This study investigates the relationship between groundwater throughflow and seawater intrusion in a high-quality coastal aquifer. It combines numerical modeling, geophysics, and 30 years of monitoring data to show that anisotropy and heterogeneity significantly impact seawater intrusion dynamics, making conventional monitoring wells and simplified models inadequate for accurate prediction. The research suggests the need for more sophisticated monitoring strategies to capture the complex interplay of factors influencing seawater intrusion.

One author is affiliated with the Department of Water and Environmental Regulation (DWER), which could potentially introduce a conflict of interest regarding groundwater management decisions.

This is a strong research paper with a multi-disciplinary approach combining numerical simulation, geophysics, and long-term monitoring data. It provides valuable insights into seawater intrusion dynamics in complex coastal aquifers, highlights limitations of current methodologies, and suggests future monitoring strategies. The study has some limitations related to uncertainties in model parameters and reliance on simplified representations of heterogeneity, but the overall methodology and findings are valuable. The potential COI with the DWER affiliation is noted but does not appear to significantly detract from the study's merit.