Restoring Nant Gain river

26 January 2024

Work has been completed to restore part of the Nant Gain river in Cilcain. The £2 million restoration project was completed ahead of schedule by the not-for-profit water company, Welsh Water.

Located at the eastern foothills of the Clwydians in Flintshire, part of the Nant Gain river, just outside the village of Cilcain, was used to create a reservoir by the construction of two dams at the end of the nineteenth century to supply drinking water to the local area. However, with homes and businesses in the area now supplied by the Alwen reservoir, Welsh Water have carried out work to remove the dams and restore the area to its original natural landscape.

The work, which took just under 8 months to complete, was carried out by contractors, Envolve along with a number of specialist teams to ensure the area was returned as closely as possible to how it was before the dams were built.

Tudur Ellis, Welsh Water Project Manager said, “The restoration process involved removing both of the dam structures at the reservoirs and creating a new channel for the riverbed. This new channel will allow the river to flow along its natural course, replicating how it would have been before the dams were built. Restoring the natural river course will bring with it many benefits including reinstating the natural fish passage as well as help to restore and improve the ecology of the area.

“Due to changes to reservoir safety legislation, keeping the reservoirs as they were previously was not an option as they required significant investment and major construction work to bring them up to current regulations. By restoring the natural landscape biodiversity in the area will be enhanced and the site will once again blend into the natural landscape of the area.”

As well as delivering the scheme ahead of schedule, the team on site carried out a number of community benefits including donations of surplus materials, visiting the local primary school to deliver an engineering and water cycle workshop as well as welcoming the school to site when the work was completed. The team have also donated materials and a bridge from the site to a local community garden group and spent the day volunteering at the Flintshare gardens. A number of local groups have also benefitted from Welsh Water’s Community Fund during the project which is aimed at groups that want to make a difference in the communities they live.

Tudur Ellis added, “It was great to be able to give back to the community in Cilcain while we carried out the project. Our team and contractors were very pleased to be able to help out on a number of different projects that benefits the local area as well as hopefully inspire some of the local school children to become future engineers!”

Work on site was completed in early November and will be closely monitored by Welsh Water for the next few years as the landscapes re-establishes and flourishes.