Groynes

Groynes 

To protect East Coast Park’s beaches from erosion, government has built groynes along the beaches. A groyne is a low wall built at right angles to prevent materials from being transported away by the longshore drift. These structures absorb energy of the sea on the shore, like headlands, reducing the impact of energy on the coast. There are 4 types of groynes: Wooden, Steel, Rubble-mound, sand-filled bag and made of concrete elements. Those found at East Coast Park are made of concrete elements.

(Positive impacts)

It traps sediments from longshore drift, forming a beach which attracts tourists, creating a positive impact on the local economy. Coastal erosion on beach is significantly reduced, as the water can only reach the cliff during high tide.

(Negative impacts)

Groynes prevent beaches down the coast from having sediments deposited there, which can lead to soil erosion. This could also destroy buildings and private land near it, causing property prices to plummet or cliff collapse when coasts are not protected from storm-driven waves which are approaching the shore perpendicularly. Protection of the shore by use of one groyne only is most often inefficient. Therefore, shore protection by groynes are designed as a group comprising from a few to tens of individual structures.

On the other side of the groyne, the beach will not be replenished by materials carried by the longshore drift. As a result, the beach further down the coast may be eroded away. While a series of groynes can help reduce this effect, they spoil the natural beauty of the coastal environment.