Caring for the area
A changing coastal landscape
The Suffolk coast and its river estuaries are constantly changing. Some of the changes are readily apparent, such as damage caused by a storm event, while others may be imperceptible to our eyes. These changes have happened naturally over countless thousands of years and, in more recent times, have also occurred because of the actions of people. Today, the communities and wildlife that depend on this coast face a number of challenges. In particular, the likelihood of rising sea levels, as a consequence of global warming, could have significant consequences for the Suffolk coast. The need to understand the processes at work on the coast and to plan for the future has never been greater. The aim of this section of the Tidal Suffolk site is to provide an introduction to this complicated subject.
The geology of the Suffolk coast
The rocks and soils that make up the Suffolk coast are fundamental to the land's ability to resist erosion. The Suffolk coast is low lying and made up of relatively soft material. It was deposited, in geological terms, comparatively recently, indeed Suffolk has some of the youngest rocks in Britain. The oldest 'rocks' are London Clay, laid down approximately 50 million years ago, but much of the area consists of much younger material known as 'Crag', laid down between 1.5 and 4 million years ago. The uppermost layer, and the one most easily seen, consists of sand and gravel deposited during the ice age. It is this material that makes up the soil of much of the Suffolk Coast and Heaths AONB and is responsible for the unique character of the area. From a coastal perspective the net result of these features is a soft, easily eroded landscape and, not surprisingly, the Suffolk coastline has changed considerably over the centuries.
How has the area changed?
The natural movement of the sea, through the daily cycle of rising and falling tides and the annual cycle of storm events, is the main force to have shaped the Suffolk coast. The erosive effect of waves, even small ones, is considerable and the cumulative effect over geological time is enormous. The actual impact of these forces depends on how hard the underlying rocks are and is also influenced by the effects of coastal currents. This can result in sediment naturally accreting in some areas while, in others, it is removed, allowing the rock to be exposed and eroded. On the Suffolk coast, the prevailing local current gives rise to an effect known as 'longshore drift' and moves material gradually southwards along the coast. One of the most striking effects of this can be seen in the large shingle spit known as Orford Ness. The spit gradually formed at the mouth of the River Alde, just to the south of Aldeburgh. Over centuries it has grown in length, forcing the river much further southwards, to run for over ten miles parallel to the sea before eventually joining it at Shingle Street. The effect of these natural processes on the Suffolk coast is extraordinarily complex and the subject of on-going study.
The influence of people on the coast
People have attempted to influence and control the effects of the sea for many hundreds of years. This has mainly been through the construction of artificial sea defences, such as groynes, concrete piles and sea and river walls. Many miles of the East Anglian coastline are protected by some form of artificial sea defence and, while some defences are hard concrete structures, other defences are less obvious. For example, they can take the form of a grassy bund along which a footpath runs, or an apparently natural shingle bank. While hard defences aim to prevent erosion or flooding, groynes are designed to break up the power of incoming waves and reduce the amount of material removed from beaches by longshore drift. They do this by trapping sand and sediments, preventing them from moving further down the coast.
Many sea defences were constructed during the Victorian era. They have been highly effective structures, allowing the construction of fashionable seaside resorts such as Southwold and Felixstowe. A renewed burst of sea defence construction followed the 1953 floods, extending and strengthening still further the walls and barriers already in place. The devastation and loss of life caused by that flood shocked the nation and, not unnaturally, made sea defence a top priority. Those defences have served us well for half a century and, not surprisingly, the need to maintain them is seen as an important priority by local people. However, the construction of hard defences on a 'soft', dynamic coast, such as Suffolk's, is not without its disadvantages. Their presence means that the coast can no longer change naturally, causing unforeseen and sometimes undesirable consequences. For example, as coastal processes have become better understood, it has become clear that hard sea defences can have a negative impact on unprotected areas elsewhere on the coast, causing erosion at faster rates than would have otherwise naturally occurred.
The situation facing the Suffolk coast today
It is a very important time for the future of our coastline. Indeed, it would not be going too far to say that decisions made now will have an impact on the future of this area for many decades to come.
The hard sea defences, that have generally served us well are, in many cases, beginning to reach the end of their intended life span. This issue cannot be underestimated because there are, including the river walls, literally hundreds of miles of defences that need to be checked and maintained. The on-going maintenance and renewal of these structures is likely to be costly, both in the short and longer term.
