We did a brief but thorough study on aqueducts and I racked my head for a week on how I could create an aqueduct building challenge. I found some great ones on the internet but most of them included water (I love my 7th graders but I don't trust them with any liquids) or they required some very expensive supplies. I finally came up with this simple but really fun challenge as I was driving to pick up my little one from daycare.
3 pieces of posterboard
roll of masking tape
access to as many books and boxes the classroom had to offer
1 ping pong ball
1 dessert plate
I'm kind of lucky because my classroom is an old chorus room. I already had the height built in but I'm sure you can replicate this in your own rooms. Each group had to have their ping pong ball travel from a desk on top of the steps (their reservoir) and down their aqueduct. At the bottom I had taped dessert plates to the ground (Rome). The challenge was to create a full ramp that would gently lay the ping pong ball onto the dessert plate without bouncing out. The dessert plate was Rome and if the ball bounced out, it meant the water was flowing too fast.