What is ground water?
For regulatory purposes, the Indiana well drilling statute defines ground water as "water occurring beneath the surface of the ground, regardless of location or form" (Indiana Code 25-39-2-10).
Many people think that ground water collects in, and is withdrawn from, underground lakes and rivers. True underground rivers-water-filled caves, for instance-are rare. Most ground water exists in small pores between rock particles and in narrow fractures in rock formations.