From reservoirs to river – returning Cilcain reservoirs to their natural state

Work is underway in Cilcain to return two of the four local reservoirs back to their natural state as part of the Nant Gain River. Situated just outside Cilcain village in the eastern foothills of the Clwydians, the four reservoirs were originally constructed in the late 19th century to supply drinking water for the local area. However, they are no longer a part of the drinking water network, with customers now being supplied from the Alwen reservoir.

The restoration process involves removing the dam structures at Cilcain 1 and 2 reservoirs, enabling the construction of a new channel. This new channel will allow the river to flow along its natural course, replicating how it would have been before the dams were built. Work started on site in March and should be finished by the end of the year.

With both reservoirs now drained and work to reinstate the river channel underway, Hannah Blythyn MS and Carolyn Thomas MS saw how the not-for-profit water company is working to restore and improve the ecology of the area.

Tudur Ellis, Welsh Water’s Project Manager for the scheme said; "It was great to welcome the Members of the Senedd to site to see our work to return these reservoirs back to their natural state. With changes to reservoir safety legislation, keeping the reservoirs as they were was not an option as they required significant investment and construction work to bring them up to current regulations, this is why Welsh Water is returning the natural landscape.

"By carefully designing the restoration process, we aim to enhance the biodiversity in the area by reinstating the natural river corridor, creating a thriving habitat for wildlife. The reservoirs are located within an Area of Outstanding Natural Beauty near Moel Famau, and restoring the site to its natural state is in keeping with the surrounding landscape."

This investment of over £2 million in Cilcain by Welsh Water follows a further £3 million investment to return Llyn Brân in Denbighshire and Llyn Anafon in Gwynedd to natural lakes.

Local Member of the Senedd, Hannah Blythyn said; "It was helpful to visit the site and see first-hand how and why Welsh Water go about decommissioning a reservoir and the careful planning that goes into recreating the river’s natural channel to how it was before it was turned into a reservoir. When work is complete it will hopefully once again blend into the natural landscape of the area just as it did before the man-made reservoirs were built."

Carolyn Thomas, North Wales Regional Member of the Senedd added; "I welcome this initiative to restore the Cilcain reservoirs to their natural state. It not only promotes the preservation of our environment but also enhances the ecological balance of the area. When the work is completed then the area will once again return to be a green lush area surrounding the reinstated Nant Gain River."

When the new river corridor has been completed, the area surrounding the river will be left for nature to carry out its work and in a few years’ time the surrounding landscape should flourish and return back to its natural green terrain.