Here is a site definitely worth checking out.
Lots of very interesting information throughout the website.
A sample is this on the Managed Retreat Page:
The potential responses to coastal erosion include seawalls, beach fill, and managed retreat. Seawalls, rock revetments and other hard structures built to hold back the advance of the sea often fail and need to be rebuilt over and over again. This approach is not desirable for several reasons, not the least of which is that these structures inevitably lead to the loss of sand from beaches
or this from the http://www.beachapedia.org/Shoreline_Structures
“Owners of beachfront property will often try to use their political influence to demand that “something be done.”
The intelligent action would be to move the building away from the ocean.
Unfortunately, what has often been done in the past has been to armor the coastline with rocks, concrete and steel.
This does not protect or maintain the beach – it only protects the buildings. “
Usually the most cost-effective, environmental solution is to move the building away from danger.
Building seawalls will buy time against natural processes, but it will not “solve the problem” of erosion by waves.