For you and your family members, knowing the location of the main water valve is one of the most important things you should know. Everyone in your home should know where the main valve is and how to shut it off in case of an emergency. Another important point is that the valve should turn easily so that anyone could turn the water off. During the course of my home inspections I tag the valve for easy identification. Many times people know where the valve is located but, when a water problem develops, they don’t remember which valve is the main valve. The tag will identify the valve and could save thousands in the event of a water leak.