D D EE C C II SS II O ON N -- M MA A KK II N NG G EE XX EE RR C C II SS EE GeoActive Online MANAGED COASTAL RETREAT: NORTH NORFOLK COAST T HE COASTLINE OF NORTH NORFOLK is being rapidly eroded by the North Sea (Figure 1), in some places by more than 2 metres a year. In this unit you will learn why erosion is taking place in this area, evaluate some of the current and proposed solutions to the problem of coastal erosion, and discover the role played by the managed retreat of coastlines. Holkham Brancaster It was during the last Ice Age, approximately 12,000 years ago, that glaciers deposited the sands and clays which make up the cliffs that line the present-day north Norfolk coastline. Since the retreat of the ice, the North Sea has constantly been wearing away these soft deposits which have not yet been consolidated into solid rock. Erosion does not take place at a consistent rate, and it causes much greater damage during storm conditions such as those of 1953 and 1978. Global warming is likely to make the situation worse, with rising sea levels and more frequent storms. Although erosion of the coastline is a natural process, it is being made worse by the actions of people. North Norfolk is one of seven locations in Great Britain by John Edwards N Wells-next-the-Sea Sheringham Cromer Bacton Happisburgh Sea Palling N O R F O L K Why is coastal erosion a problem? Coastal erosion is a natural process that has been affecting this part of the British coastline for the last 12,000 years. It is only relatively recently that the erosion has been seen as a problem, because it has affected the homes and livelihoods of people. 376 Caister-on-Sea Norwich 0 Great Yarmouth 10 km Figure 1: The north Norfolk coastline GeoActive Series 18 Issue 3 Fig 376_01 where offshore dredging takes Mac/eps/illustrator erosion11ofs/sthe British coastline. THORNESHard PUBLISHING place. In the last decadeNELSON over 100 engineering solutions may Artist: David Russell Illustration million tonnes of sand and gravel offer protection to a short have been extracted from this area stretch of coastline, for example alone. Offshore sediment helps where the coast is particularly absorb the energy of incoming vulnerable, or heavily populated. waves and reduce erosion, so They are highly visible, and so incoming waves are more easily can offer people security by able to reach and erode the shore showing exactly how the coast is where dredging has taken place. being protected. Erosion may even be made worse by the actions of people trying to stop the coast from being worn away. Groynes and revetments, although protecting one stretch of coastline from erosion, can deprive another location of the sediment needed to absorb the energy of incoming waves, leading to erosion. Solutions to coastal erosion Hard engineering solutions Sea walls and revetments are examples of hard engineering solutions (Figure 2). Such solutions were often the initial response to the problems of Series 18 Summer issue Unit 376 DME: Managed Coastal Retreat: North Norfolk Coast © 2007 Nelson Thornes This page may be photocopied for use within the purchasing institution only. In many cases, however, hard engineering solutions have failed. They attempt to halt rather than reduce the power of incoming waves – and the sea generally wins in the end. Repairs are costly, and sea walls on average cost over £500,000 per mile to build in the first place. Hard engineering solutions are often built in combination, and are visually unattractive, sometimes ruining the appearance of coastlines people want to visit. They also affect other parts of the coastline indirectly by reducing the amount of sediment carried by longshore drift which builds up their beaches. GeoActive Online Page 1 of 4 Protecting one part of the coastline can increase erosion at another place. Sea Sea Soft engineering solutions Sometimes used where hard engineering solutions have failed, soft engineering is the use of techniques that have less visual impact. An example is where the top of a shingle beach may be covered by wire mesh to prevent material from being removed by waves (Figure 3). Another is the building of an artificial barrier off shore in order to absorb the energy of incoming waves and so reduce erosion. Beach Sea Rip-rap Sea Figure 2: Hard engineering solutions Coarse wire mesh GeoActive Series 18 Issue 3 376_02 Mac/eps/illustrator 11 s/s 1m Sea NELSON THORNES PUBLISHING Artist: David Russell Illustration Beach Fig 1 km Managed retreat Until recently government policy was to decide which parts of the coastline are worth saving and then to hold back the sea, almost regardless of the cost. However, this method was not sustainable. In many situations the cost of protecting the coastline was greater than the value of the land or property being saved. The government now plans to stop maintaining coastal defences except in areas of high population density. In