Hard engineering options tend to be expensive, short-term options. They may also have a high impact on the landscape or environment and be unsustainable.
|Type of defence||Advantages||Disadvantages|
|Building a sea wall - a wall built at the edge of the coastline.||Protects the base of cliffs, land and buildings against erosion. Can prevent coastal flooding in some areas.||Expensive to build. Curved sea walls reflect the energy of the waves back to the sea. This means that the waves remain powerful. Over time the wall may begin to erode. The cost of maintenance is high.|
|Building groynes - a wooden barrier built at right angles to the beach.||Prevents the movement of beach material along the coast by longshore drift. Allows the build up of a beach. Beaches are a natural defence against erosion and an attraction for tourists.||Can be seen as unattractive. Costly to build and maintain.|
|Rock armour or boulder barriers - large boulders are piled up on the beach.||Absorb the energy of waves. Allows the build up of a beach.||Can be expensive to obtain and transport the boulders.|
Soft engineering options are often less expensive than hard engineering options. They are usually more long-term and sustainable, with less impact on the environment.
There are two main types of soft engineering.