Very large boulders for most of the dam, and pack a lot of dirt on top of that. If you really want the dam to be waterproof, then you can lay a sheet of tarp on top of the dam.
I'll list out the necessities: makeup and hair materials for show (your coaches will update you on that), electrical tape (both white and black), sunscreen (preferably over 30 SPF), sunglasses,...
You can build your own custom ship model using whatever materials your like. If you want to use a kit, you will need to review the materials provided by that...
Take waste materials to your local recycling center, but be advised that not all recycling centers accept waste paints. I advise calling them first. You can also become a member...
Yes! You can put baking soda in the balloon, and vinegar in an empty water bottle. Put the mouth of the balloon over the top of the water bottle and...