Editing Coastal erosion (section)

===Hard-erosion controls===
[[File:Seawall (Phetchaburi Province).jpg|thumb|This image represents a typical seawall that is used for preventing and controlling coastal erosion.]]

Hard-erosion control methods provide a more permanent solution than soft-erosion control methods. [[Seawall]]s and [[groynes]] serve as semi-permanent infrastructure. These structures are not immune from normal wear-and-tear and will have to be refurbished or rebuilt. It is estimated the average life span of a seawall is 50–100 years and the average for a groyne is 30–40 years.<ref name="Dean">{{cite web|url=http://dukespace.lib.duke.edu/dspace/bitstream/handle/10161/957/OceanfrontSandbags-JDean.pdf?sequence=1|title=Oceanfront Sandbag Use in North Carolina: Management Review and Suggestions for Improvement|last=Dean|first=J.|date=22 April 2009 |publisher=Nicholas School of the Environment of Duke University|access-date=11 October 2013|url-status=live|archive-url=https://web.archive.org/web/20160304083548/http://dukespace.lib.duke.edu/dspace/bitstream/handle/10161/957/OceanfrontSandbags-JDean.pdf?sequence=1|archive-date=4 March 2016}}</ref> Because of their relative permanence, it is assumed that these structures can be a final solution to erosion. Seawalls can also deprive public access to the beach and drastically alter the natural state of the beach. Groynes also drastically alter the natural state of the beach. Some claim that groynes could reduce the interval between beach nourishment projects though they are not seen as a solution to beach nourishment.<ref name="Knapp">{{cite web|url=http://dukespace.lib.duke.edu/dspace/bitstream/handle/10161/5182/Knapp_Whitney_MP.pdf?sequence=1|title=Impacts of Terminal Groins on North Carolina's Coast|last=Knapp|first=Whitney|date=20 April 2012 |publisher=Nicholas School of the Environment of Duke University|access-date=15 October 2013|url-status=live|archive-url=https://web.archive.org/web/20140312224735/http://dukespace.lib.duke.edu/dspace/bitstream/handle/10161/5182/Knapp_Whitney_MP.pdf?sequence=1|archive-date=12 March 2014}}</ref> Other criticisms of seawalls are that they can be expensive, difficult to maintain, and can sometimes cause further damage to the beach if built improperly.<ref name=":0">{{Cite book|title=Managing Coastal Erosion|publisher=National Academies Press|year=1989|isbn=9780309041430}}</ref> As we learn more about hard erosion controls it can be said for certain that these structural solutions cause more problems than they solve. They interfere with the natural water currents and prevent sand from shifting along coasts, along with the high costs to install and maintain them, their tendency to cause erosion in adjacent beaches and dunes, and the unintended diversion of stormwater and into other properties.<ref name="Coastal Erosion">{{cite web |title=Coastal Erosion |url=https://toolkit.climate.gov/topics/coastal-flood-risk/coastal-erosion#footnote1_mp5focg. |website=U.S. Climate Resilience Toolkit |publisher=New England Federal Partners |access-date=29 November 2021}}</ref>

Natural forms of hard-erosion control include planting or maintaining native vegetation, such as [[mangrove]] forests and [[coral]] reefs.