Coastal Erosion

Erosion

Coastal erosion is caused by:

» Storms and waves

» Hardened infrastructure (seawalls)

» Sea level rise

» Boat or foot traffic

» Loss or lack of vegetative root systems

» Changes in coastal landscape that affect currents

Addressing Shoreline Erosion

Property owners have many options to address coastal erosion, each with benefits and drawbacks.

More traditional approaches include beach nourishment & shoreline armoring.

  • Beach nourishment: importing sand to the area to restore the beach
    • Benefits: enhances the area of beach, highly desirable for recreational purposes
    • Drawbacks: short-term solution (erosion will continue), expensive, must find suitable sand, sand must be sourced from somewhere and this may cause impacts to the donor site, can be challenging to implement
      Source: NOAA Habitat Blueprint – Shoreline Solution Continuum, https://www.habitatblueprint.noaa.gov/living-shorelines/
  • Shoreline armoring: adding large rocks or seawalls to deflect wave energy
    • Benefits: relatively simple to implement, may be the only suitable solution for high energy settings
    • Drawbacks: expensive, increases erosion of adjacent and seaward areas,  creates barrier between land and water, loss of environmental function of shoreline, high likelihood of failure and costly repairs (low resilience), cannot adjust with changing sea level

A newer but increasingly popular method of erosion control is a living shoreline.

  • Living shorelines: enhancing natural habitat along the shoreline to dampen wave energy and accumulate sediment
    • Benefits: cost-effective, likely to adapt with changing sea levels, benefits environmental function (e.g., habitat, water quality), ability to gain (accrete) land by trapping sediments, less likely to fail and require repairs (high resilience), likely to be long-lasting
    • Drawbacks: not suitable for all sites, can be challenging to implement (because living shorelines are a relatively new approach, they lack streamlined permitting mechanisms and technical expertise is not widespread – but this situation is improving)
Source: NOAA Habitat Blueprint – Living Shorelines, https://www.habitatblueprint.noaa.gov/living-shorelines/