Llanaelhaearn WwTW Overflow
Storm overflow run by Dwr Cymru Welsh Water, discharging into Unnamed Watercourse.
"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.
Discharges we have recorded
1,834 discharge periods since 1 Jan 2023, 1 still open. 1,821 of them come from Dwr Cymru Welsh Water's own event-duration-monitoring records (published by the company, Jan 2023 – Nov 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, 13:00ongoing
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Wed 30 Sep 2026, 03:303 h 15 min
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Wed 30 Sep 2026, 02:4515 min
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Wed 30 Sep 2026, 01:4530 min
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Mon 28 Sep 2026, 12:3030 min
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Sun 27 Sep 2026, 13:001 h 15 min
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Sun 27 Sep 2026, 08:151 h 30 min
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Fri 25 Sep 2026, 10:3015 min
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Fri 25 Sep 2026, 06:453 h 0 min
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Fri 25 Sep 2026, 04:151 h 45 min
Show 30 earlier (of 1,834)
| Started (UK time) | Ended | Discharge time |
|---|---|---|
| 24 Sep 2026, 19:45 | 20:00 | 15 min |
| 24 Sep 2026, 11:15 | 12:00 | 45 min |
| 23 Sep 2026, 09:00 | 11:00 | 2 h 0 min |
| 2 Nov 2025, 22:45 | 00:00 | 59 d 1 h |
| 2 Nov 2025, 19:00 | 19:15 | 15 min |
| 2 Nov 2025, 16:45 | 17:00 | 15 min |
| 1 Nov 2025, 22:15 | 03:45 | 5 h 0 min |
| 1 Nov 2025, 21:30 | 21:45 | 15 min |
| 1 Nov 2025, 18:30 | 18:45 | 15 min |
| 1 Nov 2025, 14:30 | 14:45 | 15 min |
| 1 Nov 2025, 10:30 | 10:45 | 15 min |
| 1 Nov 2025, 08:30 | 09:00 | 30 min |
| 1 Nov 2025, 04:45 | 07:15 | 2 h 0 min |
| 31 Oct 2025, 22:45 | 03:30 | 4 h 45 min |
| 31 Oct 2025, 21:45 | 22:00 | 15 min |
| 31 Oct 2025, 19:45 | 20:00 | 15 min |
| 31 Oct 2025, 18:30 | 19:00 | 30 min |
| 31 Oct 2025, 17:45 | 18:00 | 15 min |
| 31 Oct 2025, 11:15 | 14:45 | 3 h 30 min |
| 31 Oct 2025, 09:45 | 10:00 | 15 min |
| 30 Oct 2025, 20:45 | 23:45 | 3 h 0 min |
| 30 Oct 2025, 12:30 | 12:45 | 15 min |
| 29 Oct 2025, 10:00 | 11:45 | 1 h 15 min |
| 29 Oct 2025, 06:30 | 09:30 | 2 h 45 min |
| 29 Oct 2025, 02:15 | 05:15 | 3 h 0 min |
| 28 Oct 2025, 23:30 | 01:45 | 2 h 15 min |
| 28 Oct 2025, 21:30 | 21:45 | 15 min |
| 28 Oct 2025, 19:30 | 19:45 | 15 min |
| 28 Oct 2025, 17:15 | 17:30 | 15 min |
| 28 Oct 2025, 15:15 | 15:30 | 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 2,377 raw blocks were merged into 1,834 continuous discharge periods (gaps under 15 min joined).
Rain nearby last 30 days
Nearest live rain gauge: Criccieth Raingauge, 12.8 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.