Pevensey

LOCATION

Pevensey bay is located about 2 miles east of Eastbourne along the English coastline, about 3 miles south east of the old settlement of Pevensey.

TYPE Of COASTLINE

• Pevensey bay has a constructive coastline, it experiences constructive waves. They are low waves with a long wave length, usually up to 100 m. As they approach the beach, the wave front steepens slowly, giving a gentle spill onto the beach surface. Swash rapidly loses volume and energy as water percolates through the beach material. Material is slowly moved up the beach leading to the formation of ridges.
• Pevensey bay is part of a low energy coastline. Wave heights are considerably low; waves spread outwards and energy is dissipated. This leads to the deposition of transported material.
• There is much tourism associated with Pevensey bay. Tourists are attracted by the coastal location as well as many other tourist attractions in the area. Many establishments such as the Pevensey bay hotel exist in Pevensey.

METHODS OF PROTECTION USED FOR COAST

This coastline acts as an important defence against flooding and storm damage from the sea for a large area of very low-lying land immediately behind the beach. Situated in this area are a large number of properties, recreational interests, transport links, grazing pastures and two important nature reserves. These are all at risk from flooding if a breach of the defences occurs.

The sea defences of this area are the responsibility of the National Rivers Authority, Southern Region (NRA). Despite their regular maintenance efforts the sea defences are deteriorating. To restore an appropriate standard of defence the NRA are proposing to undertake major capital works. The Babtie Group, which is an engineering consultancy, has examined the coast in detail over the past two years, and have devised three options for new defences.

Option 1

The recharged shingle beach will be accomplished by pumping material from a ship on to the beach and forming it to profile using bulldozers. The beach crest will be widened substantially by about 10 metres. The material to be brought in to build up the beach will be specified after an appraisal of likely sources. This material would be selected to match the existing beach material as closely as possible. This wide beach would bury the existing beach structures which would be either extracted or cut off. Existing outfalls to the sea may need to be extended.

Option 2

For the remainder of the frontage the low groynes and rock heads of Option 1 would be replaced by large strongpoints. The purpose of these strongpoints is to contain beach material on the frontage into a series of embayments. The size of the strongpoints will be such that the beach within the embayments can reorientate itself to a stable shape under wave action. The beach within the strongpoint bays will therefore be ungroyned. The build up of material against the strongpoints will create a far greater beach area than exists at the present time and it is expected that because the beach material is contained by the strongpoints, finer material can be utilised for the beach recharge than the existing beach. This will further improve the amenity of the beach for recreational use. In the siting of the strongpoints due consideration will be given to existing sea outfalls which would be extended as necessary.

Option 3

A recharged shingle beach.
Replacement groynes to the whole frontage.
Some timber and rock breastwork.
Offshore breakwaters.

Strategy choices and their overall impacts
There are three strategies that the NRA may adopt regarding sea defences. Briefly, these are:
Do nothing: If the sea defences were effectively abandoned, the groynes would continue to deteriorate. Beach material would be lost from the frontage and some of the properties on the beach crest would be undermined and eventually lost. The beach would continue to recede until a breach occurred. Such a breach would initially flood only part of the area behind the defences but would gradually be opened up by the sea until all the levels were regularly inundated by the tide and reverted to saltmarsh.
Maintain as at present: A programme of maintenance and emergency maintenance would continue to defend the coast in the short term. However, it would not reduce the chances of a breach to an acceptable level, nor would it be able to offer an acceptable standard of sea defence against flooding for this important area. Both the risks of flooding and breaching would be increased by future anticipated sea level rises which this strategy could not accommodate.
Major capital investments: These would involve substantial improvements to the sea defences. New structures would be added to the coast and the beach would be enlarged. This is the only strategy which the NRA considers will provide appropriate long term sea defences for this area.

Cost - A £30 million scheme to give more than 3,000 homes on the Sussex coastline better protection from flooding started in April. The project will protect properties along a 9km stretch between Eastborne and Bexhill, including properties in the Pevensey Bay area.

HAZARDS AND DANGERS THAT EXIST