Coastal erosion is a natural phenomenon and can be classified as either short-term or long-term. Short-term erosion is part of the natural cycle but can be exacerbated by large storm events, increasing the risk of potential damage to coastal infrastructure and development.
Longer-term changes to coastal conditions can lead to shoreline recession. With ongoing sea level rise, sandy coasts and dunes will need more and more sand to recover from erosion episodes and fill the gap.
In Adelaide, large quantities of sand have either been 'locked up' or removed from the beach system as a result of coastal development. For example, many of Adelaide's coastal suburbs were built on extensive coastal dune systems or alternatively, dunes were used to infill coastal swamps to provide land for housing and Adelaide's airport or mined for other purposes.
It is estimated that only a limited amount of sand enters the Adelaide beach system at Kingston Park from the south each year compared with the amount of sand moving northwards along the beaches. This sediment deficit and historic coastal development poses a unique management issue for South Australia which must be actively managed. This has led to the implementation of mechanisms such as the Coast Protection Act 1972 that contribute to the long-term management of South Australia’s coastline.