A Severn Barrage? - Energy and Climate Change Contents

4  Environmental impacts and mitigation

43. While it is clear that a tidal barrage will have a significant effect on the environment, the scale of specific impacts is difficult to determine. This section will examine some of the key environmental aspects of the Hafren Power proposal, including: flood risk issues; loss of intertidal habitat; international comparator sites; impact on fish and birds; compliance with EU environmental legislation, and mitigation measures.

Flood impacts

44. Assessments regarding the impact of a barrage on flood risk vary. Two types of flooding are relevant: fluvial flooding risk (flooding from rivers) and tidal or coastal flood risk. Hafren Power asserted that the barrage would offer protection against coastal flooding and storm surges, offering protection to 90,000 properties over an area of 500km2.[83] Engineering the Future agreed that flood risk due to storm surges would be reduced due to control of basin water level, while modelling by Professor Falconer (Expert Panel, Hafren Power Ltd and Professor of Water Management, University of Cardiff) suggested that the area around Bridgwater would experience "a small reduction of the water level" and that overall, "the mean water level [...] will stay the same."[84] The Natural Environment Research Council (NERC) noted that "In general, it is anticipated that they [barrages] will mitigate sea flood risk (particularly storm surges) by providing a physical barrier that prevents seawater ingress"[85], although Ed Mitchell (Environment Agency) pointed out that such tidal surges are "very rare".[86]

45. There is evidence to suggest that a barrage would offer some protection against flooding caused by sea level rise; in addition, research undertaken by Professor Falconer (currently unpublished) suggested that the "far-field effects"[87] of a barrage would be negligible.[88] However, fluvial flood risk is an area of concern for a number of stakeholders.[89] NERC outlined some of the potential complications of a barrage:

    For example, flood risk may be increased as a result of saltmarsh erosion, the restriction of river outfalls by the longer high water stand, and the possible siltation of outfalls as a result of hydrodynamic changes. Flood risk, freshwater supplies and local land use patterns may also be affected by changes to the water table and groundwater flow.[90]

According to Professor Falconer, under the Hafren Power barrage scheme low tide would be raised by 3m.[91] Dr Richard Creswell (Environment Agency) explained that this was a "major concern" since it might restrict river outfalls and water drainage and hence lead to increased flooding from rivers:

    "It is the 3 metres at the lower end with which we have the greatest concern because of the freeboard for getting water out of rivers. Certainly, around the Severn Estuary one of the biggest problems is land drainage."[92]

46. Overall, there is a lack of consensus regarding how flooding might be affected by the Hafren Power scheme or indeed any barrage. NERC highlighted the "apparent contradictions" when discussing barrage impacts due to a "lack of empirical evidence".[93] Regen SW and South West Marine Energy Park claimed that the impacts of an ebb-flood barrage on flooding are as yet unknown, stating that "Much more modelling and research is required to fully understand the hydrodynamic impacts of this technology."[94] The impact on flood risk is likely to be mixed, as reflected in Ed Mitchell's assessment (Environment Agency) that a barrage "has potentially both positive and negative implications for flood defence" and is therefore "probably cost neutral" (i.e. it would neither increase nor reduce costs from flood defence and damage).[95]

Loss of intertidal habitat

47. According to Professor Falconer, the Hafren Power barrage scheme would reduce tidal range in the Severn from its current range of 0m to 14m to one of 3m to 12m.[96] Low tide would therefore be raised by 3m, as noted previously, and high tide would be reduced by 2m. The overall reduction in tidal range would lead to a reduction in intertidal habitats of salt marsh and mudflats, with a resultant impact on bird populations dependent on these areas for feeding grounds. Kate Jennings (RSPB) suggested a barrage would have "significant adverse effects on the populations of 30 species" with potential "serious effects on a total of 96 European protected sites for birds".[97] The Countryside Council for Wales illustrated how changes to the estuary's morphology could further affect habitats by altering conditions in the estuary:

