List of rivers of Wales


This is a list of rivers of Wales, organised geographically. It is taken anti-clockwise from the Dee Estuary to the M48 Bridge that separates the estuary of the River Wye from the River Severn.
Tributaries are listed down the page in an upstream direction, starting with those closest to the sea. The main stem river of a catchment is given, left-bank tributaries are indicated by, and right-bank tributaries by. Note that, in general usage, the 'left bank of a river' refers to the left hand bank as seen when looking downstream. Where a named river is formed by the confluence of two differently named rivers, these are labelled as and for the left and right forks. A prime example is the formation of the River Taff from the Taf Fawr and the Taf Fechan at Cefn Coed-y-cymmer.
The list is essentially a list of the main rivers of Wales and which more or less includes every watercourse named on Ordnance Survey mapping. Difficulties arise otherwise in determining what should and what should not be included.
Certain names are encountered frequently and particular care should be taken to differentiate between the various occurrences of Clydach, Clywedog and of Dulas for example as well as those whose names refer perhaps to the colour of their waters e.g. Afon Goch, Afon Ddu and Afon Wen.

Mainland rivers flowing into Liverpool Bay

From Dee Estuary to Garth Pier, Bangor, Gwynedd

Dee catchment

Anticlockwise from Menai Bridge / Porthaethwy

Minor coastal catchments

Note "Afon Menai", known as the "Menai Strait" in English, is not technically a river, despite its Welsh name..

Mainland rivers flowing into the [Menai Strait] and [Caernarfon Bay]

From Bangor Pier to the tip of the Llŷn Peninsula

Seiont catchment

From the tip of the Llŷn Peninsula to St. David's Head
From St David's Head to St. Govan's Head

Minor catchments

From St. Govan's Head to M48 Bridge

Taf catchment

With the exception of a small part of the Rea Brook, all tributaries of the Severn downstream of the confluence of the Severn and the Vyrnwy are wholly in England. For details see List of rivers of England.
This is a table of the longest rivers wholly or partially in Wales.
Rivers only partly in Wales are included in this table in italics. Note that river lengths given by different authorities vary due to the different ways in which the measurement is made or indeed estimated. That rivers are partly fractal in nature accounts for some variation and lengths can also vary slightly over time as meanders expand or are cut off where rivers run through broad flood-plains.