Hard engineering is a coastal management strategy that involves the use of artificial structures, such as sea walls, to control natural processes. There are several types of hard engineering, including groynes, sea walls, rock armour, and gabions.

Groynes

Groynes are timber or rock structures built out to sea from the coast. They trap sediment being moved by longshore drift and help enlarge the beach. Although they can create a wider beach and serve as useful structures for fishing, they can also lead to erosion elsewhere along the coast. Groynes are relatively inexpensive, with a cost of approximately £150,000 per groyne (at every 200m).

Sea Walls

Sea walls are concrete or rock barriers placed at the foot of cliffs or the back of a beach. They have a curved face to reflect waves and are effective at stopping the sea. However, they can be obtrusive and unnatural, with high maintenance costs. The cost of sea walls is approximately £5,000-£10,000 per metre.

Rock Armour

Rock armour consists of piles of large boulders dumped at the foot of a cliff. The rocks force waves to break, absorbing their energy. While rock armour is relatively cheap and easy to maintain, the rocks can be expensive to transport and may not fit in with the natural landscape. The cost of rock armour is approximately £200,000 per 200m.

Gabions

Gabions are wire cages filled with rocks that can be built up to support a cliff or provide a buffer against the sea. They are cheap to produce and can improve drainage of cliffs. However, they may look unattractive for a while and only last 5-10 years before rusting. The cost of gabions is up to £50,000 per 100m.

When implementing hard engineering strategies for coastal management, it is essential to consider the advantages and disadvantages of each type of protection. While hard engineering can effectively control coastal erosion and flooding, it is crucial to weigh the environmental and visual impact, as well as the long-term maintenance costs.