Kids learn by doing, and nothing helps make them aware of water-wise practices better than asking them to tag along while you look for toilet, faucet and showerhead leaks. Another good option is to perform a home water audit with them. A water efficiency checklist can help you assess problems in your home and show your kids you mean business when it comes to good water management. You can find a basic checklist on the Environmental Protection Agency's (EPAs) Green Building site: Water Use Checklist. If that's not detailed enough, you might want to consider contacting your local water utility company. It may have a checklist or even an audit kit available for the asking.
Once kids learn the facts about water conservation, don't be surprised if they start asking when you plan on fixing that drip in the bathroom faucet. Having a few water detectives around the house can be refreshing for a change -- still, you might want to consider investing in a good wrench and some plumber's tape.