Energy and Climate Change CommitteeWritten evidence submitted by Wildfowl and Wetlands Trust
Executive Summary
1. In 2010 WWT submitted a final response to the DECC consultation on options for a Severn Tidal Power project in the Severn Estuary. This stated that, from the five favoured schemes, the then proposed Cardiff Western Barrage was unacceptable from at least the perspective of its impacts on wildlife. Questions also remained regarding the suitability of some of the other schemes proposed at the time (the two other barrages, and the two lagoon options). We supported the view that there was no case for Government investing in a scheme at that time and that it was appropriate to wait until 2015 to review the situation. We welcomed the prospect of a future review which could incorporate further analysis of, in particular, more innovative and potentially less environmentally damaging schemes such as those considered through the Severn Embryonic Technology schemes (SETs). We remain supportive of the search for renewable energy schemes within the estuary and agree that the location lends itself to the search.
2. Many issues, some of which remain unresolved, were raised regarding the acceptability of a large Cardiff-Western scheme; the unpopular prospect of Government being required to provide financial support for such a scheme was just one of them. As far as we can determine given the information available, very little has changed since the findings of the previous feasibility study. We have not yet had sufficient insight into the apparently reconfigured scheme design to reasonably comment on whether it has dealt with any of the previously identified barriers. We do not therefore propose to speculate as to the merits or otherwise of this new scheme. However, we have provided some initial comments based on information gleaned from meetings with the company.
3. We recommend that the impacts of the current proposal be properly and independently assessed before Government takes any decisions or promotes or supports the scheme in any way. We believe that a framework is required that requires that environmental damage is reduced as far as possible; prioritises schemes whose environmental impacts can be mitigated for in a clear and appropriate way; duly considers all possible options. It is important that this is allowed to happen at a suitable time according to the “triggers” associated with reviewing the situation, as detailed in the STPF study.
Communications
4. As far as we can ascertain, there is no clear “communication plan” relating to the current proposal. We consider it important that engagement and communication extend as soon as possible to the broader community, especially the residents and businesses who live around the estuary and are most likely to be directly impacted by such a scheme. The company’s website provides insufficient detailed information to fully inform views on the proposal and the Government/DECC website, which formerly hosted the detailed outputs from the STPF study, is no longer functioning. We have been unable to find sufficient detail of the current proposal, eg specific landing sites and exact turbine design.
5. We believe that balanced and informed decision making requires that the full range of options that could be deployed within the estuary be considered simultaneously. All of their associated impacts should be clarified, and communicated clearly to all stakeholders including the general public. Once the detail of the current proposal has been independently assessed, it should then be presented and evaluated alongside other emerging technologies and energy management options. It appears that the current proposal is being presented as the only viable and feasible option on offer, and we disagree with this approach.
We also have some concerns regarding the detail of how the current proposal is being communicated. For example:
“Fish friendly”. While there are many promising technological advances with regards to turbine designs that reduce fish mortality, especially those now being deployed throughout rivers in the United States, we have yet to see any evidence that merits the liberal use of this term in relation to this scheme. Such turbines have yet to be tested or deployed in the UK, or tested in environments as extreme as the conditions found within the Severn Estuary, or on a range of species and life stages such as those found within the Severn Estuary. The use of new designs can only lead to uncertainties relating to power yields and costs of the project. We understand that the new design may have four times as many turbines as previous designs (over 1,000), which again leads us to question how the scheme can be called “fish friendly” without empirical evidence identifying the likely cumulative impacts both direct (eg death through collision with turbine blades and differential water pressures) and indirect (eg increased predation from, for example, seals).
“Environmentally benign”. To merit this statement, it is necessary that the impacts of the scheme can be mitigated and compensated for within the realms of the law, both domestic and international. We agree that the new proposal would likely have fewer impacts on the wildlife of the estuary (in part due to the adoption of an ebb and flow design, and a lower head) than the previously proposed Cardiff Western barrage. However, to claim the scheme to be “environmentally benign” requires confidence that all damage can be adequately and appropriately compensated for. We have seen no evidence of this and until this has been confidently demonstrated we consider this term to be inappropriate and misleading.
