From “Try Out Soda Bottle Hydrology” by the Hazardous Waste Remedial Action program, U.S. Department of Energy, 1994


Students will explore hydrology by using a soda bottle to create a model hydrologic cycle.


Hydrology is the study of water. The hydrologic cycle is the endless recycling process water goes through on Earth. Heat from the sun make water evaporate. The water vapor rises into the atmosphere, where it cools and condenses forming clouds. The clouds release water through precipitation (rain sleet, snow, etc.). The water falls onto the ground and into the ocean. Some of it is absorbed into the ground into regions called aquifers, which are porous rock structures that hold water (sometimes for thousands of years.) Some of the water runs along the surface to the ocean. Then the water starts to heat up again and the cycle repeats. How long it takes water that falls from the clouds to return to the atmosphere varies greatly. Scientists predict it would take nine days to replace all of the atmospheric water and 37,000 years to replace all of the water in the ocean.

We tend to take the abundance and purity of our water for granted, but we should not do this. There is not an endless source of fresh water, and some scientists fear we could run out of it someday. Pollution and contamination of both surface and groundwater reduce the amount of clean, fresh water available. Common pollution sources include: chemical fertilizers, pesticides, waste discharge, leachate from toxic waste dumps, accidents, leaking underground gasoline/fuel storage tanks, and illegal dumping.

Since Americans use an average of 325 liters or about 85 gallons of water a day, it is very important to understand where our water comes from and how it gets there.



  1. Remove the label from the bottle.
  2. Create the model bottle by cutting off the bottom 5 cm of the bottle. Save this bottle bottom.
  3. Cut out the marking guide on the following page. Place the cut out marking guide against the bottle, and using a permanent marker pen, label the bottle with the volumes on the marking guides.
  4. Wad up the nylon screen and insert it into the neck of the model bottle. Recap the bottle.
  5. Fill your model bottle with sand to the 1,000 ml mark.
  6. Holding the bottle by hand, slowly pour in 200 ml of water. Let the water settle.
  7. Turn the cut out bottle bottom upside down and insert it into the top of the model bottle, so you can add material to the bottle bottom.
  8. Put some crushed ice into the bottle bottom (which is at the top of the model bottle).
  9. Set the bottle in a ring stand in sunlight or beside a strong lamp and observe.
  10. Based on your observations and the descriptions above, label the groundwater model bottle with the following: Groundwater, Surface water, Evaporation, Condensation, Precipitation
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