BARRIER ISLAND GROUNDWATER

Storms can have long-term impacts on the groundwater flows and subsurface salinity structure in coastal aquifers. Previous studies have shown that tides, wave driven infiltration, and storm surge elevate the groundwater level within the beach (Nielsen 1999, Cartwright 2004). The resulting bulge of high groundwater propagates inland, and may cause flooding up to several days after a storm has passed (Gallien 2016). In addition, waves, tides, and storm surge force saltwater to infiltrate into the aquifer above the fresher terrestrial groundwater, and storm-driven pulses of salinity may persist for months (Robinson et al. 2014). Here, observations of groundwater heads and salinities collected continuously for three years are used to examine the effects of ocean storms, wind-driven fluctuations in sound water levels, and morphological changes on a barrier island aquifer.