Pont Cyfyng Hydro on the Afon Llugwy

February 5, 2019
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A planning application has been submitted for the hydro electric development of Pont Cyfyng Falls on the Afon Llugwy in Capel Curig Snowdonia. This is likely to be the largest scale and possibly most damaging HEP applied for in Snowdonia since the plans to dam the Afon Conwy were rejected in 2016.

Full planning application


The application is deliberately vague and misleading in many aspects, but this is what we know so far:

The location

The development is based in a National Park, will sit in an area of woodland registered as ASNW (Ancient Semi Natural Woodland) and lies shortly upstream of a SSSI. The site sits in the heart of Capel Curig village, a hotspot for outdoor tourism containing numerous pubs, cafes, hostels and the National Mountain Training Centre at Plas y Brenin. Capel Curig is popular for the beautiful free flowing Afon Llugwy and as the access to rugged peak of Moel Siabod.

The proposal

The plan is to divert a large proportion of the river into a new channel, pass it through a 2m diameter 100m long tunnel dug by a 10-ton tunnel borer under the historic Telford road bridge. Then through a large diameter pipe to the turbine house to be built downstream on river right, between the second and third falls, where the outflow will fall into a newly excavated "plunge pool".

Many of the impacts of the scheme are un-quantifiable due to the poor quality of information provided in the application. There is no assessment of traffic impacts, effects on the footpath along the river, the timescale of construction or the size and location of construction compounds. Here is what we can work out.

Impact on Ancient Woodland

The Arboricultural report lists 87 trees in the vicinity of the development, 31 are listed to be felled, over a third. Some of these trees are suffering from Ash die back, but many are not (because they aren’t Ash trees), in any case Ash die back would not have the impact of removing all the trees in a single event.

Arboricultural report

Amount of water to be removed

The HEP will remove 70% of the river above a tiny compensation flow, up to a maximum of 4.2m3/s  (this will occur when the flow of the river reaches 6 m3/s). Using flow data from CEH (Centre for Ecology and Hydrology) we can therefore calculate that 70% of the flow will be diverted around the falls for over 75% of the year, and over 85% of the time during the summer months.

This will have 2 major impacts, firstly the dewatering of Pont Cyfyng will have a profound effect of the beauty of the falls, a major tourist draw; visible from the A5, a view point layby and the popular footpath up Moel Siabod. Secondly the ecological impact of this “depleted reach” on the bryophyte assemblages and other flora and fauna of this section is not to be underestimated. The ecological survey presented by the developer states:

One must bear in mind also that only a very small proportion of this large river will be abstracted so it is considered that any potential impact on the in stream ecology is likely to be extremely modest.

Ecological report

It can be seen from the calculations above this is simply not true. The abstraction is for the vast majority of the river to be abstracted for the vast majority of the time.


Impact of built structures on the landscape

The inlet structure to be situated on the river right bank above the falls will be huge. A 2m by 15m metal grill in full view of river users, walkers on the footpath along the river and travellers on the A5 and Telford bridge. The turbine house will be situated on the wild river bank between the second and third fall, visible from the A5 the Telford bridge and the viewpoint layby. Neither structure has a photomontage, artist impression or even detailed plan drawing to show how it will fit into the landscape.

The photo below shows the shear scale of this development compared to the site:

How much power will be produced?

The power produced is very limited compared to modern renewable production, this is one of the reasons the FIT payment subsidy this scheme will rely on to be profitable is being cancelled this year. The installed capacity of the scheme is around 400KW, roughly 1/10th of a single wind turbine of the type installed off Llandudno, or 1/20th of the new generation of one of the new wind turbines at Burbo Bank Liverpool. Whilst the application boasts that power produced will be:

the equivalent required to supply 21% of the homes and businesses per year with electricity in Betws y Coed and Capel Curig, or 71% of those in Capel Curig only.

Design and access statement

It is important to look at this more closely, the population of Capel Curig is 226 permanent residents. However the 400kw produced during the 25% of the year the scheme reaches full power is only enough for 40 people to take a shower.