    "Decreased flows and flow speeds incurred by a barrage would reduce the suspended sediment concentration within the impounded area and downstream leading to further changes in the estuary extent and composition of intertidal and subtidal habitat features of the Severn Estuary"[98]

48. DECC's Severn Tidal Power Feasibility Study estimated that a Cardiff-Weston barrage would cause loss of 40-50% of intertidal habitat (baseline figure).[99] Hafren Power stated that its new ebb-flood design would lead to 60% less habitat loss, which equates to 49km2 or 4900 hectares of lost habitat;[100] our understanding is that this is equivalent to approximately 16% loss of overall intertidal habitat.[101] Kate Jennings (RSPB) suggested that there were additional, ongoing complications after the initial impact:

    You would expect the estuary to evolve, to try to change its shape in response to barrage construction over time, which would result in on-going erosion and loss of intertidal habitat. That is significant because of what it means in terms of the intertidal habitat, the loss of that habitat and the features it supports, like the internationally important populations of birds.[102]

49. Many witnesses agreed that there was a lack of up-to-date baseline data for the estuary from which to gauge potential impacts.[103] HR Wallingford noted that while expertise has advanced, there is an "absence of robust and long-term basic data for the estuary" and recommended "A comprehensive bathymetric survey of the entire estuary"[104]. The recent POST note on environmental impacts of barrages pointed out that "studies of habitat response are limited to conceptual models only", with available models diverging in their assessment of long-term impacts to habitat.[105] Dr Simon Pryor (Natural Environment Director, National Trust) highlighted the risk of unintended consequences:

    First principles, if you look at the Severn estuary, it is a huge, very complex, very dynamic ecosystem and the hydrology, the geomorphology, the ecology are all very much interdependent, and if we intervene in a very major and quite heavy-handed way, we can expect unintended consequences.[106]

50. We conclude that the environmental impacts of the Hafren Power barrage, as currently presented to us, are very considerable and that there is a high risk of unintended and possibly damaging consequences. We also conclude that Hafren Power has not presented sufficient credible evidence relating to estuary morphology, impacts to habitats and upstream fluvial flood risk. Further data, research and modelling will be required before impacts in these areas can be assessed with any degree of certainty.

International comparator sites

51. Suggested comparators for environmental impacts include the following sites:

  • EDF's tidal barrage facility at La Rance;
  • the Annapolis Royal Tidal Barrage in Canada, an ebb-only scheme intended as a pilot for a proposed larger facility in the Bay of Fundy, and
  • the Eastern Scheldt Storm Surge Barrier in the Netherlands.

52. While Hafren Power cited the La Rance scheme as evidence of the potential for improved biodiversity with a barrage in place,[107] assessment of environmental impacts is hampered by a lack of any baseline data prior to the construction of the barrage. In addition, we have received evidence arguing that La Rance is not an appropriate comparator for the Severn since it is "a rocky river valley" unlike the sediment-rich Severn estuary.[108] Problems experienced at the Annapolis Royal site in the Bay of Fundy include "fish mortality, erosion problems downstream and the health of the river upstream". Professor Graham Daborn and Natasha Barker Bradshaw reported that tidal causeways across tributaries in the area have led to "rapid, unpredictable consequences and no foreseeable return to a state of dynamic equilibrium."[109] However, Hafren Power has drawn attention to studies which illustrate the complexity of the flows in the area which limit its comparability with the Severn. [110] Erosion issues have also been experienced at the Eastern Scheldt site, as Kate Jennings (RSPB) explained:

    Experience in the Eastern Scheldt, where they built a storm surge barrier in the 1980s—this is the site that the Severn Tidal Power Feasibility Study identified as the best comparator for a Severn Barrage—is they have found that 30-odd years after construction that estuary shows absolutely no sign of reaching a new equilibrium, so it is still attempting to change its shape and its morphology in response to the construction of the barrier. It is still losing intertidal habitat. They think it will go on losing habitat for at least a century, so the idea that the Severn will reach any rapid equilibrium of any kind—clearer water, muddier water or whatever—does not seem realistic based on the evidence.[111]

53. However, once again comparisons with the Severn are constrained due to differences in the type and source of the sediment at each site. As NERC pointed out, "only limited information is available from existing power plants [barrages], and there appear to be no examples of coherent, comprehensive monitoring."[112] We therefore conclude that the usefulness of international comparator sites is limited as a result of differences in estuary characteristics and scheme designs.

