The beach fill functions as an eroding buffer zone. As large waves strike it, sand is carried
offshore and deposited in a bar. As the bar grows, it causes these large incoming waves to break farther
offshore. The useful life of a fill, which depends on how quickly it erodes, can be completely eliminated
in a short period of time by a rapid succession of severe storms. The owner must expect, therefore, to
periodically add more fill as erosion continues. Beach fills generally have a relatively low initial cost but
a regular maintenance cost of adding new fill (periodic renourishment).
The rate at which new f ill must be added depends on the relative coarseness of the fill material
in relation to the native beach material. Ideally, fill and native beach materials should be perfectly
matched, but this is virtually impossible. Generally speaking, if the fill material is coarser than the native
material, the fill will erode more slowly and if it is finer, it will erode more quickly.