Waunfarlais Road Brynmarlais Storm 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

817 discharge periods since 1 Jan 2020. 814 of them come from Dwr Cymru Welsh Water's own event-duration-monitoring records (published by the company, Jan 2020 – Dec 2025); the live feed adds anything after that. The official annual count is the figure to quote.

• Wed 30 Sep 2026, 03:32
  3 h 42 min
  ended 07:15 · live feed · 3 blocks
• Wed 30 Sep 2026, 00:17
  2 h 27 min
  ended 02:45 · live feed · 2 blocks
• Tue 15 Sep 2026, 06:32
  27 min
  ended 07:00 · live feed
• Mon 29 Dec 2025, 07:30
  2 d 16 h
  ended 00:00 · EDM log · 2 blocks
• Mon 29 Dec 2025, 01:30
  15 min
  ended 01:45 · EDM log
• Tue 28 Oct 2025, 02:45
  61 d 8 h
  ended 00:15 · EDM log · 54 blocks · over 61 d 21 h
• Mon 27 Oct 2025, 05:30
  18 h 15 min
  ended 00:00 · EDM log · 2 blocks
• Mon 27 Oct 2025, 04:45
  15 min
  ended 05:00 · EDM log
• Sat 25 Oct 2025, 20:00
  1 d 9 h
  ended 04:15 · EDM log · 2 blocks
• Sat 25 Oct 2025, 19:00
  15 min
  ended 19:15 · EDM log

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 1,355 raw blocks were merged into 817 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.