River Ely

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.

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.

The river has flooded its banks on several occasions including 2008 when 27 homes were flooded, and in 2011, 2012 and in 2020.[4]

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.

The River Ely passes through the following:

• Leckwith Bridge
• Pont y Werin