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.
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.
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.
3 report discharging now
44 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. Every overflow traced is listed here, each stretch in full. Back to the short lists →
Above Ponthir Star Industrial Est River Station, the Llwyd’s highest gauge50 overflows · 3 discharging now
Allgood Avenue Blaenavon OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 24.0 km by river above Ponthir Star Industrial Est River Station · 2025: 0 spills, 0 h
Blaenavon Forgeside Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 23.6 km by river above Ponthir Star Industrial Est River Station · 2025: 24 spills, 168 h
Varteg Road Blaenavon OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 23.3 km by river above Ponthir Star Industrial Est River Station · 2025: 1 spill, 0.3 h
Bridge Street Blaenavon Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 23.3 km by river above Ponthir Star Industrial Est River Station · 2025: 55 spills, 212 h
Avon Road Blaenavon Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 23.0 km by river above Ponthir Star Industrial Est River Station · 2025: 42 spills, 217 h
Cwmavon Road Blaenavon No 1 Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 22.6 km by river above Ponthir Star Industrial Est River Station · 2025: 2 spills, 3.5 h
Cwmavon Road Cwmavon Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 19.3 km by river above Ponthir Star Industrial Est River Station · 2025: 38 spills, 40 h
Cwmavon Road Garndiffaith No.3 Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 17.7 km by river above Ponthir Star Industrial Est River Station · 2025: 41 spills, 62 h
Abersychan Cwmavon Road Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 17.3 km by river above Ponthir Star Industrial Est River Station · 2025: 58 spills, 138 h
Old Road Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 16.4 km by river above Ponthir Star Industrial Est River Station · 2025: 82 spills, 421 h
Pontypool Limekiln Road Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 16.1 km by river above Ponthir Star Industrial Est River Station · 2025: 0 spills, 0 h
Pontypool Leigh Road Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 15.7 km by river above Ponthir Star Industrial Est River Station · 2025: 0 spills, 0 h
Snatchwood Road Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 15.4 km by river above Ponthir Star Industrial Est River Station · 2025: 32 spills, 77 h
Freeholdland Road Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 15.3 km by river above Ponthir Star Industrial Est River Station · 2025: 52 spills, 317 h
Upper Hospital Road Pontnewynydd Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 15.1 km by river above Ponthir Star Industrial Est River Station · 2025: 1 spill, 0.3 h
Fairview Court Storm OverflowDischarging now since Dwr Cymru Welsh Water · into Afon Lwyd · 14.8 km by river above Ponthir Star Industrial Est River Station · 2025: 89 spills, 1,374 h
Mill Road Pontnewynydd 1 Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 14.7 km by river above Ponthir Star Industrial Est River Station · 2025: 77 spills, 381 h
Mill Road Pontnewynydd 2 Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 14.7 km by river above Ponthir Star Industrial Est River Station · 2025: 2 spills, 5.0 h
Pontnewyndd Hospital Road Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 14.6 km by river above Ponthir Star Industrial Est River Station · 2025: 40 spills, 47 h
Trevethin Storm Tank Storm OverflowMonitor offline Dwr Cymru Welsh Water · into Afon Lwyd · 14.5 km by river above Ponthir Star Industrial Est River Station · 2025: 12 spills, 30 h
West Wainfelin Road Pontypool OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 14.3 km by river above Ponthir Star Industrial Est River Station · 2025: 35 spills, 282 h
East Wainfelin Road Pontypool OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 14.3 km by river above Ponthir Star Industrial Est River Station · 2025: 14 spills, 14 h
Woodland View Pontypool Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 14.3 km by river above Ponthir Star Industrial Est River Station · 2025: 4 spills, 1.8 h
Crumlin Road Pontypool 2 Storm OverflowNot discharging Dwr Cymru Welsh Water · into Trosnant Brook · 13.7 km by river above Ponthir Star Industrial Est River Station · 2025: 9 spills, 3.0 h
Riverside Car Park Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 13.6 km by river above Ponthir Star Industrial Est River Station · 2025: 113 spills, 626 h
Rosemary Lane Pontypool Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 13.4 km by river above Ponthir Star Industrial Est River Station · 2025: 2 spills, 0.8 h
Pontypool Park West Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 13.3 km by river above Ponthir Star Industrial Est River Station · 2025: 65 spills, 302 h
Pontypool Hanbury Road Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 13.2 km by river above Ponthir Star Industrial Est River Station · 2025: 31 spills, 35 h
Trosnant Street Pontypool Storm OverflowNot discharging Dwr Cymru Welsh Water · into The Trosnant Brook · 12.8 km by river above Ponthir Star Industrial Est River Station · 2025: 29 spills, 88 h
