This gives you a comparitive permeability rate. Repeat with sand and clay. Collect soil samples from various locations and depths and repeat the experiment. The activities in this section are designed to used with a groundwater flow model. The flow model helps students to conceptualize the workings of an aquifer.
Commercial models are available or inexpensive ones can be made.
I have included instructions for constructing a flow model out of a two liter bottle as well as a picture of a typical commercial groundwater flow model. Position the two straws into the container and layer three inches of sand on top of the gravel. Make sure you hold the straws in place as you pour in the sand. Add two inches of top soil on top of the sand. Please note that you can change the composition of the layers to make the ground flow model more consistent with your area.