Unintended consequences of beach nourishment along the U.S. Atlantic and Gulf Coasts Seminar

Event details

Beach nourishment – the widening of eroded beaches with imported sand – has been used in the U.S. to protect coastal property and infrastructure from damage caused by natural hazards for nearly a century, but became ubiquitous along the U.S. Atlantic and Gulf Coasts after the 1960s. Nourishment projects are commissioned for a variety of reasons and involve multiple levels of government, and although some sites have long term re-nourishment plans, there is no alongshore coordination of nourishment projects among neighbouring towns. This work examines how beach nourishment projects, over large spatial scales and cumulatively over a number of years, have had the unintended consequence of increasing – not decreasing – the risk of damage from coastal hazards along the U.S. Atlantic and Gulf Coasts. Exploring systemic patterns of this phenomenon, we find indications of two mechanisms by which beach nourishment may increase risk. First, the ubiquitous application of beach nourishment may mask natural patterns of shoreline erosion along the U.S. Atlantic Coast. Second, beach nourishment and coastal development appear related by a positive feedback, indicated by more intense development in coastal zones that practice beach nourishment. Both of these mechanisms play a part in increasing not only the risk of damage from coastal hazards, but also the velocity of change in coastal risk over time.