This complicated diagram is definitely for the older students. A detailed explanation is given below the diagram. The pipes leading out of the cylinders show where the water went after being withdrawn from a river, well, etc.
Public supply represents the local water departments that supply businesses and homes with water.
Let's use one of the gray cylinders to explain the rest of the diagram. Each gray cylinder represents a category of water use. The Domestic cylinder, for instance, shows how much water the United States used, each day, for home uses, such as drinking, bathing, washing, and yard watering. The brown pipe shows the amount of water coming directly from a ground-water source, such as a well. Some Americans, mainly in rural areas, have their own well to supply their home water needs.