There is a natural process of shingle movement along the Sussex coast from west to east, which results in the build up of approximately 15,000 cubic metres of shingle annually at the east end of Shoreham Beach, where its progress is blocked by the west breakwater. It is the blocking of further eastwards shingle movement by the harbour entrance breakwaters that causes the erosion problems on Southwick Beach.
Shoreham Port has powers under the Harbour Act to undertake a programme of shingle bypassing, whereby shingle is excavated from the west side of the entrance and transported and placed on the east side. This process is split evenly between spring and autumn campaigns and care is taken to minimise the impact of the operation on local residents.
Studies have shown that as a result of shingle bypassing, beach volumes along the Port have improved and stabilised.
The shingle bypassing operation is supported by the South Downs Shoreline Management Plan and by the two coastal defence strategies that define the needs for sea defence improvements between the River Arun and Brighton Marina.
Kingston Beach Recycling
Kingston Beach is very dynamic, in that waves entering the harbour and spending themselves on the beach cause a movement of shingle from west to east.Thus the beach is eroding at its western end in front of the lighthouse and is building up at its eastern end at a terminal groyne.
In order to counter the erosion effect and to avoid shingle being lost over the terminal groyne, Shoreham Port undertakes shingle recycling operations as and when required, but typically, every four or five years, whereby shingle is excavated from the terminal groyne area and transported back to the western end, filling in areas of erosion.