Hardened vs. Soft Shorelines

Shoreline hardening such as seawalls and bulkheads interrupt natural shoreline processes, reduces nursery habitat for marine species and foraging habitat for wading birds, degrades water quality, and can actually increase erosion processes.

A developed shoreline

Seawalls:

  • Turn the gradually sloping profile into a right-angle bathtub effect with limited habitat potential.
  • Can increase erosion on adjacent property beyond both ends of seawall.
  • Are often the shoreline protection option selected to “hold-the-line”.
  • Create an abrupt transition from deep water to dry land that eliminates the inter-tidal zone where many marine and estuarine species live.
  • Do not provide any filtration of runoff as it transitions from the land into the estuary.
 A diagram that shows how way energy can undermine seawalls and eventually cause failure. NOAA

Wave energy can undermine a seawall and eventually cause failure. Source: NOAA

armored seawall

Natural shorelines, already performing their natural functions without any help from us, should not be replaced with construction projects. Shorelines are naturally dynamic environments, and “do nothing” is the first option to be considered when faced with an eroding shoreline. However, most folks are seeking solutions to the loss of their property in the face of erosion, so “do-nothing” is not an option. Sea level rise compounds erosion problems by changing the location of the coast line and exposing new areas to erosion. LSLs offer the most environmentally friendly options for doing something.