An Analysis of Replenished Beach Design Parameters on U.S. East Coast Barrier Islands

Forty-three beach replenishment projects on the United States Atlantic Coast are divided into 3 categories based on time of fill retention: (1) less-than-1-year beaches (26%), (2) l-to-5 year beaches (62%), and (3) greater-than-five-year beaches (12%). Filled or replenished beaches north of Florida generalIy have lifetimes of fewer than 5 years. Storm history is the most important factor In determining beach durability so important that the effects of the other parameters, which may also play a role in artificial beach behavior, are overshadowed. Beach length, grain size, shoreface slope, shelf width and method of fill emplacement show no correlation to regional replenished beach lifetime. Inlet proximity and a combination of shoreline orientation and dominant angle of wave approach may exert minor influence on beach behavior. Initial density of fill (volume per unit length) exerts significant influence on the percentage of fill remaining after one year, but the effect becomes less well defined beyond the first year.