Llyn Celyn improvement work


Llyn Celyn reservoir is one of our largest reservoirs in north Wales and plays an essential role in helping to provide clean, fresh drinking water.

It also plays an essential role in regulating the river level of the River Dee to protect its aquatic life and to facilitate water-based activities downstream at the National White Water Centre for Wales.

The reservoir also forms a major part of Wales’ history after the residents of the village of Capel Celyn were forced to move out to make way for the reservoir. A memorial chapel, which has recently been restored by us, sits on the banks of the reservoir to commemorate this.

What is happening?

At Welsh Water we take our responsibility to operate our reservoirs to the highest standards and to comply with all of the latest reservoir guidance seriously. Due to recent changes to guidelines in the operation of reservoirs and dams (Floods and Reservoir Safety Guidance) it has been identified that we need undertake some modification work to the dam at Llyn Celyn. The work is needed to ensure the dam can withstand the most extreme of storm events especially in light of changing weather patterns. Please be assured that this does not mean there is any immediate safety concerns with the dam.

At the moment, we are looking at different options of what work will be done, but first we need to undertake various investigations around the site which will help inform our decision. These investigations will include ecological surveys and ground investigations.

Our ground investigations are set to begin in August and you may well notice our teams on site undertaking this work. We anticipate that this work will continue through until September 2021.

The investigations will be carried out by our partner Mott Macdonald Bentley (MMB) and please be assured that they will ensure all of the work is done with the least impact possible on local habitats and wildlife.

Keeping everyone informed

As a company, we are committed to keeping customers and stakeholders informed of any work we undertake and will be doing the same here at Llyn Celyn. We are liaising closely with our regulator Natural Resources Wales on the work and our investigations. We are also liaising with Snowdonia National Park and Gwynedd Council.

We will be keeping customers in the area updated by providing regular updates on where we are with our plans. We will do this through newsletters and updates on our website. It is possible that when we have agreed on the preferred option that we will need to get planning permission for the work so we will of course make sure people are made aware of this and of how they can get involved in that process in due course.