One Supply, Two States
- Surface water: rivers, streams, lakes, ponds, reservoirs
- Underground water: held in soil and rock, reached by wells and springs
- Rain soaks in, becomes a spring, feeds a stream, and is surface water again
- Cover the ground with concrete and the wells fall, though the rain is unchanged
Presenter notes: Open with one question and hold it open for the whole period: where does the water in your tap come from, and where was it a week ago? Take answers and keep asking what came before that. A tank. Before the tank? A pipe from a spring. Before the spring? Rain, on some hillside. Ask which hillside and watch the class go quiet, because almost nobody knows. Say that by the end of the lesson they will be able to draw it. Three words are coming and they are usually confused with one another, but they are three parts of one journey, so follow the water and the words look after themselves.