Heol Y Fro Storm Overflow
Storm overflow run by Dwr Cymru Welsh Water, discharging into River Gwenfro.
"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.
Year by year
The Environment Agency's official annual returns, counted the EA's way (12/24-hour spills). 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.
A spill is the EA's 12/24-hour count: the first 12 hours of a discharge count as one, each further 24 hours with discharge as one more. "Monitor" is the share of that year the monitor was working, so a 0 beside a working monitor is a real zero; "no data" means the monitor produced no usable data that year — not zero. Years before 2024 are matched to this site by name and location, because the EA's site IDs changed that year; a monitor figure beside one of them means the outlet's permit confirms the match.
Downstream of this overflow
The next gauge downstream that the river map places is Bowling Bank River Station (Clywedog), 18.6 km along the river.
Water-sampling points downstream
The nearest Environment Agency sampling points the river map places below Bowling Bank River Station. Points between this overflow and that gauge cannot be put in order with it on the map, so they are not listed.
- River Dee at A534 Wrexham Road Bridge, Holt
37 km along the river, below Bowling Bank River Station · Last sampled 7 Mar 2025 · 19 months ago - River Dee at Farndon Bridge
38 km along the river · Last sampled 10 Aug 2026 · 52 days ago - River Dee near Eccleston
52 km along the river · Last sampled 1 Jul 2026 · 3 months ago
A sample is dated: it is not the river now, and its results are on its own page. A sample taken after a discharge does not show that the discharge caused what was measured. Samples: Environment Agency Water Quality Archive, © Environment Agency and/or database right 2026, Open Government Licence v3.0.
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 discharge period since 4 Sep 2026. Recorded from the live status feed only — Dwr Cymru Welsh Water has not published an event-level log we hold, so this is what the feed has shown us, not a complete record. The official annual count is the figure to quote.
-
Fri 4 Sep 2026, 05:4530 min
The year figures above use the EA's 12/24-hour counting method, so they are comparable with the official figures.
Rain nearby last 30 days
Nearest live rain gauge: Nant Y Ffrith Raingauge, 4.8 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?
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. Times are shown in UK local time. FloodRadar republishes the monitor's status; it does not measure discharges itself.