Time for Action: Tidal Lagoon

Severn Estuary - karen lloyd

Severn Estuary – karen lloyd

Do you share our concerns about the impact on wildlife of tidal lagoons? The local elections on 4th May are a good opportunity to make your voice heard!

The Wildlife Trust of South and West Wales support the UK’s current targets to reduce greenhouse gas emissions and increase the proportion of overall energy generated from alternative sources.  Our mantra is ‘right technology, right place’.  The enormous scale of tidal lagoons mean that they could have a major impact on biodiversity.  The State of Nature report showed 60% of our wildlife is in decline and it would be perverse to allow the development of renewable energy at the expense of our natural environment.

We are talking to AMs, MPs and the Welsh Government about our concerns.  However, the message given out by politicians, business supporters and the media is that there is overwhelming support for a tidal lagoon in Swansea Bay (and other, much larger lagoons along the Severn).  If you share our concerns, we urgently need your help to strengthen our voice. Politicians and Councillors care about your views.  You are their constituents and they are elected by you to represent your views.

Read more about our concerns and how you can help:


With climate change a reality, the drive to produce energy from alternative sources has never been greater, and new technologies open up new possibilities.  The enormous tidal range of the Severn Estuary attracts a great deal of interest.

Tidal Lagoon Power (TLP) has built up a great deal of political and business support for their plans for a tidal lagoon at Swansea Bay, which was granted development consent in 2015.  The decision about how to proceed with Swansea is vital because TLP have ambitious plans to develop much larger tidal lagoons in locations such as Cardiff and Newport, that would directly impact on areas designated for internationally important protected species and habitats.

In response to the TLP’s proposals, the UK government commissioned an independent review, led by Charles Hendry, focusing on the economic feasibility and practicality of tidal lagoon energy in the UK.  The report concluded that tidal lagoon energy could have a part to play in the UK’s future energy supply.  The report made a number of recommendations about how to proceed.  This included treating Swansea lagoon as a ‘pathfinder project’.   Hendry recommended a pause after Swansea tidal lagoon starts operating, in order to learn about the efficiency of the technology and the environmental impacts, before further lagoons are built.  However, the length of this pause was never clarified.  We think it should be 10 years, to cover two, full, fish-spawning cycles.  Any less and the monitoring of impacts would not be meaningful.

Cause for concern?

We submitted a written representation to the Public Inquiry in which we raised a number of concerns:

  1. Loss of intertidal habitat
    The development will lead to a loss of intertidal habitat, specifically having an adverse impact on the protected features Sabellaria reefs, hydroid rockpools and intertidal mudflat and sandflat.  TLP are using an innovative design on the lagoon wall to create artificial rocky reef-style habitat, but obviously this creates a new habitat type, and does not mitigate for the habitat lost.  We didn’t feel sufficient mitigation for lost habitats had been proposed.  Sabellaria reefs are to be translocated, but the results are unproven and therefore need monitoring in the long-term.  Related to the loss of mudflat and sandflat habitat is the impact this may have on birds which forage there. There may be a temporal increase in foraging opportunities due to tidal lag and artificial lighting, but there is no indication as to whether this is adequate to mitigate for the spatial loss of foraging opportunities.TLP will be creating 5ha saltmarsh, 3ha coastal maritime grassland and 5.5ha sand dunes, which is a good enhancement, but again doesn’t mitigate for the habitat that will be lost, because it is a different type of habitat.
  2. Impact on subtidal ecology and related species eg Great Crested Grebe 
    We have concerns as to loss of the subtidal sands and gravels (protected features), assessed as a ‘ major adverse significant impact’.  With the new-style rocky reef habitat on the lagoon wall, there is also no indication of whether the resulting change in biodiversity, through colonisation of the seawall, will have impacts on the natural assemblages in the area. 
    In particular this has consequences for the suitability of the area as herring spawning habitat and potential impact on the foraging opportunities for nationally important numbers of Great Crested Grebe (GCB), should mitigation not prove successful.  Monthly winter counts from Swansea Bay over the last 4 years shows a maximum number of 569 GCB in December 2016.  This puts Swansea Bay in the top 20 sites for wintering Great Crested Grebes in the UK (source – British Trust for Ornithology BTO).Again, mitigation relies on an unproven practice of introducing new spawning material via the rocky reef walls.  Also, no detail was given as to what this new ‘spawning material’ would actually be and any potential impacts.
  3. Invasive non native species 
    Whilst there is understanding of the current non native species whose introduction into the bay may be facilitated by the seawall, it cannot be predicted what new species may be a threat in the future – another reason that long-term monitoring is essential.
  4. Impact on designated sites 
    We have ongoing concerns as to the moderate/minor adverse significant impact predicted on the sand habitat of the Blackpill SSSI, especially related to the reduction in sand accretion and the impact this may have on ringed plover and sanderling.  There will be some monitoring, but no mitigation proposed, other than the consideration of potential beach replenishment. 
    We had concerns about cabling through Crymlyn Burrows SSSI, but the plans changed so that the cabling would run beside the road instead.
  5. Impact on marine mammals 
    We were disappointed as to the lack of site specific marine mammal surveys and the consequences this has on the robustness of the assessment of impacts, especially given the regularity of harbour porpoise sightings in the bay and likely hotspot around Mumbles.   Additional noise in the marine environment (during construction and operation of the tidal lagoon) can interfere with communication between marine mammals and alter migration patterns of potential prey species ultimately leading to evasive behaviour or displacement. 
    Our concerns helped to encourage TLP to plan the use of installation methods which will produce the least amount of underwater noise, and to opt for variable speed turbines which reduces the risk of fish mortality by around 11%.