Pontypool Fountain Road Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 12.2 km by river above Ponthir Star Industrial Est River Station · 2025: 60 spills, 308 h
Polo Grounds Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 11.3 km by river above Ponthir Star Industrial Est River Station · 2025: 21 spills, 23 h
New Inn New Road Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 10.8 km by river above Ponthir Star Industrial Est River Station · 2025: 80 spills, 436 h
Pontyfelin Lane Lower New Inn Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 10.3 km by river above Ponthir Star Industrial Est River Station · 2025: 16 spills, 82 h
Griffithstown Subsidiary Sewer Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 9.3 km by river above Ponthir Star Industrial Est River Station · 2025: 98 spills, 810 h
Avondale Road Sebastopol Cwmbran Storm OverflowMonitor offline Dwr Cymru Welsh Water · into Unnamed Tributary Of Afon Lwyd · 8.8 km by river above Ponthir Star Industrial Est River Station · 2025: 37 spills, 93 h
Cwmbran Chapen Lane Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 8.2 km by river above Ponthir Star Industrial Est River Station · 2025: 68 spills, 1,241 h
Brookland Terrace Recreation Ground Storm OverflowNot discharging Dwr Cymru Welsh Water · into Blaen Bran Brook · 8.0 km by river above Ponthir Star Industrial Est River Station · 2025: 49 spills, 289 h
Turners End Cwmbran OverflowNot discharging Dwr Cymru Welsh Water · into Dowlais Brook · 6.9 km by river above Ponthir Star Industrial Est River Station · 2025: 4 spills, 5.8 h
Rede Road Storm OverflowMonitor offline Dwr Cymru Welsh Water · into Nant Y Milwr · 6.9 km by river above Ponthir Star Industrial Est River Station · 2025: 24 spills, 102 h
Edlogan Way 1 OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 6.7 km by river above Ponthir Star Industrial Est River Station · 2025: 24 spills, 89 h
Ty Coch Way Storm OverflowDischarging 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
Olway Close Rear Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 4.9 km by river above Ponthir Star Industrial Est River Station · 2025: 0 spills, 0 h
Olway Close Front Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 4.9 km by river above Ponthir Star Industrial Est River Station · 2025: 5 spills, 3.8 h
Llangorse Road Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 4.9 km by river above Ponthir Star Industrial Est River Station · 2025: 0 spills, 0 h
Beaumaris Drive Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 4.4 km by river above Ponthir Star Industrial Est River Station · 2025: 7 spills, 21 h
Green Willows Storm OverflowNot discharging Dwr Cymru Welsh Water · into Dowlais Brook · 4.2 km by river above Ponthir Star Industrial Est River Station · 2025: 28 spills, 139 h
Llantarnam Covent Grounds Storm OverflowNot discharging Dwr Cymru Welsh Water · into Afon Lwyd · 3.2 km by river above Ponthir Star Industrial Est River Station · 2025: 10 spills, 19 h
Ponthir Works Inlet Storm OverflowNot 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 OverflowDischarging 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
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 OverflowNot 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 OverflowNot 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 OverflowNot 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
Cold Bath Lane Storm OverflowNot discharging Dwr Cymru Welsh Water · into River Usk Estuary · 1.7 km from Ponthir Star Industrial Est River Station in a straight line · discharges to the sea, an estuary or tidal water · 2025: 3 spills, 2.8 h
Tram Lane Storm OverflowNot discharging Dwr Cymru Welsh Water · into Blaen Bran Brook · 2.0 km from Ponthir Star Industrial Est River Station in a straight line · no mapped watercourse close enough to be sure · 2025: 10 spills, 20 h
Caerleon Storm OverflowNot discharging Dwr Cymru Welsh Water · into River Usk · 2.1 km from Ponthir Star Industrial Est River Station in a straight line · discharges into a tidal reach, where the water moves both ways · 2025: 0 spills, 0 h
Usk Road Caerleon Storm OverflowNot discharging Dwr Cymru Welsh Water · into River Usk · 2.3 km from Ponthir Star Industrial Est River Station in a straight line · discharges into a tidal reach, where the water moves both ways · 2025: 3 spills, 0.8 h
Pilton Vale Storm OverflowNot discharging Dwr Cymru Welsh Water · into Pillmawr Creek · 2.5 km from Ponthir Star Industrial Est River Station in a straight line · discharges to the sea, an estuary or tidal water · 2025: 24 spills, 147 h
Rowan Way Storm OverflowNot discharging Dwr Cymru Welsh Water · into Pillmawr Creek · 2.8 km from Ponthir Star Industrial Est River Station in a straight line · discharges to the sea, an estuary or tidal water · 2025: 37 spills, 211 h
Horrocks Close Woodlands Storm OverflowNot discharging Dwr Cymru Welsh Water · into Pillmawr Creek · 2.9 km from Ponthir Star Industrial Est River Station in a straight line · discharges to the sea, an estuary or tidal water · 2025: 19 spills, 59 h
Robertson Way Storm OverflowMonitor offline Dwr Cymru Welsh Water · into Pillmawr Creek · 3.0 km from Ponthir Star Industrial Est River Station in a straight line · discharges to the sea, an estuary or tidal water · 2025: 10 spills, 12 h