Cwm Penmachno WwTW Storm Overflow
Storm overflow operated by Dwr Cymru Welsh Water, discharging into River Machno. Storm Overflow.
Right now
"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.
Official figures
2025, from 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. The monitor reported for 100% of the year.
| Year | Spills | Hours | Monitored |
|---|---|---|---|
| 2024 | 270 | 5,976 | 99% |
| 2025 | 300 | 6,880 | 100% |
"No data" means the monitor was not working or not required to report that year — not zero spills.
Discharges we have observed
174 discharge periods since 12 Feb 2024, 1 still open. 173 of them come from Dwr Cymru Welsh Water's own event-duration-monitoring records (published by the company, Feb 2024 – Oct 2025); the live feed adds anything after that. The official annual count above is the figure to quote.
Year chips use the EA's 12/24-hour counting method (the first 12 hours of a discharge count as one spill, each further 24-hour block with discharge as one more), so they are comparable with the official figures above; the monitor log's 255 raw blocks were merged into 174 continuous discharge periods (gaps under 15 min joined).
| Started (UK time) | Ended | Discharge time | Source |
|---|---|---|---|
| 22 Sep 2026, 20:45 | ongoing | 2 d 17 h | live feed |
| 26 Oct 2025, 02:00 | 28 Dec 2025, 00:45 | 62 d 22 h | EDM log |
| 25 Oct 2025, 15:15 | 26 Oct 2025, 01:00 | 9 h 45 min | EDM log |
| 25 Oct 2025, 13:30 | 25 Oct 2025, 14:00 | 30 min | EDM log |
| 4 Oct 2025, 01:00 | 13 Oct 2025, 12:00 | 9 d 11 h | EDM log |
| 27 Sep 2025, 10:30 | 3 Oct 2025, 17:30 | 6 d 6 h | EDM log · 2 blocks |
| 12 Sep 2025, 12:30 | 27 Sep 2025, 09:45 | 14 d 21 h | EDM log · 2 blocks |
| 30 Aug 2025, 15:15 | 12 Sep 2025, 12:00 | 12 d 20 h | EDM log |
| 30 Aug 2025, 13:45 | 30 Aug 2025, 14:45 | 1 h 0 min | EDM log |
| 28 Aug 2025, 05:00 | 30 Aug 2025, 07:15 | 2 d 2 h | EDM log · 2 blocks |
| 27 Aug 2025, 11:30 | 27 Aug 2025, 12:45 | 1 h 15 min | EDM log |
| 14 Jun 2025, 01:45 | 14 Aug 2025, 11:30 | 61 d 9 h | EDM log |
| 26 May 2025, 21:15 | 14 Jun 2025, 01:00 | 18 d 3 h | EDM log |
| 26 May 2025, 16:00 | 26 May 2025, 16:45 | 45 min | EDM log |
| 24 May 2025, 19:30 | 25 May 2025, 01:30 | 6 h 0 min | EDM log |
| 20 May 2025, 15:15 | 20 May 2025, 15:45 | 30 min | EDM log |
| 20 May 2025, 14:15 | 20 May 2025, 14:45 | 30 min | EDM log |
| 10 Apr 2025, 05:15 | 17 Apr 2025, 10:00 | 7 d 0 h over 7 d 4 h | EDM log · 18 blocks |
| 10 Apr 2025, 03:15 | 10 Apr 2025, 04:45 | 1 h 0 min over 1 h 30 min | EDM log · 3 blocks |
| 10 Apr 2025, 02:30 | 10 Apr 2025, 02:45 | 15 min | EDM log |
Showing the latest 20 of 174.
Rain nearby — last 30 days
Nearest live rain gauge: Ysbyty Ifan Raingauge, 5.0 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?
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.