River Ely

River Ely (Afon Elai)
River
The river flowing through Peterston-super-Ely
Countries United Kingdom, Wales
Region South Wales
County Vale of Glamorgan, Cardiff, Rhondda Cynon Taf
Tributaries
 - left Nant Muchud, Afon Clun
 - right Nant y Drope
Cities Tonyrefail, Llantrisant, Pontyclun, Peterston-super-Ely, Ely, Cardiff, Penarth
Source
 - location Northwest of Tonyrefail, Rhondda Cynon Taf, Wales
Mouth
 - location Cardiff Bay
Length 39.6 km (25 mi)

The River Ely (Welsh: Afon Elai) is a river in South Wales flowing generally south east, from Tonyrefail to the capital city of Cardiff.

Contents

Course of the river

The river is about 24 miles, or 39 kilometres, long. Its source lies in the mountains to the south of Tonypandy, near the town of Tonyrefail. The river's numerous sources rise in the eastern slopes of Mynydd Penygraig (Penygraig) and Mynydd y Gilfach (Penrhiwfer), and the western slopes of Mynydd Dinas (Williamstown), whose eastern slopes feed the Rhondda by Porth. The source of the Ogwr Fach lies just to the west.

The Ely flows through Tonyrefail, and then through the grounds of the Royal Glamorgan Hospital at Ynysmaerdy, following the main A4119 (Tonypandy to Cardiff Bay (Welsh: Bae Caerdydd)) route through the valley pass formed between Mynydd Garthmaetwg (Llantrisant Forest), to the west and Llantrisant, to the east. Flowing through Talbot Green (Welsh: Tonysguboriau), the Ely is joined by the Afon Clun at Pontyclun, before heading east to Miskin (Welsh: Meisgyn). Although numerous smaller streams join the river, the Clun is its only large tributary.

After turning south once more, the Ely reaches the western edge of the rural lowlands of City and County of Cardiff (Welsh: Dinas a Sir Caerdydd) immediately south of Junction 34 of the M4 motorway. It passes the Museum of Welsh Life at St. Fagans and then continues through residential Cardiff suburbs such as Pentrebane and Caerau and Ely (Welsh: Trelai) before flowing into Cardiff Bay, by Penarth Marina.

Despite it being close to these densely populated settlements, major roads like the M4 motorway, and the busy South Wales Main Line, it still retains a rural feel.

Quality

The Ely has had a long history of moderate to severe pollution from which it is now recovering. Prior to the 1980s it had received large volumes of poorly treated or untreated sewage from the urban areas in the valleys. Even after the construction of sewage treatment works at Miskin and Rhiwsaeson, the quality of the effluent continued to cause pollution until the late 1980s.

These problems were exacerbated by the highly polluting discharge from Coedely coke ovens. At the mouth of the river, the effluent a large paper mill rendered large parts of the estuary anoxic for most of the tidal cycle preventing the passage of migratory fish. The recovery of the river since that time owes much to the regulatory effort of the NRA, and more lately the Environment Agency Wales, and to the massive capital investment made by Dŵr Cymru / Welsh Water.

Ecology

As the pollution of the river abated, so fish populations slowly returned to the river from the many small tributaries. Roach, Brown trout, perch, chub, eel, grayling, sea trout and salmon and more recently some barbel.

Ely Valley Trail

The Countryside Council for Wales and Cardiff Council are developing a cycleway beside the river known as the Ely Trail. The intended benefits are to allow people from urban western Cardiff easier access to the countryside, and for people in rural areas to have another commuting option into the city centre. Parts of this trail are now open.

See also