Beach sediments are generally enriches with sand and salt fractions which have a high porosity 
and permeability. When there is rainfall, fresh rain water percolates via this porous medium, saturate the sand medium and form fresh ground water table. The reasons for getting fresh water on the beach is that fresh water has a lower density (1000g/cm) than sea water and tends to float over the saline water (1.0255g/cm).
