Evaluation of Submerged Narrow Crested Breakwaters for Shoreline Protection

The Prefabricated Erosion Prevention (P.E.P) Reef was deployed in 1996 and was monitored on a quarterly basis until June 2000. This paper summarizes the performance of the Vero Beach, Florida installation of the P.E.P. Reef. A three-year monitoring program was conducted to provide an evaluation of the effectiveness of the P.E.P. Reef system. This monitoring program included quarterly beach profile surveys, multiple wave gage deployments, breakwater settlement monitoring, and scour rod measurements, as well as an analysis of pre-project historical shoreline change. The purpose of the monitoring program was to: 1) determine changes in the shoreline response to the P.E.P Reef relative to control locations along the adjacent shoreline, 2) changes in bathymetry of the study area to identify patterns of erosion and accretion, 3) changes in beach profile and resulting sediment volume to identify impacts of natural hardbottom, seawalls and the P.E.P. Reef on coastal processes, 4) wave transmission effects, 5) modifications to wave induced currents, 6) scour around the reef segments, and 7) settlement of the reef units over time. The results of each of these objectives are given herein.