many cases, therefore, coastal defences will be allowed to fail. This is central to the strategy of managed retreat. The long-term defence of many sections of the British coastline is not sustainable. Where the cost of sea defences is greater than that GeoActive Online Page 2 of 4 Sea-wall defences Beach Soft engineering solutions are usually much cheaper than sea walls or revetments. They rarely last for long, however, and are only able to protect short stretches of coastline. The responsibility for protecting the coastline lies with the local council as there is no national coastal protection agency. Local councils such as North Norfolk Council do not have the financial resources to protect the whole of the coastline, and so have to rely on the government for support. Rock protection Concrete sea wall Planting dunes with marram grass Shingle beach 10 m Sea Beach Defensive Sea offshore boom Figure 3: Soft engineering solutions people will lose their homes and of the land or property being and they currently defended, erosion will beGeoActive Serieslivelihoods, 18 Issue 3 Fig 376_03 Mac/eps/illustrator receive 11 nos/spayment in allowed to take its natural THORNEScompensation PUBLISHING for the loss of course. People affectedNELSON will need Artist: David Russell Illustration their homes to the sea. to be re-housed, and may lose their livelihood as well as their homes, for example through the How does this affect the loss of farmland. Allowing the north Norfolk coastline? coast to retreat naturally is also The north Norfolk coastline is more sustainable for wildlife, and quite sparsely populated. A series prevents the problem of erosion of small villages lie near to the occurring at another location shore, but overall the population further along the coast. density is low. The area attracts Managed retreat is seen as the most sustainable option for the future, but it is controversial. Only the most heavily populated coastal areas will receive protection. Elsewhere, where the sea is allowed to erode the shore, many tourists and day trippers, but these people are not included in the government’s calculations regarding sea defences. The government has decided that the coastline of north Norfolk is not worth protecting from erosion Series 18 Summer issue Unit 376 DME: Managed Coastal Retreat: North Norfolk Coast © 2007 Nelson Thornes This page may be photocopied for use within the purchasing institution only. by the sea. Population density is low, and the government has decided that most settlements lie too far away from the sea to be under imminent threat from erosion. New defences would cost more than the value of the land and property to be protected. This means that the coastline will be allowed to retreat naturally. People at risk will need to move and be re-housed. At present they will receive no compensation for loss of their home. Residents argue that although the sea defences are inadequate now, they were maintained when they bought their house – many people have lived near the sea for many years. Faced with this problem, some local councils have tried to take their own local measures, but with little effect. Case Study Happisburgh Happisburgh (pronounced ‘Hazeburra’) is one example of a village where the local council has invested nearly £200,000 to build a barrier of boulders in an attempt to halt the waves. This is not sustainable, however, as the defences will fail and the council cannot maintain the level of spending over a long period of time. The North Norfolk District Council is responsible for protection of the coastline at Happisburgh (and elsewhere along this stretch of coast). Defences are so expensive that a local council, faced with other calls upon its expenditure, cannot afford to foot the bill alone. The government, through the Department of Environment, Food and Rural Affairs (DEFRA) will support the payment for sea defences – if it decides that the money is worth spending. The problem for Happisburgh is that DEFRA has decided not to subsidise the cost of defences along this part of the coast, and that the sea should therefore be left to its own devices. The future of Happisburgh looks uncertain. Without government funding the local council will be unable to protect the coastline in the long term and it is difficult to see any other outcome than the sea destroying this coastal village – along with others. Although the coastline at Happisburgh has been eroding ever since the last Ice Age, it is only since settlements have been under threat that the process has been seen as a problem. Severe storms such as that of 1953 caused major problems to this stretch of coastline, leading to the immediate construction of revetments and a sea wall. As well as being expensive, the relatively short lifespan of such measures was illustrated in 2003 when a 30-metre stretch of cliff was lost to the sea during storms – along with the buildings at the top