Proposed energy scheme in Eryri National Park prompts first Judicial Review in Society’s 60-year history

Proposed energy scheme in Eryri National Park prompts first Judicial Review in Society’s 60-year history

 Cymdeithas Eryri (Snowdonia Society) has applied for a Judicial Review of Eryri National Park Authority’s decision to approve a scheme campaigners argue will damage one of the National Park’s most iconic waterfalls.

This is not where Cymdeithas Eryri wanted to be.

On 24 June, Eryri National Park Authority’s (‘ENPA’) Planning & Access Committee resolved to grant planning permission for a hydro-electric scheme at one of the National Park’s most iconic waterfalls – Rhaeadr y Cwm, above Llan Ffestiniog.  The decision notice granting planning permission was issued on 15 July.  This is a scheme that Cymdeithas Eryri and other like-minded organisations have consistently opposed: at times, nearly 70% of the water would be diverted away from the waterfall into a plastic pipe, threatening the sensory experience and unique environment associated with this special place.

The waterfall is located in the Cwm Cynfal Site of Special Scientific Interest (SSSI) and forms part of the wider Migneint–Arenig–Dduallt Special Area of Conservation (SAC) and Special Protection Area (SPA): an internationally important area for blanket bog and upland heath. The site supports rare bryophytes (mosses and liverworts) typical of humid ravines and a range of animals including bats, insects, birds and small mammals typical of ancient Celtic rainforest remnants. The SSSI also lies wholly within the Eryri National Park and within the Ardudwy Historic Landscape of Outstanding Interest.

Environmental organisations have raised concerns throughout the application process around the potential harmful impacts of reduced waterflows on the sensitive ecology of the local environment, notably the harm that could be caused to rare and declining species of bryophytes.  The vote to approve the application was close – an 8 to 7 majority – with, notably, five of the six Welsh Government appointees to the Authority’s Board voting against it and the sixth unable to participate in the process.

Cymdeithas Eryri was hugely disappointed by the outcome of the vote – but also had grave concerns about aspects of the decision-making.  This includes ENPA’s failure to explain and apply the requirements of national planning policy (Planning Policy Wales: PPW) regarding the circumstances in which approval for proposals damaging an SSSI can be granted and to satisfy the requirement that there are “wholly exceptional circumstances” for granting permission, as also set out in PPW.

As a result, in the weeks immediately following the vote, Cymdeithas Eryri and our supporters took time to seek legal advice and carefully consider our options, with the only recourse being to apply to the High Court for a Judicial Review of ENPA’s grant of planning permission.  Ultimately, we finally decided that we had no choice.  This was a fight too important not to take further.

Our legal team filed a claim for judicial review on 26 August 2026.  The Cardiff Administrative Court issued the sealed claim form on 8 September 2026 and the claim has been formally served on the parties.  A decision on whether we have permission to proceed to a full hearing is likely to be made before the end of 2026 with a final decision unlikely until mid/late 2027.

Cymdeithas Eryri have launched a campaign to help fund the legal costs associated with this Judicial Review – costs that are likely to amount to over £60,000 – and have already secured a pledge of £7,500.  Supporters are invited to visit www.justgiving.com/campaign/cwm-cynfal and give what they feel they can, with the Society’s grateful thanks for anything received.

Graeme Cotterill, Director of Cymdeithas Eryri, said: “Taking this step is unprecedented for Cymdeithas Eryri.  In our 60-year history, we have engaged with countless Eryri National Park Authority planning decisions – but this is the first time we’ve legally challenged one.  Whilst our close working relationship with the Authority in recent years benefits everybody and we intend it to continue, it is important that we challenge decisions that we and our supporters feel are not made in the Park’s best interest.”

Cymdeithas Eryri is represented by Ricardo Gama, Carol Day, Lily Hartley-Matthews and Romany Kisbee-Batho of Leigh Day.

Lily Hartley-Mathews, solicitor, said: “The fact that Cymdeithas Eyri has taken this unprecedented step demonstrates how seriously it views this decision. This case concerns one of the most iconic waterfalls in Wales and a landscape afforded some of the highest levels of environmental protection available. At its heart, the claim is about ensuring that this decision to approve major development in Eryri National Park has been taken lawfully and in accordance with the national and local planning policies intended to protect places of such significance.”