Get your towels ready to control the flooding! But, I promise, cross my heart, it will be worth it.
And it’s just water, after all.
It’s the Great Flood Barrier Challenge and it is one of our absolute favorites. I love it because it involves experimentation and keeping data and then making decisions based on the data.
The kids love it because…. well it’s messy!
The first part of this challenge is to think about absorbency and what will work and then test some items. The first time I tried this challenge I literally just opened cabinets (I do this a lot) and grabbed about 8 different items that might or might not have been absorbent. Things like foam cups, packing peanuts, cotton balls, and paper towels.
Then I had to think of a testing procedure. That’s why you need towels.
Basically, kids try the absorbent items one at a time and record the amount of water that leaks through the items. The less water the more absorbent the item is.
So, how do you make something leak? Well, you make a hole in the bottom of a cup and the water will run through. Hopefully, there is a cup under it to catch all that leaking water. Notice I said “hopefully”!
The kids record the amounts of water leakage and this helps them determine which works best. By the way, packing peanuts are not absorbent. Kids definitely were surprised by this. They also thought foam cups would be absorbent. Then I heard this:
“But, if cups were absorbent then you could not drink out of them. All your liquid would be absorbed!”
Making Decisions to Control the Flooding
Next, you analyze the gathered data. Such great discussions and comparing the numbers. Clearly, we had some definite winners. The cotton balls and paper towels often had zero leakage.
Now, it is time to design the barrier that will control the flooding of the little house we are using- which just happens to be made of paper. The kids had a budget for the materials, which included rather expensive absorbent materials!
This was a perfect time to also talk about supply and demand. I made the items that students needed more expensive. They noticed! So, we had a good discussion about why that happens in real life, too!
Gathering Materials (and Staying on Budget)
I stocked our supply table with all the materials and kids brought their budget lists to shop for the items. It was just so fun to watch them go through baskets of items to pick out the best. Like sponges. The groups that wanted sponges would pick through the basket and try to get the same colors of exactly the same sizes. They were very serious about this controlling the flooding project!
Creating the Barrier to Control the Flooding
As soon as the materials were gathered the kids started creating that barrier. We built inside of dishpans. They just placed their items inside and determined ways to surround and close off the paper house.
(The paper house came from the party section at a dollar store. It’s actually a little goodie box and I just cut off the handles.)
Testing (This Is Where You Need More Towels)
Finally, it is time to test the barriers!
We did this by pouring two cups of water into the pans and watching closely for leakage through the barriers.
One bonus this year was the little dogs. Our paper houses are actually dog houses and some groups used clay scraps to make little dog figures.
In the photos you can see the water being poured into the pan and then the group lifted up the dog house to reveal their little dry dog!
(Look closely beside the little dog and you can see the water!)
This challenge takes us two class sessions to complete. The first session is all about experimenting and the second is building the barrier and testing it. In the end, we toss all the wet things and I take the towels home to be washed. We use real towels because they are more absorbent. One group will use one towel. If I give them paper towels they will use entire rolls! I guess that is also something we have learned from making messes!
You might also enjoy these Experiment and Design Challenges: