Why Are There Groynes on the Beach?

Groynes were originally installed along the coastline in 1915. Groynes control beach material and prevent undermining of the promenade seawall. Groynes interrupt wave action and protect the beach from being washed away by longshore drift. Longshore drift is the wave action that slowly erodes the beach.

What are the advantages of groins?

The advantage of the combined solution of groyne fields and nourishment is that well-designed groynes prevent or mitigate erosion of the beach. However, groynes are less effective during extreme events; in such situations they only slow down the rate of coastal erosion caused by offshore movement of the sand.

How do groynes build up a beach?

The groynes are strategically placed at right angles along the coastline at varying points down the beach. They interrupt the water flow and capture the material, trapping it, which helps build up the beach and extend the land rather than it eroding away with the continuous tide.