Coastal erosion is the process of the removal of sediment supply within a specific beach segment over a fixed period of time. Ongoing for thousands of years, coastal erosion is impacting several beaches within Sydney, and the issue is rapidly expanding along the coastline away from larger urban areas. The degree of coastal erosion can be measured through the calculation of the volume of beach sediment, such as sand and gravel, lost during a particular event, or the movement of significant beach features towards land.
The causes of coastal erosion are due to both natural and human activity. These different process can be divided up into: exogenic processes, natural disasters and human occupancy.