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ATTIYA REHMAN
Assessing coastal defence schemes
Sheringham is a seaside town in Norfolk, England, west of Cromer with a population of
7,143. On the coast the wind blows the waves from a north east direction. This is direction
of the cold northern seas and oceans, e.g the Norwegian sea and the arctic ocean. Suchstrong waves carry large amounts of energy, and easily erode away the soft boulder clays of
the coastline. The cliffs of Sheringham are made of soft sandy material deposited during the
Ice Agea and therefore are vulnerable to erosion. Sheringhams beaches not only suffer from
coastal erosion and different types of weathering but also from long shore drift. Longshore
drift is a process that moves sediment from the beach up a coastline.
The coastal protection on the Sheringham coastline includes seawalls and groynes. The
storm surge of 1953 damaged Sheringham’s wooden sea defences so they were then
reconstructed. In front of the sea wall are groynes, armoured at their bases with large
blocks of natural rock, which prevent long shore drift. There are numerous drains along the
frontage. To the east towards West Runton the seawall ends just below Beeston Bump.
From there a timber revetment and groyne system, designed and constructed in 1976, runs
eastwards for 2 km (just over a mile) to West Runton Gap.
In the latest coastal protection scheme, there was the repair and renovation of 900 metersof the existing sea walls and the placing of large rock armour stone in front of them to act as
There is evidence of cliff slumping along
the Sheringham coastline caused by
powerful destructive waves
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ATTIYA REHMAN
buttresses and to absorb the energy of the breaking waves. This Stage of the project was
completed in 1995 at a cost of £3.4 Million.
The second stage works involved a lot of work on the groyne system at Sheringham. All five
of the old timber groynes at the west end from the Lifeboat Station to the Admiralty Slip
were renewed or replaced with new timber groynes and an extra groyne was built.
These sea walls and groynes have been recently reconstructed or build and sea walls have a
typical life span of 50-75 years and groynes up to 40 years. This shows that they are still in
good shape and can continue to protect the coast. However tourism is high in Sheringham
so the groynes may be damaged a lot more so may last a shorter time than expected. Sea
walls aren’t very attractive so they have large visual impact on the environment which may
in turn affect the tourist industry as people wouldn’t visit coasts that are unattractive.
Sheringham: SEA WALLSNegative evaluation factor -3 -2 -1 1 2 3 Positive evaluation factor
Vulnerable to erosion X Effective protection against erosion
Vulnerable to overtopping X Effective against overtopping
Ugly (poor aesthetic value) X Enhances natural environment
Poor access to beach X Good provision made for access to
beach
High risk safety hazard to general
public
X No obvious safety risk to general public
Short life span. High maintenance
costs
X Good life expectancy/ low maintenance
costsHigh levels of disturbance caused to
local people during construction
X Low levels of disturbance caused to local
people during construction
Disturbs natural coastal processes
and habitats
X Maintains natural coastal processes and
habitats
Total value: -1
Protection is being given to the highest value areas i.e. where cliffs have soft rock and are
most vulnerable to erosion and transport of sediment along the coast. The shoreline
protection in place – sea walls and groynes prevent the erosion of cliffs and land at the rightareas.
Protection
Technique
Approx cost Total length
used
Total cost Typical
lifespan
Concrete sea walls £2500 per metre 1,800 (m) £4500000 50-75 years
Groynes £20,000 each 5 used £100,000 25-40
Overall I think groynes are more cost effective as they don’t cost that much and have quite a
long life span. They are effective at preventing longshore drift along the coast. If these werenot in place, sediment would be transported up the coast. Sea walls are also quite effective
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ATTIYA REHMAN
and can last up to 75 years. Even though the initial cost is high, they are really effective at
preventing coastal erosion. If they were not in place, many houses and buildings along the
coast can be destroyed effecting people socially and economically as they would have to
find a new place to live and have high insurance costs on their homes.
The scheme is meant to stop coastal erosion and longshore dift. Effective management
schemes have been put in place to prevent this and to slow down coastal erosion.