Maintaining Seawalls and Other Structures
Prior to coastal management policies and regulations, protecting coastal shorelines often meant structural projects like seawalls, revetments, and groins. With the improved understanding of natural shoreline function, there is a growing acceptance that structural solutions frequently cause more problems than they solve, and they are often not allowed under the Massachusetts Wetlands Protection Act. Structural protective measures often:
- Are expensive.
- Are not permissible under local and state regulations.
- Cause erosion to beaches and dunes, leading to a loss of recreational and tourism resources and diminished storm damage protection.
- Arenít permanent, in fact require costly maintenance to ensure that they continue to provide protection.
- Divert stormwater and waves onto other properties.
- Adversely affect other properties by starving beaches of needed sediment sources.
- Create a false sense of security.
- Disturb the land and disrupt natural water flows.
In 2006, the Coastal Hazards Commission recognized that existing shoreline stabilization structures need to be maintained and initiated an inventory of publically owned seawalls, revetments, groins, jetties, and other structures. A series of reports produced from 2006 to 2009 for the Massachusetts Office of Coastal Zone Management and the Department of Conservation and Recreation provide ratings for the condition of these structures and estimates for repair or reconstruction costs. These ratings and estimates were determined by civil engineers who surveyed the structures.
New structural protection should only be considered as a last resort, knowing that it may not be permissible, will be an ongoing expense, and may increase overall damage to land, buildings, and other structures within the natural system. Whenever structural protection is pursued, including reconstruction of failed structures, improvements to the design to reduce adverse impacts, hybrid technology (such as combinations of low-profile rock, cobble berms, and vegetative planting, or combinations of marsh plantings and coconut fiber rolls) should be considered as a means of reducing the negative impacts of the structure.
For more information on which permits are needed and the permittability of various structures, please see the StormSmart Regulations and Development Standards.