The sea wall and riprap protected the initial area, by stopping the erosion. Although in turn this meant less material was been carried down the coast, because there was less been eroded by the sea. The beaches along the Holderness coast were already very small, as only 30% of the glacial till eroded are heavy enough to be deposited and form a beach. The beaches down coast of the defenses began to shrink in size, as material usually deposited there was either not eroded, or stuck behind the groyne. This meant that the waves concentrated all their energy on the base of the weak cliff, because the beaches were not big enough to absorb the waves. This caused the cliffs to erode at a faster rate, threatening many buildings once thought of as safe. At Easington, the Gas terminal is under threat sitting right on the edge of the cliff, with no beach to protect it. They will either have to move it, or build some of their own sea defenses. Cowden Farm just down the coast from the Mappleton groyne, is starting to fall into the sea. Here erosion increased as a direct result of the defenses, there is almost visibly no beach remaining at the foot of the cliff. Many other properties have already fallen into the sea or are about to do so soon.
Gravel extraction occurs in many offshore areas around Britain, gravel is removed in large volumes for commercial purposes each year. More than 20 million tons were been dredged in 1989. The removal of this gravel was thought to be a good method, as no extra quarries would have to open therefore creating no protests from any local people. The problem is removing all this sand and gravel is leading to the gradual wearing away of shores and cliffs, adding to coastal erosion. When large amounts of material are removed from the seabed, the directions of currents move more material back into the dredged area. The area dredged will be replenished with material, and this material will be taken from elsewhere along the coastline.
