00 | 15 min |
| 7 Dec 2021, 19:15 | 20:00 | 30 min |
| 7 Dec 2021, 12:15 | 17:00 | 4 h 30 min |
| 31 Oct 2021, 05:15 | 02:15 | 1 d 19 h |
| 29 Oct 2021, 04:15 | 01:30 | 1 d 21 h |
| 28 Oct 2021, 17:45 | 03:45 | 9 h 15 min |
| 20 Oct 2021, 22:30 | 23:15 | 30 min |
| 20 Oct 2021, 19:15 | 20:45 | 1 h 15 min |
| 20 Oct 2021, 09:00 | 11:45 | 2 h 30 min |
| 19 Oct 2021, 19:45 | 00:45 | 4 h 45 min |
| 19 Oct 2021, 17:45 | 18:00 | 15 min |
| 4 Oct 2021, 21:15 | 16:00 | 17 h 45 min |
| 4 Oct 2021, 08:30 | 10:30 | 1 h 45 min |
| 4 Oct 2021, 05:30 | 05:45 | 15 min |
| 2 Oct 2021, 10:30 | 19:45 | 9 h 0 min |
| 1 Oct 2021, 03:15 | 13:00 | 9 h 15 min |
| 30 Sep 2021, 11:15 | 20:30 | 9 h 0 min |
| 30 Sep 2021, 10:30 | 10:45 | 15 min |
| 28 Sep 2021, 14:30 | 22:30 | 6 h 45 min |
| 27 Sep 2021, 05:30 | 06:30 | 45 min |
| 21 Aug 2021, 12:45 | 13:00 | 15 min |
| 21 Aug 2021, 10:45 | 11:45 | 45 min |
| 9 Aug 2021, 05:45 | 07:15 | 1 h 15 min |
| 8 Aug 2021, 03:30 | 03:45 | 15 min |
| 5 Aug 2021, 17:30 | 20:45 | 3 h 0 min |
| 30 Jul 2021, 09:15 | 12:30 | 3 h 0 min |
| 30 Jul 2021, 00:30 | 01:30 | 45 min |
| 27 Jul 2021, 16:15 | 17:00 | 30 min |
| 24 Jul 2021, 07:00 | 07:15 | 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 1,968 raw blocks were merged into 210 continuous discharge periods (gaps under 15 min joined).
Rain nearby last 30 days
Nearest live rain gauge: Ynysfro Raingauge, 3.2 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.