There are some environmental issues that make you feel a bit like Bill Murray in Groundhog Day.  Now I accept I am not as funny as Bill Murray but the current debate about another barrage in the Severn Estuary does have remarkable similarities to the debate in which I took part  between 2006-10 and no doubt the one in the 1970s and probably even to those that inspired the famous Thomas Fulljames painting of 1849.

The attraction is obvious.  The estuary has the second largest tidal range in the world and the Severn Bore has been known to travel 14km inland.  It is not surprising that many have been obsessed with harnessing the power of the Severn to generate large quantities of renewable electricity.

In those dim and distant days of the Naughties, a consortium argued that they had the solution to harnessing the considerable tidal power of the Severn at a cost that could form part of a financially viable plan for renewable energy.  The now defunct Sustainable Development Commission scoped this further concluding that the project was necessary only if the project was publicly led and publicly funded.  It also concluded that a barrage would effectively destroy the estuary.

The then Energy Secretary, John Hutton, decided that the energy potential was sufficient justification for initiating a two year £9m scoping study to pose the question as to whether there was a Severn tidal power project that the Government could support and under what terms.

The debate continued during Ed Miliband's time as Energy Secretary before Chris Huhne as part of the new coalition government concluded that there was no strategic case for supporting a tidal power project.  He said in 2010 that unless or until the strategic case changed (particular in terms of cost or renewable energy needed) that the government would not reconsider supporting a proposal and certainly not in the life of this parliament.  Oh and the environmental assessment suggested that a traditional barrage from Cardiff to Weston Super Mare would cause the loss of up to half of the entire intertidal habitat in the Severn Estuary, and increase flood risk to over 45,000 residential properties. It would also reduce the populations of up to 30 bird species, and severely affect fish populations with local extinctions and population collapses.   

And now? Well a new proposal has emerged.  It has a big political supporter in Peter Hain MP and is currently subject to an inquiry by the Energy and Climate Change Select Committee.  We give evidence to this inquiry today alongside the Angling Trust, National Trust and Wildfowl and Wetlands Trust.  You can read the written submissions by RSPB and others here.

I am slightly surprised to find ourselves discussing yet another proposal for a Cardiff to Weston barrage so soon after the Decc study completed particularly as I gather that the consortium backing it would require significant financial guarantees from government.  Hafren Power has come forward with a new £25 billion scheme on the same alignment as the Cardiff-Weston barrage considered as part of the Government’s 2010 Feasibility Study, and claims that the new proposal would be less damaging. 

To date, there is no detailed information to allow the RSPB – or anybody else – to assess the extent to which these claims are valid, but the RSPB is deeply sceptical that any shore-to shore barrage on the scale of that envisaged can be delivered without significant damage to the estuary, its wildlife and heritage, and the tourism, recreational and commercial activity that this supports.  I would like to be wrong as we need benign forms of clean electricity.  But experience of putting big structures in analogous estuaries (such as the Eastern Scheldt) makes it extremely unlikely that engineers are able to prevent serious environmental harm when erecting major structures in highly energetic estuaries.

In addition to giving evidence at the inquiry, and following a meeting with both Peter Hain MP and Hafren Power in October 2012, a coalition of NGOs including the RSPB, has sent a direct response to Hafren Power setting out our key concerns about the scheme and the challenges it poses.

In our letter we emphasise that we support the deployment of renewable energy as an essential element of the steps required to decarbonise the UK economy, and genuinely acknowledge the potential of the Severn Estuary for renewable energy generation. However, we also stress the international importance of this unique ecosystem, and that unacceptable impacts on the estuary and its wildlife can and should be avoided.

The 2010 Government feasibility study found that there are a range of promising innovative renewable energy technologies that could be used in the Severn with potentially fewer environmental impacts.  It was frustrating that support for such schemes died the day that the Decc study closed.  However, ideas about how to harness power from the Severn while reducing risks to the environment and to other uses of the estuary have since continued to develop - a partnership of organisations in the South West recently published this report for example – but they need more support.

The RSPB is keen to work with other stakeholders around the Severn to develop a more compelling vision for the future of the estuary that both secures renewable power generation AND safeguards its status as an internationally important estuary system. 