Impact on fish

54. The Severn estuary is an important habitat for many species of fish. Martin Salter (Angling Trust) described the species composition of the estuary:

    In terms of fish, there are 83 species of fish recorded in the Severn estuary. It is an incredibly dynamic habitat, both for migratory fish and freshwater fish upstream of the intertidal zone and obviously as a nursery area for bass and many other important sea fish. There are five Annex II species. These are the highly protected species under the Habitats Directive. They are the twait shads, the lamprey and the salmon. There are 11 BAP protected species. That is the UK Biodiversity Action Plan. That includes high-value species like sea trout as well as a whole range of sea species.[113]

55. The presence of turbines across the estuary poses a number of concerns, in particular to migratory fish. Consequences include: death or injury when passing through turbines as a result of blade strikes; disorientation caused by pressure changes and noise, and delayed or terminated migration due to physical barriers.[114] For the Cardiff-Weston barrage studied under the Severn Tidal Power Feasibility Study, local extinctions and population collapses were predicted for designated fish including Atlantic salmon and twaite shad, with the possible loss of the latter as a breeding species in the UK.[115]


56. Hafren Power's stated aim is to "accomplish zero mortality for fish passage through its turbines" through the use of a new, bi-directional Very-Low-Head (VLH) turbine design. The Hafren turbine would operate at a tip speed of 9m/s, which is below the "limit of negligible fish mortality" suggested by Oak Ridge National Laboratory research, as published by Idaho National Laboratory.[116] However, most trials of turbine related fish mortality have been carried out using small-sized salmon, a notoriously robust species.[117] These trials do not encompass the diversity of fish, invertebrates and crustaceans found in estuaries. In addition, estimates of fish mortality are based on fish making a single pass through a turbine: fish living in an estuary may make multiple passes in a day, increasing their risk of mortality.[118] Hafren Power also drew attention to the "fully operational VLH turbine" developed to prototype by French company MJ2 Technologies on which "full-scale field tests using live European eels" have been carried out which indicate a 100% survival rate.[119] While such initial results are encouraging, further research will need to be carried out with different fish species and sizes, in addition to upstream studies, before firm conclusions can be drawn. As yet, no prototype of the Hafren turbine has been built and tested. "Indirect impacts", such as sub-lethal injuries and predation, may constitute a significant source of overall mortality but there has been little research in this area.[120]

57. Regarding Hafren Power's proposed VLH turbine, Ed Mitchell (Environment Agency) stated that "it is difficult to envisage how that could be fish friendly"[121]. We note that the Environment Agency claims that it is "not aware of any turbine designs which would allow the safe, repeated passage of fish through a barrage at the scale proposed."[122] While claims that a barrage would lead to very extensive fish mortality may be exaggerated, existing figures of low level fish mortality tend to derive from a single species and do not encompass the diversity of species found in estuaries. Studies have largely focused on only direct mortality. However initial studies on indirect mortality suggest it may constitute a significant source of overall mortality. Field testing a prototype in an estuary on a range of fish species and sizes will need to be carried out before the claimed "fish-friendliness" of Hafren Power's proposed turbine can be determined.

