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Coastal Management: Alternative strategies
East Anglia and Essex coast
Background
Major floods along the east coast of England took place on 31st January 1953. 307 people died and 22,000 were left homeless. After the event, major engineering works took place. These took the form of earth and concrete structures. Now a more radical idea is becoming popular. The suggestion is that a more sustainable method of coastal protection would be to destroy the hard engineering schemes.
600km of sea wall cover the east coast of Essex alone. On high tides, the sea once covered large areas of land (salt marsh). Some believe we should return some land to the sea and re-establish flood plains and salt marshes, 2% of which are lost per year. The problem in Essex is that sea level rise is taking place and will probably get worse. The coast is becoming constricted and is fighting against flood walls.
The amount of marshland in 1870 was huge. Large areas were used as expansion areas to cope with flooding. Sea walls have been built. As a result, the expansion area is reduced, forcing sea levels to rise.
How should the area be managed in future?
Environment Agency suggests that where sea defences are weak, they should be left and not repaired. The sea should be allowed to flood the land behind and re-establish old salt marshes. The gently sloping land would then absorb the energy of the flood waters. Many sea walls are crumbling and will need much money spent on them if they are to be repaired. UCE state that it makes more sense to release the tension rather than trying to hold back the sea. The MP responsible for flood management agrees and has renamed the strategy from Managed Retreat to Managed Realignment.
An experiment into the feasibility of such an approach began in 2000 on the east coast of England. Currently as the channel in estuaries narrow, water is pushed up and up by the reinforced walls. Bit to allow some water to escape through the existing sea walls and flood the old salt marshes, it should lower the levels further up the estuary.
As part of the feasibility study conducted by the EA, the sea wall at Abbotshall has been breached in five places. Essex Wildlife Trust have purchased the land to make it an inter-tidal area suitable for wildlife. The WWF also contributed £500,000 so that they could assess the costs and benefits of the project. Monitoring will take 5 to 10 years. Only then can accurate assessments be made. Independent scientists have been employed to measure river levels, tide height and wave height.
What are the arguments against this strategy?
•· The biggest sceptics are the farmers. They have a vested interest and do not want to lose their agricultural land. They feel that the fertile land would be wasted if it was returned to the sea. On the other hand, some argue that the land has been borrowed from the sea and it has become too expensive to keep protecting the land.
•· Another group who are not keen about the project are the Oystermen along the estuary. If silt is washed into the new salt marshes this could ruin the Oyster beds. Consequently yields would fall resulting in a loss of livelihood.
•· Environment Agency workers do not necessarily agree with managed realignment. Some don't feel right about destroying sea walls.
D.Drake 2010
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