A variable-density groundwater flow and solute transport model representing the Pompano Beach area in southeastern Florida was developed to simulate the historical pattern of saltwater intrusion in response to drainage and wetland reclamation, groundwater withdrawals, rainfall, and water-management practices. Simulations of the past century (1900-2005) produce water-quality trends that closely correspond to historical chloride concentrations measured at observation wells. Sensitivity analyses indicate that the position of the saltwater intrusion line is most sensitive to changes in groundwater withdrawals and to decreases in rainfall.