Llanbrynmair Tafolwern WwTW Storm Overflow

Storm overflow run by Dwr Cymru Welsh Water, discharging into Afon Iaen.

Storm Overflow
Right now
Not discharging
Last discharge ended 14:34 on 1 Oct 2026 (4 hours ago).
Times are UK time · company feed updated 10 min ago

"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.

2026 so far
9spills
2.4 h discharging on 9 days · live feed since 28 Feb, not yet official
2025 official
95spills
1,856 h
Rank in Dwr Cymru Welsh Water
—
No ranking for this overflow.
Monitor in 2025
94.4% working
Share of the year the monitor reported

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.

2025
95 spills · 1,856 hmonitor 94.4%
2026since 28 Feb
9 spills · 2.4 h

"No data" means the monitor was not working or not required to report that year — not zero.

Downstream of this overflow

The next gauge downstream that the river map places is Afon Dyfi River Station (Dyfi), 19.2 km along the river.

A river gauge measures the level of the river; it does not measure this overflow's discharge, and a spill does not by itself explain a change there. Traced on OS Open Rivers (edition 2026-04), which leaves out many small channels.

Contains OS data © Crown copyright and database rights 2026.

Discharges we have recorded

1,273 discharge periods since 1 Jan 2020. 1,229 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.

Show 30 earlier (of 1,273)
Started (UK time)EndedDischarge time
30 Sep 2026, 17:4317:463 min
30 Sep 2026, 12:0612:093 min
30 Sep 2026, 08:0808:091 min
30 Sep 2026, 07:3907:412 min
30 Sep 2026, 07:1407:162 min
30 Sep 2026, 06:3906:401 min
30 Sep 2026, 05:0005:3124 min
30 Sep 2026, 02:2802:313 min
29 Sep 2026, 19:2219:231 min
29 Sep 2026, 12:5913:012 min
29 Sep 2026, 07:3407:362 min
29 Sep 2026, 00:1400:162 min
28 Sep 2026, 17:5517:583 min
28 Sep 2026, 11:2211:242 min
28 Sep 2026, 07:1107:143 min
28 Sep 2026, 00:2700:292 min
27 Sep 2026, 18:5218:575 min
27 Sep 2026, 13:3513:383 min
27 Sep 2026, 09:1109:143 min
27 Sep 2026, 03:0003:022 min
26 Sep 2026, 21:5621:593 min
26 Sep 2026, 16:4416:462 min
26 Sep 2026, 11:4511:483 min
26 Sep 2026, 09:3309:352 min
26 Sep 2026, 07:0207:042 min
26 Sep 2026, 00:5901:023 min
25 Sep 2026, 20:0720:103 min
25 Sep 2026, 15:1115:143 min
25 Sep 2026, 10:2110:254 min
25 Sep 2026, 01:1601:182 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 1,645 raw blocks were merged into 1,273 continuous discharge periods (gaps under 15 min joined).

Rain nearby last 30 days

Nearest live rain gauge: Llanbrynmair 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

Nearest river gauge
Afon Dyfi River Station (Dyfi) · 14.7 km
Nearest rain gauge
Site reference
DCWW1510
Coordinates
52.60943, -3.63567

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.