Seawall erosion control
Seawalls are near-vertical structures commonly constructed of timber, concrete, steel or aluminum sheet piling.
The structure is installed parallel to the shore and is intended to retain or prevent the sliding and slumping of land while protecting the adjacent upland area from wave action. Seawalls should not be used where wave action will overtop the structure, causing bank erosion to continue as if the bulkheads were not there. Seawalls can also lead to the erosion of beaches fronting the structure. Technical shore protection methods by far have the least natural scenic beauty of all shore protection options, due to the lack of natural materials used in construction, and the aesthetics of the environment in which they are placed.
In general, construction and placement of technical shoreline erosion control structures reduces complex natural habitat elements; riprap replaces natural complex substrate elements with coarse substrates, while sea walls result in less habitat diversity. Shorelines with erosion control structures generally lack woody debris and hanging cover; however, these important habitat cover types are present at sites with no structures. Shorelines with erosion control structures also have less emergent and floating vegetation than sites with no structure. Conversely, the area of coverage and height of aquatic plants growing beneath the surface is greater at sites with structures; this is most likely related to increased depth associated with sites.