Download printable Experiment Sheet here.
An aquifer is an underground layer of rock that is capable of storing water. Holes, or "pores", in the rock allow water to reside within it. The size and quantity of holes in rock is called a rock's "porosity". Holes may touch together, allowing water to flow through the rock, a characteristic we call "permeability".
In this experiment, we will create a simulated rock aquifer with porosity and permeability. We will demonstrate how water is stored and moves through this layer.
Plastic Soda Bottles
Sand (Medium to Coarse grained)
Jars (to hold bottles)
- Carefully cut away the bottoms off of the bottles.
- While leaving the soda bottle cap screwed on, turn one bottle over and add modelling clay to the bottle neck area.
- Add a layer of sand to the bottle, then saturate with water. Then add a second layer of clay on top.
- In the other bottle just add a layer of sand, with no clay at all.
- Pour water into both bottles and observe what happens when the bottle cap is removed.
Questions to consider:
- Does the water pass through the sand layer only? vs. the sand+clay layer?
- Why would water not pass through clay, when it does pass through the sand?
- How do you think you could get to the water of the aquifer if the upper layer of clay is confining it? if we add a layer of sand above the upper clay, does it get wet from the layer below?