Since we input to the planning inquiry, our concerns have grown:

Impact on fish.
In a briefing for Local Fisheries Groups published by Natural Resources Wales in February 2017, they stated that Salmon stock levels in Wales are considerably below the level considered to be sustainable, and that some sea trout stocks are similarly low and in an unsustainable condition.  Their evidence shows that numbers of returning adult fish are at historic lows, and that there is a significant and worrying reduction in the number of young fish in our streams.

The briefing note can be read here:
NRW Briefing for Local Fishery Groups

When Natural Resources Wales reviewed the information about the potential impacts of the tidal lagoon in Swansea Bay, they concluded that it could have a 'major adverse effect' on migratory fish due to injury as they pass through the turbines.   NRW estimates that 21% of salmon and 25% of sea trout, species of national importance, could be killed every year as they migrate to and from local rivers, mainly the Tawe, Neath and Afan.  These estimates are far higher than the numbers provided by Tidal Lagoon Power.  TLP has consistently claimed that the impact on fisheries would be minor.

Smaller impacts are predicted on other migratory fish species but since these include shad, lamprey and eel which are deemed of international importance, these are also classed as “major adverse effects” by NRW.

The Hendry review provides only a partial answer to the energy question on the Severn Estuary, focusing on the economic viability of tidal lagoon power.  We expect the environmental impacts to be fully accounted for these projects.  Alternative ways to harness wave power should also be considered, which may have less impact on the environment we are trying to protect.

What happens next?

We are still awaiting the Government’s response to the Hendry Review, to see whether or not they agree that the scheme presents good value for money.  The scheme is estimated to cost around £1.3 billion, and the Government will also look at the cost of the energy produced.  The Government then need to agree a subsidy support level (also called ‘strike price’) through a Contract for Difference (CfD).  CfD agreements are the financial mechanism through which the UK government is financing the construction of new power generation capacity in the UK. In order to make the energy generated by tidal lagoons affordable, TLP are asking for this contract to extend over 90 years, a much longer time period than usual.

NRW needs to issue a Marine Licence, for which it will need to consider the potential impacts described above.

TLP need to negotiate a lease for the sea-bed from the Crown Estate

Neath Port Talbot and Swansea Councils need to consider those elements of the development that would be built on or affect the land, including buildings, transport of materials and laying cables.

Despite this complex and extended process, the Welsh Government, MPs, Welsh Assembly Members, financial backers of the lagoon and many businesses are pushing for quick decisions, financial backing and full support from all agencies involved.  Those that support the scheme like the fact that this is a large infrastructure project, because any large infrastructure project can create jobs.  They also like the fact that as the technology is relatively new, there are opportunities for it to be exported.  Also, and more worryingly, the development is being labelled as ‘green’ because it is harnessing alternative energy (whilst ignoring the impacts on biodiversity). You can read our thoughts on some of these claims in the Tidal Lagoons top 10 Q and A.

How you can help

The Wildlife Trust of South and West Wales are talking to AMs, MPs and the Welsh Government about our concerns.  However, the message given out by politicians, business supporters and the media is that there is overwhelming support for a tidal lagoon in Swansea Bay, so we need your help to strengthen our voice.   Politicians and Councillors care about your views.  You are their constituents and they are elected by you to represent your views.  If, like us, you have concerns about the environmental impact of a tidal lagoon in Swansea Bay, it is crucial that you make your concerns known to the politicians and Councillors who represent you.
If you live in Swansea or Neath Port Talbot then there is an important date coming up very soon!  Local elections will be held in Wales on Thursday 4 May 2017 to elect members of all 22 local authorities. The next set of Councillors in Swansea and Neath Port Talbot Councils will be key in the planning decisions affecting Swansea tidal lagoon.  So if you live in one of these two wards, it is important that you make your concerns known to the candidates:

  1. You can write to the candidates who want to be elected to express your concerns, ask them what their position is on the tidal lagoon and make it clear that their answer will affect your vote.
  2. You can ask questions of any candidates who are canvassing support where you live (Suggested Q and A's).
  3. You can mention your concerns about the tidal lagoon in surveys that you might be asked to participate in, in the lead up to the local elections.

Wherever you live, you can help by contacting your local AM and MP using the template letters provided below:

Template Advocacy Letter for AMs

Template Advocacy Letter for MPs

When contacting an AM or MP, do personalise your letter and add in one or two questions of your own, so that their reply also has to be personalised. Add your own name and address to the letter so that the AM or MP know that you are in their constituency, otherwise they may not reply to you.