How does construction along coasts cause beach erosion?

Question

How does construction along coasts cause beach erosion?

Answer 1

There are currents in the ocean that can change because of construction.  For instance a jetty at the mouth of a river causes sand from the on shore flow of a current to be deposited farther "down stream" on the shore. The area where it used to be deposited now gets sand taken away somewhat like an eddy in a river can scour out a portion of land. this web site explains it better than I.   http://whyfiles.org/091beach/4.html