Shore-to-shore barrage proposals entail huge costs, huge risks and huge environmental impacts - we think its time to put our collective effort behind achieving a positive future for the Severn, and focussing on how to achieve delivery of the maximum capacity of renewable energy for the minimum impact on the natural environment.

And if in the current episode of Groundhog Day, the current Energy Secretary gets excited about the prospect of lots of clean electricity from the Severn, then I hope that he builds on what we have learnt from the various debates to date.  He should give a clear signal that he will support the project that delivers the maximum renewable electricity with minimal harm to the natural environment at a cost that the taxpayer can afford.

Do you think we should be seeking to harness the tidal power of the Severn and if so how?

It would be great to hear your views.

  • What shocked me if I remember it right was that this barrage would produce the magnificent?? sum of 5% of our electricity= to 3,000 wind turbines.So does that mean to rely on wind turbines completely even on the good days we would need a mere 60,000 of them.

    Come on get real we need as our main source of energy a combination of Nuclear,Gas,oil and coal with the fringe coming from renewables until someone squares the circle.

  • "It also concluded that a barrage would effectively destroy the estuary".   To see a comment like this frightens me silly.  

    I do have to declare a personal interest in that as I grew up I spent a lot of days watching the Severn estuary, walking and fishing the edge of it and using the banks as a playground.   Taking my grandchildren back to stand at Lydney Harbour just reminds me how much this estuary impacts on and controls the area surrounding it.   To alter the natural tidal network is bound to affect the surrounding land and streams and rivers running into it; let alone the economic activities of the people and businesses that border it.

    I can understand that this is a vast energy resource that can be tapped but only if it is cost effective and does not impact on the whole estuary.  Surely there are wave and tidal turbines that can be used without the excess impact of this structure.

  • Mmm; well after two generations of debate  that I am aware of , not a single watt of power is being generated from a globally significant tidal resource. Martin you claim that further work is required on the alternatives but that you fail to identify ie how much cost, how much less it will generate and from where and how much of the intertidal resource it will use ? Lagoons are very large structures indeed..........

    Also I have seen one paper so far identifying sea level rises of 4-6 metres in the next 100 years without including increases due methane release or other feedback loops ie loss of arctic reflectivity; so whats the cost of 10 metre flood defences on the equivalent barrage area; what's the cost of this interminable delay and what is the alternative are you proposing ? Which lagoons and reefs and where and whats the flood defence impact at worst case scenarios ie 6-10 metres plus sea level rise?

  • I think we should be harnessing the tidal energy on the Severn and I am appalled by the re-appearance of the total barrage scheme which comes straight out of the 1960s. The Government's generous award of £500,000 for research into alternatives last time round summed the whole thing up for me: sounds a lot, but it was just 1: 40,000th of the proposed spend on a complete barrage.

    There is a deep and serious underlying problem here spreading across much of RSPB's work and un-joined up Government and severely undermining the 'greening' of the economy: single minded projects, usually led by engineers, that completely fail to take into account anything but the proponents narrow view of the world. The wind farm proposals I've been involved in focussed entirely on the narrow technicalities of grid connections, wind speeds etc and saw the planning process and public concerns as a peripheral to be blasted through by paying ecological and planning consultants. It hasn't worked and just like with upland conifer forestry, the resistance to onshore wind has gone beyond the point of recovery however sensitive any new plans might be to people's concerns.

    Its the same with biomass - the emergence of lunatic proposals to ship wood from north america to the UK to fuel our power stations while the Americans power ahead with fracking and tar sands to meet their own needs, whilst we are all forced to support rainforest destruction every time we fill our cars because of the disastrously well intentioned 5% bio-fuel required by the EU, and being supplied from tropical palm oil plantations.

    What is hugely important here is that, contrary to the norm, everyone is losing - brutal proposals like the barrage are costing the proposers huge amounts of money, they are costing all us RSPB members huge amounts of money - and I will be contributing to your appeal to fight the barrage when it pops through my letterbox - and the engineers aren't getting to build their wind turbines, new docks (Dibden Bay) and hopefully tidal barrages and mud flat airports. A rethink needed perhaps ?