When vegetation near streams and rivers is disturbed or removed, it can no longer hold the soil in place. When this happens, soil may flow into streams and rivers. What activities might cause vegetation to be disturbed near streams and rivers? To answer this question, you will build a model of a stream bed and pond to simulate what happens to the surrounding soils during the rain. Materials: A cardboard box lined with plastic A smaller bowl to act as the “pond” Soil, pebbles, and small rocks Wat Topics: Active Forest Management, Water, Erosion, Experiment, Hands-on, Indoor Activity, Modeling, Outdoor Activity.