Llyn Celyn Reservoir Auxiliary Spillway Project has won the ICE Wales Cymru the George Gibby Award sponsored by Walters.
This outstanding project was delivered by Dŵr Cymru Welsh Water who accepted their prize at a prestigious ceremony of over 250 industry professionals on Friday.
ICE Wales Cymru works to promote and celebrate the outstanding work of members. It organises awards to recognise exceptional projects, teamwork and individual excellence.
Its Project Awards celebrate innovative projects across Cymru. Its winners showcase the innovation, expertise, and dedication driving civil engineering forward.
The George Gibby Award is for a project over £5m. It is in memory of George H Gibby who instigated project awards for major civil engineering projects in Wales to bring to the public’s attention to the contribution made by civil engineers to South Wales.
The project delivered a nationally significant upgrade to Wales’ largest reservoir, ensuring long‑term safety, resilience and environmental stewardship within the protected landscape of Eryri National Park. The £30 million scheme introduced one of the UK’s most advanced spillway systems, centred on the country’s largest reinforced concrete tipping gates.
The design combines hydraulic innovation, rigorous modelling and digital engineering to optimise performance while reducing carbon, cost and landscape impact.
It delivered a 70° soil‑nailed excavation, efficient concrete delivery, and a robust dam safety management plan. The project was delivered with stakeholder collaboration, environmental sensitivity and community engagement.
ICE Wales Cymru Director, Keith Jones, said:
“The project successfully applied innovative principles and techniques to enable works within the protected landscape of the National park. It will provide sustainably and reservoir safety to meet the increasing challenge of future flood events affecting a significant population. As the UK’s most advanced spillway systems, this outstanding project shows the calibre of Welsh civil engineering”.
