Water. Where does our fresh water come from? Does it come from different places/sources depending on where you live?
How can we conserve water? Why is it important to use water wisely? Are there places where there is a shortage of water?
Is water recycled? How is waste water treated? Can you drink it after it is treated? How is seawater desalinated?
Write a brochure about where your water comes from. Create a poster about the importance of water conservation. Research where people in different places get their water from and create a chart… So many authentic project ideas, so many ways to go with this very important topic.