This is a report that is the result of a seven year study of the movement of sand on the beaches. North Carolina beaches have the character of a sedimentary shelf with sand on top of this sedimentary shelf. Also, there is little off shore sand, making renourishment by dredge less practical. You can read the summary of the report at the link, and if you want to read the entire PDF report you can get it from the right column of the linked page.
http://pubs.usgs.gov/circ/circ1339/
