Rassau Road Flyover Storm Overflow

Storm overflow run by Dwr Cymru Welsh Water, discharging into Rasa Brook.

Storm Overflow
Right now
Not discharging
Last discharge ended 09:00 on 27 Jan 2026 (247 days 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
1spill
1.0 h discharging on 1 day · live feed since 28 Feb, not yet official
2025 official
3spills
0.8 h · −94% on 2024
Rank in Dwr Cymru Welsh Water
—
No ranking for this overflow.
Monitor in 2025
99.1% 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.

2022
54 spills · 97 hmonitor 99.2%
2023
53 spills · 122 hmonitor 99.0%
2024
49 spills · 145 hmonitor 99.2%
2025
3 spills · 0.8 hmonitor 99.1%
2026since 28 Feb
1 spill · 1.0 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 Cwm Elm Street River Station (Ebbw), 7.2 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

395 discharge periods since 9 Jan 2020. 394 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 395)
Started (UK time)EndedDischarge time
1 Dec 2024, 07:0007:4530 min
25 Nov 2024, 03:3003:4515 min
24 Nov 2024, 07:4520:3012 h 15 min
24 Nov 2024, 07:0007:1515 min
23 Nov 2024, 08:1506:0020 h 45 min
23 Nov 2024, 07:0007:1515 min
19 Nov 2024, 05:3005:4515 min
20 Oct 2024, 11:0011:1515 min
19 Oct 2024, 00:3000:4515 min
16 Oct 2024, 15:1522:156 h 45 min
16 Oct 2024, 13:4514:3030 min
16 Oct 2024, 12:4513:0015 min
16 Oct 2024, 09:4510:3030 min
16 Oct 2024, 07:4508:0015 min
16 Oct 2024, 07:0007:1515 min
16 Oct 2024, 00:1501:0030 min
8 Oct 2024, 00:0000:1515 min
7 Oct 2024, 23:0023:1515 min
6 Oct 2024, 16:1516:3015 min
30 Sep 2024, 01:4502:0015 min
30 Sep 2024, 00:0001:151 h 0 min
26 Sep 2024, 22:0023:151 h 0 min
26 Sep 2024, 19:4521:301 h 30 min
26 Sep 2024, 17:0017:1515 min
26 Sep 2024, 16:0016:1515 min
26 Sep 2024, 04:0004:1515 min
22 Sep 2024, 14:4515:0015 min
21 Sep 2024, 10:3010:4515 min
21 Sep 2024, 09:1509:3015 min
8 Sep 2024, 06:4507:0015 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 620 raw blocks were merged into 395 continuous discharge periods (gaps under 15 min joined).

Rain nearby last 30 days

Nearest live rain gauge: Carno Reservoir Raingauge, 1.5 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
Nant Y Bwch River Station (Sirhowy) · 2.8 km
Nearest rain gauge
Site reference
DCWW787
Coordinates
51.79606, -3.21870

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.