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Science Rocks!

Build a Dam


your results

Sent in by:
Tommy of Sandwich, MA

A dam is a structure that stops a river from flowing. Can you build one out of popsicle sticks and small rocks?

Materials Needed

  • long, shallow, clear Tupperware container
  • sand
  • small rocks (like aquarium gravel)
  • popsicle sticks
  • bucket full of water



  1. Fill the Tupperware container with sand.
  2. Dig the path of a river in the sand.
  3. Choose a spot somewhere along the river to build your dam.
  4. Use popsicle sticks and small rocks to construct a dam that will let only a little bit of water come through, but not too much. Keep in mind that the deeper the water, the greater the water pressure. So, the bottom of your dam will need to support more pressure than the top of your dam. If you built your dam in a triangular shape, then the bottom will be wider and will be able to support more pressure.
  5. Test your dam by pouring water from a bucket down the river path.

How did your dam work? Did you have to make adjustments to your design after testing it? Use our ZOOMsci feedback form to tell us what you did and how it worked out. Every week we'll post a whole bunch.

Some of your Results

Sneha, age 9 of Newmarket, ON wrote:
when I tried to build a dame in summer we tested if it would work by putting our dog Fate on it and it brok! so we tried again but this time we used mud to keep it together and voila it did not break! so now I know that if you put mud on a dam it wont break!

Joshua, age 6 of Bellevue, WA wrote:
need:1brick rocks mud leaves. make:put brick in the middle, than rocks, than leavas. secret:need sticks, use mud for glue!

Ruchi, age 13 of Muzaffarpur, India wrote:
It is really awsome. I enjoy in making this dam and I like it

Mikayla, age 9 of Hamilton, ON wrote:
When I did it worked like a real dam. every one in my class thout it was cool.

Jake, age 14 of Erie, PA wrote:
The water was able to hold up at the top for over 2 minutes, then it soaked to the bottom.

Emily wrote:
it did not work at first then I added more logs to it then it worked.

Keaton, age 9 of Formosa, ON wrote:
You can bild dams like I do all the time at home without using any popsicul sticks. 1. dig a deep hole. 2. Bild up a walls around it. 3. Dig a litle trenge to the nerest drain. 4. If you more water at once you can be like the water hydro compenes and bild another dam up ahead or dig very small trenches to the first dam you bilt. 5. Ad a pipe in front of the dam. Tip: Add sticks in your dam for it to be stronger.

Colton, age 13 of Indianapolis, IN wrote:
no water went through.

Tyler, age 9 of Gretna, NE wrote:
all the water stopped and the rocks I used stopped it and even some mud!

Vicky, age 11 of Hamilton wrote:
it did not work.

Madison, age 10 of Stockton, IA wrote:
When I built my dam it worked thans a bunch!!!

Gabby, age 13 of Urbana, OH wrote:
i thought that activity was really asome.

Shantell, age 9 of Alola, OR wrote:
When I bilut a dam and pord lots of water and it broke. Wuy did it brake?

Gertrude, age 6 of Universal City wrote:
This Wasn't Much Help! >:( It Didn't Work!:P

Ramon, age 10 of El Paso wrote:
The water did not pass threu.

Burgundy, age 9 of Mesquite, NV wrote:
it stayed togater for a minuite or two

Sarah, age 10 of Maui, HI wrote:
When I did my beaver dam it was a DISASTER! It took hours to do it properly and it still didn't work but you guys did awesome!

Sam, age 13 of Alabama, AL wrote:
it broke down

Shaina, age 8 of Canada wrote:
It fell apart when it was done!!! Wyerd isinit

Arely, age 11 of Zapata, TX wrote:
it was so much fun

Kevin, age 9 of San Jose, CA wrote:
The dam didn't block things for me like water and liquids.

Aubrianna & Megen of Eagle River, AK wrote:
It keep going throw

Johnny, age 10 of Corner Brook wrote:
i built a dam buy poring water into a bucket and I put the water in a muddy spot wuth some branches and it started flowing and forming into a dam

Brianna, age 12 of N. Attleboro, MA wrote:
i love makeing a dam it really cool

Caleb, age 8 of Goshen, OH wrote:
i built a dam in the water to slow the water down and I want to stop the water from flowing but I cant how can i???

Rodney, age 8 of Davenport, IA wrote:
When I tried to make a dam the water went threw the popsicle sticks.

Deanna, age 10 of Lima, OH wrote:
When I did the Build a dam, I used it with straws to hold the water back!!! And guess what it worked!!! why don't u guys try it on your show and see if it works.

Kayland, age 10 of Saint John, NB wrote:
the water stayed in the dam for a secent or two then the water started to come out little holes.

Haley, age 10 of Appleton, ME wrote:
well first I took some sticks and I put them in a brooke and it wasnt a strong brooke and I left it there and it wasnt knoked down yet

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