Compliance with EU legislation

58. Hafren Power acknowledges in its evidence that the barrage project would need to comply with the following legislation:[123]

  • Water Framework Directive[124]
  • The Floods Directive[125]
  • The Habitats Directive[126]
  • The Birds Directive[127]
  • The Environmental Impact Assessment Directive[128]

59. The Habitats and Birds Directives are likely to be the most challenging legislative requirements for the Hafren Power project to meet, due to the significant impact a barrage would have on a number of Annex I and II species of wild flora and fauna, protected by law under the Directives. The Severn estuary is designated as a UK Site of Special Scientific Interest (SSSI) and a Special Area of Conservation (SAC) under the EU Habitats Directive, recognising its extensive intertidal mud flats and importance for migrating birds.[129] Its international importance for wildlife is also recognised through its designation as a Special Protection Area (SPA) under the Birds Directive and a Ramsar site.[130] Under the Habitats Directive, the Severn region forms part of "Natura 2000", an EU-wide network of SACs and SPAs established to assure the long-term survival of Europe's most valuable and threatened species and habitats.[131]

60. Representatives of the RSPB and the Angling Trust stated they would support the Hafren Power barrage project if it were able to comply with European Directives.[132] The Sustainable Development Commission's 2007 report "Turning the Tide: Tidal Power in the UK" recommended that "any proposal for a Severn barrage must fully comply with the Directives and adhere rigorously to the process they set out."[133]

EU process under the Habitats Directive

61. As a project affecting a Natura 2000 site, the barrage would trigger an "appropriate assessment" under EU law to determine whether there were adverse environmental impacts. Alan Seatter (European Commission) indicated that "a base line of data in relation to the objectives for conserving that site" would be used in order to "inform public authorities as to what kind of impacts might happen and what you would need to do to address those".[134] If the barrage were found to have an adverse effect on the integrity of the site, the project could only go ahead via the derogation process under Article 6(4) of the Habitats Directive. That process requires that the following three sequential tests are met:

  • There must be no feasible alternative solutions to the plan or project which are less damaging to the affected European site(s);
  • There must be "imperative reasons of overriding public interest" (IROPI) for the plan or project to proceed, and
  • All necessary compensatory measures must be secured to ensure that the overall coherence of the network of European sites is protected.[135]


62. Chapter 7 examines alternatives to a fixed barrage in more detail. In terms of the legislative requirements of the Directive, alternatives must be "financially, legally and technically feasible" to be acceptable, and must "deliver the overall objective of the original proposal."[136] It is clear that alternatives to the barrage do not deliver energy on the same scale as the barrage (16.5 TWh/year), although the Minister has suggested that alternatives do exist:

    If there were no alternative to the barrage that would enable us to meet our 2050 target, then I think the question that you pose would be at its most acute, i.e. unless we went down the road of the barrage Britain would miss its 2050 target, but I am not aware that anyone is seriously saying that is the case.[137]

63. Guidance from the Department for Environment, Food and Rural Affairs (Defra) states that the relevant competent authority would need to "use its judgment to decide what is reasonable in each case" when considering alternatives.[138] In oral evidence, Mr Seatter drew attention to how discussions about alternatives could lead to a change in the project's design in order to mitigate impacts: "It is difficult to find an example where there isn't a discussion involving project design that then changes during the course of a process."[139]


64. Alan Seatter (European Commission) indicated that a barrage scheme could pass the IROPI test as a renewable infrastructure project. Mr Seatter stated that the "elected people" - as opposed to the European Commission - would be responsible for balancing climate change and environmental considerations: "You cannot say in one case it is more important than another, but clearly the fight against climate change in a major project is a question of great public interest."[140] The Minister indicated that such considerations would be weighed in the context of "our 2050 commitments", noting that the barrage "is not deemed as yet to be an essential element of a successful 2050 package".[141]

Clarity in application of the EU Habitats Directive

65. Alan Seatter confirmed in evidence that a project on this scale was "completely unprecedented" in the Commission's experience of projects subject to the Habitats Directive.[142] This underlines the uncertainty identified by DECC during the Severn Tidal Power Feasibility Study as to how the regulatory framework of EU Directives might apply to a large-scale barrage.[143] Mr Seatter also characterised the Habitats Directive as "a directive that is implemented by member states in the way that they feel best meets their own requirements and the requirements of the directive", which clearly indicates that the onus is on the UK Government to judge compliance with European legislation, and indeed suggests some leeway in the way it is applied.[144] Several further points of uncertainty regarding the Habitats Directive were also explored in questioning:

