Seawalls, revetments and groins are generally used to protect valuable waterfront property from the water's erosive powers. There are millions of kilometres of shorelines, rivers and streams in the world. These areas have great economic, social, and environmental value providing recreational areas, transportation, and habitats for aquatic and land plants and animals.
Seawalls and revetments normally run parallel to the shoreline.
The classical "hard engineered" shore protection solutions use stone, concrete, and steel sheet pile facings and retaining walls.
Groins are low rubble-mound structures oriented roughly perpendicular to shore to protect against erosion by trapping sediment.
Unfortunately studies are now showing that classical "hard engineered" shore protections like these are causing significant damage to the natural habitats of both plants and animals. Civil engineers are now starting to study and implement natural or bioengineered shore protection techniques. Soil bioengineering uses living plants and other organic products to help stabilize the banks and control erosion. This also helps to enhance habitats and to purify and filter the overland runoff.
Submerged wave filters may be used as artificial reefs for coastal protection. They are invisible from the shore, make it possible for water to circulate, require less space than the old traditional "hard" shore protection and have a wide operating range.