A new paper looking structural shore protection in Massachusetts and Hawaii finds a few things to like, and a lot to cause consternation.
Among the benefits:
- Stabilizes the upland
- Protects infrastructure
- Maintains property values for some
. . . And the detriments:
- Source sediment impoundment resulting in increased erosion of the fronting and adjacent beach due to Sediment budget reduction
- Passive erosion resulting in the eventual loss of the dry beach and possibly the loss of the inter-tidal area along eroding shores
- Loss of lateral beach access
- Loss or changes to marine habitat
- Reduction of and possible loss of marine organisms and associated ecological functions
- Adjacent property impacts, such as end scour or flanking erosion and,
- Placement loss resulting in the direct loss of beach and possibly habitat
In the end, the author concludes that site-specific conditions must be taken into consideration when exploring the idea of using structures to protect land:
Identifying the potential impacts of coastal armoring on a site- or littoral-cell specific basis is critical in assisting coastal managers with decisions on whether to permit coastal armoring, to suggest alterations that may have less impact, or to assist in developing mitigation techniques for potential adverse impacts, if possible or feasible.
Shoreline and beach management plans identifying areas that should be preserved for their unique natural and beneficial functions, such as important sediment sources to adjacent beaches, dunes and barrier beaches, or beaches of economic importance, are vital to the preservation of coastal community character, and maintain a viable economic base.
For more on structural mitigation, see “Flood and Erosion Control Structures“.
“Shoreline Armoring Impacts and Management Along the Shores of Massachusetts and Kauai, Hawaii,” by James F. O’Connell (PDF).