Mentone beach renourishment: a study in the management of a coastal system in Port Phillip Bay [also includes Artificial renourishment: a literature review]

About 20 percent of the world's coast is sandy and backed by beach ridge dunes or other sandy depositional terrain. Of this more than 75 percent has shown net erosion over the past few decades (Bird, 1985). Interference with the sand supply, by the construction and mining of river drainage systems and the quarrying of sand or gravel from beaches, interruption of littoral drift processes by groynes, breakwaters and the development of harbours and marinas have all compounded the growing problem of disappearing beaches. This is an important issue, as beaches provide valuable protection to coastal properties, recreation space and income for the tourist industry and related services. The latest technique to combat this problem has been to supply sand artificially to the shore. Artificial renourishment is a sand-moving operation where sediments are taken from a borrow site and moved mechanically to the coastline, to be dumped on the backshore, creating a section of beach sand above mean high water level. It is an expensive process, and the diversity of methods described in early literature reflect the various attempts to produce a successful cost-effective beach fill project. During the late 1970's to early 1980's a number of technical papers emerged, evaluating potential beach fill designs and sources, and the factors influencing fill retention. There has been some debate over the relative importance placed on sand grain size in the success of an artificially renourished beach. The literature cited in this review is primarily on the development of various methods of beach renourishment, and the factors influencing the behaviour of beach fills