GCSE Geography | Coastal Management: Coastal Realignment (Coastal Landscapes 12)

Sometimes decisions are made to stop 'holding the line' against coastal erosion and flooding, i.e. to stop protecting the coastline. This usually happens where the land is not considered economically valuable enough to protect, so nature is allowed to take its course and low-lying land is allowed to flood. People are moved out, homes and buildings are knocked down, and a breach is made in the existing defences so sea water can flood low-lying land.

This is called coastal realignment as the coastline moves inland and is realigned. It is also known as a managed retreat, because the way in which the land is flooded is managed.

Coastal realignment is controversial as some people will lose their land (although they will be compensated for this), however it does create mud flats and salt marshes which are important wildlife habitats, and will act as natural sea defences. The removal of old sea defences also allows sediment to be transported along the coastline by longshore drift, which enables beaches further down the coastline to have their sand re-charged, which were previously starved of sediment.

Benefits of coastal realignment

There are many benefits to coastal realignment, for example, it allows material sediment to be transported further along the coastline, so beaches there will build up, reducing the risk of erosion and coastal flooding as wide beaches absorb wave energy. Another benefit is that although initially this strategy is expensive due to land owners needing to be compensated, it is much cheaper than continuing to maintain hard engineering strategies, such as sea walls and groynes. Finally, one of the most important benefits is that new habitats are created in the inter-tidal zones, on the new mud flats and salt marshes.

Drawbacks of coastal realignment

The biggest drawback of coastal realignment is the relocation of homes and businesses which have to make way for coastal flooding - this process is extremely disruptive but also very distressing. An example where this may happen is North Norfolk, where coastal erosion is a huge issue. The shoreline management plan (SMP) is to allow 40 square kilometres of coastline to retreat naturally, and whilst this will be good for the environment, it will mean the loss of six villages, and the relocation of hundreds of people. People living in areas where this strategy has been chosen often feel very let down by the local council, despite compensation packages. These compensation packages also mean that initially coastal realignment schemes are extremely expensive, despite being much cheaper in the long run. Many councils can't afford to stump up these costs up front, so end up having to spend money on repairing sea defences to protect land that is not economically valuable. Finally, huge areas of agricultural land will be lost, along with important coastal habitats. Over time new habitats will establish on the new mudflats and salt marshes, but these will take years to establish fully.