Save Our Rivers believes the scale of this scheme and the impact it will have on the Afon Llugwy and its surrounding Ancient Woodland. Along with the social and economic impact it will have on the tourism dependant community of Capel Curig is disproportional to the extremely limited impact it will have on combating climate change.

On a more basic level Save Our Rivers believes the free flowing rivers and falls of our National Park are worth far more in their natural state than when diverted and dammed to make kilowatts and pounds.

We urge everyone to attend the public meeting on Friday 8th Feb at 7.00pm Capel Curig Community Centre and raise their concerns with the developer there.

Details on how to respond to the planning application will provided when we have more information.


The proposed inlet and defunct leat, including the ancient woodland adjactent to the Afon Llugwy.


Tagged: Hydro · Llugwy · Pont Cyfyng · Save Our Rivers
Mike Lees
Is this scheme going ahead – if so we need to start planning now to make it uneconomic!!
David masding
Please keep mea informed
This should never be allowed to happen , disgraceful .
Louise Harvey
When and where is the meeting on Friday? Thanks, I’m interested in finding out more.
Nick Corney
No no, this poor old river has been subject to several miscalculated schemes over the many years. I have known and lived by this beautiful river for 52 years. Due to these erroneous schemes the river now rises far to quickly and in turn drops alarmingly quickly and way below the level that it did 20/30 years ago. These changes have had a terrible impact on its eco system. Leave it alone and NRW remember that ‘natural resources’ also must prioritise the preservation of the environment and its many eco systems. Just say no to any abstraction licence and by doing so you wont waste your time or ours!!
Margery Hall
Is there an online petition please ?
Charlie Jenkinson
This development is not of sufficient economic value compared to the significant environmental impact.
Kathy Morton
dreadful. expected a petition at the end of this. Amy plans?
Anna Heyworth
This cannot happen.
We have little enough ancient natural woodland left in this country – we should not be considering losing any more of it for any reason. I am against this proposal. Pauline Greenhalgh
jan lewis
What are the red & blue lines ?
could do with explaining.
Tom Laws
Hi Jan,
Sorry, only just found your comment, it seems the Spam filter is working overtime. The full plans are on the planning application, the red is the border of the site that will be built at the inlet, blue is the river.
How do I protest?
Helen Berry
Plan to be at the public meeting on Friday night. This MUST be stopped. Thanks for your work.
Hugh Foreman
I am fully against such a visual impact within the Snowdonia National Park and an area of outstanding beauty. I understand we need electricity but this is to damage and a cost to this raw part of the environment is unacceptable. To construct will cause so much environmental damage that it could not be repaired or put right in a person’s lifetime. I hope sense is found and this proposal is completely rejected.
John Hall
We must not let this happen.
Dr Jonathan F Dean
All very interesting but at this scale it really cannot be economic, never mind the environmental impacts
Kevin Evans
Leave nature alone.
John Hall
This would be a great loss of beautiful scenery and habitat and not worth the gain.
I oppose this project completely. John Hall
David Smith
While I applaud efforts to tackle climate change the energy produced by this project in no way compensates for the damage caused to the local environment.
Gareth Williams
Do the maths, it does make sense! 400kW is naff all. What is this nonsense greenwash? Without doing the maths, I would hypothesise that the amount of CO2 emitted to construct this project is unlikely to be recouped during the facility’s operation.
Rhos Quarry Holdings
We arranged an open meeting at the Community Centre from 10am through until 6.30pm on Friday to accommodate those people not able to attend an evening meeting .
All of the information surrounding the scheme will be available to view (including large scale drawings) and the people involved will also be present to answer questions. You might find it useful to check things over prior to your 7.00pm public meeting and it would also be an opportunity for you to put your point of view across to those people not able to attend your evening session.
Reading through the above, the negatives with this scheme appear to outweigh the positives.
The Arboreal Report is comprehensive, but they should learn to spellcheck, especially when they fail to spell the name of a tree correctly when it is a report about trees!
