- We are glad to see that the planned programme of analysis of the probable environmental impact of the development of the Sizewell C nuclear power stations will be so wide ranging and that it is recognised that a robust understanding of the complex hydrological and hydro-geological conditions is essential. (4.10.11) The fact that many of the proposed studies summarised in tables 4.11.2 ,4.12.2 and 4.13.2 have either not started or are in their very early stages makes it impossible for us to comment in any substance on many of the issues identified beyond agreeing that work should proceed as rapidly as possible. We wish to be assured that we will have a continuing engagement with the process and receive regular reports on their progress. This will enable us to build up a picture of the likely effect that the complex elements of the development will have, cumulatively, on the Minsmere Levels.
2. We are most concerned about the impact over the short, medium and long term of the whole development on the outflow of inland ground water, and in particular that of the reinforcement of the station’s site and the new access road. We note that it is intended that there should be very considerable areas of hard surface beside the site during the construction phase and we seriously question the need for a land take of in excess of 300 acres for the purpose of lying down. Despite assurances given to us at a meeting with EDF officials on 17 January we continue to fear that the run off of surface water will also affect volume of the outflow into the Levels and await the outcome of a number of studies commissioned by EDF that still have to report.
3. We note (4.10.13) that dewatering of the site will be required during the construction process. We wish to know whether it is intended that the discharge should be into the existing drainage system of the Levels or direct into the sea.
4. We wish to be fully informed of the likely impact of the development on Leiston Sewage works and its discharge into the Minsmere drainage system.
5. Factors which may affect the continued viability of the Minsmere Sluice are acknowledged in paragraphs 4.11.19., 4.12.14 and elsewhere. Cumulatively, the increased outflow resulting from the development, together with the natural consequences of increased rainfall, rising sea levels and climate change will accelerate the point at which the existing gravity fed sluice will no longer be able handle the volume of discharge. This will have a seriously adverse impact on the Levels relative to the existing situation and result in alternative solutions, including installation of a pump, becoming essential. We wish to be assured that EDF will recognise its responsibility to make a major contribution towards such mitigation. The Meteorological Office have just confirmed (reported Telegraph 4th Jan 2013) that 2012 had the highest rainfall in England since records began in 1910, with 4 of the 5 wettest years since then occurring this century. They also predict, based on analysis of 30 year trends, that more extreme rainfall events (heavy rainfall which occurs once every 100 days) are now occurring about once every 70 days, and that the long-term trend towards wetter weather, in particular periods of intense rainfall, is likely to continue as global air temperatures rise.
6. A particular feature of the Minsmere Levels is the complex interaction between the challenge of managing the system for the drainage of inland water and the defence of the coast line. The report acknowledges the significance of the Minsmere Sluice as a ‘hard point’ protecting the coast line, but goes on to acknowledge factors that could lead to a re-alignment of the Sizewell shoreline, and thus lead to a breach of the shoreline (4.11.18) and the reactivation of the former Minsmere Estuary. We need to know a great deal more of the projected impact of the development on the Minsmere coastline both during the construction phase and also over the course of lifetime of the station. The Minsmere sluice was originally built in 1812 and has stayed in the same place ever since. The line of the shingle beach wall from Dunwich cliff to Sizewell has also remained sensibly the same over that 200 year period, with some local maintenance. Experience along the Walberswick beach shows that storm surges can break the shingle bank, but such breaches will rapidly self repair. The predicted long term trend is for the whole coast to erode slowly, between the strong points at Southwold and Thorpeness. (E.g. comments by Professor John Pethwick to Sizewell Stakeholder group in 2006) We therefore ask that EDF produce a fluvial/tidal model which will show likely breach developments and the subsequent land use change which will evolve from a tidal estuary.
7. January 31 2013 marks the 60th anniversary of the 1953 storm surge and associated catastrophic flooding. The Environment Agency now indicates that projected sea level rise will mean that surges of this severity will occur much more frequently. Events which in 2000 were considered likely once in 200 years will, by 2100, have to be expected between every two and ten years. The storm surge of November 2006 was originally expected once in one hundred years; when a second storm surge occurred in 2007 that figure was revised to once in forty years. Sea level rise would present a major challenge to the Minsmere Levels even without the Sizewell C development, but it is vital that we understand the added complexities which it will present.
8. It is probable that the structure of the station will still be in place 2150. Paragraph 4.11.12 acknowledges the potential of the Sizewell C site to be subject the flooding from both its landward, and (debatably) to a lesser extent the seaward side. Serious flooding from a storm surge should also be considered very seriously, the Japanese experience at Fukushima in 2012 shows that even one in 1000 year events CAN occur and overwhelm defences. We need a great deal more information as to how it is intended to ensure its protection from storm surges and the associated flooding during the entire lifetime of the structure.
9. A number of imponderables will determine the impact that Sizewell C has on the Minsmere Levels. Many will only be revealed during the life of the station. We consider it essential from the outset that EDF acknowledges, as a good neighbour, its moral obligation to share in the protection and preservation of the Levels and their coastline for as long as its vast structure overshadowing them remains in place.
10. The Engineer to the East Suffolk Inland Drainage Board and senior staff of the Minsmere RSPB reserve have contributed to the preparation of this response and wish to be associated with it.
John Rea Price
Secretary, Minsmere Levels Stakeholders Group 30 January 2013