River Usk
| River Usk | |
|---|---|
| Native name | Afon Wysg (Welsh) |
| Location | |
| Country | Wales |
| County | Powys, Carmarthenshire, Monmouthshire, Newport |
| Physical characteristics | |
| Source | |
| • location | Fan Brycheiniog, Carmarthenshire / Powys, Wales |
| • coordinates | 51°54′3″N 3°43′19″W / 51.90083°N 3.72194°W |
| • elevation | 502 m (1,647 ft) |
| Mouth | Severn Estuary |
• location | Uskmouth, Newport, Wales |
• coordinates | 51°32′31″N 2°59′6″W / 51.54194°N 2.98500°W |
• elevation | 0 m (0 ft) |
| Length | 125 km (78 mi) |
| Discharge | |
| • location | Chain Bridge (Usk) for 1957-2012 |
| • average | 27.919 m3/s (986.0 cu ft/s)for 1957-2012 |
| • minimum | 1.58 m3/s (56 cu ft/s)on 27 Aug 2003 |
| • maximum | 585.4 m3/s (20,670 cu ft/s)on 27 Dec 1979 |
| Basin features | |
| Tributaries | |
| • left | Cilieni, Nant Brân, Ysgir, Honddu, Rhiangoll, Grwyne Fawr, Gavenny, Olway Brook |
| • right | Hydfer, Crai, Senni, Tarell, Cyrig, Nant Menasgin, Caerfanell, Crawnon, Clydach, Berthin Brook, Sôr Brook, Llwyd, Ebbw |
The River Usk (/ʌsk/; Welsh: Afon Wysg) rises on the northern slopes of the Black Mountain (y Mynydd Du), Wales, in the westernmost part of the Brecon Beacons National Park. Initially forming the boundary between Carmarthenshire and Powys, it flows north into Usk Reservoir, then east through Sennybridge to Brecon before turning southeast to flow by Talybont-on-Usk, Crickhowell and Abergavenny, after which it takes a more southerly course.
Beyond the eponymous town of Usk, it passes the Roman legionary fortress of Caerleon to flow through the heart of the city of Newport and into the Severn Estuary at Uskmouth near the Newport Wetlands. The river is about 125 kilometres (78 miles) long. According to the Encyclopaedia of Wales (which gives a figure of 137 km (85 mi)), the river is the longest to flow wholly within Wales.
The Monmouthshire and Brecon Canal follows the Usk for most of the length of the canal.