Many of the trees are colonisers, and the Ash are suffering from disease, so these on their own would unlikely be grounds to prevent the work. I would be interested to read the Ecological Report, but the link is broken.
Sonia Goulding
Thank you for bringing this to our attention. I belong to a Facebook group called Britain’s Ancient and Sacred Trees, so I’ll share your post there, too.
Mike Hammill
The amount of power promised is insignificant compared to the environmental and visual damage involved. The recently completed hydro schemes in the treeless upland areas up valley from Llanberis have now largely faded into the hillsides and seem to be far better. The scheme would involve a considerable amount of destruction to the local transport network in order to allow access by the machinery needed. If we get a say I would vote against it.
Mike Hammill
Cris Martindale
I will be going to the meeting.
No one has any right over this area it is nature and there for us and the future generations to enjoy……..this is just an early April fool……!!
Marie-Louise Kellett
Those of us who understand the value of free flowing rivers need to support each other. Please let me know how we can lodgr an objection.
From #SaveTheZambezi
Lyn Jack
This plan is sacrilege it cannot go ahead surely? So much damage for so little return.
paul southgate
There is no justification for destroying this beautiful river !The benefits are minimal, the deficits enormous.Hands off! From an English visitor who is appalled at this threat.
John Quayle
This is an horrific proposal purely in the name of greed. Please keep me updated so I can voice my formal objections.
Shan Ashton
Thank you for this. My terraced house sits above the proposed turbine house – 45 foot long and 10/12 foot high. It will be about 50 foot from my front door. On advice from an independent engineer, it has been suggested that though the turbines themselves will be realitely quiet, as they will be built on a steel framed structure, vibrations will, without doubt, create a permanent loud humming noise. I know the land here well and how on earth they will fit a 45 foot building here without major destruction is beyond me. The land leading to it is steep and uneven, the shore made up of narrow, undulating rock ridges. The space is tight. The destruction of the trees is beyond belief. The hazels are of a large size and old, the oaks are home to a host of nature, To build this turbine house, a new track will be brought in from the ‘old’ road and storage facilities for all the building and engineering work built on the riverbank. The land is often waterlogged, it will require serious track building to avoid flooding and sinking. The works will cross close by the lower remains of the old Rhos Quarry adit, directly in front of the various homes above the river. The ecological report suggests this is a an ‘empty’ place fauna wise – I counteract that with sightings of water voles, otters, grass snakes, slow worms, nesting herons, varieties of ducks, dippers, tree creepers, woodpeckers, pipistrelle bats (live in my shed roof) , owls and more! I have been told there are fresh water crayfish but also been told it’s too acidic for them – worth checking out though. I am not an expert on flora but am very aware of the carpets of lichens and mosses on the trees and rocks around. The immediate area is not highly grazed – spring lambing time being the busiest. The numbers are low as there is good grazing further downstream.
The old road, from the south side of the Ugly House bridge, will be one of the acces points for the works, it may require the widening of the road. This road crosses the site of a Roman marching camp, it is the emergency road used when the A5 is closed by an accident, it is a key part of the lower level footpath network for walkers and also the road from which Siabod is accessed – in terms of hillwalking and farming access it is essential. It is also essential re access for the 20 families that live here – acces to work and school on a daily basis. This whole stretch of river has high amenity standing and is used by wild swimmers, canoeists and is visible for walkers and general tourists.
Given the production statistics mentioned above it does not hold the promise of efficiency when compared with other renewable schemes.
Shan Ashton
Claire Cheong-Leen
Thank you for posting this up and for making me aware of the meeting on Friday. I Plan to attend.
This is beyond comprehension and frankly must never reach the table, another money grabbing scheme which is just unbelievable. This small area is one of the delights of Snowdonia and once it’s changed its changed forever. If the SNPA, NRW don’t stop this in its tracks then we must fight to make sure it never ever goes ahead, is there no shame in the mind of the proposer who are willing to allow this to happen.

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