Trace the route of the Panama Canal on a map. Use clay or other materials to build a model on a piece of plywood. Label the bodies of water surrounding Panama. Find other examples of an isthmus on a world map or globe. Water flows across or under the land on its way to a stream, river or lake.
Streams flow to rivers and eventually to the ocean.
Your watershed may have to contend with its own problems. Use a topographic or physical map to identify your watershed. Many local conservation groups sponsor watershed programs. Some schools are involved in projects that monitor water quality and are helping to clean up watersheds. Find out what environmental groups are doing near you.