The highest recharge rate from SWB-run off model is grassland, followed by shrubland, cropland, barevegetation land, and tree cover with a range of 163 to 500 mm/year.
High recharge areas are reflected in the natural groundwater chemistry which indicates pristine conditions in the dunes and naturally increasing mineralization along the flow system towards the shore and other low-lying areas.
Problems of contamination are found especially in the residential areas with high nitrate concentration, and seawater intrusion due to pumping. Due to the high dependence of the island on groundwater, there is a need to protect the resource and optimize pumping practices.