  • the distinction between "like-for-like" and "equal value" compensatory habitat;[145]
  • the possibility of providing compensatory habitat outside the member state, currently unprecedented,[146] (see also next section) and
  • if the Commission is called upon to review a decision, what considerations inform the Commission's view on whether the benefits of a particular project outweigh environmental harm caused.[147]

66. Research from Bournemouth University drew attention to the "legal paradox" underpinning the Severn barrage and other large-scale renewable energy infrastructure projects where there is "a damaging impact to the environment caused by development designed to mitigate the damaging impact to the environment".[148] This research suggested that the principle of IROPI ('Imperative Reasons of Overriding Public Interest') could be applied to all climate change mitigation development, potentially opening the door to all manner of environmentally damaging projects and overriding the statutory protections of Habitats Directive. In response to our enquiries on this issue, Alan Seatter (European Commission) confirmed that IROPI could potentially be applied to all developments which involve climate change mitigation, but assured us that "such projects could not be given the green light regardless of their impacts." The question of public interest would need to be considered:

    What is expected here is that the importance of the public interest is weighed against the severity of the impact on the site. Is the public interest truly overriding? If so, the Member State must then show that it has taken all compensatory measures necessary to ensure that the overall coherence of Natura 2000 is protected and inform the Commission of these measures.[149]

67. Before giving further consideration to the project, the Government should establish greater clarity in the terms and application of the Habitats Directive to major renewable infrastructure projects, in particular regarding the derogation process and principle of 'Imperative Reasons of Overriding Public Interest' (IROPI).


68. Hafren Power proposed a number of mitigation measures to offset adverse environmental impacts, based on "the operation of the barrage and the optimisation of the turbine design." The company suggested that the use of a "fish-friendly" VLH turbine together with an ebb-flood mode of generation which "more closely emulate[s] the natural tidal flows" would reduce environmental impacts. The Consortium also stated that "screening technologies" based on fish behaviour, use of fish ladders and fish passes could help prevent or reduce the passage of fish through turbines.[150] However, the overall efficacy of such measures has not been determined, with potentially "contradictory effects on different species" and "limited research on marine species."[151] As noted previously, the environmental impacts of a new bi-directional VLH turbine have yet to be fully modelled.

69. The EU Habitats Directive requires provision of compensatory habitat to replace that which is lost. European Commission guidance states that any compensation must "fully offset any loss or damage to the site" and must be "feasible and operational" within a specified timescale. The guidance also states that ratios for compensatory habitat "should be generally well above 1:1" unless habitat is known to be 100% effective. [152] Alan Seatter (European Commission) confirmed that compensation "should be in place before the project is completed" and that Member States are responsible for deciding on the adequacy of compensation provided.[153] Hafren Power suggested that marine construction techniques such as topographic raising could be used to "increase foraging space for wading birds" and provide additional mudflat and saltmarsh habitat.[154] Engineering the Future explained:

    To mitigate the loss of inter-tidal habitat, material dredged from beneath the caissons and from the shipping channels could be used to raise the bed of the estuary in selected places replacing some of the bird feeding habitat that would become submerged.[155]

70. However, extensive areas of compensatory habitat would need to be created. Hafren Power estimated that 49 km2 (4900 hectares) of habitat would be lost as a result of the barrage, which at a 2:1 ratio would require the implementation of 9800 hectares of compensatory habitat. Even with the "up to £1 bn [billion]" [156] that Hafren Power is prepared to invest in the creation of alternative habitats, provision of compensation on this scale remains a great challenge and could prove a lengthy process. As part of the Severn estuary flood risk management strategy, Environment Agency proposals to create 400 hectares of compensatory intertidal habitat were reported to have taken "eight years in the negotiations."[157]

71. Creating fish habitat, as opposed to intertidal habitat, could present particular difficulties. Mike Evans (Environment Agency) outlined some of the challenges:

    Of course the other difficulty then is that with salmon they are loyal to their natal rivers. They do return to the same river to spawn, so there is a particular challenge there. We have poor understanding of shad, which only spawn in four rivers in the United Kingdom at present, three of which would potentially be upstream of the Severn barrage. We don't quite know what makes a shad prefer those three rivers to similar adjacent rivers, which they do run into but don't successfully spawn in.[158]