of the cliff. Series 18 Summer issue Unit 376 DME: Managed Coastal Retreat: North Norfolk Coast © 2007 Nelson Thornes This page may be photocopied for use within the purchasing institution only. GeoActive Online Page 3 of 4 Activities 1 Engineer There’s still much to be said for the use of sea walls and other similar structures to protect the coastline. This is the most common form of coastal protection in Britain, and that’s mostly because it works! People can see that their homes are being protected. Although it’s not possible to protect large coastal areas this way, this sort of solution is ideal to safeguard areas at particular risk. The coast of north Norfolk is particularly vulnerable. This is where erosion is taking place most rapidly, and so this is where the forefront of the battle should be. Don’t forget that, as well as protecting the coastline, we are safeguarding the inland areas as well for the future – notably the Norfolk Broads. 2 Town planner We know that hard engineering solutions don’t work in the long run, and are very costly. They are used by politicians in the short term to convince people that they are doing something to protect them, but it’s better in the long run to use softer solutions. We know these do not last forever, but you build that into the cost – which is not as great as building sea walls. A major advantage for the north Norfolk coast is that these so-called softer solutions don’t ruin the look of the landscape. This is vital if the main industry of the area is to be maintained – tourism. 3 Conservationist We should do nothing, and let nature take its course. After all, coastal erosion is a natural process. It’s not possible to protect the whole of the British coastline, and wrong to prioritise some areas at the expense of others. The problem has been around for years, so why do people start complaining now? They know the problems of living near the coast, just like someone buying a house near a motorway or airport. If they don’t like it, then they can always move. The money would be better spent on improving local facilities and amenities, for the benefit of all rather than just the small number of people who live right by the coast. 4 Local resident The council should stop all development in the area. After all, it’s more the actions of people causing the problem – erosion has taken place for years, but it’s only since they started dredging that the problems have got worse. And the government gets millions of pounds from the dredging – they should put this back into preserving the area for the local people – we’re the taxpayers, after all. 5 Government official We have to follow the policy of managed retreat. It is too expensive to continue to pay for coastal protection measures in Norfolk – and this area would not be a top priority for protection anyway. The value of the buildings and land is far less than the cost of building and maintaining defences. This is the only solution in the long run. The number of people who have to move in the near future is very small, not the thousands that some people claim. We have to consider the impact on the environment as a whole – the natural landscape, and wildlife. This is about much more than just protecting people’s houses for a few years. 1 Explain why erosion is a problem along the north Norfolk coastline. 2 To what extent do you think it is correct to say that coastal erosion is as much a problem caused by people as by natural processes? 3 Explain why soft engineering solutions are generally preferable to hard engineering. 4 What is meant by the ‘managed retreat’ of coastlines? What are its main advantages and drawbacks? DECISION MAKING EXERCISE Protecting the north Norfolk coastline The government has decided that it is not worth protecting the north Norfolk coastline from further erosion by the sea. This is because defending the coastline in the future would cost more than the value of the land and property in the area, and also because most settlements are not under immediate threat of erosion. Do you think this is the correct decision? Has the government taken into account all of the important factors, or is it just concerned with saving money? Look at the viewpoints shown in Figure 4. Using these views, information in this unit and your own knowledge, write a report of approximately 500 words to: (a) summarise the main features of each viewpoint in Figure 4 (b) explain which you think is the most appropriate option for the future for the north Norfolk coastline (c) explain why you did not choose the other options (d) suggest any other ways in which the coastline of the British Isles might be protected in the future. GeoActive Online Page 4 of 4 Figure 4: Viewpoints on coastal protection Series 18 Summer issue Unit 376 DME: Managed Coastal Retreat: North Norfolk Coast © 2007 Nelson Thornes This page may be photocopied for use within the purchasing institution only.
