Blaen Y Cwm Road Blaencwm Overflow

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

159 discharge periods since 19 Dec 2020. 158 of them come from Dwr Cymru Welsh Water's own event-duration-monitoring records (published by the company, Dec 2020 – Dec 2025); the live feed adds anything after that. The official annual count is the figure to quote.

• Thu 18 Dec 2025, 02:00
  17 min
  ended 02:17 · live feed
• Wed 17 Dec 2025, 20:15
  4 h 45 min
  ended 01:15 · EDM log · 2 blocks
• Tue 9 Dec 2025, 10:00
  8 h 15 min
  ended 18:30 · EDM log · 2 blocks
• Tue 9 Dec 2025, 08:15
  30 min
  ended 09:00 · EDM log · 2 blocks
• Tue 9 Dec 2025, 06:45
  15 min
  ended 07:00 · EDM log
• Tue 9 Dec 2025, 03:15
  2 h 30 min
  ended 06:00 · EDM log · 2 blocks
• Mon 1 Dec 2025, 15:00
  4 h 0 min
  ended 19:15 · EDM log · 2 blocks
• Mon 1 Dec 2025, 12:00
  1 h 45 min
  ended 14:00 · EDM log · 2 blocks
• Mon 1 Dec 2025, 05:45
  5 h 0 min
  ended 11:00 · EDM log · 2 blocks
• Tue 4 Nov 2025, 17:00
  5 h 30 min
  ended 22:45 · EDM log · 2 blocks

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 225 raw blocks were merged into 159 continuous discharge periods (gaps under 15 min joined).

Concerned about this overflow?

Report pollution you can see or smell to the regulator straight away; the company handles complaints about the overflow itself.