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Gwendraeth Fach water levels

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

1gauge
0above normal
2overflows upstream discharging

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Gauges

Monitoring stations, source to mouth

StationTownLevel nowStatusTrend
Llangendeirne River Station—1.06 m 33m 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 Gwendraeth Fach above one of its gauges, from the source down. Named streams without a gauge that have a page here are listed at the end.

No gauged tributary joins the Gwendraeth Fach above Llangendeirne River Station on the river map. Streams without a gauge are not counted here.

Where the Gwendraeth Fach goes

No gauge below Llangendeirne 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 Gwendraeth Fach 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 Dulais (joins about 4.8 km above Llangendeirne River Station)
  • Nant Rhydian-ddu (joins about 7.5 km above Llangendeirne River Station)

Storm overflows upstream

6 storm overflows are traced upstream of Llangendeirne River Station, the Gwendraeth Fach’s lowest gauge on the river map: on the Gwendraeth Fach 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 Llangendeirne River Station: 354 spills over 5,491 hours in total, across the 5 that have a figure. 1 has no 2025 figure.

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 Gwendraeth Fach includes the smaller streams that join it there.

Above Llangendeirne River Station, the Gwendraeth Fach’s highest gauge6 overflows · 2 discharging now
  • Mynydd Cerrig Storm Overflow Monitor offline
    Dwr Cymru Welsh Water · into River Dulais · 10.3 km by river above Llangendeirne River Station · 2025: 106 spills, 1,319 h
  • Porthyrhyd Storm Overflow Discharging now since
    Dwr Cymru Welsh Water · into Nant Rhydian Ddu · 7.5 km by river above Llangendeirne River Station · 2025: 94 spills, 1,336 h
  • Llanddarog Storm Overflow Not discharging
    Dwr Cymru Welsh Water · into Gwendraeth Fach · 6.3 km by river above Llangendeirne River Station · 2025: 11 spills, 20 h
  • Llanddarog Overflow Not discharging
    Dwr Cymru Welsh Water · into Tributary Of Afon Y Bantwen · 5.9 km by river above Llangendeirne River Station · 2024: 94 spills, 640 h
  • Llanddarog WwTW Storm Overflow Discharging now since
    Dwr Cymru Welsh Water · into Gwendraeth Fach · 5.9 km by river above Llangendeirne River Station · 2025: 139 spills, 2,804 h
  • Llangyndeyrn Storm Overflow Not discharging
    Dwr Cymru Welsh Water · into Unnamed Tributary Of Gwendraeth Fach · 580 m by river above Llangendeirne River Station · 2025: 4 spills, 13 h

1 other overflow within 3 km of these gauges is placed below the Gwendraeth Fach’s lowest gauge or on another river, so not listed.

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.