Groins trap sand on one side, but tend to increase erosion in down drift locations.

Question

Quizplus · Accepted Answer

Groins are structures built perpendicular to the beach to trap sand on one side, but because they interrupt the natural flow of sand along the beach, they can cause increased erosion on the down drift side of the groin. This is because the sand that would normally flow down the beach and contribute to building up the down drift area is trapped by the groin, leading to a lack of sand and increased erosion in that area.

Groins Trap Sand on One Side, but Tend to Increase