Coastal Protection Using Hard Structures
Coastal structures are frequently constructed to prevent erosion of coastal landscapes and infrastructure and mitigate the risks to the populations and economic activities dependent on the coastal zone. Coastal structures, sometimes referred to as “hard” structures, are usually built using materials (at least for certain coasts and beaches) that do not form naturally, such as of concrete, large armor stone, steel, or timber, are relatively permanent (typical 50-yr design life), and are spatially-fixed within an otherwise dynamic coastal zone. The most important hard structure types are dikes (levees), seawalls, breakwaters, groins, and jetties. The following descriptions are taken directly from the USACE Coastal Engineering Manual, the primary reference for coastal structure design in the U.S. Next, read about the hard structures and what each one does to protect the coast.