Porosity and Permeability

Understand how water moves under the surface.

While sources of fresh water are usually associated with visible bodies of water such as lakes, rivers, ponds, and streams, the majority of fresh water on Earth is actually underground, collectively referred to as groundwater. Like fresh water found on the surface, groundwater can flow beneath the surface of the planet. Porosity and permeability are two factors that affect both how much groundwater may be found in a given area and the ability of this water to move beneath the surface as well as affect the degree in which certain environmental issues, such as water pollution, may impact different areas. In this activity, students will examine three different substrates and determine the porosity of each. After finding the volume of water each substrate can hold, students will then compare the permeability of the different substrates in order to determine how each may affect the ability of water to move beneath the surface.