This will be particularly challenging if a barrage necessitates "creation or restoration of 25% of the salmon habitat in England and Wales" as was suggested by Kate Jennings (RSPB).[159]

72. Anthony Pryor (Hafren Power) suggested that a barrage project could follow a similar process to HS2 [the High Speed Two rail network]:

    If I may just mention the parallel example of HS2. The Minister for Transport stood up at least 12 months ago and said, "We will have a hybrid Bill approach to this project". They put a project team in place. I do not think they had even settled the line of the railway track when she said that. So there was not much data out at that time. It is exactly the same process for major projects of this nature.[160]

However, a barrage project is unprecedented in the UK and, as we have highlighted, the environmental impacts are uncertain. In the case of HS2 Phase 1,[161] an Appraisal of Sustainability (AoS), including a Habitats Regulation Assessment, was prepared as a "starting point" for the full Environmental Impact Assessment (EIA); the resultant Environmental Statement will be presented alongside the Hybrid Bill when it is introduced to Parliament.[162] The objective of the AoS was to "determine the extent to which HS2 reflects and promotes sustainable development through the integration of environmental, social and economic considerations." [163] The AoS consultation process concluded prior to the announcement of Government support for the project.[164] Tidal Lagoon Power Ltd have submitted an Environmental Impact Assessment scoping report to the Planning Inspectorate in relation to their proposed tidal lagoon in Swansea Bay; this is to help identify the scope of a formal EIA.[165] An EIA scoping report for the barrage would help to provide greater certainty regarding potential environmental impacts and compensatory habitat requirement.

73. Serious questions remain about the effectiveness and feasibility of providing compensatory habitat on the scale required for the proposed Hafren Power barrage scheme. While optimisation of barrage design and operation offer possibilities for mitigation, the requirements of the EU Habitats Directive are a significant challenge. We note that smaller scale projects may face fewer obstacles in achieving compliance with European legislation.

74. We appreciate the financial outlay implied in, for example, developing a full Environmental Impact Assessment of the proposed project. But it is clear that such a large-scale, high risk and high cost project cannot go ahead in a designated area without supporting evidence and assessments in place. Without such evidence the project will not achieve political and public acceptability.

83   Ev 153 Back

84   Ev 107; Qq 148, 156 Back

85   Ev w103 Back

86   Q 281 Back

87   In this context, "far-field effects" refer to effects on water levels beyond the Bristol channel. Back

88   Ev w5, Ev w61, Ev w66, Ev 107, Ev w103, Ev w134, Ev w158; Zhou, J., Pan, S. And Falconer, R.A., 2013, Effects of Open Boundary Location on the Far-Field Hydrodynamic Impact of a Severn barrage (in draft), Cardiff University Back

89   Ev w26, Ev w43, Ev 143, Ev 115, Ev w103 Back

90   Ev w103 Back

91   Q 147 Back

92   Q 284 Back

93   Ev w103 Back

94   Ev 91 Back

95   Q 280 Back

96   Q 147 Back

97   Q 57 Back

98   Ev w70 Back

99   DECC, Error! Bookmark not defined., October 2010 Back

100   Ev 153; Ev 153a describes how the "60% less" figure was arrived at;  Back

101   [49km2)/total intertidal habitat (310km2)]*100 = 16% habitat loss rounded to nearest percent. Figure for total intertidal habitat rounded to nearest km2 and taken from DECC, Severn Tidal Power Sea Environmental Report, May 2010 Back

102   Q 52 Back

103   Ev w32, Ev w61, Ev w64, Ev w70, Ev w103, Ev 143, Ev 189 Back

104   Ev w32 Back

105   Environmental Impact of Tidal Barrages, Draft provisional POSTnote 435, Parliamentary Office of Science and Technology, June 2013 Back

