24 August 2012
Shingle beaches can be found along much of the coast of Sussex and they form a superb, natural defence against the ravages of the sea. They are formed when waves erode soft material such as chalk and clay from the foreshore. Smaller particles of the soft material are carried away in suspension or solution and larger particles (mostly flint pebbles and sand on our shore) are deposited on the seaward side of the eroding land.
But that’s far from the end of the story! The wind along our coast comes most often from the south west and, since waves are created by the wind, that’s the direction the waves come from too. As the waves come from the prevailing south west wind direction, they move the shingle and sand along the shore from west to east and where there are natural or man-made obstructions to the movement of the shingle, it builds up in a bank until the easterly movement of shingle carries on around the obstruction. That’s why Beachy Head is so called (though the disappearance of its huge shingle beaches in modern times is another story)!
Of course, the shingle doesn’t just belong to the length of shore where it was formed and when Shoreham Harbour was set up by Act of Parliament, it was charged with ensuring that shingle continued to move from west to east past the new harbour arms so that communities to the east, like Brighton, are not deprived of their protective beaches. We have never moved all of the shingle building up against the western harbour arm, though, and this has led to a continuous increase in the size of the shingle bank to the west, which in turn has enabled the community of Shoreham Beach to be developed.
Surveys taken every year by the Environment Agency show that the beach is still building up year after year and threatening to close the entrance to Shoreham Harbour, but if there is no port, there would be no need to maintain the harbour arms that cause the build-up. If the harbour arms collapse, then the build-up disappears and that imposes the threat of erosion on the community of Shoreham Beach.
Tony Parker, Director of Engineering at Shoreham Port concluded “So we need to look after the interests of every community along our frontage including port and harbour users, and that’s why we shall continue to manage the delicate balance between erosion and accretion by moving shingle. Just as we are commanded to do by Act of Parliament “
