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Dyfi water levels

1 gauge, at Afon Dyfi River Station. It is not above its typical high. 2 storm overflows upstream are discharging now. Gauges in Gwynedd; levels are checked every 15 minutes.

1gauge
0above normal
2overflows upstream discharging

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Gauges

Monitoring stations, source to mouth

StationTownLevel nowStatusTrend
Afon Dyfi River Station—2.05 m 32m agoWithin its typical range▼

Stations are listed from source to mouth as the water flows, traced on the river map (OS Open Rivers) and the Environment Agency’s own links between its gauges. A distance “by river” is along the river, and is shown only where the map traces the path.

Contains OS data © Crown copyright and database rights 2026.

Gauged tributaries

Streams and rivers with a gauge whose water joins the Dyfi above one of its gauges, from the source down. Named streams without a gauge that have a page here are listed at the end.

1 gauged tributary, 1 gauge

Cerist

Joins the Dyfi above Afon Dyfi River Station, its highest gauge, no more than 29.0 km by river above Afon Dyfi River Station.

Afon Cerist River Station0.25 m 17m agoWithin its typical range

Its water passes every gauge on the Dyfi, from Afon Dyfi River Station down.

Where the Dyfi goes

No gauge below Afon Dyfi River Station is known on the river map.

Tributaries and where they join are traced on the river map (OS Open Rivers, edition 2026-04) and the Environment Agency’s links between its gauges. The map holds distances between gauges, not the junctions themselves, so a junction is placed between two gauges, and no further up than the tributary’s own lowest gauge. Contains OS data © Crown copyright and database rights 2026.

Streams without a gauge

Named streams on the river map that flow into the Dyfi and have no gauge of their own. Each has a page with what is known about it: the next gauge downstream, and any storm overflows or water-sampling points placed on it.

  • Afon Angell (joins about 16 km above Afon Dyfi River Station)
  • Afon Dulas (joins about 860 m above Afon Dyfi River Station)
  • Afon Twymyn (joins about 9.6 km above Afon Dyfi River Station)

Storm overflows upstream

6 storm overflows are traced upstream of Afon Dyfi River Station, the Dyfi’s lowest gauge on the river map: on the Dyfi itself, on its gauged tributaries, and on smaller streams that join above there.

  • 2 report discharging now
  • 3 not discharging
  • 1 offline or silent: 1 monitor offline, 0 status unknown, 0 no live feed

Official figures for 2025, for the overflows traced upstream of Afon Dyfi River Station: 293 spills over 5,344 hours in total, across all 6.

Each overflow is listed in the stretch above the first gauge its water reaches, from the source down, as on the Gauges tab. A stretch of the Dyfi includes the smaller streams that join it there.

Above Afon Dyfi River Station, the Dyfi’s highest gauge6 overflows · 2 discharging now
  • Bontdolgadfan Storm Overflow Not discharging
    Dwr Cymru Welsh Water · into River Twymyn · 22.8 km by river above Afon Dyfi River Station · 2025: 0 spills, 0 h
  • Llanbrynmair Tafolwern WwTW Storm Overflow Discharging now since
    Dwr Cymru Welsh Water · into Afon Iaen · 19.2 km by river above Afon Dyfi River Station · 2025: 95 spills, 1,856 h
  • Afon Angell Bridge Aberangell Storm Overflow Not discharging
    Dwr Cymru Welsh Water · into Afon Angell · 16.5 km by river above Afon Dyfi River Station · 2025: 1 spill, 8.5 h
  • Commins Coch Storm Overflow Discharging now since
    Dwr Cymru Welsh Water · into River Twymyn · 13.5 km by river above Afon Dyfi River Station · 2025: 120 spills, 2,676 h
  • Minffordd Street Corris Storm Overflow Not discharging
    Dwr Cymru Welsh Water · into River Deri · 8.7 km by river above Afon Dyfi River Station · 2025: 5 spills, 3.8 h
  • Corris WwTW Storm Overflow Monitor offline
    Dwr Cymru Welsh Water · into Afon Dulas · 8.4 km by river above Afon Dyfi River Station · 2025: 72 spills, 801 h

Near these gauges, connection not known

Within 3 km of one of the Dyfi’s gauges in a straight line, but the river map cannot say whether their water reaches it.

  • Heol Y Doll Machynlleth Storm Overflow Not discharging
    Dwr Cymru Welsh Water · into Garsiwn Ditch · 790 m from Afon Dyfi River Station in a straight line · no mapped watercourse close enough to be sure · 2025: 62 spills, 86 h
  • Machynlleth WwTW Inlet Storm Overflow Not discharging
    Dwr Cymru Welsh Water · into Garsiwn Ditch · 1.0 km from Afon Dyfi River Station in a straight line · no mapped watercourse close enough to be sure · 2024: 0 spills, 0 h
  • Garsiwn Ditch Storm Overflow Not discharging
    Dwr Cymru Welsh Water · into Garsiwn Ditch · 1.1 km from Afon Dyfi River Station in a straight line · no mapped watercourse close enough to be sure · 2025: 14 spills, 8.3 h
  • Machynlleth WwTW Settled Storm Overflow Not discharging
    Dwr Cymru Welsh Water · into Garsiwn Ffos · 1.1 km from Afon Dyfi River Station in a straight line · no mapped watercourse close enough to be sure · 2025: 65 spills, 461 h
  • Machynlleth WwTW Storm Overflow Not discharging
    Dwr Cymru Welsh Water · into River Dyfi · 1.1 km from Afon Dyfi River Station in a straight line · no mapped watercourse close enough to be sure · 2025: 55 spills, 410 h
  • Machynlleth Popular Terrace Storm Overflow Not discharging
    Dwr Cymru Welsh Water · into Unnamed Ditch · 1.2 km from Afon Dyfi River Station in a straight line · no mapped watercourse close enough to be sure · 2025: 21 spills, 7.8 h

A status is the water company’s own monitor: it says whether an overflow is discharging, never how much or why, and a spill does not by itself explain a change in a river level. A status older than two hours is shown as unknown. Annual figures are the official returns: 12/24-hour spills for England and Wales, overflow events for Scotland (Scottish Water counts differently, so the two cannot be compared). “No data” means the monitor produced no usable data that year, not zero. Overflows are placed on OS Open Rivers (edition 2026-04), which leaves out many small channels: an overflow the map cannot place may still drain here. Contains OS data © Crown copyright and database rights 2026. Sewage in Britain’s rivers →

Live status: © Dŵr Cymru Welsh Water, from its Storm Overflow Map. Annual figures for Wales: Dŵr Cymru Welsh Water’s return to Natural Resources Wales, as compiled by The Rivers Trust, Open Government Licence.