106   Q52 Back

107   Ev 153 Back

108   Ev w41, Ev w48, Ev w70, Ev 91, Ev w78, Ev 107, SEV 54, Ev 115, Ev 122, Ev w114, Ev w134; Q 60 Back

109   Ev w114 Back

110   See Ev 175, reference to Aretxabaleta et al., Model Simulations of the Bay of Funday Gyre Back

111   Q 60 Back

112   Ev w103 Back

113   Q 57 Back

114   Environmental Impact of Tidal Barrages, Draft provisional POSTnote 435, Parliamentary Office of Science and Technology, June 2013 Back

115   DECC, Error! Bookmark not defined., October 2010 Back

116   Ev 153a Back

117   Environmental Impact of Tidal Barrages, Draft provisional POSTnote 435, Parliamentary Office of Science and Technology, June 2013 Back

118   Environmental Impact of Tidal Barrages, Draft provisional POSTnote 435, Parliamentary Office of Science and Technology, June 2013 Back

119   Ev 153a, See also MJ2 Technologies website: Error! Bookmark not defined.  Back

120   Environmental Impact of Tidal Barrages, Draft provisional POSTnote 435, Parliamentary Office of Science and Technology, May 2013 Back

121   Q 291 Back

122   Ev 115 Back

123   Ev 153 Back

124   Directive 2000/60/EC  Back

125   Directive 2007/60/EC Back

126   Directive 92/43/EEC Back

127   Directive 2009/147/EC Back

128   Directive 2011/92/EU Back

129   Directive 92/43/EEC  Back

130   Ramsar sites are wetlands of international importance, designated under the Ramsar Convention. Back

131   For more information see 'Natura 2000' section: Error! Bookmark not defined. Back

132   Q 81 Back

133   Sustainable Development Commission, Turning the Tide: Tidal Power in the UK, October 2007 Back

134   Q 307 Back

135   Error! Bookmark not defined. Back

136   Error! Bookmark not defined. Back

137   Ev 153; Q 377 Back

138   Error! Bookmark not defined. Back

139   Q 324 Back

140   Qq 327-328 Back

141   Q 377 Back

142   Q 311 Back

143   DECC, Error! Bookmark not defined., October 2010 Back

144   Q 314, 28 February Back

145   Qq 330,333 Back

146   Q 315 Back

147   Qq 337-339 Back

148   Ginige TA, Thornton A, Ball F, The Severn Tidal Barrage Project: A Legal Paradox?, Journal of Water Law 21:66-77 Article number 2 2011  Back

149   Ev 192 Back

150   Ev 153 Back

151   Environmental Impact of Tidal Barrages, Draft provisional POSTnote 435, Parliamentary Office of Science and Technology, May 2013 Back

152   Error! Bookmark not defined. Back

153   Q 331-332 Back

154   See Ev 153: "Marine construction works: These can provide additional or improved intertidal mudflats and saltmarsh habitat for wintering birds upstream of the barrage. For example, topographic raising to increase foraging space for wading birds which, in combination with habitat enhancement, can improve quality of feeding, ameliorating the loss of habitat. Salt marsh creation is also beneficial to support wildlife and offset habitat loss." Back

155   Ev 107 Back

156   Ev 153 Back

157   Q 302 Back

158   Q 299 Back

159   Q 59 Back

160   Q 195 Back

161   Phase 1 refers to the proposed London to West Midlands route;  Back

162   Booz& Co. (UK) Ltd and Temple Group Ltd, HS2 London to the West Midlands Appraisal of Sustainability, Main Report Volume 1, February 2011 and Appendix 4 - Associated Assessment Reports Back

163   Booz& Co. (UK) Ltd and Temple Group Ltd, HS2 London to the West Midlands Appraisal of Sustainability, Main Report Volume 1, February 2011  Back

164   HC Deb, 10 January 2012, col 23 Back

165   Infrastructure planning portal, Proposed Tidal Lagoon Development in Swansea Bay, South Wales, Environmental Impact Scoping Report, October 2012, http://infrastructure.planningportal.gov.uk Back

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Prepared 10 June 2013