Pontardawe and Swansea Angling Society

© 2009-17

Tidal Lagoon proposed for Swansea Bay

Tidal Lagoon (Swansea Bay) plc (TLSB) want to build a lagoon in Swansea Bay to generate power from the tides, as shown in the plan alongside and on their website…

This is a huge scheme with a wall length of 9.5km, 16 turbines with 7m diameter blades, costing at least £850 million. If approved, it will sit between the Tawe and the Neath. The developers want to start construction in 2015.

We are against the proposal because we believe it’s likely to interfere with migrations of salmon and sea trout to and from our rivers and harm our salmon and sea trout fisheries. We are opposing it in conjunction with other local clubs, the Angling Trust (AT) and Fish Legal (FL).


Click on the plan for a larger version.


13 July 2017

The proposals and impacts

The proposals (and the impacts forecast by the developer) are set out in detail in their application for consent here…

The application consists of almost 400 documents amounting apparently to about 5,000 pages. An overall description can be seen in the 41-page “Non-Technical Summary” here…

The environmental impact assessment alone consists of over 200 documents, covering such topics as:

Obviously we are mainly concerned with the effects on salmon and sea trout but many other people, including Natural Resources Wales and other reputable bodies, are concerned about other impacts, as shown in their initial “Relevant Representation” here…

Our concerns

Our main concerns are that salmon and sea trout will be harmed as a result of:

These are the concerns that occurred to us as soon as we started studying the proposals - not as scientists but as fishermen who understand fish and their environment.

We’ve been in this situation before - with the Tawe Barrage in the 1980s. When we opposed that development in Parliament, we set out our concerns in petitions to the Houses of Lords and Commons (the petition to the Lords can be seen here… ) and everything that we predicted then has come to pass, despite the infuriating assurances of the developer and their highly-paid consultants. We referred in our petition to “any or all of these effects and possibly others unforeseen” but were still amazed, after all the thought and talk beforehand, to find when it was commissioned that the barrage created a wholly unnatural and harmful “upstream waterfall” on an incoming tide, which no-one had predicted and which creates intolerable conditions for incoming fish.

So we have every reason to be sceptical about the effects of this scheme and to mistrust the assurances of the developer and their expert advisers.



What are we doing about it?

It’s a big job but we are trying, together with other local clubs and with the invaluable support and guidance of Fish Legal and the Angling Trust, to ensure that our concerns are taken fully into account.

The  planning consent procedures and the actions we have taken are set out in detail on a separate pages. Follow the links at the top of the page.



Independent expert review commissioned by us

Having seen the first draft of the Environment Statement, we came to the conclusion that we needed independent expert fisheries assistance with the assessment of the proposals. Fish Legal commissioned a review by APEM Ltd (paid for by three local clubs, Angling Trust and Fish Legal). Received in February 2014 it supported our view that the TLSB environmental impact assessment was flawed and understated the likely harm to salmon and sea trout. The report is here…



What do others think?

We are not the only ones to have concerns about the proposal. Scrutiny of initial representations published on the Planning Inspectorate website here…  shows that there are significant objections from a wide range of organisations, including particularly Natural Resources Wales (No 220).

As the examination of the proposal has progressed, many further representations have been made. We’ve drawn attention to some significant ones on the pages dealing with the applications for consent. Follow the links at the top of the page.




Flows

(Drawings and extracts are from the developer’s consent application).

The current flow regime in Swansea Bay is generally anti-clockwise, as shown in this extract from  figure 6.40, full version here (PDF 1.2MB)…

The effects of the scheme are illustrated in this extract from figure 6.41, full version here (PDF 1.2MB)…

Differences in mean current speeds with the scheme in place are shown in these extracts from figure 6.33 (metres per second), full version here (PDF 250KB)…  

and figure 6.34 (%), full version here (PDF 250KB)…

Maximum flows of up to 6,000 cubic metres per second are shown in figure 6.38 here (PDF 306KB)…

The biggest flow ever recorded in the River Tawe (a 1 in 200 year flood in December 1979) was 400 cubic metres per second.

Fish are likely to be repelled by strong flows on an ebbing tide and drawn to the turbines by strong flows on an incoming tide.

Turbine encounters

We are worried that salmon and sea trout (smolts, returning adults and kelts) will be drawn into the massive turbines and killed or trapped in the lagoon.

The proposed turbines are to be 7 metres in diameter, with three blades rotating at about 60 rpm. That’s 3 blades a second past any particular point. The layout is shown in this extract from figure 9.22, full version on page 9-64 of the Environmental Statement here (PDF 5.8MB)

Click for larger version

We find it highly likely that fish will be drawn into these turbines and unlikely that they’ll survive such passage. The TLSB environmental impact, however, suggests the opposite - that encounters are likely to be low and that survival rates are likely to be high. See chapter 9 of the Environmental Statement here (PDF 5.8MB)…

The TLSB view is based on theoretical modelling described in Appendices to the Environmental Statement:

and a plan to incorporate acoustic deterrent devices to keep fish away from the turbines!

We think the modelling is flawed in various ways and fails to set out “worst case” effects, eg:

Illustrations of the turbine encounter modelling can be seen here…  This is an extract from the one for adult salmon, which might look impressive if you know nothing about the way these fish behave.

It assumes that all returning salmon approach from the west, that they make straight for the river mouth, that having found it they carry on upstream regardless of river conditions and don’t drop back into the Bay, all of which we know to be wrong, even without allowing for the effects of the Tawe Barrage..

For salmon and sea trout look at these:

Without the lagoon: salmon smolt… adult salmon… sea trout smolt… adult sea trout…

With the lagoon: salmon smolt… adult salmon… sea trout smolt… adult sea trout…

Nothing there for kelts, despite their importance, particularly in the case of sea trout.

Overview of the project and our concerns - this page

Details of the consents required here…

Progress of the Development Consent application and our involvement here…

Links to development consent documents here…

Progress of the Marine Licence application and our involvement here…