“A saviour for the estuaries wildlife”. We are alarmed that claims are being made that a barrage of this nature is required in order to safeguard the wildlife of the estuary in light of sea level rise. Were the natural processes associated with the Severn Estuary disrupted by a large barrage, even if it were in part permeable and allowing ebb and flow tides, then the outlook of the wildlife it supports would become entirely dependent upon an inflexible and static defence system. We consider that the best long-term prospects for the wildlife for which the estuary is designated require management systems that can be adapted to changing sea level and work with, not against, the natural processes that have resulted in its unique ecology. In addition, although the wildlife complement of the estuary may change somewhat in response to climate change, it may become even more important as a refuge for species that require new climate space, moving on from elsewhere. Additionally, Government is already obliged to compensate for the impacts of climate change on intertidal and coastal habitats and species under the terms of the Birds and Habitats Directive. To this end, the Environment Agency has already delivered a number of compensatory schemes within the estuary (eg the Steart Peninsular Managed Realignment project managed by WWT, which will create 429 ha of habitat of which 324 ha will be intertidal habitat), and is actively looking for other opportunities to offset future losses. By 2025 there will be a loss of 639 ha of internationally designated intertidal habitat, which the Steart Peninsular Project is making the major contribution towards offsetting. A barrage to protect the wildlife is therefore not the answer to this problem. There is legal precedence and a procedure already underway in order to support a more sustainable way of safeguarding the estuaries wildlife. The message that a barrage is needed in order to protect wildlife is particularly confusing and misleading.
“Cost neutral”. The suggestion is that this scheme would be privately funded, and therefore of little burden to UK Government and tax payers. The reality is that a certain amount of financial risk associated with such a project would always need to be underpinned by Government. We know that electricity generation would be expensive from this scheme in comparison to other forms of technology, and that previous estimates of costs have needed to be repeatedly revised upwards. The previous feasibility study only scraped the surface in terms of identifying wider costs (in addition to benefits), and we have seen no evidence as yet of how these further impacts would be ameliorated, or whether the costs will also be covered by the private finances. There needs to be a full and transparent evaluation of costs before this or any scheme can be communicated as cost neutral.
Implications for Wildlife
6. The predicted impacts of a Cardiff-Western barrage on the wildlife and ecosystem of the Severn Estuary were immense compared with previous development projects in the UK. We appreciate that under the requirements of the Habitats Directive, significant development within a Natura 2000 site can take place under specific circumstances (eg imperative reasons of overriding public interest), but this has to be sustainable development which includes appropriate safeguards and compensation measures. We can only comment in detail in relation to the previous Cardiff-Western scheme design as insufficient information has been provided on the detail of the new scheme. The impacts associated with such a large barrage scheme were multi-faceted:
Drastic reductions in populations of protected wetland birds including: circ 50% reduction in each of Wigeon, Teal, Pintail, Shoveler, Knot, Dunlin, Ruff, Curlew, and Redshank. It is not known how a Cardiff-Western barrage would affect species for which Slimbridge is particularly iconic, the European White-fronted Goose, and the Bewick swan, but impacts have been qualitatively assessed as negative. In total, a large barrage of this kind would adversely impact 30 species of birds. We have seen no evidence that impacts on all affected bird species can be confidently compensated for.
Drastic reductions in the extent of intertidal habitat of around 45% (again, based on the design as promoted in 2008).
Significant impacts on economically and ecologically important fish stocks, some of which are genetically distinct to the region including Salmon and Shad in rivers such as the Wye, Usk, Severn and Taff. It is thought that a Cardiff-Western barrage would totally eliminate populations of Shad. In addition, the Severn Estuary is one of the most important nursery ground for Eels, a species whose population has drastically plummeted of late, and which is now protected via a dedicated EU instrument.
Significant loss of locally important habitats and nationally important biotopes including honey comb worm reefs and piddock-bored bedrock.
Further likely impacts on: 25 Special Areas of Conservation (SACs), 231 Sites of Special Scientific Interest (SSSIs), 5 Ramsar sites, 22 National Nature Reserves (NNRs) and 44 Local Nature Reserves (LNRs) and the potential for impacts on a further 302 rare plant species and 20 mammals were also considered likely under a Cardiff-Western barrage scheme.
7. The reality of mitigating and compensating for the impacts of a Cardiff Western style proposal are compounded by:
The sheer extent of compensation habitat required (over and above that which could be mitigated for within the project design), much of which would inevitably be sought outside of the confines of the Severn Estuary. A compensation ratio has not been suggested for this project, but similar (but much smaller schemes) have been required to deliver between 2.6:1 (Cardiff Bay) and 14.5:1 (TGV schemes in France). The upper figure of likely habitat damage from the previous Cardiff-Western is 163 sq kms.
Functional habitat has to be in place before construction commences. This may take many years to locate and many further to develop into a functional state that target species can make use of. Although compensation habitat might be theoretically available on the east coast, this would not fulfil the same functions as the Severn Estuary.
The inability to compensate for the full range of features found within the estuary, for which it is also designated eg the tidal range itself, and associated mudflat conditions.
The inherent risks involved in delivering large scale compensation habitat, and in predicting the exact consequences of a large scheme on a still poorly understood ecosystem.
The technical complexity involved (extensive land purchase/swaps, likely use of compulsory purchase) with securing appropriate compensatory habitat, and the long-term land management implications associated with delivery.
The need to ensure acceptability of compensation schemes to local stakeholders, which is critically important.