It is now generally accepted that sea levels will rise during the next century, although it is still unclear how great the rise may be. Even the most optimistic predictions could have very serious implications for the Suffolk coast and it is essential that we have a plan for the future management of the area - both for human communities and for the internationally important wildlife that use estuaries, beaches and coastal wetlands.
For more information about Climate Change, click on the following links:
The climate section of the BBC website
What are the options?
Many people like the Suffolk coast the way it is now and question the need to accept any changes at all. It is argued that, with greater investment in sea defences, there is no reason why the present coastline should not be maintained into the future, almost exactly as it is today.
In practice, however, this would be difficult to achieve. Suffolk's coast is, after all, a dynamic, changeable environment, making it naturally resistant to our attempts to control it. Even if it were possible, the costs involved would be likely to be high and the need to protect remote, isolated areas and individual properties would mean that far more of the Suffolk coastline would have to be protected by sea defences than is the case today. This could destroy much of the natural beauty for which the coast is rightly famous - would we really want to see large granite boulders piled along many miles of the coast?
Another problem that would be created by keeping the existing coastline is called 'coastal squeeze'. Most of Suffolk's river estuaries are surrounded by river walls, created over hundreds of years as the land in the valleys was reclaimed for agriculture. These walls prevent flooding but also constrain the mudflats and saltmarshes that support some of our most important wildlife, in particular wildfowl and wading birds. If sea levels rise as predicted these intertidal areas will become progressively 'squeezed' between the rising water levels and the river walls. The consequence of this would be the gradual loss of these areas, either because they would be covered by the higher tides or by increased erosion - with disastrous effects on our internationally important bird populations.
It is the issue of sea level rise that presents the biggest challenge to Suffolk's existing coastline. Holding the line in the short term would require considerable investment; maintaining the present situation in the face of rising sea levels over many decades may be impossible - even with greater investment. While the wish to keep things as they are now is understandable, trying to maintain the whole Suffolk coastline in its present form is probably not a viable or realistic alternative in either the short or longer term.
Accepting change as a positive option.
The certainty of sea level rise poses a real challenge for the Suffolk coast, but it is not necessarily something to be feared. Indeed it holds many opportunities for making changes that will bring real improvements for both people and wildlife.
Accepting the need for change is difficult and, understandably, some proposals for the way the coast should be managed and, particularly, the abandonment of some existing sea and river defences, have caused considerable local concern. Whilst it is not surprising that terms such has 'managed realignmnet' have met with suspicion and even anger, it would be a pity if this overshadowed the wider debate about the need for a new approach to the management of the coast.
It is essential that a new realism should prevail, coupled with new and more environmentally sensitive solutions to the problem of coastal defence. It must be understood that our hard sea defences have given us a false sense of our own ability to control the Suffolk coastline. Paradoxically, rather than being solutions, they have actually created some of the problems we face today. The challenge for the future is to accept that some change is inevitable, indeed desirable, and that we must manage it so that the best possible solution can be achieved in the longer term. After all, who knows what sort of world we'll find in 100 years from now.
To meet the challenge of the coast successfully, new approaches are needed:
- greater investment in coastal planning and infrastructure allied to a better understanding of coastal processes
- a willingness to think afresh and embrace the possibility of change
- flexible, environmentally sensitive solutions that support the needs of people and wildlife
- engagement with local people to build understanding and support
- continued protection for the majority with appropriate support for the small number adversely affected.
With these building blocks in place there is no reason why the likely changes to the coast and estuaries should not be extremely beneficial for the area as a whole, even though some losses, both of land and property, are unavoidable. It is worth remembering that our sea defences are comparatively recent structures and artificially separate the land from the sea. With a small adjustment in thinking it is not hard to imagine a future Suffolk coastline that features both hard and soft sea defences. A flexible approach based on better understanding, where some erosion is allowed and planned for and where some flooding is actively encouraged for the environmental and economic benefits it will bring. An approach that works with nature, rather than against her, allowing communities to be protected and glorious 'wet-lands' and intertidal areas are established and recreated, blurring once more the distinction between the land and the sea - with potentially enormous benefits for people and wildlife alike.