You might want to begin with some learning...
...about properties of water
But It's Full
Baby Powder Snowstorm
A Hole in the Water
Boat Races
Bending Water
Capillary Action in Action
Balancing Act
Mystery Jars
Drops on a Penny
Penny Boats
...about the water we have on Earth
Who Dirtied the Water
Earth's Water Necklace
Earth Ball Catch
And, since it is summer, make sure you include some fun water games - sponge tosses, relay races, water balloon catch, drip-drip-splash (a.k.a. duck-duck-goose, with a wet twist!). I found a great list of water games (including various versions of the games I just mentioned), with the rules, for camp here. I'm thinking I want to try the T-shirt Freeze. I would be especially great if you've made the Sharpie t-shirts (or some other shirt) during camp and still have those in your possession - what a fun way to distribute the shirts to the students!