8. Due to the large scale of impacts from a Cardiff-Western barrage, and even if it could account for many of the impacts detailed above, Government would almost certainly need to breach the Habitats Directive were it to proceed. This is due to a likely inability to secure sufficient compensation habitat, and impacts on fish populations that can probably not be legally compensated for. Investigations into the potential to re-interpret the EU Commission guidance detailing the responsibilities imposed on a Member State in order to deliver a “coherent network” of Natura 2000 sites have already been undertaken. Together with a number of other NGOs, WWT commissioned legal advice to determine whether such reinterpretations (known at the time as “equal value”) could be compliant with the Directive (this can be provided on request). The findings of this advice were unequivocal in reporting that such a concept—of delivering “alike”(similar wetland habitat types) but not the same type of habitat in compensation for damage, and of undertaking species conservation measures outside of the UK in compensation for damage particularly to fish stocks—did not meet the legal requirements of the Directive.
Implications for WWT
9. WWT was established on the shores of the Severn Estuary in 1946 by the late Sir Peter Scott. Our Slimbridge Wetland Centre is the headquarters for the entire organisation, which includes nine other wetland centres throughout the UK. We are a major tourist attraction in the region, welcoming in the region of 160,000 each year. A large barrage, such as a Cardiff-Western barrage would likely affect us in the following ways:
A potential major reduction in the numbers of key wetland bird species visiting and utilising our wetland reserve, which is connected to the estuary.
Implications for how we manage our wetland reserve—with the potential for increased salinity levels, and for damned water to back up into the reserve requiring pumping.
Implications for the ability of our business to attract customers, offer educational experiences and experience close contact with nature. Many of our visitors come purely to see the wildlife that we attract, wildlife which makes use of both the estuary and our reserve and which would be affected by a large scheme. Although a large barrage could benefit some species that also visit our wetlands (in contrast to reducing the populations of around 30 species) the species that would benefit (eg Common Gull) are not those which our visitors typically seek out and for which we are famous (eg Bewick Swan).
10. The ramifications of a large destructive scheme on Sir Peter Scott’s legacy and all who cherish it have not been quantified. We estimate that many land managers and businesses around the estuary would be affected in similar ways to our Slimbridge centre, and these impacts should be identified, quantified and compensated for.
Other Energy Generation Options in the Severn Estuary
11. The STPF study considered a number of alternative options for energy generation in the estuary, investigating some particularly interesting and innovative ones including a tidal fence scheme, explored via the SETs. It concluded that these schemes had merit, but required much more development to increase confidence that they would be both effective and commercially viable. The STPF study also concluded that one of the lagoon schemes was technically feasibility, the Bridgewater Bay option. Low head barrages have also been considered in the past, and we understand that the current proposal may be of a low head design. The impacts of low head barrages have not yet been sufficiently explored or modelled, especially in a UK context, and so extensive work would be required to understand the impacts. There is potential to explore tidal stream technology devices, in addition to other locations for the deployment of lagoons. “Tidal Lagoon Power” are currently investigating installing a lagoon near Swansea to generate power. Were this to be successful, up to five other sites on the Severn could potentially accommodate lagoons, producing up to 2GW per site. Free standing tidal turbines offer potential, as does further exploration of tidal fence options which access (largely) tidal stream energy and may have significantly less impact on wildlife while also allowing compatibility with the deployment of other technologies such as lagoons. There may also be scope to harvest energy via the deployment of wave energy devices, but these prospects seem least developed. VerdErg’s proposal for a scheme in the estuary developed under the SETs offered a form of technology that contained no direct turbines and promised a much reduced impact on intertidal habitat. Such a design is actively being considered in the Solway. However, this may possibly have continued to have adverse impacts on fish due to pressure effects on swim bladders and we do not know whether this impact has been or could be overcome.
12. In summary we would conclude that many interesting forms of technology and means to generate electricity from the estuary exist, or are under development. Many of these have the potential for either few or manageable impacts on the natural environment and could be sequenced in delivery to maximise energy generation and reduce risks if deployed holistically. We do not consider it necessary or appropriate to opt for a scheme which would cause significant environmental damage and reduce the options for more natural adaptive management of the estuary in response to climate change. We believe that all options for energy generation from the estuary, along with their cumulative environmental, social and economic costs and benefits, should be evaluated.
Other Examples to Learn from
13. We believe there is significant merit in incorporating lessons from the development of barrage technologies elsewhere across the world, for example in France, Canada and in South Korea. In both La Rance and the Bay of Fundy small-scale barrage technology has been deployed, however environmental concerns have led to no further deployments. These concerns include shoreline erosion, concentration of pollutants, and trapping instances of large mammals. WWT recently hosted a representative from the South Korean Government for two years, to compare and contrast approaches to tidal barrage technologies between the two countries. We would be happy to provide further details of the findings of this work.
December 2012