Where does groundwater come from?
Ground water comes from precipitations e.g. rainfall. This is an established fact based on empirical evidence. Groundwater is recharged during the rainy season and it level rises. Reverse is the case during dry season.
Common mistake: It should be noted that groundwater does not come directly from sea water. The speculation that groundwater is from sea water had been on for many centuries. People speculated that the groundwater is directly from the sea and the sea water gets itself purified of the salt through the ground. This is wrong. Groundwater comes from precipitation not from the sea.
This is the scientific explanation for groundwater.
(Photo Credits: nysgolfbmp.cals.comell.edu)