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Build a Dam

Block the flow of water and see what happens.  


  • a sloping area of blacktop or dirt
  • water containers (plastic buckets, bottles, and cups)
  • digging tools and sticks
  • rocks, pebbles, bricks, pieces of wood, sand, and other objects that could block water
  • clipboards, paper, markers,
  • garden hose
  • camera

Key Science Concepts

  • You can stop the flow of water by building dams.


Encourage children to use words related to water such as pour, squirt, flow, splash, absorb, shape, direction, dam and science process words such as observe, notice, compare, same, different, change, test, and predict.


Tell children that they will go outdoors, build more streams, and then build dams to block the water from going into the streams.       

  1. Have children use the hose or a container of water to create a stream of water either on blacktop or in dirt.
  2. Tell them they can use any of the materials you’ve provided to makes a dam. As they build, ask,
    • Did the water stop flowing or is it passing through to the other side of your dam?
    • Where is water passing through? What do you think you can you do to stop the water from going through?   
  1. Take photographs and/or videos, which you can show later during Closing Circle.

Reflect and Share

Once their dams are built, ask, 

  • What materials worked best to make a dam?
  • When the water from the stream pushed against your dam, what happened?
  • Did you have any problems building your dam? How did you solve them?