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Llwyd water levels

2 gauges. None is above its typical high. 2 storm overflows upstream are discharging now. Gauges in Torfaen; levels are checked every 15 minutes.

2gauges
0above normal
2overflows upstream discharging

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Gauges

Monitoring stations, source to mouth

StationTownLevel nowStatusTrend
Pontnewynydd Abersychan River Stationplace estimated—0.22 m 1h agoWithin its typical range▲
Ponthir Star Industrial Est River Stationplace estimatedPonthir0.75 m 17m 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 Llwyd above one of its gauges, from the source down. The river map knows where gauges are, not every stream, so a tributary without a gauge is not listed here.

No gauged tributary joins the Llwyd above Ponthir Star Industrial Est River Station on the river map. Streams without a gauge are not counted here.

Where the Llwyd goes

No gauge below Ponthir Star Industrial Est 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.

Storm overflows upstream

50 storm overflows are traced upstream of Ponthir Star Industrial Est River Station, the Llwyd’s lowest gauge on the river map: on the Llwyd itself, on its gauged tributaries, and on smaller streams that join above there.

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

Official figures for 2025, for the overflows traced upstream of Ponthir Star Industrial Est River Station: 1,658 spills over 10,062 hours in total, across the 48 that have a figure. 2 have 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 Llwyd includes the smaller streams that join it there. Where a stretch or a tributary has more than 4, the 3 discharging now or nearest its gauge are listed, the rest are counted, and every one is in that gauge’s “Upstream of here” list. Show every overflow in every stretch →

Above Ponthir Star Industrial Est River Station, the Llwyd’s highest gauge50 overflows · 2 discharging now
  • Ty Coch Way Storm Overflow Discharging now since
    Dwr Cymru Welsh Water · into Dowlais Brook · 5.1 km by river above Ponthir Star Industrial Est River Station · 2025: 56 spills, 431 h
  • Ponthir Works Inlet Storm Overflow Not discharging
    Dwr Cymru Welsh Water · into Afon Lwyd · 1.4 km by river above Ponthir Star Industrial Est River Station · no official annual figure
  • Llanfrechfa Storm Tanks Overflow Discharging now since
    Dwr Cymru Welsh Water · into Afon Lwyd · 1.4 km by river above Ponthir Star Industrial Est River Station · no official annual figure

and 47 more: show all 50 overflows on this stretch → All above Ponthir Star Industrial Est River Station, nearest first →

Near these gauges, connection not known

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

  • Caerleon Road Ponthir Overflow Not discharging
    Dwr Cymru Welsh Water · into Afon Lwyd · 20 m from Ponthir Star Industrial Est River Station in a straight line · too close to Ponthir Star Industrial Est River Station to say which side · 2025: 81 spills, 207 h
  • St. Cadoc's Hospital Storm Overflow Not discharging
    Dwr Cymru Welsh Water · into River Usk · 1.6 km from Ponthir Star Industrial Est River Station in a straight line · discharges into a tidal reach, where the water moves both ways · 2025: 51 spills, 150 h
  • Lodge Road Storm Overflow Not discharging
    Dwr Cymru Welsh Water · into Tributary Of Afon Wysg · 1.7 km from Ponthir Star Industrial Est River Station in a straight line · discharges into a tidal reach, where the water moves both ways · 2025: 1 spill, 0.8 h

8 more near these gauges whose connection is not known.

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.