Accelerated sea-level rise and potential future increases in storminess due to climate change will threaten the vitality of barrier islands by lowering their relative elevation and altering overwash frequency. High-density development may further increase island vulnerability by restricting delivery of overwash to the subaerial island. I analyzed pre- and post-Hurricane Sandy (2012) LiDAR surveys of the New Jersey coast to assess human influence. I compared natural environments to two developed environments (commercial and residential) using shore-perpendicular topographic profiles. The volume of overwash delivered to residential and commercial areas is reduced by 40% and 90%, respectively, of that delivered to the natural environment. I use this analysis and an exploratory barrier island evolution model to assess long-term impacts of anthropogenic structures. Simulations suggest natural barrier islands may persist under a range of likely future sea-level rise scenarios (7–13 mm/yr) whereas developed barrier islands will have a long-term tendency toward drowning.