Make a dam using materials you already have at home. Try this at-home STEM activity with your little ones!

What is a dam?

Around 2950-2750 B.C, the ancient Egyptians built the first known dam to exist. A dam is a barrier that stops or restricts the flow of surface water or underground streams. Dams help us store water and prevent droughts and floods. The water collected by dams in manmade lakes is used for agriculture, recreation and to prevent droughts. This activity is a fun way to introduce your little one to how dams work.

Make a dam

What you’ll need:

  1. A bathtub 
  2. Tap water 
  3. Clear tape/scissors 
  4. A small bowl
  5. Aluminum foil
  6. Colored clay
  7. Corrugated Plastic Sheet
scissors aluminum foil playdoh corrugated plastic sheets bowl bathtub tap water

What you’ll need


  1. Use aluminum foil to create a river.

    aluminum foil folded to make a channel. Children use a watering can to fill the channel with water, creating a "river"

  2. Set it up on the Corrugated Plastic Sheet. Use clear tape to secure the river on the sheet.
  3. Using the below pictures as guides to build a dam at the middle of the river. Or you can design your own.
  4. Put the top of the river on the bathtub’s edge.
  5. Use a bowl to pour water from the top.
  6. See which one is the best at slowing the water down and holding the water.
  7. Design the gate which you can close or open when needed.
  8. You can put soil, sand, plants, and small houses to make a realistic environment.

Questions you may ask:

  1. How is a dam made?  
  2. How will a dam change the environments upstream and downstream?
  3. What do engineers need to consider before building a dam?

Scientific facts 

  1. Earth Science – Floods are when dry land is covered by water. Floods are very dangerous. If they are very bad, homes can be destroyed, and people can die. Floods can happen from three different sources: an ocean, a river, or a lake. Floods begin when too much water is flowing in an area that cannot support it.
  2. There are several ways to protect our land and people from floods. Dams keep water from rushing downstream. Channels filter the water out to sea in safe amounts. Dikes, flood walls, and levees, can be built to help keep water off the land.
  3. Erosion is one common force of nature. Over time, the land on either side of a stream can erode. When it rains really hard a little stream can fill with water and flood. A flood may last for an hour. It may last for a few days.
  4. The plants on a hillside have roots that reach deep into the soil. The roots hold the soil together. When it rains, or when the wind blows hard, the plant roots hold the soil in place. Without plants, the soil starts to erode.
  5. During a big flood, the entire landscape can be changed. A flooded river can tear apart plants, trees, and soil.
  6. First, the topsoil is removed. This is the richest soil, where you find most of the nutrients and decaying matter. Once the topsoil is washed away, the forces of nature slowly eat away at the clay and rock underneath.