Hard Engineering

Hard Engineering

1. Sea Walls

   • Description: Stone or concrete walls at the foot of a cliff, or a the top of a beach. They usually have a curved face and can reflect the waves back into sea
   • Advantages: Effective prevention of erosion. They often have a promenade for people to walk along
   • Disadvantages: They reflect the wave eneergy rather than abosorping it. They can be instrusive and unnatural looking. They are very expensive to build and maintain.
   • £6000/m
   • Sustainability: 1
   • 1 - Protects agaisnt the destructive waves well as it reflects the wave energy back into the sea. It also adds potential for tourism as they are normallypaired with a promenade. NOTE: The normal flat sea walls aren't as good as protecting against the waves as the deflected wave energy erodes the foundations

2. Groynes

   • Description: Timber of rock strucutrres built at right angles to the coast. They trap sediment being moved along the coast by longshore drift- building up the beach.
   • Advantages: Work with natural resources to build up the bach, which increases tourist potential and protects the land behind it. Not too expensive
   • Disadvantages: Starve beaches futher along the coast of fresh sediment (because they interrupt LSD) often leading to increased erosion elsewhere. Unnatural and can be unattractive
   • £5000 - 10,000 each @ 200m intervals
   • Sustainability: 3
   • Prevent the action of LSD meaning the beach remains providing good tourism opp. Does prevent the natural flow of sediment along the beach and could starve and destroy other beaches

3. Rip Rap

   • Description: Large rocks placed at the foot of a cliff or at the top of a beach. It forms a permeable barrier to the sea - breaking up the waves, but allowing some water to pass through
   • Advantages: Relatively cheap and easy to construct and maintain. Often used for recreation - fishing, sunbathing
   • Disadvantages: Can be intrusive. The rocks used are usually not local and can look out of place with local geology. Can be dangerous for people clambering over them
   • £100,000 - £300,000/100m
   • Sustainability: 3

4. Revetments

   • Description: Sloping, wooden, concrete or rock structures placed at the foot of a cliff or the top of a beach. They break up the waves energy.
   • Advantages: They are relatively inexpensive to build
   • Disadvantages: Intrusive and very unnatural looking. They can need very high levels of maintenance
   • £4500/m
   • Sustainability: 2

5. Offshore Breakwater

   • Description: A partly submerged rock barrier, designed to break up the waves before they reach the coast
   • Advantages: An effective permeable barrier
   • Disadvantages: Visually unappealing and a potential navigation hazard
   • £100,000 - £300,000/m
   • Sustainability: 4

6. Gabions

   • Description: Rock cages placed at the bottom of a cliff or the top of a beach
   • Advantages: Inexpensive, easy to setup, provide a quick way of protecting personal propety
   • Disadvantages: Looks out of place in the local geology, the cages may rust and become and an eyesore
   • Sustainability: 3

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