Sea Level Rise and Groundwater

Rising sea levels pose a direct threat to coastal communities through permanent inundation of low-elevation areas and greater and more widespread temporary inundation from possibly more intense storms and king tides atop a higher sea level baseline. Sea level rise will also cause higher groundwater levels in coastal areas causing inundation of low-lying areas and impacts to shallowly buried infrastructure. The risks posed by rising sea levels are compounded by the large and growing populations of coastal urban areas. Areas vulnerable to direct marine inundation and groundwater inundation sea level are most commonly screened using the hydrostatic or “bathtub” approach, which assumes that sea level and the water table rises at the same rate everywhere in a coastal study area, or more accurate dynamic and groundwater modeling. Sea level rise will contribute to the salinization of coastal aquifers through more frequent and greater extent overwash events and saline water intrusion, with the later evaluated through density-dependent numerical groundwater modeling.